11th International Conference of Non-Invasive Cardiovascular Imaging

Journal of Nuclear Cardiology, Jun 2013

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11th International Conference of Non-Invasive Cardiovascular Imaging

0 Advanced Accelerator Applications , colleretto Giacosa , Italy 1 Inserm U698-Hospital Bichat-Claude Bernard , Paris , France 2 AP-HP-Hospital Bichat-Claude Bernard, Department of Nuclear Medicine , Paris , France 3 MediCity Research Laboratory, University of Turku, and National Institute of Health and Welfare , Turku , Finland 4 J.M.U. Johanna Silvola 5 A.I. Virtanen Institute for Molecular Sciences at the University of Eastern Finland , Kuopio , Finland 6 Turku PET Centre, University of Turku & Turku University Hospital , Turku , Finland 7 Turku University Hospital, Department of Medicine , Turku , Finland 8 Isala Hospital , Zwolle , Netherlands 9 North Cardiology Hospital , Paris , France 10 Mount Sinai School of Medicine , New York , United States of America 11 University of Ottawa , Ottawa , Canada 12 Gabriele Monasterio Foundation, Department of Cardiovascular Medicine , Pisa , Italy 13 University Hospital Zurich , Zurich , Switzerland 14 Alfred Hospital , Melbourne , Australia 15 Emory University , Atlanta , United States of America 16 St. Luke's Mid America Heart Institute , Kansas City , United States of America 17 University of Missouri-Kansas City , Kansas City , United States of America 18 Cardiology Center Monzino (IRCCS), Department of Cardiovascular Sciences, University of Milan , Milan , Italy 19 Cardiology Center Monzino (IRCCS) , Milan , Italy 20 Isala Hospital-Department of Nuclear Medicine , Zwolle , Netherlands 21 Isala Hospital-Department of Clinical Physics , Zwolle , Netherlands 22 University of Twente, MIRA-Institute for Biomedical Technology & Technical Medicine , Enschede , Netherlands 23 Cardiology Unit-University Hospital , Ferrara , Italy 24 Cardiology Unit-Delta's Hospital , Lagosanto , Italy 25 Nuclear Medicine Unit-University Hospital , Ferrara , Italy 26 C.J. Cornelis Jacobus Roos 27 Leiden University Medical Center, Department of Cardiology , Leiden , Netherlands 28 Institute Euromedica-Encephalos , Athens , Greece 29 Institute Euromedica-Encephalos, 251 Hellenic Airforce Hospital , Athens , Greece 30 Euroclinic Hospital, Institute Euromedica-Encephalos , Athens , Greece 31 251 Hellenic Airforce Hospital , Athens , Greece 32 Leiden University Medical Center, Department of Radiology, Division of Image Processing , Leiden , Netherlands 33 M.A. Michiel De Graaf 34 Medicine Faculty, Department of Biostatistics , Tirana , Albania 35 University Hospital ''Nene Teresa'' , Tirana , Albania 36 American Hospital, Balkan Alliance Group , Tirana , Albania 37 Upper Silesian Cardiology Center , Katowice , Poland 38 Medical University of Silesia , Katowice , Poland 39 Upper-Silesian Cardiology Center , Katowice , Poland 40 University of Michigan , Ann Arbor , United States of America 41 National Guard Hospital, King Abdulaziz Cardiac Center (KACC) , Riyadh , Saudi Arabia 42 University Hospital ''Nene Teresa'' , Tirana , Albania 43 University of Tirana, Faculty of Medicine, Department of Public Health, Division of Biostatistics , Tirana , Albania 44 Bethanien Hospital , Frankfurt , Germany 45 Heart Centre & Department of Public Health & Clinical Medicine, Umea University , Umea , Sweden 46 T.M. Tarek Mohamed Bengrid - Abstracts of original contributions 11th International Conference of Non-Invasive Cardiovascular Imaging May 58, 2013 Berlin, Germany Organised in conjunction with American Society of Nuclear Cardiology Cardiovascular Committee of the European Association of Nuclear Medicine and the Working Group on Nuclear Cardiology and Cardiac CT of the European Society of Cardiology Welcome address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Acknowledgements Graders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Committees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Abstracts Presented on Monday 6 May 2013 Oral Abstract Session 1: Young Investigator Award Competition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oral Abstract Session 2: SPECT MPI: New approaches and applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Moderated Posters 1 Morning: Advances in instrumentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Poster Session 1 Morning: Advances in instrumentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Moderated Posters 2 Afternoon: New pharmaceuticals: regandenosin and MIBG . . . . . . . . . . . . . . . . . . . . . . . . . . . Poster Session 2 Afternoon: New pharmaceuticals: PET, regandenosin and MIBG . . . . . . . . . . . . . . . . . . . . . . . . Abstracts Presented on Tuesday 7 May 2013 Oral Abstract Session 3: Advances in PET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oral Abstract Session 4: Refining cardiac risk assessment with imaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Moderated Posters 3 Morning: Imaging cardiovascular disease mechanisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Poster Session 3 Morning: Imaging cardiovascular disease mechanisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Moderated Posters 4 Afternoon: Left ventricular function and new insights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Poster Session 4 Afternoon: Left ventricular function and new insights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Abstracts Presented on Wednesday 8 May 2013 Oral Abstract Session 5: Novel cardiovascular molecular imaging probes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oral Abstract Session 6: Cardiac CT: New approaches and applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Poster Session 5 Morning: Clinical General and Outcome: Cardiac CT Posters . . . . . . . . . . . . . . . . . . . . . . . . . . . Author Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Index of Topics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . This supplement was not sponsored by outside commercial interests. It was funded entirely by the International Conference on Nuclear Cardiology. Welcome Address Dear Colleagues and Friends, It is our great pleasure to welcome you to ICNC11, the International Conference on Nuclear Cardiology and Cardiac CT. The ICNC meeting has been a key international scientific event for nuclear cardiology and cardiac CT imaging for more than 20 years. It provides the opportunity for practitioners from all over the world to gather to learn about new advances and to exchange scientific ideas and experiences in a distinctive environment. Over the next few days the meeting will provide an exciting and diversified scientific programme which offers a full spectrum of educational opportunities ranging from continuing education to cutting-edge presentations of new and original scientific research. A core curriculum, as well as advanced and research tracks will be available. As in the past, submitted abstracts will come from a wide geographical area which reinforces the message that ICNC is an important international scientific event. Many Read with the Experts case review sessions will allow participants to improve their interpretative skills for cardiac CT and SPECT and PET examinations. Unique to this meeting will be an even greater emphasis on presentations by young investigators. In addition to the awards and grants we already offer such as the ESC Working Group Travel Grants and the free registration for presenters in the Young Investigator Awards session, this year we will be offering two new categories of grants, the ICNC Grants and the ICNC Young Scientist Award. These 25 grants attributed to abstract presenters and young cardiologists will be generously provided by the ICNC Organising Committee and will carry a stipend of 1 500 per person. The Young Scientist Award will carry a stipend of 5 000. The winner will be announced at the gala dinner on Tuesday, 6 May. The beautiful city of Berlin is the venue for ICNC11. Germanys capital city combines all the things necessary for a successful congress, including a robust medical science community, a rich history, lively entertainment and affordability. Indeed, the ICNC organisers have selected this city for its popularity not only within Europe but because it is a favoured destination from the Americas, Asia and throughout the world. Thank you for choosing to attend ICNC11. We are pleased that you are here and hope you enjoy the meeting and the wonderful city of Berlin. Organising Committee Frank Bengel, DE Organising Co-Chair Robert Gropler, US Organising Co-Chair Robert Beanlands, CA Industry Liaison Programme Committee Chairpersons Sharmila Dorbala, US Programme Chair Michael Zellweger, CH Programme Chair Randall Thompson, US Programme Chair Robert Hendel, US Meeting Services Juhani Knuuti, FI Scientific Advisor Acknowledgements The Programme Committee for the International Conference of Non-Invasive Cardiovascular Imaging gratefully acknowledges the assistance of the following individuals who served as Abstract Graders for the original contributions sessions. Our experts graded the abstracts anonymously. The authors names and details were not known at any point in time during the grading process. Ichiro Matsunari, Japan Jennifer H Mieres, United States of America James Min, United States of America Fernando Mut, Uruguay Tomoaki Nakata, Japan Danilo Neglia, Italy Stephan Nekolla, Germany Pasquale Perrone-Filardi, Italy Steven C Port, United States of America John O Prior, Switzerland Paolo Raggi, Canada Ornella Rimoldi, Italy Dieter Ropers, Germany Terrence D Ruddy, Canada Michael Schaefers, Germany Heinrich R Schelbert, United States of America Thomas Hellmut Schindler, Switzerland Arthur Scholte, Netherlands Stephen Schroeder, Germany Joanne D Schuijf, Netherlands Karl Heinz Schuleri, United States of America Markus Schwaiger, Germany Udo Sechtem, Germany Albert Sinusas, United States of America Riemer Hja Slart, Netherlands Piotr Slomka, United States of America Paola Smanio, Brazil Stephen Stowers, United States of America Raymond Taillefer, Canada Nagara Tamaki, Japan Randall Thompson, United States of America Mark Travin, United States of America Mustafa Unlu, Turkey Berthe Van Eck-Smit, Netherlands Joao V Vitola, Brazil Juergen Vom Dahl, Germany Frans Wackers, United States of America Lee Samuel Wann, United States of America Kim Allan Williams, United States of America Michael JohannesZellweger, Switzerland STATISTICS Committees Organising Committee Frank Bengel, DE Organising Co-Chair Robert Gropler, US Organising Co-Chair Robert Beanlands, CA Industry Liaison Robert Hendel, US Meeting Services Juhani Knuuti, FI Scientific Advisor Programme Committee Sharmila Dorbala, US Programme Chair Michael Zellweger, CH Programme Chair Randall Thompson, US Programme Chair Advisors to the Programme Committee G DePuey, US M Freeman, CA E Garcia, US G Germano, US D Glover, US G Heller, US L Hofstra, NL P Kaufmann, CH A Kitsiou, GR I Saeed, US Y Sasaki, JP M Schaefers, DE H Schelbert, US B Zaret, US J Ziffer, US Oral Abstract Session Young Investigator Award Competition Monday 6 May, 2013, 14:0015:30 S. Fuerst1; M. Souvatzoglou1; C. Rischpler1; S.I. Ziegler1; M. Schwaiger1; S.G. Nekolla1 1Hospital rechts der Isar of the TU Munich, Department of Nuclear Medicine, Munich, Germany Purpose: Gadolinium-based MR contrast agents (CA) do not significantly affect PET annihilation photons. However, by enhancing the MR signal they possibly influence the MR-derived attenuation correction in hybrid PET/MR. The aim was to assess this effect on attenuation map (lmap) generation and PET quantification with the Biograph mMR PET/MR. Methods: lmaps were generated by acquiring MR data with a 2-point DIXON sequence and segmenting them using thresholds. 22 patients referred for viability imaging were scanned before and after CA administration. These PET images were reconstructed: post-CA data/ lmap and post-CA data/pre-CA lmap. Volumes of lung, fat and soft tissue in the lmaps were determined and the response to CA investigated over time. Myocardial uptake in the left ventricle (LV) was volumetrically quantified in 17 segment and regional differences between the data sets were assessed. Results: For all patients, the volume of lung tissue and fat in the lmaps after injection of CA was reduced, whereas the amount of soft tissue was increased. The changes were on average (-12.9 24.9)%, (-35.8 18.4)% and (16.2 8.3)% for lung, fat and soft tissue. In none of the patients, the lmap composition recovered to the state before CA injection until the exam finished. An effect on the SUV of more than 10% was found in 42.9% of the segments, whereas the respective global SUV variations ranged between -3.0% and +26.8%. Conclusions: MR CA has both significant local and global effects in cardiothoracic imaging. Tissue misclassifications are independent of the investigated range of delays after CA injection, leading to hampered quantification of otherwise adequate PET raw data. Thus, lmaps should be acquired pre-CA and CA-optimized segmentation parameters are needed. Room 4 A05 M. Mohamed Mouden1; J.P. Ottervanger1; J.R. Timmer1; S. Reiffers1; A.H.J. Oostdijk1; S. Knollema1; P.L. Jager1 1Isala Hospital, Zwolle, Netherlands Purpose: We investigated the influence of coronary artery calcium (CAC) scores on the visual interpretation of myocardial perfusion imaging in stable patients referred for the diagnostic work-up of suspected coronary artery disease (CAD). Methods: Patients without a previous history of CAD in whom CAC scoring was concomitantly performed with a hybrid 64-slice SPECT/ CT device were retrospectively identified. For the current analysis we selected all 151 patients who underwent invasive angiography within 3 months after myocardial perfusion imaging. Experienced readers interpreted myocardial perfusion images in two separate sessions with and without knowledge of a patients CAC score. We compared both readings with regard to the frequency of equivocal readings, and calculated changes in diagnostic accuracy using angiography with C70% luminal narrowing as a reference standard for obstructive CAD. Results: The addition of the CAC score changed the interpretation of myocardial perfusion images in 56 patients (37%) with a major effect on diagnostic accuracy in 39 patients (26%). The frequency of equivocal perfusion interpretations decreased from 21% to 9% (P = .002). Sensitivity of myocardial perfusion imaging increased from 48% to 64% (P = .019) with comparable specificity (72% to 68%, P = .628). Conclusions: In this highly selected group knowledge of the CAC score improved the interpretation of myocardial perfusion imaging and reduced the number of equivocal readings. Objectives: 99mTc-HYNIC-AnnexinA5 (99mTc-HYNIC-Anx) has been shown to allow in vivo scintigraphic detection of cardiomyocytes death in experimental myocarditis, via high-affinity binding to phosphatidylserines. Anx-128 is a new mutant of AnnexinA5 which possesses an endogenous peptidic chelation site at its N terminus. 99mTc-Anx-128 has been produced according to GMP procedure. The aim of this study was to compare 99mTc-Anx-128 to 99mTc-HYNIC-Anx in a rat model of acute myocarditis, to determine its potential interest for further clinical applications in patients with myocarditis. Methods: Acute myocarditis was induced in 13 Wistar rats by immunization with purified rat cardiomyosin (600 lg 9 2, in Freund adjuvant). Rats were imaged 3 weeks after immunization with both 99mTc-Anx-128 then 99mTc-HYNIC-Anx or vice versa at 2 days intervals. SPECT/CT images were acquired on a NanoSPECT/CTplus (Bioscan Inc.) device, 1 hour after tracers injection (60 MBq). Autoradiography (Beta ImagerTM, Biospace Lab) and histological studies of heart sections were performed after the second scan. All experiments were also performed in eight control rats injected with Freund adjuvant. Results: All immunized rats had positive dual imaging, with similar myocardial uptake of the two tracers in terms of topography and intensity. Myocardial-to-background activity ratio was 2.3 1.46* in immunized rats vs 0.9 0.32 in controls P = .01 using 99mTc- HYNIC-Anx, and 2.7 1.3* vs 1.16 0.18; P = .004 using 99mTc-Anx128 (*NS). Autoradiographic and histological data confirmed co-localization of both tracers in myocardial areas of cardiomyocytes death, and no uptake in normal myocardium of control rats. Conclusions: 99mTc-Anx-128 is accurate and comparable to 99mTcHYNIC-Anx for in vivo detection of cardiomyocytes death in experimental acute myocarditis. These results confirm potential interest of this new tracer for clinical application in patients with myocarditis. 41 Combining preoperative information from speckle tracking echocardiography, cardiac CT scan and MRI scan adds important information in patients receiving cardiac resynchronization therapy implants Purpose: To evaluate the incremental value of using preoperative cardiac CT and MRI in combination with echocardiography evaluation of segmental mechanical delay, for guiding optimal left ventricular lead placement in cardiac resynchronization therapy (CRT). Methods: 23 patients (70 9 years, 78% male, 86% with LBBB, 57% with ischemic CMP, 91% C NYHA 3) eligible for CRT were included consecutively. The left ventricular segment with latest mechanical activation was determined using echocardiography with speckle tracking radial strain. Cardiac CT scan was used for evaluation of coronary sinus anatomy. Cardiac MRI was used for evaluation of viability in each segment. A composite bulls-eye plot was constructed for each patient, indicating the optimal site for LV lead placement (Figure 1). Results: The latest mechanical delay was in the mid inferolateral segment (n = 4), base inferolateral (5), mid anterolateral (3), base anterolateral (2), mid anterior (3), base anterior (1), mid inferior (3) or base inferior (2). There were 2.5 0.8 veins of suitable size (C1.5 mm in diameter), and in 13 patients there was a matching vein in the segment with the latest mechanical delay, i.e. an optimal placement was possible. In 9/10 of those patients who had no eligible vein anatomy at the optimal segment, an adjacent segment was available. In the total group, MRI showed nontransmural (\50%) infarction in 24% of all segments and transmural infarction (50-100%) in 7%. In one patient there was transmural infarction in the optimal segment, thereby altering the optimal LV lead placement. Conclusions: Using cardiac CT in combination with echocardiography and MRI makes it possible to determine if an optimal lead placement is possible already preoperatively, and can be helpful in planning the targeted implant procedure. Purpose: Vascular adhesion protein-1 (VAP-1) plays a key role in recruiting leukocytes into sites of inflammation. VAP-1 is stored in intracellular granules of endothelial cells, but upon inflammation it is rapidly translocated to the endothelial cell surface. Using a phage display approach, we have recently discovered that sialic acid-binding Ig-like lectin 9 (Siglec-9) is a granulocyte ligand for vascular adhesion protein 1 (VAP-1) and a 68Ga-Siglec-9 peptide specifically detects VAP-1 in vasculature at sites of inflammation. Since the inflammation has a prominent role also in atherosclerosis, the novel 68Ga-Siglec-9 peptide may be a potential tracer for imaging of inflammation associated with atherosclerotic plaques. This study investigated the uptake of 68Ga-Siglec-9 in atherosclerotic plaques in mice. Methods: Six-month-old atherosclerotic low-density lipoprotein receptor deficient mice expressing only apolipoprotein B100 (LDLR-/-ApoB100/100, n = 15) fed with high-fat diet for four months and normally fed two-month-old C57BL/6 control mice (n = 11) were intravenously injected with 19 5 MBq of 68Ga-Siglec-9. The aorta and other tissues were excised at 25 minutes after tracer injection and measured by gamma counter to clarify biodistribution of radioactivity. The uptake of 68Ga-Siglec-9 in aorta was studied in more detailed by autoradiography and histology analyses. Results: The six-month-old LDLR-/-ApoB100/100 mice demonstrated highly inflamed and extensive atherosclerotic plaques after 4 months of a high-fat diet, presenting a suitable model for studying the imaging of atherosclerotic plaque inflammation. The 68Ga-Siglec9 peptide was rapidly excreted through the kidneys to the urine. At 25minutes post-injection the blood radioactivity was still relatively high. However, the uptake of 68Ga-Siglec-9 in the aorta was significantly higher in the LDLR-/-ApoB100/100 mice (0.88 0.32%IA/g) than in the control mice (0.45 0.11%IA/g, P = .0003), and an autoradiography demonstrated focal uptake of 68Ga-Siglec-9 in atherosclerotic plaques. Conclusion: Our preliminary results provide evidence that 68Ga-Siglec-9 peptide is accumulated into the plaques of atherosclerotic mice and that it might be a promising and novel PET tracer to detect plaque inflammation. Further studies are warranted to determine the expression level of VAP-1 at different stages of atherosclerotic plaque development. 43 Dynamic computed tomography perfusion imaging for the detection of functionally significant coronary lesions A. Rossi1; A. Wragg2; A. Dharampal1; S.E. Petersen2; E. Klotz3; P.J. De Feyter1; F. Pugliese2 1Erasmus MC, Rotterdam, Netherlands; 2Barts and The London NIHR Cardiovascular Biomedical Research Unit, London, United Kingdom; 3Siemens Healthcare Sector, Forchheim, Germany Purpose: To evaluate the performance of hyperaemic myocardial blood flow (MBF) derived from stress computed tomography perfusion (CTP) imaging in the detection of functionally significant coronary lesions in a prospective cohort of patients with stable chest pain. Lesions were defined functionally significant by fractional flow reserve (FFR) B0.75. Methods and Materials: Coronary computed tomography angiography (CTCA) and CTP were performed in 80 patients (63 males/17 females; mean age 60 10 years) referred for invasive angiography. A second-generation dual-source CT scanner (Somatom Definition Flash, Siemens) with a dynamic ECG-triggered axial shuttle mode was used. This technique provides an arterial input function and myocardial timeattenuation curves fitted to a two-compartment model to give MBF. Hyperaemia was induced by infusion of adenosine (140 lg/kg body weight). Three to four minutes into the infusion, 60 mL of contrast were injected. Gantry rotation time was 285 ms, collimation 64 9 0.6 mm, tube voltage 100 kV and the tube current-time product was 300 mAs/rotation. Results: Data from 210 coronary vessels and 210 corresponding myocardial territories were available for comparison and were included in the analysis. Functionally significant coronary lesions were found in 56/210 vessels (27%). MBF was 62 (51-74) mL/100 mL/minute in myocardial territories supplied by vessels with functionally significant coronary lesions and 109 (92-136) mL/100 mL/minute in the remote myocardium (P \ .001). The optimal cut-off value of MBF to discriminate functionally significant coronary lesions was 78 mL/ 100 mL/minute. MBF had 88% sensitivity and 90% specificity and an area under the receiver operating characteristics curve (AUC) of 0.95 (95% CI, 0.92-0.98, P \ .001). By comparison, visual CTCA analysis yielded 80% sensitivity, 76% specificity and an AUC of 0.78 (95% CI, 0.71-0.85, P \ .001). Conclusions: MBF performs better than visual CTCA analysis to predict functionally significant coronary lesions (FFR B 0.75). Oral Abstract Session SPECT MPI: New approaches and applications Monday 6 May, 2013, 16:3018:00 Purpose: The introduction of high-efficiency SPECT cameras for MPI represents one of the most important hardware developments in decades. Approximately, 30 laboratories have the multi-pinhole CZT camera installed as of the summer of 2012. There are no current guidelines for dosing and imaging times for these cameras. Methods: A questionnaire was distributed to eight early adopters who published peer reviewed papers utilizing the multi-pinhole CZT camera in Europe (N = 4), Australia (N = 1) and North America (N = 3) requesting yearly patient volume, low and high Tc-99m doses, low and high dose imaging times, time from low and high dose injection to imaging, and information about the use of attenuation correction. Results: Surveyed labs perform close to 20,000 studies a year with 6 of 8 using a stress-rest protocol (rest imaging optional). The stress:rest dose ratio varies from 1:2 to 1:3, with stress doses ranging from 3 to 10 mCi and stress imaging time from 5 to 11 minutes. The largest variation was noted in time to rest imaging (3-60 minutes). North American labs are more likely to perform rest-stress imaging with a 1:3 to 1:4 rest:stress dose ratio and rest doses usually of 5 mCi. Calculated radiation dose to the patients for low-dose stress only studies was B3 mSV per study and 3.6-9.1 mSv for a full study. All sites use either CT or prone imaging attenuation correction. Room 4 A05 Conclusions: Using CZT SPECT technology results in significant decreases in radiation doses and imaging time. Sufficient data is now available to propose unified guidelines for CZT SPECT imaging. J.G. Romero Farina1; S. Aguade-Bruix1; G. Cuberas-Borros1; M.N. Pizzi1; G. De Leon1; J. Castell-Conesa1; D. Garcia-Dorado1; J. Candell-Riera1 1Hospital Universitari Vall dHebron, Barcelona, Spain Purpose: To evaluate the warranty period (WP) of a normal stress-rest myocardial perfusion SPECT for exercise stress (ES), ES plus pharmacologic stress (PhS), and PhS and in different clinical conditions. WP of normal SPECT is important in order to establish appropriate use of this technique in different subgroups of patients. Methods: A cohort of 2,922 patients (62.9 13 years; 53.4% women) with normal stress-rest myocardial perfusion SPECT was studied. WP was defined as the time in which a patient remained at low risk (\1% complications/year) for total mortality (TM) and for hard events (HE) (cardiovascular death or nonfatal acute myocardial infarction. Multivariate Cox proportional hazards models and Kaplan-Meier curves analysis were used to estimate the WP. Results: 2051 patients underwent ES, 461 underwent ES plus PhS, and 410 underwent PhS. During a follow-up of 5 3.3 years, a significant (P \ .05) increased of annual TM (1.47%, 2.3% and 4%) and annual HE (0.4%, 0.9% and 2%) were observed for ES, ES plus PhS, and PhS respectively. A significant (P \ .05) WP reductions of TM [13.5, 9.6 and 8 months], and HE [34.8, 20.5 and 8.2 months] was observed for ES, ES plus PhS, and PhS respectively. Clinical variables (age, gender, diabetes and known coronary artery disease) were other determinants of the WP. An abnormal gated SPECT (ejection fraction \ 50%) significantly decreased WP for HE in patients underwent ES plus PhS (P = 0.001) or PhS (P = .007). Table of the abstract 56 1012 5 8 5 7 5 56 5 4 5 8 3 Conclusions: WP of a normal stress-rest myocardial perfusion SPECT is very variable since it is mainly determined by the type of stress, clinical characteristics and left ventricular ejection fraction. M. Milena Henzlova1; E.J. Levine1; S. Moonthungal1; M. Fardanesh1; L.B. Croft1; W.L. Duvall1; 1Mount Sinai School of Medicine, New York, United States of America Purpose: Previous literature suggests that the results of myocardial perfusion imaging (MPI) add little to the prognosis of patients who exercise C10 METS during stress testing. With this in mind, we attempted to determine if a provisional injection protocol could be developed in which a patient would not receive an injection of radioisotope if adequate exercise was achieved without symptoms and a negative ECG response. This protocol would save a substantial amount of time, radiation exposure, and cost. Methods: All patients who underwent a stress SPECT MPI over a 6.5 year period from 2004 to 2010 were included. Patients who would have been considered for a standby injection protocol were: exercise stress, age \ 65, no known CAD, and an interpretable ECG. Patients were retrospectively divided into two groups based on whether they would have received radioisotope or not. Criteria for not injecting included a maximal predicted heart rate C 85%, C 10 METS of exercise, no symptoms of chest pain or shortness of breath, and no ECG changes (ST depression or arrhythmia). The two groups were then compared based on MPI results and all-cause mortality derived from the Social Security Death Index. Results: A total of 24,689 patients underwent SPECT MPI during this period, and 5,352 would have been eligible for a provisional injection protocol. There were 3,791 (70.8%) who would have been injected and 1,561 (29.2%) who would not have been. Perfusion results were abnormal in 5.9% of non-injected group compared to 14.4% in those who would have been injected. After a mean follow-up of 60.6 21.4 months, 1.1% had died in the non-injected cohort compared to 2.2% in the injected group. Conclusion: A provisional injection protocol defined as age \65, normal rest ECG, no history of CAD, and high level exercise with a negative ECG response and no symptoms, has a very low 5 year allcause mortality and low yield of MPI. If adopted it would decrease radiation exposure, save time and health care costs without jeopardizing prognosis. 59 Is necessary to perform an exercise myocardial perfusion gated SPECT in patients with D-Transposition of the great arteries after arterial switch operation? A single centre long-term follow-up M.N. Pizzi1; S. Aguade-Bruix2; E. Franquet2; G. Cuberas-Borros1; B. Manso3; J. Casaldaliga4; G. Romero-Farina5; J. Castell-Conesa2; D. Garcia-Dorado6; J. Candell-Riera6 1Universitary Hospital Vall dHebron, Cardiology Department, Nuclear Cardiology and Cardiac CT Unit, Barcelona, Spain; 2Universitary Hospital Vall dHebron, Nuclear Medicine Department, Barcelona, Spain; 3Universitary Hospital Vall dHebron, Paediatric Department, Barcelona, Spain; 4Universitary Hospital Vall dHebron, Cardiology Department, Adult Congenital Heart Disease Unit, Barcelona, Spain; 5Hospital Vall dHebron, Cardiology Department, Epidemiology Unit, Barcelona, Spain; 6Universitary Hospital Vall dHebron, Cardiology Department, Barcelona, Spain Objectives: Arterial switch operation (ASO) is the preferred technique for the correction of transposition of the great arteries (TGA), but translocation and re-implantation of the coronary arteries can produce myocardial ischemia. There is no consensus on the need to monitor these patients to detect abnormalities in myocardial perfusion. The purpose of this study is to report our experience with exercise myocardial perfusion gated SPECT with 99mTc-tetrofosmine to evaluate myocardial perfusion and exercise tolerance after ASO. Methods: We performed exercise-rest myocardial perfusion gated SPECT in 67 patients (48 boys, 9.9 3.2 years old), including five who had referred symptoms and 62 who were asymptomatic. Myocardial perfusion and left ventricular (LV) wall motion, thickening, volumes and ejection fraction (EF) were evaluated. We compared patients with (n: 4) and without (n: 63) peri-operative complications, and patients with A (normal) (n: 45) and non-A (n: 22) coronary pattern. Results: During exercise testing 67 patients reached 9.8 3.05 METs and 73.58 14.24% of the predicted peak heart rate. Fifty-nine patients (88%) had normal myocardial perfusion while only 2 patients (3%) had reversible defects, and 6 patients (9%) had fixed defects. All patients with peri-operative ischemic complications had myocardial perfusion defects (100%) while only 4 patients (6.35%) without ischemic complications had an abnormal perfusion (P = .0005). We did not find a significant difference between patients who had an A and non-A coronary pattern. Conclusions: The high rate of normality of myocardial perfusion gated SPECT in our study suggests that myocardial perfusion gated SPECT should be reserved for patients who have suffered peri-operative ischemic complications, or those with symptoms, at least during the first 10 years after the surgery. Purpose: Cardiac allograft vasculopathy (CAV) is common among orthotopic heart transplant (OHT) patients and is the major factor affecting mortality. Serial myocardial perfusion imaging (MPI) is useful diagnostically and prognostically, and with current technology can be performed at minimal dosimetry. However, neither the time course to positivity nor the correlates of this are known. Methods: Using the OHT and MPI electronic databases at a single center, we identified 192 patients who had undergone OHT and serial MPIs between January 1, 2000 and December 31, 2011. Collected data included gender, age, diabetes, hyperlipidemia, hypertension, smoking, family history of premature CAD and time to an abnormal MPI (AMPI) defined by a summed stress score [3. Results: The 192 OHT patients underwent 801 MPIs over a mean follow up period of 5.6 (+2.7) years. A total of 54 patients (28%) ultimately developed an AMPI. Of these 54 patients, 11% (6 patients) had an AMPI by 1 year, 57% (31 pts) by 3 years, 78% (42 pts) by 5 years, 93% (50 pts) by 7 years, and thereafter only 1 patient per year had an AMPI in the final 4 years. The average time to AMPI was 6 years. Demographic and atherosclerotic risk factor data were not statistically different between the 54 patients who developed an AMPI vs those who did not. Conclusions: Serial MPI is helpful in identifying CAV following OHT, with significant conversion to abnormality even during the first several years following OHT. Traditional risk factors do not correlate with those OHT patients who develop early post-transplant cardiac allograft vasculopathy. Conversion to abnormal MPI over time Moderated Posters Advances in instrumentation Monday 6 May, 2013, 08:3012:30 D. Daniel Zalkind1; V.T. Tsatkin1; Y.L. Liu1; A.S. Sinusas1; 1Yale-New Haven Medical Center, New Haven, United States of Purpose: The utility of CT based attenuation correction (AC) has been shown in previous multi-center trials for SPECT cameras with sodium iodide (NaI) detectors, although remains undefined for hybrid highsensitivity cadmium-zinc-tellurium (CZT) SPECT cameras with diagnostic 64-slice CT (Discovery NMCT570c). The CZT detectors allow imaging with decreased radiotracer dose. The aim of this study was to further reduce the dose by applying one higher dose AC CT scan to both rest and stress images, and to evaluate the impact on quantification of SPECT integrated defect size (IDS, %LV volume). Methods: Forty-four consecutive hybrid SPECT/CT rest and stress scans were processed using the GE Xeleris software. Patient had a mean age of 63.1 15.8 years, mean BMI 29.4 5.4 and 66% male gender. IDS was calculated at rest using a gender-matched low-risk database, after attenuation correction with either the phase-matched rest CT (120 kV and 20 mA) or the phase mismatched stress CT (120 kV and 80 mA) AC maps using the Yale WLCQ software. A paired two-tail Student t-test and Pearson correlation were used to compare IDS within each coronary distribution (LAD, LCX, and RCA) after processing with the low and high dose CT attenuation maps. Results: The AC CT for the stress phase resulted in a radiation dose of 2.72 mSv (high dose) and the CT for the rest phase resulted in a low radiation dose of 0.33 mSv (low dose). There was no statistically significant difference in IDS between the rest perfusion processed with the low-dose CT at rest, and the rest perfusion images processed with the high-dose stress CT within each coronary distributions (LAD: 0.39 0.31, P = .9, r = 0.61; LCX: 1.2 4.8, P = .93, r = 0.97, RCA: 0.62 0.77, P = .52, r = .87). Conclusions: The application of the stress CT AC map to the rest SPECT images did not significantly change the rest IDS. Therefore, one can eliminate the low dose rest CT AC map without compromising SPECT quantification, further reducing the radiation dose associated with hybrid CZT SPECT/CT. 62 Assessment of left ventricular ejection fraction (LVEF) with hybrid solid-state cadmiun zinc telluride (CZT) SPECT imaging with and without CT attenuation correction: comparison to 2D echocardiography M.J. Maria Jimena Salas P.1; V. Tsatkin1; Y. Liu1; R. Russell1; A.J. Sinusas1 1Yale University, New Haven, United States of America Purpose: Gated SPECT is used to calculate LVEF and provides results comparable to other methods. However, data is limited on accuracy of hybrid solid state CZT SPECT for estimation of LVEF using an integrated 64-slice CT for attenuation corrected (AC). We sought to compare the LVEF determined by gated SPECT with and without AC (no AC) and 2D echocardiography (2DE). Methods: We retrospectively reviewed all rest 99mTc-tetrofosmin SPECT scans performed on a hybrid CZT SPECT/CT (Discovery NM570c) in patients having 2DE within 24 hours of SPECT processed with AC and no AC over a 6 month period. CT was performed using low dose protocol and free breathing. LVEF was calculated from SPECT with WLCQ software with and without AC. Two operators independently processed the LVEFs. 2DE EF was measured by the biplane disk method. Interobserver variability was defined and Pearsons correlation coefficients used for comparisons. Results: 52 patients were identified, 32 males and 20 females, meeting the inclusion criteria. The interobserver variability for LVEF was low (SEM = 2.7%) and correlation high (r = 0.99). There was excellent correlation between no AC and AC LVEF (r = 0.98). 2DE LVEF correlated with SPECT LVEF with AC (r = 0.73) and no AC (r = 0.74). There were differences in the correlation between 2DE and SPECT LVEF when patients were grouped by gender (females: r = 0.90; males: r = 0.70), presence/absence of LV hypertrophy (LVH: r = 0.89; no LVH: r = 0.81), and patients with high ([80 mL) or low (\80 ml) LVEDV (low EDV: r = 0.60; high EDV: r = 0.78). Conclusions: LVEF assessed using a hybrid CZT SPECT/64-slice CT was similar with AC and no AC, and correlated highly with 2DE LVEF. There was an improved correlation in females, high LVEDV, and no LVH, suggesting an influence of LV wall thickness. C. Chunlei Han1; H. Merisaari1; V. Oikonen1; S. Nesterov1; Purpose: In analysis of cardiac PET water perfusion data, several studies have suggested that the spillover activity from right ventricular cavity (RV) to the septum should be corrected. Despite this, the correction is not implemented in routine analysis. This study investigates the bias in perfusion estimation without RV spill-over correction, based on simulation data. Methods: Time-active curves (TAC) from left (LV) and right ventricular cavities were derived from typical clinical 15O-labelled water studies. One-tissue compartment model (Iida et al., 1989) was employed to simulate noise free curves according to our study protocol. Water model without RV spill-over correction (LVModel) as implemented in Carimas v2.6 (a data analysis package) was compared with a new model with RV spill-over correction (LV_RVModel), which was implemented to Carimas v2.6 as a modeling plugin. In LV_RVModel, the myocardial ROI TAC was expressed as: ROI(t) = Va_lv*LV(t) + Va_rv*RV(t) + alpha*C(t), where Va_lv and Va_rv are spill-over fractions from LV and RV, respectively, and alpha is perfusable tissue fraction. Results: RV affects significantly the perfusion estimation and this effect becomes bigger for higher perfusion values and larger Va_rv. When ground values of Va_rv = 0.1, 0.15, 0.2, 0.25 mL/mL, for ground flow value of 0.98 mL/g/minute (as rest condition), estimated flow values with LVModel were 0.94(-13%), 0.85(-20%), 0.78(-27%) and 0.72(-33%) mL/g/minute, respectively; for ground flow value of 3.2 mL/g/minute (as stress condition), estimated values with LVModel were 2.66(-17%), 2.34(-27%), 2.07(-36%) and 1.84(-43%) mL/g/ minute, respectively. Meanwhile, estimated flow values from LV_RVModel were very close to ground values (error \ 2%). Conclusions: Simulations confirm that spill-over from RV leads to severe underestimation of perfusion in septum, unless correction is applied in the analysis tool. I. Casans-Tormo1; R. Diaz-Exposito1; A.C. Orozco-Molano1; E. Plancha-Burguera2 1Nuclear Medicine, Hospital Clnico Universitario, Valencia, Spain; 2Cardiology, Hospital Francisco de Borja, Gandia, Spain Purpose: To assess the influence of 128 3 128 acquisition matrix in GSPECT image quality analyzed in function of patients (p) characteristics. Material and Methods: We have studied a prospective group of 71 p (31 women-43.7%), mean age 65 10 (42-82 y/o, more than 70 (28/ 71-39.4%) with known or suspected CAD, submitted to detect possible myocardial ischemia. GSPECT was performed 1 hour after injection of a 99mTc-tracer (2 day-protocol, 20 mCi-70 kg), obtaining two simultaneous acquisitions with 64 3 64 and 128 3 128 matrix at stress and at rest in 52 p and stress only in 16 p, with a total of 240 explorations, 120 with each matrix size (68 stress and 52 rest), Butterworth filter (order 5, cutoff 0.56 (64)-0.30 (128), pixel size mm 6.3 (64)-3.1(128), QGS program. We perform visual semi-quantitative analysis of global image quality (IQ), delimitation of ventricular cavity (VC) and of perfusion defect (PD) considering 1-poor, 2-middle, 3-good, 4-excellent, analyzing differences between the two matrix size studies respect to age, gender, body mass index (BMI), rest end-systolic volume (ESV) existence of perfusion defects or rest FE \ 50%, obtained from usual 64 3 64 GSPECT, and also assessing possible interference of intestinal activity. Results: Mean BMI was 31.2 6.5 (22.5-58.6), with 21/71 (29.6%) more than 30. 31/71 p (43.7%) with ESV \ 25 mL, 32/71 (45.1%) with PD, 18/71 (25.3 %) with FE \ 50% and 15/71 (21.1%) with intestinal interference. Visual parameters graded 2-4. Global Q was in general better in 128 than 64, without age differences. Better IQ at S and R in 128 than 64 in women and p with ESV \ 25 mL (24/3177.4% of women had ESV \ 25 mL), higher IQ and PD in 128 than 64 at R in p with BMI more than 30 (80.9%) vs lower than 30 (32%) p:0.03, better VC in 71.8% p without perfusion defects or attenuation only vs 40.6% with perfusion defects (p:0.04) and in p with FE C 50% than \50% (p:0.002). Better delimitation with intestinal activity in 11/15 (73%) of p that showed intestinal interference. Conclusion: In this study with simultaneous acquisition in 128 3 128 and 64 3 64 matrix size, we obtained higher quality images in general with 128 than 64, specially in patients with BMI [ 30, ESV \ 25 ml (77% were women), without perfusion defects, with FE [ 50%, and also better delimitation with intestinal activity, all of that could improve interpretative certainly and diagnostic accuracy. 65 Rapid SPECT MPI using 128 3 128 matrix acquisition with iterative resolution recovery and attenuation correction A. Amelia Jimenez-Heffernan1; A. Ortega-Carpio2; C. Salgado-Garcia1; E. Sanchez De Mora1; J. Lopez-Martin1; C. Ramos-Font1; R. Lopez-Aguilar1; S. Aguade-Bruix3 1Hospital Juan Ramon Jimenez, Department of Diagnostic Imaging, Huelva, Spain; 2Centro de Salud El Torrejon, Huelva, Spain; 3Hospital Vall dHebron, Department of Nuclear Medicine, Barcelona, Spain Purpose: To assess the contribution of 128 3 128 matrix acquisition to improving the diagnostic quality and reducing LVEF overestimation of rapid SPECT/CT reconstruction with ordered subset expectation maximum and resolution recovery (OSEM-RR) with attenuation correction (AC). Methods: We studied 461 consecutive patients (54% male, age: 64.5 11.7 years, weight: 79.5 15.2 kg) referred for 99mTc SPECT/CT MPI using a 128 3 128 matrix and OSEM-RR reconstruction with AC. For comparison we used a group of 572 patient who underwent rapid SPECT with the usual 64 3 64 matrix, all other parameters identical. 60 frames of 12 second duration were acquired over 908 using a standard hybrid system. Our protocol performs 12 iterations with a maximum number of 10 subsets. A 2-day stress/rest protocol was used. Stress was exercise combined with adenosine in 365 and regadenoson in 96 patients respectively. Image quality (poor, medium, good or very good), diagnostic performance (normal, abnormal and normalcy rate) and LVEF quantification were assessed. Results: Images were of very good quality, clearly showing or suggesting the papillary muscles in all cases. MPI was reported as normal in 46.7%, abnormal in 51.3% and equivocal in 2% of patients respectively. Normalcy rate using a very low pretest likelihood of disease (Millers score modified) was 57.8%. In the 64 3 64 matrix group reports were normal in 55%, abnormal in 43.6% and equivocal in 1.4% of patients respectively and the normalcy rate was 68.6%. The lower normalcy rate and increment of abnormal studies with the 128 3 128 matrix was mostly due to small basal inferolateral defects, which we hypothesize could be related to the higher activity of the adjacent posteromedial papillary muscle. Mean LVEF in normal perfusion patients was 63.3% for 128 3 128 and 67.2% for 64 3 64 matrix respectively, a significant difference (P \ .05). Conclusion: The 128 3 128 matrix produces higher quality images with lower overestimation of LVEF, nevertheless careful attention must be paid to the area basal to the posteromedial papillary muscle in order to avoid false positive readings. R. Conwell1; C. Chuanyong Bai1; L. Abreu1; J. Maddahi2 1Digirad Corporation, Poway, United States of America; 2UCLA-David Geffen School of Medicine, Los Angeles, CA, United States of America Purpose: Patient radiation dose in conventional myocardial perfusion SPECT (MPI) is approximately 11.4 mSv using the standard one-day rest/stress protocol with 370 MBq rest and 1017.5 MBq stress Tc-99m sestamibi injection. In this work, we evaluated the potential of submSv (\1 mSv) patient radiation dose through the use of highsensitivity SPECT systems, advanced reconstruction algorithms, and modified imaging protocols. Methods: Sixty-six consecutive patient studies with list-mode data acquisition were performed on a triple-head dedicated cardiac SPECT camera with solid-state detectors. The average injection was 340.4 and 1306.1 MBq and the average acquisition time was 11.4 and 4.2 minutes for rest and stress studies, respectively. For each patient, a full time dataset and a 1/3 time dataset were generated from the list-mode data with the latter using every third of the list-mode events. The full time data was reconstructed using a 3D-OSEM algorithm with resolution recovery (nSPEED). The 1/3 time data was reconstructed with an improved 3D-OSEM algorithm (nSPEED2) that incorporated a 3D maximum a posteriori technique and a weighted-Gaussian filter for better noise/resolution trade-off. Images were interpreted by a blinded expert nuclear cardiologist for quality and diagnostic equivalence. Results: The 1/3 time nSPEED2 images showed diagnostic agreement with the full time nSPEED images in 64/66 (97%) of the studies. The quality of the 1/3 time nSPEED2 images was better than or equivalent to that of the full time nSPEED images in 65/66 (99%) stress and 62/66 (94%) rest studies. The 1/3 time data corresponded to 3.8-minutes rest and 1.4-minutes stress acquisitions; hence, if using longer acquisition time, the patient dose can be reduced to \1 mSv at 15 minutes (see Table). Conclusion: Patient studies showed potential sub-mSv rest and stress radiation dose when using a high-sensitivity camera for data acquisition and an advanced algorithm (nSPEED2) for image reconstruction. Overall sub-mSv MPI radiation dose can be achieved for patients with normal stress diagnosis when using stress-only protocols. Patient dose vs acquisition time Caution is required when comparing left ventricular function calculated using newer gated SPECT iterative reconstruction algorithms to the previously used filtered backprojection reconstruction method D. Doumit Daou1; C. Coaguila2; M. Tawileh1 1APHP, Cochin Hospital, Department of Nuclear medicine, Paris, France; 2Hospital Sud-Francilien, Corbeil-Essonnes, France Purpose: Gated SPECT myocardial perfusion (GSPECT) has been extensively validated for the quantification of left ventricular (LV) function especially with QGS. This was done with filtered backprojection reconstruction method (FBP). Recent developments in nuclear medicine technologies allow simple application of iterative reconstruction with and without resolution recovery. We aimed to compare the performance of the QGS software for the quantification LV function when using FBP as compared to iterative reconstruction (OSEM) and iterative reconstruction combined to resolution recovery (3DFlash, Siemens). Methods: Our study included 51 consecutive patients addressed for myocardial perfusion scintigraphy. Studies were acquired on a twoheaded gamma-camera (Symbia, Siemens). GSPECT studies were reconstructed using three different methods (FBP, OSEM, and 3DFlash) and then processed with the QGS software. LV end diastolic volumes (EDV), end systolic volumes (ESV) and LVEF were compared. Results: LVEF was higher with FBP (72 13%) than OSEM (70 11%, P \ .0001) and 3D-Flash (69 12%, P \ .0001), respectively. LV EDV was lower with FBP (70 23 mL) than OSEM (74 25 mL, P \ .0001) and 3D-Flash (80 26 mL, P \ .0001), respectively. LV ESV was lower with FBP (22 14 mL) than OSEM (24 16 mL, P \ .0001) and 3D-Flash (27 17 mL, P \ .0001), respectively. Bland-Altman analysis for the combined EDV and ESV (n = 102) between FBP and 3D-Flash showed that the difference in LV volumes between the two methods increased with their average LV volumes (r = 0.61, P \ .0001). This also was also verified for FBP and OSEM: r = 0.44 (P \ .0001). Conclusions: Newer iterative reconstruction methods (OSEM, 3DFlash) give significantly different LVEF and volumes than those obtained with FBP. This should be considered when adopting newer reconstruction algorithms in clinical practice. Poster Session 1 Advances in Instrumentation Monday 6 May, 2013, 08:3012:30 70 Correlation of myocardial ischemia with contraction asynchrony measured by single photon emission computed tomography synchronized with electrocardiogram C. Carlos Guizar1; E. Alexanderson1; S. Hernandez1; Objective: To establish the correlation between regional changes in the synchrony of ventricular contraction and the presence of moderate to severe ischemia on gated-SPECT. Methods: We included men and women over age 40 who underwent gatedSPECT in the period from January 1, 2006 to January 1, 2008 and had moderate to severe myocardial ischemia, expressed as a summed difference score (SDS) C 9 points, with no evidence of infarction. For the image analysis we used Emory Cardiac ToolboxTM 3.1 (Emory University Atlanta Georgia) software. Myocardial perfusion was analyzed in 17-segment polar maps, obtaining the summed stress score (SSS), the summed rest score (SRS) and the summed difference score (SDS). End diastolic volume, end systolic volume and ejection fraction of the left ventricle were also obtained. The sequential activation of the left ventricle was assessed in visual form from the polar map, thereby detecting the territories in which the activation occurred delayed. Synchrony indices were obtained as the standard deviation of timing phase angles and bandwidth. Results: We included 34 patients, with a mean age of 67.5 9.2 years, 67% were male patients (n = 23) and 33% female (n = 11). The 47% had severe ischemia and 53% moderate ischemia. The mean SSS was 14.12 5.77, whereas for the SRS was 0. The mean ejection fraction was 66.21 12.31%, the end diastolic volume of 84.85 mL, and the end systolic 32.84 33.03 23.89 mL. Ischemia was observed on the anteroseptal region in 38% of cases, on the inferior wall in 29%, on the lateral wall in 21% and on the apex in 12%. The synchrony polar map showed contraction delay in the ischemic region in 58.8% of cases. Patients with asynchrony in the polar map had a significantly larger bandwidth than those without delay in the polar map, with 60 22 and 44 16 , respectively (P = .02). There was no significant difference in the standard deviation (21.5 10 vs 21.44 9 , P = .94). There was also no association between the degree of ischemia and the presence of asynchrony in the polar map (P = .315). Conclusions: Moderate to severe ischemia was associated with the presence of delay in the contraction of the same region with considerable frequency (58.8%), but the delay was slight. Only the bandwidth measurement was significantly increased in these cases, so this index is probably more sensitive than the standard deviation to detect slight delays in contraction associated with myocardial ischemia. 71 Coronary stent evaluation with MDCT: comparison between low-osmolar, high-iodine concentration iomeprol-400 and iso-osmolar, lower-iodine concentration iodixanol-320 Purpose: To compare Iomeprol-400 with Iodixanol-320 for multidetector computed tomography coronary angiography (MDCT-CA) evaluation of coronary stents. Appropriateness of MDCT-CA stents evaluation is still a matter for debate and is unknown if contrast medium characteristics may affect MDCT-CA diagnostic performance. Methods: We randomized 254 patients undergoing MDCT-CA coronary stent follow-up to Iomeprol-400 at 5.0 mL/second flow rate (group 1, n = 83), Iodixanol-320 at 6.2 mL/second flow rate (group 2, n = 87) and Iodixanol-320 at 5.0 mL/second flow rate (group 3, n = 84). Heart rate (HR) before and after scanning, HR variation, premature heart beats (PHB) and heat sensation by visual analog scale (VAS) during scanning were recorded. Mean attenuation was measured in the aortic root and coronary arteries. Image quality score and type of artifacts were assessed. Results: In group 3, VAS was significantly lower than in groups 2 (4.3 vs 5.3 mm) and 1 (4.3 vs 8 mm) and HR after imaging was significantly lower than in groups 2 (53.7 vs 56.7 bpm) and 1 (53.7 vs 56.2 bpm). Number of patients with PHB during the scan was significantly lower in group 3 than in other groups. Mean attenuation was significantly lower in group 3 than in other groups. In group 3, stent evaluability was significantly higher and artifact rate was significantly lower than in group 2 (99% vs 91% and 4% vs 15%) and 1 (99% vs 92% and 4% vs 17%), respectively. Conclusions: Iodixanol-320 provides better image quality of coronary stents, allowing higher MDCT-CA evaluability in comparison with Iomeprol-400. V. Vitaliy Androshchuk1; L. Hossen1; E. Reyes1; K. Wechalekar1; J. Bailey1; S. Gregg1; S.R. Underwood1 1Royal Brompton Hospital, London, United Kingdom Background: Myocardial perfusion scintigraphy (MPS) is degraded by scattering of photons, which can reduce diagnostic accuracy. Scatter correction (SC) using the triple-energy-window (TEW) technique can correct for the degradation but Monte Carlo (MC) simulation is thought to be more accurate. We have compared a MC-based SC reconstruction (Hybrid recon, Hermes Medical Solutions) with a TEW technique (Xeleris, GE Healthcare). Methods: Twenty consecutive patients with known or suspected coronary disease and a clinical referral for MPS were selected retrospectively. MPS was performed using 99mTc-tetrofosmin (250 + 750 MBq 1-day stress-rest protocol) with a dual detector camera and CT attenuation correction (Infinia Hawkeye, GE Healthcare). Tomograms were reconstructed using iterative reconstruction alone (NC) and were compared with reconstructions using MC correction with attenuation and resolution recovery (AR-MC), and TEW correction with attenuation correction (A-TEW). The studies were reviewed by an experienced observer blinded to the reconstruction technique and to the previous clinical report. Parameters recorded were diagnostic interpretation (normal, reversible, fixed or mixed defects), interpretative confidence (3-high to 0-absent), image quality score (3-0), artefact scores (3-0), summed segmental scores, left ventricular ejection fraction (LVEF) and end-diastolic volume (EDV). The reconstructions were then viewed in pairs for observer preference. Advances in Instrumentation / Journal of Nuclear Cardiology Supplement (2013) 20 (Supplement 1) Results: There was no difference in diagnosis between NC, AR-MC, A-TEW (P = .98). Also, there was no difference in diagnostic confidence scores between NC, AR-MC and A-TEW (1.90 0.72, 2.00 0.73, 1.95 0.89, respectively; P = .68). Stress image quality was higher with AR-MC (2.30 0.66) and NC (2.25 0.64) than A-TEW (1.65 0.59) (P = .0029 and P = .0018, respectively). ARMC had less stress low count artefact than A-TEW (0.25 0.55 vs 0.75 0.55, P = .0066). AR-MC and NC were both preferred over A-TEW but were equally preferred to each other. Left ventricular functional data and summed perfusion scores were not significantly different between techniques. Conclusion: Imaging performance of MPS with iterative reconstruction (NC) can be improved more by AR-MC than by A-TEW. Although the advantage of AR-MC over NC is small at conventional doses of tracer, it may allow reduction of dose without loss of diagnostic performance, but this application remains to be studied. Introduction: The new multipinhole cardiac SPECT/CT cameras with cadmium zinc-telluride (CZT) detectors are highly sensitive, produce high image quality but rely on dedicated reconstruction algorithms. The influence of image processing steps may be different as compared to standard SPECT protocols. We determined the intra- and interoperator variability of these processing steps on the final result of myocardial perfusion imaging studies. Methods: The population consisted of 20 consecutive patients (7 women and 13 men, BMI 22-40, age 34-79) who underwent a oneday protocol stress- and rest CZT-SPECT/CT (GE Discovery NM/ CT 570c) using Tc99m-tetrofosmin. Data were processed twice by three experienced operators. Processing steps include determining of myocardial axes and boundaries, masking of the myocardium and manual SPECT/CT co-registration for attenuation correction. We used a 17-segment cardiac model and calculated the difference between stress and rest of % segmental uptake values (after normalisation of peak activity to 100%) for non-corrected (NC) and attenuation-corrected (AC) image sets. AC includes one extra processing step, i.e. SPECT/CT co-registration. Operator variation was considered significant for the diagnosis of ischemia when greater than 5%. Results: As a measure of inter-operator variation, the mean operator variation across all 340 segments was 2.5% (Q1-Q3: 1.8-2.8%) for the NCand 4.2% (Q1-Q3: 3.2-5.1%) for AC images (P \ .01). In more than 3% (NC) and 28% (AC) of the cases, inter-operator variation was greater than 5%. The mean intra-operator variation across all 680 segments was 2.2% (Q1-Q3: 1.6-2.2%) for the NCand 3.4% (Q1-Q3: 2.6-3.9%) for AC images. In more than 5% (NC) and 13% (AC) of the cases, intra-operator variation was greater than 5%. Conclusion: Intra- and inter-operator variation in image processing of SPECT-CT CZT gamma camera data is significant and may influence the final diagnosis of ischemia. Especially the use of attenuation correction significantly increases this variation. Clearer guidelines for image processing are necessary in order to improve the reproducibility of the results and to obtain a more reliable diagnosis of ischemia. A. Alp Notghi1; G. James1; A. Jennings1; J. Obrien1 1Sandwell and West Birmingham Hospitals NHS Trust, Birmingham, United Kingdom We have looked at repeatability of LV function parameters in the same patient using gated myocardial perfusion scan (MPS). 16 patients (6 male, 10 female) were entered into this study, median age of 69 (range 34-69 years), mean weight of 76 kg (range 44-90 kg). Each patient had three consecutive MPS. Rest MPS (400 MBq tetrofosmin) was followed on the same day with stress MPS (800 MBq), pattient then returned for a second rest MPS (400 MBq) the next day. On each occasion two consecutive MPI acquisitions were performed (180 degrees, 60 projections 18 seconds/projection, 8 bin gating). The two consecutive studies were added to obtain the equivalent of a standard full time acquisition for each occasion. Cedar Sinai QGS (Autoquant7 Philips Medical Systems) was used to obtain EDV, ESV and LVEF. Paired t-test (P) and Pearson correlation (r) was calculated to compare data. There was a wide range of EDV (76-333 mL), ESV (7-226 mL) and EF (21-73%). The full-time stress data were analysed twice (n = 16), to establish the repeatability of the QGS calculations. There was no significant difference in the EDV, ESV and EF when same data were analysed twice (Pearson correlation 0.993, 0.998 and 0.971 respectively, mean difference 0.38 mL, 0.68 mL, 0% respectively, P NS). Then day one and day two rest studies were compared (n = 16). This compared results obtained at separate occasions from the same patient. There was no significant difference in calculated EDV, ESV or EF between the two separate rest studies (Pearson correlation 0.989, 0.992 and 0.938 respectively, mean difference 0.44 mL, 0.81 mL, 0.37% respectively, P NS). Finally the half-time consecutive studies where compared (n = 32) to see if the QGS calculations are reliably reproducible in low count acquisitions when conceivable the ventricular wall delineation may be difficult. There was again no difference in the results of paired EDV, ESV, and EF (Pearson correlation 0.996, 0.996 and 0.961 respectively, mean difference 0.61 mL, 1.00 mL, 0.82% respectively, P NS). Conclusion: QGS gives reproducible parameters for consecutive measurements of left ventricular function. The results suggest very high accuracy of reproducibility for individual patients even with very low count studies. 75 Gated blood pool SPECT: QBS software performs better with iterative reconstruction combined to resolution recovery than with filtered backprojection D. Doumit Daou1; C. Coaguila2; C. Meyer1; F. Amegassi1 1APHP, Cochin Hospital, Department of Nuclear Medicine, Paris, France; 2Hospital Sud-Francilien, Corbeil-Essonnes, France Purpose: Gated blood pool SPECT (GSPECT RNA) radionuclide angiography (RNA) is interesting for the evaluation of cardiac function. We previously validated the use of QBS software (Cedars Sinai) for the quantification of both left ventricular (LV) and right ventricular (RV) function. This was done with filtered backprojection reconstruction method (FBP). We aimed to study the performance of the QBS software for the quantification LV and RV function when using FBP as compared to iterative reconstruction with resolution recovery (3D-Flash, Siemens). Poster Session 5 Clinical General and Outcome: Cardiac CT Posters Wednesday 8 May, 2013, 08:3012:30 350 Quantitative cardiac SPECT and coronary calcium score in the detection of coronary artery disease: Validation of findings by coronary angiography M. Kaminek1; I. Metelkova1; M. Budikova1; E. Buriankova1; R. Formanek1; L. Henzlova1; P. Koranda1; E. Sovova1; V. Kincl2 1University Hospital Olomouc, Olomouc, Czech Republic; 2CMI, ICRC-FNUSA, Brno, Czech Republic Purpose: To analyse sensitivity and specificity of SPECT and to assess the diagnostic potential of quantitative parameters of perfusion, left ventricular function and coronary artery calcium (CAC) score to identify high risk patients with multivessel coronary artery disease. Methods: 702 patients underwent stress gated SPECT study and then coronary angiography. We quantified summed difference score (converted to % of ischemic myocardium), left ventricular ejection fraction (LVEF), end-diastolic/end-systolic volumes, transient ischemic dilatation (TID) ratio. In patients with a dilated left ventricle, we measured CAC score. Results: Sensitivity and specificity of SPECT were 91% (456/502) and 76% (151/200), respectively. There was not significant difference between sensitivity in men and women (91% vs 90%, P = NS). Sensitivity was significantly higher in patients with multivessel disease (87% in 1-vessel disease vs 95% and 94% in 2- and 3-vessel disease, respectively, P \ 0.05). In quantitative analysis, % of ischemic myocardium rose with a number of diseased vessels: 11% 11%, 15% 12% and 19% 14% in patients with 1-, 2- and 3-vessel disease, respectively. The sign of postischemic left ventricular stunning (poststress worsening of the LVEF [ 5% and/or TID ratio [ 1.17) was observed in 46%, 49%, and 63% of patients with 1-, 2- and 3-vessel disease, respectively. In the subgroup of 81 patients with a dilated left ventricle, combining SPECT with CAC score (at a cutoff of 1000) improved sensitivity from 80% to 91% and negative predictive value from 66% to 81% (P \ .05), in association with not significant change in specificity and positive predictive value. Conclusions: Quantitative SPECT enables identification of high risk patients with a large ischemia and postischemic stunning with probable multivessel disease. In patients with a dilated left ventricle, the accuracy of SPECT has been improved by combination with CAC score. 351 Simultaneous evaluation of myocardial perfusion imaging (MPI) and coronary calcium score (CCS) in patients with intermediate likelihood of CAD: A 5 year follow-up study Aim: Hybrid SPECT-CT tomographs offer the opportunity to simultaneously evaluate both functional (MPI) and morphoanatomical (CCS) aspects of the atherosclerosis. The aim of this study is to assess the additional prognostic value of CCS in adjunct to MPI in the evaluation of patients with intermediate-risk of CAD. Materials and Methods: Study population consisted of 367 prospective patients who were clinically scheduled for MPI and classified at intermediate risk on the basis of the Framingham Risk Score. All subjects underwent contextual rest sestamibi MPI and CCS evaluation as a part of a standard two-days stress-rest MPI protocol. Studies were acquired with an hybrid Symbia T2 tomograph (Siemens). Summed Stress Scores (SSS) and Agatston data were calculated for all patients and MPI studies were considered positive (+) if SSS [ 3. Subjects were divided into four groups on the basis of tests results: MPI- and CCS \ 400 (group A); MPI- and CCS C 400 (group B); MPI+and CCS \ 400 (group C); and MPI+ and CCS C 400 (group D). Results: Fifteen patients were excluded because of sub-optimal quality of imaging and other 22 subjects did not complete the follow-up. The remaining 330 patients (216 men, mean age 67 12 years) were prospectively followed for an average of 63 9 months and the outcome events considered were: cardiac death, non-fatal myocardial infarction, hospitalization for unstable angina and late ([90 days) coronary revascularization. Group A consisted of 126 patients, group B of 58, group C of 32 and group D of 114. The cardiac event rate in the study population was 2.7%/year. Annual event rates for overall cardiac events in group A, B, C and D were 0.3, 1.4, 4.4 and 5.6%/year respectively. Patients with a normal MPI had higher survival free of cardiac events (P \ .01); additionally an increase in global chi-square in predicting all cardiac events occurred when CCS data were added to MPI information. Kaplan-Meier curves showed a significant difference in event-free survival at 5 years in the four groups. Conclusions: Although this study suffers from several limitations it outlines that an hybrid approach, combining an anatomic assessment of coronary atherosclerotic plaque burden (which probably better estimates longer-term prognosis) with a functional evaluation of myocardial ischemia (more closely related to a short-term risk) may contribute to refine temporal risk stratification among subjects at intermediate likelihood of CAD. Multicenter trials are mandatory to confirm these preliminary findings and to assess their potential impact in larger clinical settings. M.N. Pizzi1; A. Roque2; S. Aguade-Bruix3; G. Cuberas-Borros4; H. Cuellar-Calabria2; B. Garcia Del Blanco4; G. Romero-Farina4; J. Castell-Conesa3; D. Garcia-Dorado4; J. Candell-Riera4 1Universitary Hospital Vall dHebron, Cardiology Department, Nuclear Cardiology and Cardiac CT Unit, Barcelona, Spain; 2Universitary Hospital Vall dHebron, Radiology Department, Barcelona, Spain; 3Universitary Hospital Vall dHebron, Nuclear Medicine Department, Barcelona, Spain; 4Universitary Hospital Vall dHebron, Cardiology Department, Barcelona, Spain Introduction and Objectives: The anatomic extension and severity of the coronary disease have routinely used in the prognosis evaluation of patients and the decision of revascularization. However, this is a unidimensional viewpoint of a multi-dimensional problem. We have now the possibility of integrating non-invasively function and anatomic images to improve our understanding of the coronary artery disease, especially helpful in the determination of the culprit lesion. Methods: We analyzed 30 patients (mean age: 65.5 6.77 years, 90% men, pre-test prevalence of 63.3% 21.88%) with known significant coronary artery disease ([50% stenoses) in at least one vessel who had undergone a gated SPECT, a coronary computed tomography angiography (CTA) and an invasive angiography (IA). We looked for the ability of the different techniques in the determination of the culprit lesion (the most stenotic lesion in the anatomic explorations and the most severe perfusion defect in the functional test) using the hybrid imaging as the gold standard. In the hybrid images we considered the culprit vessel the one with a significant stenosis causing the most severe perfusion defect. Results: In 3 of 30 CTA (10%), in 4 of 30 IA (13%), and in 3 of 30 SPECT (10%) we could not determine only one culprit vessel-region due to the presence of two similar stenoses or two similar perfusion defects. In all these cases SPECT-CTA hybrid images could determine culprit lesion. After the exclusion of these doubtful cases, we observed an 81% (22/27) concordance (kappa: 0.692) between SPECT and hybrid images, 85% (23/27) of concordance (kappa: 0.776) between CTA and hybrid images, and 88% (23/26) concordance (kappa: 0.817) between IA and hybrid images. Concordance between SPECT and hybrid images was 100% for left anterior descending artery (LDA) but only 64% (9/14) for right coronary-left circumflex artery. Concordance between anatomic explorations was 80% (20/25) for LDA and 93% (26/28) for right coronary-left circumflex artery. Conclusions: When analyzed separately, SPECT, CTA and IA could not determine the culprit vessel-region in 10-13% of patients while hybrid images could do it in all cases. There is 80-85% of concordance between SPECT, CTA, IA and hybrid images for the diagnosis of the culprit lesion. SPECT was more accurate in the LDA territory while anatomic explorations did it better in the inferior territory. C. Christos Graidis1; T. Christoforidou1; D. Dimitriadis1; V. Karasavvidis1; V. Psifos1; K. Gourgiotis1; G. Karakostas1; M. Giannadaki1; I. Neroladakis1; G. Dimitriadis1 1Euromedica-Blue Cross Hospital, Thessaloniki, Greece Background: Myocardial bridging (MB) is a congenital structural variant in which a segment of the epicardial coronary artery tunnels into and is surrounded by the myocardium. The depiction rate of MB varies significantly between catheter coronary angiography and autopsy studies. Conventional coronary angiography is the gold standard for detection, but it is invasive and may not be sensitive enough to detect a thin bridge. Purpose: The aim of this study was to assess the depiction rate of MB by coronary computed tomographic angiography in Northern Greece and to determine the anatomical features of the tunneling vessels. Methods: Between January 2009 and March 2012, a total of 1884 consecutive patients who underwent 64-row MDCT coronary angiography in our institution, were retrospectively reviewed to identify the presence and the location of MB and determine morphologic features and relation to atherosclerosis. Results: A total of 338 (226 males, 44 females; mean age, 55.4 12.6 years; age range 24-90 years) out of 1,884 (17.9%) patients showed 353 cases of MB. One hundred ninety-one tunneling segments (54.2%) were situated in the middle portion of the left anterior descending coronary artery (LAD), 103 segments (29.2%) were in the distal portion of the LAD, 38 segments were in the proximal part of the LAD (10.8%), 6 (1.7%) in the first diagonal branch, 6 (1.7%) in the ramus intermediate, 3 (0.8%) in the second diagonal branch, and 3 (0.8%) in the Right coronary artery. Depth ranged from 0.1 to 4.1 mm. Intramuscular segment length ranged from 9 to 38 mm. All intramuscular segments were without evidence of atherosclerosis. We found proximal intima to be without atherosclerosis in 44.1% of patients (149/338) and with atherosclerosis in 55.9%. Distally atherosclerosis was absent in 95.9% of cases. Conclusions: Our study showed that MDCT is a reliable and noninvasive tool for diagnosing coronary myocardial bridging, since it accurately determines the location, depth, and length of MB. We found the incidence of myocardial bridging in this patient group to be 17.9%, higher than the depiction rate of MB by catheter CAG reported in the literature and in concordance with other studies using MDCT. The most common location of MB was in the LAD. We also observed that most atherosclerotic plaques in the host vessel were located at the segment proximal to the tunneled segment there was no evidence of atherosclerosis within any intramuscular segment. M. Zapparoli1; J. Vitola1; F.R. Farias1; S.S. Zier1; C. Cunha1; J.J. Cerci1; O.J. Kormann1; A. Stier Jr1; O. Franca Neto1; R.J. Cerci1 1Quanta Diagnostico e Terapia, Curitiba, Brazil Purpose: To determine the cost effectiveness of performing coronary CT angiography (CCTA) as a gatekeeper for invasive angiography (ICA) in patients with suspected coronary artery disease and mild ischemia on SPECT-MPI. Methods: Data from patients without known coronary artery disease (CAD), with mild ischemia (SSS ranging from 4 to 8) detected on SPECT-MPI and submitted or not to CCTA between 12/2011 and 08/2012, were retrospectively analyzed from Quanta database (Curitiba, Brazil). We modeled two diagnostic scenarios in which patients would be: (1) submitted directly to ICA (U$ 800.00 per procedure) after the abnormal SPECT; (2) submitted to CCTA (U$ 500.00 per procedure), followed by ICA only when obstructive disease was detected. For cost analysis purposes, the CCTA frequencies of normal, non-obstructive (\50% stenosis) and obstructive (C50% stenosis) CAD results of the subgroup submitted to CCTA were extrapolated to the whole cohort. Results: During the observation period of 9 months, 5,345 patients were referred for SPECT-MPI. Of these, 1,450 had mild ischemia on SPECT-MPI, but 564 had previous history of CAD. From the remaining 886 patients suitable for analysis, CCTA was performed in only 75 (8.5%). The clinical and SPECT characteristics of the groups submitted or not to CCTA are presented in the Table. There were 36 (48%) normal, 26 (34.7%) non-obstructive and only 13 (18.3%) obstructive results by CCTA. The CCTA first strategy would avoid an unnecessary ICA in 82.7% of patients. Applying the procedures costs in each strategy, the total cost would be U$ 708,800.00 on the direct ICA group and U$ 566,200.00 on the CCTA first strategy, with a net economy of 20.1%. Conclusion: A CAD diagnostic strategy in which CCTA is applied as a gatekeeper to ICA in patients with mild ischemia by SPECT is very cost-effective, but still remains highly underused in Curitiba, Brazil. Clinical and SPECT variables by group 355 Integration of single-photon emission computed tomography (SPECT) and cardiac computed tomography (CCT) for the triage of patients with equivocal stenoses in clinical practice L. Luigi Di Serafino1; G. Toth1; S.A. Pyxaras1; F. De Vroey1; J. Geraedts2; H. Declercq2; P. Vanhoenacker1; B. De Bruyne1; W. Wijns1; C. Van Mieghem1 1OLV Hospital Aalst, Cardiovascular Center, Aalst, Belgium; 2St Blasius Hospital, Dendermonde, Belgium Purposes: The aim of this study was to evaluate the diagnostic accuracy of sequential CCT and SPECT imaging in the evaluation of patients with CAD and at least one equivocal stenosis detected at CCT, in comparison with invasive coronary angiography (ICA) and FFR. Methods: All consecutive patients with stable angina and at least one equivocal stenosis (% diameter stenosis between 30% and 70%) detected at CCT (Dual source CT), underwent SPECT followed by ICA and FFR measurement. At CCT, an equivocal stenosis was assessed as being significant (50-70%) by visual estimation. Intravenous (IV) adenosine infusion was used as stressor for SPECT. At quantitative coronary angiography, a lesion was considered significant when the %DS was [50%. FFR was measured for all equivocal stenoses detected by CCT using a 0.014 pressure guide wire system (St Jude Medical Systems). Maximum hyperemia was induced by IV adenosine infusion. An FFR B 0.80 was used as threshold to define a functionally significant stenosis. Results: A total of 51 patients were prospectively enrolled and 121 stenoses were evaluated. At CCT, 60 stenoses (49%) in 43 patients (84%), were considered anatomically significant. Using SPECT, inducible myocardial ischemia was detected in only 30 patients. At ICA, 45 stenoses (37%), in 29 patients (57%), were found to be anatomically significant. Using FFR, only 36 stenoses (30%), in 28 patients (55%), were determined as being functionally significant: these patients subsequently underwent revascularization. In comparison with ICA, CCT showed high sensitivity (90%) and lower specificity (77%), when assessing anatomical severity of CAD. In comparison with FFR, CCT was suboptimal for determining the functional significance of a stenosis (sensitivity: 89%, specificity: 22%). Combining CCT with SPECT imaging (hybrid imaging), as compared with FFR, did not improve diagnostic accuracy (sensitivity: 64%, specificity: 48%). In addition, hybrid imaging was significantly less sensitive (64% vs 89%, P = .05) as compared with CCT alone. Considering patient management, the FFR result was used as decisive to proceed with revascularization. The noninvasive hybrid approach resulted in appropriate patient triage in 65% of the patients: 17 of the 22 patients who underwent revascularization were correctly identified, 16 of the 29 patients who were treated medically had a normal CCT-SPECT result. Conclusions: In patients with equivocal stenoses at CCT, the combination with SPECT imaging did not improve diagnostic accuracy to detect ischemia-provoking CAD. This combination of tests did not result in reliable patient management. 356 Pre-operative CT coronary angiography in patients with mitral valve prolapse referred for surgical repair: Comparison of accuracy, radiation dose and cost versus invasive coronary angiography Purpose: To evaluate the accuracy of low dose multidetector computed tomography coronary angiography (MDCT) vs invasive coronary angiography (ICA) in ruling out CAD in patients with mitral valve prolapse and severe mitral regurgitation (MVP) before cardiac surgery and to compare the overall effective radiation dose (ED) and cost of a diagnostic approach in which conventional ICA should be performed only in patients with significant CAD as detected by MDCT. Materials and Methods: Eighty patients with MVP and without history of CAD were randomized to MDCT (Group 1) or ICA (Group 2) to rule out CAD before surgery. However, ICA was also performed as gold standard reference in Group 1 to test the diagnostic accuracy of MDCT. A diagnostic work-up A in whom all patients underwent lowdose MDCT as initial diagnostic test and those with positive findings were referred for ICA was compared with work-up B in which all patients were referred for ICA according to the standard of care in terms of ED and cost. Results: The two groups were homogeneous in terms of gender, age and body mass index. The overall feasibility and accuracy in a patientbased model were 99% and 93%, respectively. The overall ED and costs were significantly lower in diagnostic work-up A compared to diagnostic work-up B. Conclusions: The accuracy of low dose MDCT for ruling out the presence of significant CAD in patients undergoing elective valve surgery for mitral valve prolapse is excellent with a reduction of overall radiation dose exposure and costs. 357 Association of atherosclerosis of the descending thoracic aorta with coronary artery disease on multi-detector row computed tomography in patients with suspected coronary artery disease Purpose: The association between atherosclerosis in the descending thoracic aorta (DTA) visualized on CTA and CAD has not been extensively explored. Therefore, we assessed the presence, severity and extent of DTA atherosclerosis and evaluated the association of DTA atherosclerosis with CAD in patients with suspected CAD who underwent CTA. Methods: A total of 345 patients (54 12 years, 54% men) with suspected CAD underwent a non-contrast enhanced scan for calcium scoring and a CTA to evaluate CAD. CTA scans were classified as non-significant CAD or significant CAD, based on \50% or C50% luminal stenosis, respectively. The DTA was divided into segments according to the posterior intercostal arteries. Per segment maximal wall thickness was measured and the presence of plaque (C2 mm wall thickness) was determined. In addition, plaque composition was scored as non-calcified or mixed and mean wall thickness was calculated. Results: Significant CAD was present in 152 (44%) patients. DTA atherosclerotic plaque was identified in 279 (81%) patients. Differences in DTA atherosclerosis between patients with and without CAD are presented in the table. Multivariate linear regression analysis corrected for age and other risk factors demonstrated independent associations of DTA wall thickness (OR 2.3, 95% CI 1.4-3.8, P = .001) and presence of DTA plaque (OR 6.8, 95% CI 1.4-32.6, P = .017) with significant CAD. Conclusions: The presence, severity and extent of DTA atherosclerosis were independently related with significant CAD on CTA in patients with suspected CAD. Table of the abstract 357 358 Cardiac CT and non-invasive electrocardiographic imaging of chronic myocardial infarction arrhythmia substrates F. Fady Dawoud1; K.H. Schuleri1; R. Beinart1; M. Horacek2; H. Halperin1; A.C. Lardo1 1Johns Hopkins University, Baltimore, United States of America; 2Dalhousie University, Halifax, Canada Introduction: Chronic myocardial infarction (MI) constitutes a substrate for ventricular tachyarrhythmias (VT) and its delineation is important to facilitate catheter ablation procedures. While MI can be delineated with cardiac CT, electrical propagation can only be identified with electrophysiological techniques. We investigated the feasibility of cardiac CT combined with a novel non-invasive electrical imaging technique (ECGI) to delineate scar and gain insight into VT reentry mechanism. Methods: MI was induced in three pigs by LAD occlusion. Whole body ECG mapping was performed during native rhythm and VT induction 6 months post MI. Delayed-enhancement CT (DE-CT) was acquired 7.5-minutes post contrast injection. Inverse electrograms were reconstructed according to previously developed methodology utilizing CT-segmented torso- and heart geometries. Regional electrical activation times were computed and Q-wave integral maps were used to estimate scar from inverse electrograms. Results: Figure 1 shows an example of DE-CT volume-rendered image showing the MI (pink outline, AHA segments 2, 7, 8, 13, 14 in panel A) and Q-wave integral map from ECGI in pig 1 showing scar (values \ 0, pink outlined shadowed with black, segments 2, 7, 6, 8, 12, 13, 14 in panel B top) over extending to lateral segments while the inferior/infero-lateral segments show viable tissue (values [ 0, green to red, panel B bottom). The reconstructed VT activation map shows early antero-apical activation at the scar border implying an exit site of the reentrant VT. Similar patterns were observed in other animals. Conclusion: We demonstrated a promising application of CT in combination with ECGI to delineate the location of MI and reconstruct activation times during VT which can greatly guide planning of catheter ablation procedures. 359 Influence of calcium channel blocker usage on results of 123I-mIBG myocardial scintigraphy in heart failure patients: Diagnostic and prognostic implications A. Arnold Jacobson1 1GE Healthcare, Princeton, United States of America Background: Previous studies have suggested that calcium (Ca) channel blockers may interfere with stimulation of neuronal cell bodies and may also inhibit release of meta-iodobenzylguanidine (mIBG). The present analysis examined the influence of Ca channel blocker usage on 123I-mIBG imaging results and clinical outcomes during 2 years follow-up of HF subjects in the ADMIRE-HFX study. Methods: Of the 961 HF subjects in ADMIRE-HFX (LVEF B 35%; 83% NYHA II, 17% NYHA III), 78 (8%) were using Ca channel blockers at the time of 123I-mIBG imaging. Cardiac 123I-mIBG uptake was quantified as the heart/mediastinum ratio (H/M) on early (15 minute) and late (4-hour) anterior planar (p) images, backgroundcorrected washout (WO) rate between the two planar images, and H/M on OSEM-reconstructed SPECT (s) images. Outcomes determined during median 2 years follow-up were cardiac death, and all-cause mortality. Summary statistics were compared using t-tests, while survival was compared using Kaplan Meier analyses and log-rank tests (P \ .05 considered significant). Results: During follow-up, there were 64 cardiac (7%) and 101 total deaths (11%). In the total population, there was no difference in baseline 123I-mIBG parameters between subjects who were and were not using Ca channel blockers (With vs without Ca blockers: Mean Early H/Mp: 1.55 vs 1.57 (P = .38); Mean Late H/Mp: 1.41 vs 1.45 (P = .16); Mean WO Rate: 39.2% vs 37.3% (P = .36); Mean H/Ms: 2.19 vs 2.19 (P = .99)). However, when subjects were categorized as having either reduced (late H/Mp \ 1.60) or preserved (late H/Mp C 1.60) myocardial innervation, those using Ca blockers had lower 2 year all-cause mortality rates (With vs without Ca blockers: 8.3% vs 16.8% for late H/Mp \ 1.60, 0 vs 3.2% for late H/Mp C 1.60; P = .002) and lower 2 year cardiac mortality rates (With vs without Ca blockers: 6.7% vs 11.5% for late H/Mp \ 1.60, 0 vs 3.2% for late H/Mp C 1.60; P = .013). Conclusions: Although Ca channel blockers had no effect on population-based measures of myocardial 123I-mIBG uptake, HF subjects using these medications had lower cardiac and all-cause mortality rates during 2-year follow-up. In light of the higher mortality rate among subjects with reduced myocardial innervation, the potential value of addition of Ca channel blockers to the therapeutic regimen of such subjects may warrant further investigation. Epicardial fat volume (EFV) measurement, using cardiac computed tomography (CT) has been shown to be a reliable marker of coronary atherosclerosis, and greater EFV is associated with coronary artery disease (CAD). However, little is known on the relation between the amount of EAT and the severity of coronary atherosclerosis in identifying high risk patients with subclinical CAD. Purpose: The aim of this study was to investigate the relationship between EFV and severity of coronary artery disease measured by CT. Methods: We retrospectively analyzed data of 600 individuals who were referred for evaluation of CAD with cardiac CT from 2007 to 2012. Subjects who had history of primary coronary intervention or coronary artery by-pass graft were excluded. Thickness of epicardial adipose tissue (EAT cm3), was measured on noncontrast multiplanar reformat images with parasternal short axis view at basal, mid-ventricular and apical levels and horizontal long axis view as the sum of the EAT areas with 2 mm thick from the whole heart. CAD severity was determined by, the presence of significant coronary stenosis ([50% luminal narrowing of at least one major coronary artery), high coronary artery calcium score (CACS [ 100) and plaque characteristics (any plaque causing significant stenosis and/or vulnerable plaques), in the subsequent CT angiography. Results: In the finally studied population of 434 individuals, 155 (35.7%) had atherosclerotic coronary artery disease and 279 (64.3%) of them were normal. Overall, 75.2% were male; mean age was 58 18 years with a mean EAT 155.54 cm3. Patients with coronary atherosclerosis had significantly greater mean EAT compared to normals (P = .011). Linear regression analysis revealed that the incidence of significant stenosis, atherosclerotic plaque and high calcium score increased with EFV (P \ .01). Conclusion: EFV measured by 64-slice CT scanning, was closely associated with significant CAD and its measurement might be used in addition to CT angiography as an early indicator of increased risk of coronary atherosclerosis. 361 Incidence of coronary artery disease at CT coronary angiography in patients with hypertrophic cardiomyopathy presenting with chest pain or angina-equivalent symptoms M. Shariat1; A.M. Crean1 1University Health Network, Toronto, Canada Incidence of coronary artery disease at CT coronary angiography in patients with hypertrophic cardiomyopathy presenting with chest pain or angina-equivalent symptoms. Background: Angina is a frequent symptom in patients with hypertrophic cardiomyopathy (HCM). Many of these patients will present with exertional chest pain or angina-equivalent symptoms, such as effort-related breathlessness, which appear indistinguishable from symptoms in the arteriopathic population. CT coronary angiography (CTCA) is often regarded as the non-invasive test of choice to rule out significant coronary artery disease in the low and medium risk patient group categoryinto which many of these patients fall. Objectives: To describe the prevalence of severe coronary artery disease in patients with HCM referred to CTCA for investigation of anginal symptoms. Patients and Methods: We retrospectively reviewed CTCA studies of 93 patients who were known to have HCM or in whom the diagnosis was unequivocally present based on the CTCA images. CTCA studies were done on 320 slice CT scanner. Volumetric data acquisition was done at 0.5 mm slice thickness and 0.25 mm gap. The coronary arteries were carefully evaluated and any luminal narrowing more than 70% was labeled severe. Any narrowing less than 50% was labeled mild and between 50% and 70% was called moderate. Cases were reviewed by two blinded observers. Disagreements were arbitrated by a third reader. Results: The indications for the CTCA included chest pain in 87 patients (93.5%) and shortness of breath in 6 patients (6.5%). Out of 93 patients, 14 (15.1%) had apical HCM, 13 (14%) had concentric hypertrophy and 66 (70.9%) had asymmetric septal hypertrophy. 54 patients (58%) had completely normal coronary arteries, 31 (33.3%) had mild disease and 6 (6.5%) had moderate disease. Only 2 patients (2.2%) had severe disease in at least one segment of the coronary arteries. The left anterior descending artery was the most commonly involved vessel. It showed mild disease in 28 patients, moderate disease in five patients and severe disease in 1 patient. Myocardial bridging was present in 34 patients (36.6%) and it involved the LAD in 31 patients (33.3%). Conclusion: Although angina is a common symptom in patients with HCM, in our study, only 2.2% of these symptomatic patients had severe coronary artery disease on CTCA. Coronary CTA may be useful for preventing inappropriate treatment of HCM patients with antianginal and lipid lowering therapies. Purpose: Computed tomography coronary angiography (CTA) has important prognostic value. Additionally, QCT provides a more detailed, accurate assessment of CAD on CTA. Potentially, a score incorporating all quantitative stenosis parameters allows for accurate risk stratification. Therefore, the purpose of this study was to determine if a detailed automatic assessment of coronary atherosclerosis using QCT combined into a single risk score allows automatic risk stratification of patients. Methods: In 300 consecutive patients QCT was performed. First, using an automatic tree labeling algorithm, segments were labeled according to the AHA 17-segment model. Second, vessel wall and lumen were automatically segmented. Finally, an automatic lesion detection algorithm identified all lesions in the coronary tree. Using QCT, patients risk was calculated based on plaque extent, severity, composition and location on a segment basis and integrated into a single score (0-42). During follow-up, the composite endpoint of all cause mortality, PCI and non-fatal infarction was recorded. Results: At present, results are available for 65 of the 300 patients. Event rate was 12%. In all eight patients with events an automatic, quantitative assessed significant stenosis was present. Furthermore, in these patients the median risk score was higher compared to patients without events (median 8.6 (IQR 4.7-12.8) vs median 0 (IQR 0-4.8) respectively) (P = .007). Conclusion: Integration of detailed plaque characteristics on QCT into a single risk score could provide accurate risk stratification. Evaluation of nonculprit vulnerable plaque with 64-Slice multidetector computed tomography in comparison to intravascular ultrasound Background: Coronary atherosclerotic plaque composition plays an important role in the progression of future coronary event. Especially, coronary atherosclerotic plaque with intravascular ultrasound (IVUS) attenuation might be related to the deterioration of coronary flow and worse long-term outcomes after coronary artery disease (CAD) and interventions. Noninvasively characterizing vulnerable plaque is an important method in risk stratification and following the progression of coronary plaques. Multidetector computed tomography (MDCT) is most reliable method to evaluate coronary plaque composition. The aim of this study is to evaluate possibility of 64-slice MDCT to detect nonculprit IVUS attenuated plaque and identification of atherosclerotic plaque with future coronary events. Methods and Results: Fifty-seven patients (15 with ACS, 42 with stable CAD) and 240 plaques were evaluated by 64-slice MDCT. One hundred sixty-eight nonculprit plaques of the 240 plaques were evaluated by IVUS. Of the 168 plaques, 59 (47 calcified and 12 mixed plaques) were excluded from the present analysis. The remaining 109 plaques (40 soft plaques, 30 attenuated plaques, 39 fibrous plaques) represent the present analysis. In the attenuated plaques, CT density had significantly higher than soft plaques (70 9 HU vs 40 6 HU; P \ .001) and lower than fibrous plaques (70 9 HU vs 94 6 HU; P \ .001). Spotty calcification with lipid pool was more common (37% vs 13%; P \ .05) in the attenuated plaques compared to the soft plaques. The attenuated plaques were present significantly more frequently in patients with lower high-density lipoprotein cholesterol levels than those without attenuated plaques (40 9 vs 48 9 mg/dL; P \ .001, 40 9 vs 47 11 mg/dL; P \ .005). Conclusions: Nonculprit plaque analysis by MDCT would be a useful method for predicting atherosclerotic plaque with high risk of future coronary events. C. Christos Graidis1; T. Christoforidou1; D. Dimitriadis1; V. Karasavvidis1; K. Gourgiotis1; M. Giannadaki1; I. Neroladakis1; G. Karakostas1; N. Karadimitras1; G. Dimitriadis1 1Euromedica-Blue Cross Hospital, Thessaloniki, Greece Background: Congenital coronary anomalies are uncommon with an incidence ranging from 0.17% in autopsy cases to 1.2% in angiographically evaluated cases. The recent development of ECG-gated multi-detector row computed tomography (MDCT) coronary angiography allows accurate and noninvasive depiction of coronary artery anomalies. Purpose: The aim of this study was to evaluate the prevalence of anomalous origin, course and termination of coronary arteries in consecutive symptomatic patients, who underwent cardiac 64- slice MDCT coronary angiography. Methods-Results: This retrospective study included 2572 patients who underwent coronary 64-slice MDCT coronary angiography from January 2008 to March 2012. Of the 2572 patients, 60 (2.33%) were diagnosed with coronary artery anomalies (CAAs), with a mean age of 53.6 11.8 years. High take-off of the RCA was seen in 16 patients (0.62%), of the left main coronary artery (LMCA) in 2 patients (0.08%) and both of them in 2 patients (0.08%). Separate origin of the LAD and Cx from Left Sinus of Valsalva (LSV) was found in 15 patients (an incidence of 0.58%). In 9 patients (0.35%) the RCA arose from the opposite sinus of Valsalva with a separate ostium. In 6 patients (0.23%) an abnormal origin of LCX from the right sinus of Valsalva (RSV) was found. A single coronary artery was seen in 3 patients (0.12%). In 2 patients (0.08%) left coronary trunk was found to originate from the RSV with separate ostium from the RCA. LCA from the pulmonary artery was seen in one patient (0.04%). A coronary artery fistula was detected in 4 patients (0.15%). Conclusion: The results of this study support the use MDCT coronary angiography as a safe and effective noninvasive imaging modality for defining CAAs in an appropriate clinical setting, providing detailed three-dimensional anatomic information that may be difficult to obtain with invasive angiography. Aortic valve sclerocalcification (AVSC) and mitral annulus calcification (MAC) is common with aging and have been considered as a manifestation of generalized atherosclerosis in elderly population. However, the significance of these calcifications in younger populations has not been previously determined. AVSC and MAC can be easily detected by transthoracic echocardiography (TTE). Recently, Coronary CT angiography (CTA) has become widely available in detecting occult coronary atherosclerosis disease (CAD). Purpose: We hypothesized that in subjects age \ 60 years, AVSC and MAC would be associated with a higher prevalence of positive CCTA. Methods: In a prospective, cohort study, we identified patients younger that 60 years, who all underwent both CCTA and TTE for various clinical indications. We utilized positive CTA as a surrogate for angiographically CAD. All known risk factors for atherosclerosis including age, gender, hypertension, smoking, dyslipidemia, diabetes and family history were also investigated. Results: The mean age of our study population included 155 patients (109 men and 46 women) was 50 4.2 years. When the cohort was divided by the presence of atherosclerosis, we found that 81 patients had CAD and 74 had normal coronary arteries (75.8% vs 24.2%). Of the 81 patients with CAD, 69 had AVSC compared with 22 in the nonCAD group (P \ .001).Hypertension and MAC were found significantly more prevalent in the CAD group than in non-CAD group, respectively (61% vs 39%, with P = .006 and 70.4 vs 29.6, with P = 0,042). Multivariate analysis identified only AVSC and age as independent predictors of coronary atherosclerosis. The sensitivity, specificity, positive and negative predictive values for AVSC in diagnosing CAD were 72.2.1%, 60%, 81% and 50%, respectively. Although AVS is highly associated with CAD, it has only modest sensitivity and specificity (72% and 60%), respectively. Despite a low negative predictive value (50%), it has a high positive predictive value (81%) for the presence of significant CAD. Conclusion: Our study demonstrates that aortic valve sclerocalcification and coronary atherosclerosis are significantly associated with each-other, even in a juvenile population. The presence of aortal sclerocalcifications may help in predicting CAD and should be added to conventional risk factors. J. Jingjing Gai1; L.Y. Gai1; H.Y. Qiao1; S.Y. Zhang1; Z.W. Guan2; L. Yang3; Y.D. Chen1 1China PLA General Hospital, Department of Cardiology, Beijing, Peoples Republic of China; 2China PLA General Hospital, Department of Nuclear Medicine, Beijing, Peoples Republic of China; 3China PLA General Hospital, Department of Radiology, Beijing, Peoples Republic of China Objective: Major adverse cardiac events (MACE) often occur suddenly resulting in high mortality and morbidity. Analyzing the characteristics of coronary plaque by Coronary Computed Tomography Angiography (CCTA) may help forecasting the MACE. Methods: The patients who underwent CCTA from Jan 2008 to Feb 2010 were consecutively enrolled in the study. The hospital data base was screened for patients who later developed acute ST elevated myocardial infarction (STEMI) or non ST elevated acute myocardial infarction (NSTEMI) or cardiac death. The definition of the plaque score as follow: 1. Minor plaque, 1 point; 2. Moderate plaque, 2 points; 3. Severe localized stenosis, 3 points; 4. The erosive plaque, 5 points; 5. Calcification, 1 point; 6. DES, 5 points; 7. Plaque with positive remodeling, 3 points; 8. Complete occlusion, 3 points; 9. Diffused moderate lesions, 2 points. Two-way analysis of variance was performed. Results: A total of 8557 consecutive cases of CCTA were performed in the institution. Among them 1055 were hospitalized during which 25 patients developed MACE, including 6 cases of deaths, 2 cases of heart failure, 11 cases of STEMI and 6 cases of NSTEMI. One way ANOVA analysis showed that advanced age, AF, past history of PCI, low Hb, tachycardia and high Grace Score contributed to death and heart failure. The differences were significant, P \ .05. The plaque characteristics of the plaques were analyzed. The patients who had erosion plaques and high degree localized lesions had high likelihood of developing MACE, 95% CI: 0.6472-1.538, P = .000. The death and heart failure had the highest plaque score, 95% CI: 0.4882-1.379, P = .000. Conclusion: The plaque characteristics identify high risk patients. 368 Comparation of agatston coronary artery calcium score using contrast-enhanced CT coronary angiography, framingham score and multiple blood biomarkers as predictors of coronary artery stenosis A. Ana Lanca1; Z. Madzar1; D. Javoran1; V. Bursic1; V. Pehar-Pejcinovic1; V. Persic1; M. Boban1 1Clinical Hospital Thalassotherapia Opatija, Opatija, Croatia Purpose: To analyze efficiency of Agatston score, Framingham risk score, and multiple blood biomarkers as predictors of coronary artery stenosis in patients with nonspecific chest pain. Methods: The study included 161 patients (mean age 63 7.7, 70% of females) with atypical chest pain and unknown coronary heart disease, who underwent coronary multi detector computed tomography coronarography and obtained Agatston score. Scanning was done with the Definition Flash 2 9 128 slice CT scanner by dual source technique, and the mean received amount radiation was 4.6 1.2 mSv. The mean heart rate during scanning was 68 9.3/minute, and patients body mass index (BMI) 27.4 4.3. Patients with known cardiovascular risk factors, including hypertension (77%), diabetes mellitus (25%), dyslipidemia (77%) or smoking (28%) and various Framingham risk score values (0.6-59.9, mean 22.3 12.7) were considered. Blood biomarkers included glucose, C-reactive protein (CRP), total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, creatinine, eGFR and uric acid. Participants were divided in two groups, based on coronary artery stenosis greater than 50% (40 of participants), and the other with stenosis smaller than 50% (121 of participants). Frequency of demographic and clinical characteries, blood biomarkers and risk factors were tested between the groups by using Chi square test and Student T test as appropriate. To test for factors associated with predicting coronary artery stenosis, Likelihood Ratio, and Receiver Operating Characteristics (ROC) analyses were used. Relative Risk was calculated in context of developing coronary artery stenosis greater than 50% in participants with Agatston score above 100. Results: The most accurate predictor of coronary artery stenosis greater then 50% was Agatstone score (AUC 0.99, P \ .0001). Agatstone score higher than 100, had relative risk for developing of coronary stenosis over 50%, 17 times higher than values under 100. CRP (AUC 0.76), glucose (AUC 0.59), uric acid (AUC 0.61) and Framingham risk score (AUC 0.57) had high sensitivity but low specificity for coronary artery stenosis. Conclusion: Among all considered demographic and clinical characteristics, blood biomarkers and risk factors, Agatstone score was the most accurate predictor for developing of coronary artery stenosis. G. Scrima1; G. Giovanni Bertuccio2 Myocardial bridge is the most frequent congenital coronary anomaly (about 1.5% of patients already undergone to coronary angiography). Prognosis is quite variable: a negative prognosis could be related to the so-called type III bridges (deep intra-myocardial course; [ 10 mm length; [ 75% systolic milking) with myocardial ischemia and major ventricular arrhythmias (0,6% among Patients pertaining to our department). We have considered consecutively all symptomatic patients with type III myocardial bridge afferent to our department from 01/08 to 01/ 11. All of them were submitted to coronary angiography. We selected 22 patients out of them, 13 with stable angina symptoms (angina CCS II-III): 11/13 with exercise test positive for ischemia; 2/13 had a positive SPECT with mild/moderate amounts of anterior ischemia in the absence of specific medical therapy. The remaining 9 Patients exhibited a clinical SCA (2 antero-lateral STEMI; 7 anterior/UA NSTEMI) related to the myocardial bridge on IVA. All Patients with stable angina symptoms were treated with betablockers, followed by myocardial SPECT resulted negative for inducible ischemia in the same site. All of them were asymptomatic to the clinical follow-up (22 months). All Patients, with bridge-related SCA, were treated with PTCA and medicated stent (DES). This procedure in 8/9 Patients was guided by intracoronary ultrasound (IVUS) that allowed the diameters optimization and the length of the implanted stent (in-flow and out-flow of the stent at least 3 mm before and after the intra-myocardial stretch), as well its final relaxation. Only the patient submitted to PTCA without IVUS was hospitalized again for a SCA recurrence 7 months after first procedure, secondary to the re-stenosis of the medicated stent. The IVUS control demonstrated an evident under-sizing of the implanted stent compared to the native vessel; it was solved with a simply re-PTCA using an adequate diameter NC balloon. Finally we could affirm that: Patients with myocardial bridge on IVA with stable angina symptoms have indication to medical therapy with Beta-blockers or, if not indicated, Ca-antagonist. They should be subjected to a myocardial SPECT with full therapy to evaluate the residual functional significance of the bridge during medical therapy. PTCA is useful with persisting ischemia despite medical treatment. In SCA bridge-related, IVUS guided percutaneous treatment with medicated stent appears to be safe and effective because it isnt related to late thrombotic events (no patient in our casistic) and its associated with a very low restenosis rate. Background: Cardiovascular disease is the leading cause of mortality in the world. An early investigation and management can improve survival. The non-invasive diagnostic methods in the evaluation of coronary artery disease have been widely used even those that submit patients (p) to radiation. If the association of myocardial perfusion imaging (MPI) and coronary calcium score (CAC) is important in the management of low to intermediate risk of coronary artery disease (CAD) patients (p) is not yet well established. Purpose: The aim of this study was to evaluate if the information of MPI add value to CAC in a low to intermediate risk of CAD group of patients. Methods: It was analyzed 212 p that performed CAC and MPI between 01 and 07 of 2012 without any cardiac procedure in between. From the total, 166 p (78.3%) were male, mean age of 47 years, 49 p (23.1%) with diabetes, 122 p (57.5%) with dyslipidemia, 48 p (22.6%) with hypertension, and none p had known CAD or cardiac symptoms. The CAC and the sestamibi-Tc-99m MPI were performed by standard techniques. CAC were divided in zero (101 p), \100 (27 p), 100-400 (44 p) and [400 (40 p). MPI was considered normal if no perfusion defect and suggestive of ischemia if reversible perfusion defect after stress phase. Statistical analysis was performed by Fisher exact test, being considered significant P values B 0.05. Results: In the group of CAC zero 2 p (1.9%) had presented ischemia on MPI. In the other groups with CAC \ 100, CAC 100-400 and CAC [ 400, 1 p (3.7%), 6 p (13.6%) and 14 p (35%) had presented ischemia on MPI, respectively (P B 0.05). The three patients who presented ischemia on MPI and had CAC zero or \100 had suggestive of soft plaque on coronary tomography. Male gender and presence of diabetes were associated with ischemia in the group of patients with CAC 100-400 (P \ 0.05). In the group with CAC [ 400 only diabetes was associated with presence of ischemia on the MPI (P \ 0.05). Conclusion: The obtained results may suggested that MPI can add diagnostic information to CAC in a low to intermediate risk of CAD group of patients because of the detection of ischemia in p with soft plaques. Aim: To characterize coronary artery calcification in patients with giant coronary aneurysms (GAA) caused by Kawasaki disease (KD) using multi-detector x-ray computed tomography (MDCT). Methods: Subjects were 25 pediatric and young adult patients (19 male and 6 female) with history of KD who had GAA with [8.0 mm of coronary artery diameter confirmed by coronary angiography (CAG). Using MDCT, calcification of the coronary arteries was identified and classified according to the degree of circumferential calcification; Type A, \90 ; B 90180 ; C, 180-359 ; D, 360 ; E, luminal occlusion and internal lumen was evaluated at these calcified segments. Results: Patients age at onset and at study were 2.6 2.8 and 23.5 7.1 (10.8-40.4) years old, with median of 20.8 (9.8-40.1) years after the onset. In these 25 patients, 11 (44%) underwent either catheter or surgical interventions for coronary stenosis. On MDCT, all 25 patients showed calcification of the coronary arteries in total of 47 segments (1.9, range 1-4 segments for each patient). In these 47 segments, GAA presented in 36 (77%) segments, small to moderate aneurysms with diameter \8.0 mm in 11 (23%). Calcification was located at #1 in 15, #2 in 5, #3 in 5, #5 in 5, #6 in 12, and #11 in 15 patients. Degree of calcification was calcified as Type A, 28%; B, 6%; C, 17%; D, 34%; E, 15%. Among 29 segments where calcification presented with patent coronary lumen, we could evaluate the degree of stenosis in 18 of 19 (95%) segments of Type A, B, and C, but it was possible only 3 of 10 (30%) segments of Type D with complete circumferential calcification. Conclusions: All patients with GAA after KD showed calcification at more than 10 years after the onset at proximal coronary segments, even at segments with small to moderate coronary aneurysms. Complete circumferential calcification present in one third of segments and preclude accurate evaluation of the internal lumen with current setting of the MDCT, hence other modalities including CAG or cardiac magnetic resonance imaging must be the choice of diagnostic test in these patients. Multi-slice computed tomography (MSCT) offers possibility to visualize the relations between left circumflex artery (LCx) and coronary sinus (CS) before percutaneous mitral annuloplasty (PMA) to exclude patients with potentially dangerous relations LCx/CS. There are no data available showing quality of visualization both vessels in MSCT. Methods: MSCT (Aquilion64) in 196 pts. (109 M; aged 56 11) with suspected CAD was performed using retrospective scan with ECGgating. In each case 3D VR and 2D MPR reconstructions were created (0.5 mm). A subjective assessment of the quality of visualization to find the optimal phases of visualization for LCx, CS and both vessels together (relations) was used. The quality of visualization was graded by 2 experts on 6-points scale: 0 = lack of vessel; 1 = image not diagnostic; 5 = smoothly bordered vascular structure. Independent 2 mm reconstructions optimized for the LCx (diastolic 70-80-90% RR) and CS (systolic 30-40-50% RR) were also performed. Results: In parallel visualization of LCx and CS optimal image quality (score 5 and 4) was obtained in diastolic phases (70-80%)72 cases (36.7%). Exact scoring for independent visualization in optimal phases is presented in the table below (n; %). Optimal score was achieved in 85 cases (43.4%) for LCx and in 133 cases (67.9%) for CS. Not diagnostic images (score 1) was obtained in 7 (3.6%) cases (LCx: 2; 1.0% CS: 5; 2.5%). Conclusions: Quality of parallel as well as independent visualization of LCx and CS confirm potential role of MSCT before PMA procedures. Parallel visualization should be performed in diastolic phases as an addition for independent visualization. Quality of visualization Score 2 Score 1 Quality of visualization LCx Phase 70% 17; 9.7% 12; 6.8% Phase 80% 25; 14.2% 23; 13.1% Phase 90% 5; 2.8% 3; 1.7% Quality of visualization CS Phase 30% 19; 10.8% 9; 5.1% Phase 40% 61; 34.6% 31; 17.6% Phase 50% 8; 4.5% 5; 2.8% LCx, Left circumflex artery; CS, coronary sinus. Table of the abstract 373 R. Mlynarski1; A. Mlynarska2; M. Sosnowski3 1Upper-Silesian Cardiology Center, Katowice, Poland; 2Medical University of Silesia, Katowice, Poland; 3Medical University of Slesia, Katowice, Poland Cardiac imaging is almost mandatory in techniques like percutaneous mitral annuloplasty (PMA). During PMA the relationship between coronary sinus (CS) and circumflex artery (Cx) in relations to mitral valve (MV) is of special importance. In such circumstances, a new image reconstruction algorithm might be potentially useful. Methods: In 46 pts (24 M) a 64 slice computed tomography (Aquilion 64) was performed. Pts with critical changes in LCx were excluded. A scan with ECG-gating was performed using: slice 0.5 mm, helical pitch 12.8 and tube voltage 135 kV (380 mA). 100 ml of non-ionic contrast agent at a rate of 4.5 mL/second was given. In each case 3D VR and 2D MPR reconstructions were created (Vitrea 2). In all pts various visualization modes were tested (MPR measurements and visualizations) to create optimal visualization LCx/CS/MV, defined as a consensus between 2 experienced observers to fulfill PMA requirements. Results: The following stages in post-processing were recognized as optimal: 3DVR visualization of lateral view of the heart (Figure A); 3x (10 ) virtual cutting of the of the heart (Figure B); digital analysis (own projectFigure C) of the relations LCx/CS/MV. Examples of image preparation are presented on the figures below. Presented method was applicable in all patients. Selected 2D measurements vessels of interest (Figure C) were as follow: LCx diameter 3.7 0.7 mm, CS diameter 4.9 1.5 mm, LCx-MVd diameter 44.5 7.9 mm, and CS-MVd diameter 42.8 6.6 mm. In 26 pts (56.5%) the LCx run closer to the MVit potentially cause problems (LCx occlusion) after PMA device implantation. Conclusions: Presented method may be useful for visualization of LCx/CS/MV in cardiac CT in patients before PMA, however applicability of this method requires verification in further clinical studies. Scheme of CT image post-processing Usefulness of computed tomography coronary angiography in screening patients in the presence of atypical chest pain and risk factors for coronary disease R. Moran1; O. Rana1; R. Patel1; R. Swallow1; J. Kingston1; T. Levy1 1Royal Bournemouth Hospital, Bournemouth, United Kingdom Purpose: Assessment of patients with chest pain and risk factors for coronary artery disease (CAD) in the presence of atypical symptoms can be difficult. Such patients often have equivocal exercise tolerance tests or cannot perform one. Consequently they undergo quantitative coronary angiography to exclude significant CAD, with normal results in up to 25%. Non-invasive imaging modalities such as computed tomography coronary angiography (CTCA) have emerged as alternatives. We performed a retrospective review to assess the hypothesis that CTCA is diagnostically useful in this cohort. Methods: We examined the referral pathway of 168 consecutive patients (58.4 11.3 years) over 14 months who had been referred to 3 cardiologists for possible CAD. All had atypical chest pain with coexisting risk factors (see table) and either had an equivocal exercise tolerance test or were unable to perform one. The cohort had an intermediate pre-test probability of CAD (52.1% 26.4) derived from the United Kingdom national guidelines. All patients underwent CTCA (Aquilion 1 Toshiba, Japan) and proceeded to invasive coronary angiography only if CTCA showed significant CAD (defined as at least one moderate lesion, [50% stenosis). Results: Of 168 patients, 123 (73.2%) were normal (63, 37.5%) or had non-significant CAD (60, 35.7%) based on CTCA. The remaining 45 patients (26.8%) underwent quantitative coronary angiography, revealing severe CAD ([70% stenosis) in only 13 patients (7.7%). All 13 had been correctly identified by CTCA. Moderate CAD (50-70% stenosis) was seen in the other 32 (19%), CTCA being concordant with this in 28 patients (88%). CTCA overestimated CAD severity in the other 4 (12%). Conclusions: Our data suggest CTCA is an alternative to quantitative coronary angiography in screening patients with atypical chest pain and equivocal exercise tolerance tests, despite the presence of risk factors for CAD. Risk scores appear to overestimate the true incidence of significant CAD. Frequency of CAD risk factors (%) Smoking history Family history Hyperlipidaemia Hypertension Diabetes mellitus M.J. Moncy Jacob Oommen1; L. Nazar1 1Division of Cardiology, RIPAS Hospital, Brunei, BANDER SERI BEGAWAN, Brunei Darussalam Introduction: Patients with inconclusive stress tests and suspected CAD often present a diagnostic challenge in a non interventional cardiac centre. In deed the yield of invasive CAG in this group of patients is not significant. Coronary CTA in patients with equivocal stress test is considered as an appropriate indication. Objectives: We attempted to determine the clinical events of the patients who had the inconclusive stress tests and CTA, tried to classify these a patients based on the risk factors, severity of CAD by CTA and tried to find the significance of the risk factors and CTA results with the clinical events during this period. Methods: We studied 175 patients who had suspected CAD and inconclusive stress tests done from April 2007 to December 2009. All these patients had 64 slice cardiac CTA. Patients are classified based on age, sex risk profile, CCS and CTA results of the CAD severity. Patients are reviewed for the cardiac events in the followup clinic. The primary outcome of the study was all cause mortality, cardiac admissions for ACS or for CAG and PCI. However only 139 patients were followed up in the clinic and by telephonic interview till date. Results: 43% of the patients were in the age group 50 to 69, 53% were females, 69% has hypertension 44% hyperlidaemia. 40% had atypical chest pain, 70% had CCS less than 100. CTA results showed no CAD in 54% patients. Follow up of these patients with significant CAD once in six months till date showed 69% of these patients had no cardiac events, there was one death (0.7%, 8 (5.6%) admissions for ACS, 34 (24%) patients had CAG and PCI. Conclusion: Among patients with inconclusive stress tests, a significant number did not show any obstructive CAD by CTA. During the follow up study, clinical events are higher in patients with increasing severity of CAD by CTA. This clinical approach based on CTA is useful for short term prognostic assessment in this group of patients especially in a non interventional cardiac centre. Purpose: Fractional flow reserve (FFR) is an easily obtained index of the physiologic significance of coronary stenosis that can optimize treatment strategy. The purpose of this work was to compare diagnostic performance of noninvasive computed FFR (FFRct) with standard invasive FFR angiogram patient data and to assess the impact of FFRct on diagnostic improvement in borderline coronary lesions. Methods: Three patients admitted for coronary artery disease underwent coronary CT angiography (Siemens 256-slice SOMATOM Definition CT scanner) and cardiac catheterization with FFR assessment. Internally designed software was used for computer simulation of FFR based on the coronary CT angiogram. The 3D blood flow was described by the Navier-Stokes equations, in conjunction with the continuity equation. A parabolic flow waveform was applied at the location of aortic root, while outlet boundary conditions were configured to an inverse resistance of the corresponding diameter. Results: Coronary CT angiography discovered that two patients had single vessel CAD with significant stenosis ([50%) observed on ACD and LAD respectively, and one patient had triple vessel CAD. There was no difference between the FFR and FFRct values (P [ .22). Coronary CT angiogram designated 2 (66%) lesions as significant and after performing FFRct none of these lesions proved to be hemodynamically significant. Coronary CT angiogram tended to overestimate the degree of stenosis but with no statistical difference compared to coronary angiography (P = .75). Conclusions: We found a solid correlation between standard FFR and FFRct results. Computer simulation may offer distinct advantage due to non-invasive nature of the analysis, and as such may prove to be of particular benefit when assessing borderline cardiac patients. Assessment of coronary vessels surrounding left ventricle in the atrioventricular sulcus is an important step before percutaneous mitral annuloplasty (PMA). There are no research evidencing whether and how the presence of flow-limiting stenosis in the left circumflex artery (LCx) influence the venous circulation of the heart. Methods: In 66 consecutive patients (41 M, aged 61.7 10.4), a 64-slice CT (Aquilion 64) was performed due to a CAD suspicion. Pts were divided into two groups according to the presence of stenosis in LCx: 38 pts with LCx stenosis (stenosis) and 28 pts without changes in LCx (control). A scan with ECG-gating was performed using: slice 0.5 mm; helical pitch: 12.8; rotation time: 0.4 seconds and average tube voltage: 135 kV at 380 mA. 100 mL of non-ionic contrast agent at a rate of 4-5 mL/second was given. All measurements were performed on 2D MPR and VR reconstructions. Following measurements were made: CS ostium diameter (mm), angle of entrance CS to RA (8), average LCx diameter (mm), average CS diameter (mm), max distance between CS and LCx (mm), minimal distance between CS and LCx (mm), distance between LAD and CS/LCx intersection (mm) examples Fig below. Results: A significant reduction of angle of entrance CS to the right atrium was observed in the group with LCx stenosis: 102.3 8.5 (stenosis) vs 110.5 8.3 (control); P \ .001. In this group, a significant increase of the maximum distance between CS and LCx was also observed: 16.9 4.9 (stenosis) vs 13.6 4.4 (control); P \ .01. Differences in the other analyzed parameters did not reach statistical significance. Conclusions: Presence of stenosis in the left circumflex branch of left coronary artery influence the anatomy of coronary sinus, however further studies are necessary to explore clinical significance of our findings. Example of measurements S. Huidu1; D. Dimulescu1; A. Popescu1; S. Lacau1; S. Barsan1; L. Ionescu1; I. Stanca1; L. Arama1 1Elias Emergency Universitary Hospital, Bucharest, Romania Purpose: We evaluated the feasibility and image quality of coronary CT to 120 patients screening for CT angiography in Elias-Prolife Hospital between 2010 and 1012. Method: All patients were symptomatic with low or intermediate probability of having severe coronary stenosis. Other patients had known coronary heart disease and CT were performed to check for patency of coronary stents or by-passes. 120 patients were screen. Were excluded those who had renal insufficiency or allergy to contrast substance. Inclusion criteria were: age over 29 years, weight less than 100 kg, heart rate below 60 bpm after administration of premedication betablockers. It is known that about 60 bpm heart rate allows a better image quality in CT angiography. It influences body weight and image quality. Of the 120 patients, 11 were excluded by the inability to obtain a heart rate below 60/minute after 100 mg of atenolol 10-20 mg metoprolol IV, 5 were excluded by the presence of renal insufficiency, 4 because of marked obesity. To 100 patients were performed CT angiographies. Among patients who carried angio CT all 100 images were good results without having no interpretable. 32% of patients were women and 68% men; 46 patients were aged below 60 years. Results: Calcium score was 0 in 26% patients. 9% had PCI with stent in one or two coronary arteries prior CT and 2% CABG 2, 3 coronary arteries. All the stenosis more than 50% was considered significant stenosis. One patient had a significant lesion on LM segment, 18 cases had LAD stenosis, 8 cases CD and 13 casescircumflex artery. 11 patients had two or more coronary arteries with stenosis. 76% patients had insignificant coronary stenosis. Of all patients, 24 were sent for coronary lesions confirmation to CG, and one single false positive result was found. 12 patients had confirmed the lesions through CG. 11 patients had indication to perform CG because of significant stenosis but did not complete it. Conclusion: Angio CT remains a noninvasive method for assessing coronary stenosis that is recommended to patients with low or moderate probability of significant coronary stenosis and provides excellent image quality for non-obese patients with AV below 60/minute. W. Wilson Pimentel1; W. Custodio1; J. Buchler1; S. Assis1; M. Macedo Soares1; E. Bocchi1 1Beneficencia Portuguesa Hospital, Sao Paulo, Brazil Aims: The aim of this study was to evaluate the diagnostic performance of coronary computed tomographic angiography (CCTA) and its influence on modification of percutaneous coronary interventions (PCI) strategies that means, we discuss the potential application of CCTA for the guidance of PCI. Methods and Results: The study included two groups of patients: a main group (MG), including 200 patients screened with a suspect of severe CAD by CCTA and indication for coronary cineangiography (CINE), and a control group (CG) for comparison, including 200 patients selected during the same period, with indication for CINE according to clinical criteria or by positive functional tests. We evaluated the performance of CCTA for the diagnosis of lesions [50% in coronary segments, arteries and patients and the revascularization strategies adopted. Results: The sensitivity, specificity and positive and negative predictive values of CCTA were 85%, 85%, 71% and 98% for the coronary segments, 90%, 91%, 82% and 100% for the coronary arteries and 100%, 88%, 96% and 98% for patients, respectively. In the MG, percutaneous coronary intervention (PCI) was performed in 90% of the patients, whereas in the CG, percutaneous coronary intervention was performed in 43% of the patients (P = .01). Conclusions: CCTA had a high diagnostic performance in detecting CAD and allowed ad hoc PCI to be performed in 90% of the patients. This strategy, however, must await randomized studies to confirm these results. 382 Superiority of CT coronary angiography over catheter angiography in detection of variants/anomalies/disease of the coronary arteries: A problem solver A. Abhishek Bansal1; M.M. Dsouza1; H. Wardhan2; R. Sharma1; P.K. Chugh1; R.P. Tripathi1 1Institute of Nuclear Medicine and Allied Sciences, New Delhi, India; 2Dr. Ram Manohar Lohia Hospital, New Delhi, India Purpose: To describe various coronary artery variants/ anomalies and diseases that were identified on coronary CT angiography (CCTA), and better delineated and characterized than on the catheter angiography (CAG), thus, emphasizing the increasing role of CCTA in accurately diagnosing such conditions which went unnoticed previously. Methods: We retrospectively studied 94 patients who had undergone CCTA at our institute. Out of these, we identified 10 patients showing variations/anomalies/disease of the coronary arteries, which were not adequately assessed on CAG. The CCTA was then performed on a 40-slice MDCT scanner (SOMATOM Sensation, Siemens Medical Systems). Informed consent was taken from each patient. Results: Patients ranged in age from 22-64 years. Out of 10 patients, 4 were females and 6 were males. In 2 patients, the right coronary artery (RCA) showed an intra-atrial course in the right atrium for variable lengths, which was not identified on CAG. A patient with Tetralogy of Fallot demonstrated markedly tortuous and dilated coronary arteries with multiple coronary-cameral fistulae. CCTA also depicted all the characteristic abnormalities namely, ventricular septal defect, overriding of aorta, infundibular pulmonary stenosis and right ventricular hypertrophy. 1 patient with single coronary artery arising from the right coronary sinus was identified. The exact course of all the branches was delineated accurately on CCTA only. In another patient, the RCA was seen arising from the ascending aorta anteriorly, which was not identified on the CAG. 1 patient had the left main coronary artery (LMCA) arising from the non-coronary sinus. In another patient, CAG showed complete occlusion of the RCA in its proximal part, the cause of which- an intra-luminal thrombus and its exact extent was identified on CCTA only. In another patient the LAD had an aberrant course on CAG, the cause of which was identified as marked dilatation of the right atrium and ventricle exerting pressure effects over the LAD on CCTA. 1 patient showed a non-enhancing mass in the left ventricular cavity, diagnosed as a cystic thrombus on CCTA. In 1 patient the RCA showed focal long segment ectatic dilatation. Conclusions: This study illustrates the utility of CCTA in depiction of coronary artery anomalies/variants and its superiority over CAG. It is highly likely that such anomalies/variants of the coronary arteries were missed in the past due to the availability of only CAG. CCTA allows simultaneous depiction of coronary arteries, surrounding tissue and cardiac chambers and comprehensive evaluation of the arterial course in multiple planes. Multidetector ct angiography as a noninvasive tool to assess graft patency of surgically reconstructed diffusely diseased coronary arteries A. Rezk1; M. Bazid1; Z. Saad2 1King Fahad Military Hospital, Southern Region, Kamis Mushyat, Saudi Arabia; 2Aseer Central Hospital, Abha, Saudi Arabia Background: Long reconstruction of the diffusely diseased vessel may be a useful surgical option for patients with diffuse coronary artery disease. Close and careful follow up of such subgroup of patients is mandatory. Invasive graft angiography serves as the diagnostic standard for follow up of graft patency for such extensive procedure; however, because of the risks, discomfort, and costs of a hospital stay, a noninvasive diagnostic tool is desirable. The purpose of current study is to evaluate the results of extensive reconstruction of the diffusely diseased left anterior descending coronary artery (LAD) using an left internal thoracic artery (LITA) graft and assess the reliability of multidetector computed tomography (MDCT) angiography as a noninvasive and safe alternative to assess graft patency in asymptomatic patients after (coronary artery bypass surgery (CABG) with reconstructed diffusely diseased vessels. Methods: 25 patients with the diffusely diseased LAD underwent a long-segmental reconstruction procedure with a LITA graft. The diffusely diseased LAD was extensively incised, additional endarterectomy was performed if necessary, and then the LAD was reconstructed with an ITA graft in a long on-lay fashion. Postoperative MDCT angiography as a non-invasive single tool was performed in 25 asymptomatic patients to assess graft patency. Results: The cohort consisted of 23 men (92%) and 2 women (8%). The mean age was 58.5 9.2 years. The mean length of the arteriotomy incision was 3.5 1.2 cm. Endarterectomy was performed in 3 patients (12%). Preoperative MI was recorded among 1 patient (4%). While all arterial grafts 27 (100%) were classified as patent, 51 venous grafts (89%) were considered as patent where 11% of venous grafts were considered as non patent. All the significant stenosis were found in the body of venous graft. Conclusion: Extensive reconstruction of the diffusely diseased LAD using an ITA graft could be performed safely with very encouraging results. MDCT angiography is an excellent non invasive tool not only to evaluate graft patency in the reconstructed LAD but also to detect other findings in asymptomatic patients with diffuse coronary artery disease for better and more close follow up. 384 Non-invasive assessment by Cardiac CT of bypass grafts and native coronary versus invasive coronary angiography N. Nieves Romero Rodriguez1; F.J. Guerrero Marquez1; P. Cristobo Sainz1; S. Navarro Herrero1; M.P. Serrano Gotarredona1; J.L. Martos Maine1; A. Martinez Martinez1 1Virgen del Rocio University Hospital, Seville, Spain Introduction: Cardiac CT has proven usefulness in the study of coronary patients, especially with low and intermediate risk profile. However there are few published studies on its usefulness in the diagnosis of patients who have underwent coronary bypass graft. This study attempts to determine its diagnostic accuracy in this area. Methods: From October 2008 to January 2012 a total of 632 coronary CT have been performed in our center of which 12 occurred in patients with coronary bypass. Finally 9 of them underwent coronary angiography, on which this study is based. We analyzed the diagnostic accuracy in the evaluation of both types of grafts and in the assessment of segments distal to the anastomosis. Results: A total of 8 males were included with 23 aortocoronary grafts (12 arterial and 11 venous). 18 were visualized by CT angiography with a sensitivity of 100% and specificity of 90.9% and with positive and negative predictive values of 75% and 100% respectively. We also analyzed the 18 vessels distal to the anastomosis detected (11 anterior descending, 5 circumflex and 3 right coronary artery), with a sensitivity of 100%, specificity of 91.6%, negative predictive value of 66.7% and positive predictive value of 100%. Conclusions: Cardiac CT has a high sensitivity in the assessment of coronary grafts and native arteries in this setting. 385 Does the pre-test probability of CAD improve prediction of coronary artery calcification and stenosis on CTA? M.C. Maria Cecilia Ziadi1; R.L.V. Villavicencio1 1Diagnostico Medico Orono, Rosario, Argentina Objective: Computed tomography angiography (CTA) is mainly applied to patients (pts) with low to intermediate risk of coronary artery disease (CAD). Our goal was to assess how the clinical pre-test categorization impacts on the coronary calcium score (CCS) and the presence of severe CAD evaluated with non-invasive CTA. Methods: We identified 133 consecutive adult pts with suspected CAD, who underwent CTA. According to the pre-test likelihood of CAD, pts were divided into 3 groups: I (low), II (intermediate) and III (high). CCS was categorized as follows: 0, 1-100, 101-400 and [400. Coronary artery lumen was classified into normal = 0%, mild = 149%, moderate = 50-69% and severe C70% stenosis. Results: Mean age was 57 (14) years old, 56% were males. A CCS = 0 was present in 43 of 65 (66%) and in 15 of 48 (31%) pts from groups I and II, respectively. Conversely, none of the pts from group III had a CCS = 0, but 70% (14/20) presented with CCS [ 400 (P \ .05). The prevalence of severe obstructive CAD was 3.1% (n = 2) in group I, 8.3% (n = 4) in group II and it was significantly higher in pts from group III, 65% (n = 13), (P \ .05) (Figure). CTA ruled out obstructive CAD in 95.4% of pts in group I and in 79.2% of pts in group II. Regardless of the pre-test likelihood of CAD, C70% stenosis was present 1 of 58 (1.7%) pts with CCS = 0, in 2 of 33 (6.1%) pts with CCS B 100, in 5 of 16 (31.2%) pts with CCS = 100400 and in 11 of 26 (42.3%) pts with CCS [ 400, (P \ .05). Conclusions: There is a direct correlation between the clinical probability of CAD and the calcified atherosclerotic burden. Pre-test likelihood assessment facilitates prediction of severe coronary stenosis with non-invasive CTA. These findings underscore the role of clinical categorization for appropriate selection of pts referred for CTA. Pre-test probability vs CTA lumen Predictors of significant coronary lesions in patients with abnormal myocardial single photon emission computed tomography V.A. Vadim Kuznetsov1; E.I. Yaroslavskaya1; D.V. Krinochkin1; G.V. Kolunin1; E.A. Gorbatenko1 1Tyumen Cardiology Center, Tyumen, Russian Federation Background: It is difficult often to detect coronary artery disease (CAD) without coronary angiography (CAG) in atypical patients by clinical and echocardiography and single photon emission computed tomography (SPECT) data. Purpose: The present study aimed to reveal predictors of significant coronary lesions in patients with myocardial perfusion abnormalities by SPECT. Methods: From 13,283 consecutive patients suspected CAD we selected patients after (99)Tc(m)-methoxyisobutylisonitrile (MIBI) gated SPECT and CAG who had no more than 3 months between the tests. There were 47 patients among them who had abnormal SPECT. We divided these patients in two groups: with significant coronary lesions (C50% of lumen) on CAG and without. Results: In 16 patients (34%) with abnormal SPECT and CAD compared to patient without CAD we observed more often acute myocardial infarction (37.1% vs 6.5%, P = .005) and higher level of serum glucose (6.9 2.5 vs 5.3 0.8 mmol/L, P = .007). Reduced left ventricular (LV) systolic function (LV ejection fraction \ 50%) was more frequent in these patients (17.4% vs 7.4%, P \ .001), as well as mild, moderate or severe mitral regurgitation (81.3% vs 59.4%, P = .026). They had higher extent and index of LV wall motion abnormalities (20.8% 18.0% vs 2.0% 5.5%, 20.8% 18.0% vs 2.0% 5.5%, respectively), and only patients of this group had signs of myocardial scars detected by echocardiography (31.3%, all P \ .001). According to the results of discriminant analysis, CAD was associated with index of LV wall motion abnormalities and mitral regurgitation. The obtained sensitivity, specificity, and positive predictivity were 80.6%, 81.8%, and 80.9%, respectively. Conclusion: An extent of LV wall motion abnormalities and mitral regurgitation are independent predictors of CAD in patients suspected CAD with abnormal SPECT. A. Andrea Peter1; S. Lucic1; M. Lucic1; R. Jung2; S. Tadic2; S. Stojsic2; M. Stefanovic2 1Institute of Oncology of Vojvodina, Sremska Kamenica, Serbia; 2Institute of Cardiovascular Diseases of Vojvodina, Sremska Kamenica, Serbia Introduction: Noninvasive coronary angiography (CTA) using multidetector computed tomography is used to detect anatomical coronary artery stenosis in patients who are suspected to have coronary artery disease (CAD) with an intermediate to high pretest likelihood. Stress myocardial perfusion imaging (MPI) is an important diagnostic tool since it provides information about the functional severity of the detected coronary artery lesion. Aim of the Study: To evaluate the findings of MPI after CTA detected coronary artery lesions and follow up of these patients in terms of therapeutic decision making and potential cardiac events. Material and Methods: In 25 patients MPI was performed after CT coronarography detected coronary artery stenoses. A two-day protocol, dipyridamole stress/ rest Tc-99m-MIBI myocardial perfusion imaging (MPI) was performed. Myocardial perfusion images were analyzed quantitatively, perfusion scores (Summed Stress ScoreSSS and Summed Difference ScoreSDS), ejection fraction (EF) and the percentage of affected left ventricle myocardium was calculated using 4DMSPECT commercial software package. Results: Average age in the examined group was 67.78 8.22 years. A total number of 46 coronary stenoses were verified during CT coronarography and the majority had two or mutlivessel coronary artery disease. The percentage of coronary stenoses detected on CT coronarography ranged from a minimal of 30% to a maximal narrowing of 98%. The findings of stress MPI showed normal perfusion of the left ventricle in 22 patients (88%) and reversible ischemia was detected in 3 patients (12%). The group with normal MPI finding had an average follow up period of 29.20 9.75 month and out of this group only one patient was admitted to the hospital because of suspected acute coronary syndrome and coronarography was performed, non-significant narrowings were found on the coronary arteries. Out of the group with reversible ischemia all of them underwent coronarography and have been treated with stent implantation on coronary arteries that had functionaly significant stenosis on stress MPI. The average follow up period in this group was 18.20 3.65 months and during this period they had no symptoms and were without any major cardiovascular incidents. Conclusion: The evaluation of functional significance of coronary artery lesions with stress MPI is a very important tool in the diagnostic algorithm of stenoses verified on CT coronarography. Stress MPI successfully identifies patients with coronary artery lesions that need revascularization. Introduction: The aim of this analysis is to evaluate the reproducibility of CAC calculated on different commercial softwares. Methods: We included 159 patients who underwent CAC scoring with use of 64-slice multidetector computed tomography (CT) with prospective electrocardiographic gating for clinical reasons. The data sets were evaluated on two different commercially available softwares (4DM from INVIA, Ann Arbor, MI (software A) and Smart score from General Electric, Milwaukee, WI (software B)) by two blinded independent readers using the method of Agatston with a threshold of 130 Hounsfield units. Comparative analysis of CAC scores between the different software was performed by using Spearman rank correlation and Bland Altman analysis. Results: Each software produced different absolute numeric results for Agatston score. CAC was detected on 107 scan on both softwares. A total of 59 scans (37%) had the same reading of which 50 patients are without detected calcium. In contrast, CAC reading were within 10 units in 86 scans (52%) There was excellent statistical correlation between the two softwares (r = 0.948, p400), 132 (87%) of the scans were in the same group by both softwares. Conclusion: Our analysis shows that there is a close correlation between the different software calculation of CAC although the different CAC software different absolute CAC scores. The two softwares concordantly classified 87% of the study population prognostically. Bland Altman plot of the abstract 388 390 Coronary artery calcium scores on admission trauma CT scans and their Association with in-hospital survival H.D. Death1; K. Oakland1; C. Davies1; K. Brohi1 1Royal London Hospital, London, United Kingdom Purpose: The presence of coronary artery calcium on Computerised Tomography (CT) scans is indicative of Coronary Heart Disease (CHD). Formal scoring of coronary artery calcium in patients with heart disease is a useful prognostic tool, and is predictive of future adverse cardiac events and survival. The ability to estimate coronary artery calcium scores (CACS) on CT scans undertaken in trauma patients has not been explored. The purpose of this study was to determine the feasibility of estimating CACS on trauma triage scans, and thereby determine the incidence of heart disease in injured patients. Finally, the study aimed to explore the relationship between coronary artery calcium and in-hospital mortality following injury. Methods: A single centre retrospective cohort study of all injured patients aged 45 years or over presenting to a trauma centre between 2009 and 2011. Two observers estimated and graded CACS (none, mild, moderate, severe and extensive) on admission CT scans of the thorax, and the relationship with in-hospital mortality was determined. Results: Four hundred and seventy four trauma patients had a CT scan of the thorax, of which the calcium scores of 432 (91%) were interpretable. No coronary artery calcium on CT was found in 137 (32%), whilst 292 (68%) patients had evidence of calcium. Patients with coronary calcium were older (60 years vs 50, P \ .001) and had more co-morbidities (132 vs 46, P = .03, respectively). Of the patients with calcium, 139 (32%) had a mild score, 75 (17%) moderate, 64 (15%) severe and 17 (4%) had evidence of extensive coronary artery calcium. Only patients with severe coronary artery calcification had higher death rates (OR 2.4, 95% CI 1.1-4.9), whilst patients with mild, moderate and extensive calcium scores had similar death rates to those without evidence of calcification. Inter-observer agreement for calcium grading was substantial (j = 0.74). Conclusions: Admission trauma CT scans of injured patients may be used to determine CACS. These estimates demonstrated that the incidence of CHD approaches 70% in trauma patients aged C45 years. Only evidence of severe coronary artery calcium placed patients at an increased risk of in-hospital death following injury. Coronary artery disease among patients with low coronary calcium score: A call for definition of low coronary artery calcium score-Multi-Detector Computed Tomography ANIN Registry E. Edyta Kaczmarska1; C. Kepka1; Z. Dzielinska1; R. Pracon1; K. Kryczka1; J. Pregowski2; M. Kruk1; M. Demkow1 1National Institute of Cardiology, Department of Coronary Heart Disease, Warsaw, Poland; 2Department of Interventional Cardiology and Angiology Institute of Cardiology, Warsaw, Poland Objectives: The prospective study was conducted to find the cut-off point for low CAC score and evaluated the incidence of CAD in relation to the low CAC score among patients with intermediate probability of CAD. Methods: Consecutive patients (n = 1132) were included to the analysis (58.7 10.9 years, 46.7% males). Coronary computed tomography (CCT) angiography was performed by multi-detector computed tomography scanner. CAC score was calculated by Agatston method. CAD was defined as presence of coronary artery stenosis C50% on CCT angiography. Results: CAD was diagnosed in nearly one-fourth of patients (n = 272, 24%). CAD in subjects with CAC score B10 and B100 were detected in 4.9% (56 patients) and 12.4% (140 patients), respectively. In the ROC curve analysis, CAC score of 10 presented as optimal cutoff point for the discriminating the CAD (sensitivity 0.79, specificity 0.75, P \ .0001). Whereas for CAC score of 100, the sensitivity and specificity was 0.48 and 0.92, respectively. Conclusions: The cut-off point of 10 for CAC score with the best sensitivity and specificity determined patients with CAD. Furthermore, CAC score \ 10 better defined patients with high risk obstructive plaque prone to rupture (non- or low calcified obstructive plaque) than CAC score 100. CAC score \ 10 should be classified as low. Several studies have been suggested that the presence of multiple extracoronary sites with calcium deposits would infer a greater risk for CAD. But, most of them are based in echocardiographic studies that used categorical variables with poor reproducibility and does not quantify calcium. Cardio-vascular calcium screening with the use of EBCT is emerging as a potentially useful test to diagnose atherosclerotic burden. Purpose: The aim of this study was to determine whether there is a significant association between calcification of the aortic/mitral annulus and/or thoracic aortic calcified plaques and coronary artery disease (CAD) in patients undergoing 64-slices angio-CT scan. If an association could be established between cardiovascular calcifications and CAD, their presence might be used as a marker of coronary atherosclerosis. Methods: We identified the presence, absence and amount of calcification in each of the three extracoronary calcification (ECC) sites: aortic root, mitral annulus and ascending aorta, using Agatston calcium score. We applied a digitized method to quantify ECC so we had a good reproducibility in identifying them. All known cardiac risk factors for atherosclerosis including age, gender, hypertension, smoking, dyslipidemia, diabetes and family history were investigated. Results: The mean age of our study population included 305 patients (184 men and 121 women) was 57 11.28 years. These patients were divided in two groups, age and sex-matched 166 (58.7%) in the ECC group and 139 (41.3%) in the control group. The ECC group had a higher prevalence of positive CT for the presence of CAD (75.8 vs 19%, with P \ .001). Multivariate analysis identified only ECC and age as independent predictors of coronary atherosclerosis. Logistic regression analysis showed also that ECC was strongly and significantly associated with CAD after adjusting for all coronary risk factors, except age (OR = 6.637; 95% CI 2.5-7.464, P \ .001), hence patients with ECC had a sixfold higher risk for CAD than those without. The sensitivity, specificity, positive and negative predictive values for ECC in diagnosing CAD were 85.1%, 70%, 76% and 91%, respectively. Conclusion: Calcium deposits at two or more sites may help in identifying patients with atherosclerosis. Their absence is a stronger predictor for absence also of CAD. Measuring extracoronary calcification using CTA is accurate, reproducible and may be clinically relevant. Coronary calcification is generally recognised as a form of subclinical atherosclerosis and has been found, in various severities, in asymptomatic populations. Its relevance in predicting significant coronary artery (CA) stenosis in symptomatic patients remains uncertain. We retrospectively studied 360 patients, mean age 65, 58% males, who presented with angina-like symptoms and who underwent CT coronary calcium scoring CAC, conventional angiography and exercise tolerance testing (ETT). A CAC score [ 0 was superior to ETT for prediction of significant coronary artery stenosis (C50% narrowing), with sensitivity 97% vs 39% (P \ .001) but specificity was only 26% vs 70% (P \ .001). Patients aged C70 had higher sensitivity of CAC C 400 in predicting CA stenosis C 50% compared to those aged \70 (62% vs 26%, P = .018) and in predicting single vessel disease (SVD) (65% vs 28%, P = .008) and multivessel disease (MVD) (74% vs 28%, P = .039). The respective specificities for CAC [ 0 were significantly lower in those aged C70 compared to age \ 70 for SVD (9% vs 60%, P = .052) and MVD (5% vs 26%, P = .018). ROC curve analysis showed a CAC score of 46.5 as having the highest sensitivity and specificity (83% and 62%, respectively, P \ .001) for predicting [50% CA stenosis with area under the curve (AUC) of 76%. Conclusion: In symptomatic patients, coronary artery calcium score is more accurate in predicting the presence of significant stenosis but exercise tolerance testing is more specific in excluding significant multivessel disease. Authors Index Qiao, H.Y., 366 Queneau, M., 77 Qureshi, W., 207, 348 Xhabija, N.X.H., 365, 392 Index of topics Acute ischaemia/Acute ischaemic syndromes/ Injury imaging, 160, 163, 217, 258, 295, 297, 317 Arrhythmias and sudden death, 142, 358 Attenuation correction clinical, 38, 61, 62, 94, 100 CAD and diabetes, renal disease, gender risk factors, 137, 145, 224, 225, 233, 238, 243, 244, 245, 246, 247, 248, 249, 250, 252, 253, 254, 256 Calcium scoring, 39, 344, 348, 388, 390, 391, 392, 393 Comparative techniques clinical, 83, 86, 92, 257, 271, 272, 288, 290, 355, 368, 381 Congestive heart failure, 110, 216, 277, 278, 296 Coronary revascularisation, 87, 283, 302 Cost effectiveness, health economics, quality assurance and guidelines, 223, 234 CT angiography, 71, 79, 80, 82, 90, 117, 229, 286, 292, 299, 345, 346, 347, 353, 354, 357, 361, 364, 366, 371, 375, 376, 379, 382, 383, 385 CT - Other, 99, 218, 360, 363, 373, 374 Diagnosis of CAD, 222, 235, 236, 239, 240, 242, 263, 268, 350, 352, 356, 369, 370, 378, 380, 386 Exercise ECG, 227, 232 Free fatty acid imaging, 213 Image patterns, artifact, 84 Instrumentation - other, 105 Instrumentation, software and image processing, 63, 72, 78, 88, 89, 91, 97, 103

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11th International Conference of Non-Invasive Cardiovascular Imaging, Journal of Nuclear Cardiology, 2013, 1-113, DOI: 10.1007/s12350-013-9685-3