Abdominal Aortic Intimal Flap Motion Characterization in Acute Aortic Dissection: Assessed with Retrospective ECG-Gated Thoracoabdominal Aorta Dual-Source CT Angiography

PLOS ONE, Dec 2019

Objectives To evaluate the feasibility of dose-modulated retrospective ECG-gated thoracoabdominal aorta CT angiography (CTA) assessing abdominal aortic intimal flap motion and investigate the motion characteristics of intimal flap in acute aortic dissection (AAD). Materials and Methods 49 patients who had thoracoabdominal aorta retrospective ECG-gated CTA scan were enrolled. 20 datasets were reconstructed in 5% steps between 0 and 95% of the R-R interval in each case. The aortic intimal flap motion was assessed by measuring the short axis diameters of the true lumen and false lumen 2 cm above of celiac trunk ostium in different R-R intervals. Intimal flap motion and configuration was assessed by two independent observers. Results In these 49 patients, 37 had AAD, 7 had intramural hematoma, and 5 had negative result for acute aortic disorder. 620 datasets of 31 patients who showed double lumens in abdominal aorta were enrolled in evaluating intimal flap motion. The maximum and minimum true lumen diameter were 12.2±4.1 mm (range 2.6∼17.4) and 6.7±4.1 mm (range 0∼15.3) respectively. The range of intimal flap motion in all patients was 5.5±2.6 mm (range 1.8∼10.2). The extent of maximum true lumen diameter decreased during a cardiac cycle was 49.5%±23.5% (range 12%∼100%). The maximum motion phase of true lumen diameter was in systolic phase (5%∼40% of R-R interval). Maximum and minimum intimal flap motion was at 15% and 75% of the R-R interval respectively. Intimal flap configuration had correlation with the phase of cardiac cycle. Conclusions Abdominal intimal flap position and configuration varied greatly during a cardiac cycle. Retrospective ECG-gated thoracoabdominal aorta CTA can reflect the actual status of the true lumen and provide more information about true lumen collapse. This information may be helpful to diagnosis and differential diagnosis of dynamic abstraction.

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Abdominal Aortic Intimal Flap Motion Characterization in Acute Aortic Dissection: Assessed with Retrospective ECG-Gated Thoracoabdominal Aorta Dual-Source CT Angiography

et al. (2014) Abdominal Aortic Intimal Flap Motion Characterization in Acute Aortic Dissection: Assessed with Retrospective ECG-Gated Thoracoabdominal Aorta Dual-Source CT Angiography. PLoS ONE 9(2): e87664. doi:10.1371/journal.pone.0087664 Abdominal Aortic Intimal Flap Motion Characterization in Acute Aortic Dissection: Assessed with Retrospective ECG-Gated Thoracoabdominal Aorta Dual-Source CT Angiography Shifeng Yang 0 Xia Li 0 Baoting Chao 0 Lebin Wu 0 Zhaoping Cheng 0 Yanhua Duan 0 Dawei Wu 0 Yiqiang Zhan 0 Jiuhong Chen 0 Bo Liu 0 Xiaopeng Ji 0 Pei Nie 0 Ximing Wang 0 Rudolf Kirchmair, Medical University Innsbruck, Austria 0 1 Shandong Medical Imaging Research Institute, Shandong University , Jinan, Shandong , P.R. China , 2 Departments of Ultrasound, Shandong Provincial Hospital , Jinan, Shandong , P. R. China , 3 Unit of Periodontology, University of Greifswald , Greifswald, Germany, 4 CT Research Collaboration , Siemens Ltd. , China, Beijing , P.R. China, 5 Healthcare Sector , Siemens Ltd. , China, Shanghai , P.R. China Objectives: To evaluate the feasibility of dose-modulated retrospective ECG-gated thoracoabdominal aorta CT angiography (CTA) assessing abdominal aortic intimal flap motion and investigate the motion characteristics of intimal flap in acute aortic dissection (AAD). Materials and Methods: 49 patients who had thoracoabdominal aorta retrospective ECG-gated CTA scan were enrolled. 20 datasets were reconstructed in 5% steps between 0 and 95% of the R-R interval in each case. The aortic intimal flap motion was assessed by measuring the short axis diameters of the true lumen and false lumen 2 cm above of celiac trunk ostium in different R-R intervals. Intimal flap motion and configuration was assessed by two independent observers. Results: In these 49 patients, 37 had AAD, 7 had intramural hematoma, and 5 had negative result for acute aortic disorder. 620 datasets of 31 patients who showed double lumens in abdominal aorta were enrolled in evaluating intimal flap motion. The maximum and minimum true lumen diameter were 12.264.1 mm (range 2.6,17.4) and 6.764.1 mm (range 0,15.3) respectively. The range of intimal flap motion in all patients was 5.562.6 mm (range 1.8,10.2). The extent of maximum true lumen diameter decreased during a cardiac cycle was 49.5%623.5% (range 12%,100%). The maximum motion phase of true lumen diameter was in systolic phase (5%,40% of R-R interval). Maximum and minimum intimal flap motion was at 15% and 75% of the R-R interval respectively. Intimal flap configuration had correlation with the phase of cardiac cycle. Conclusions: Abdominal intimal flap position and configuration varied greatly during a cardiac cycle. Retrospective ECGgated thoracoabdominal aorta CTA can reflect the actual status of the true lumen and provide more information about true lumen collapse. This information may be helpful to diagnosis and differential diagnosis of dynamic abstraction. - Acute aortic dissection (AAD) is a catastrophic disease with fatal outcomes. The overall in-hospital mortality of AAD was 27.4% [1]. The abdominal aortic branch obstruction is the key risk factor for AAD of both type A and type B [2,3,4]. Branch obstruction is classified as either static or dynamic with anatomical features [5]. Treatment decision of AAD has to be made depending on the branch obstruction mechanisms [6]. In the type of dynamic obstruction, the intimal flap spared the origin of the vessel, whereas compressed the true lumen at or above the origin of the aortic branch like a curtain [7]. Previous studies have demonstrated that the position and configuration of intimal flap were correlated with dynamic obstruction [5,8]. Furthermore, the aorta is a dynamic structure and the intimal flap often oscillates as a result of changing flow conditions [9]. Therefore the diagnostic information of intimal flap dynamics is important. Conventional CT angiography (CTA) without ECG-gated only can capture the static images of intimal flap and reflect the conformation of the intimal flap at an arbitrary time point. Retrospective ECG-gated CTA allows the phase-resolved cine imaging and visualization. The four dimension images can assess the dynamics of the intimal flap movement within a cardiac cycle [9,10,11]. In addition, the artifacts of the ascending aorta caused by the cardiac pulsation can be eliminated by this technique. And the accurate anatomical information on entire aorta can lead to a higher diagnostic confidence [12]. However, comparing to the conventional CTA, the retrospective ECG-gated CTA is accompanied by higher radiation dose and longer acquisition time [13]. These disadvantages limit the application of the thoracoabdominal retrospective ECG-gated aorta CTA [14]. As a result, the tailored protocols of the combination of retrospective ECG-gated acquisition of the thoracic aorta with standard protocol for the abdominal aorta were used in the clinical practice [9,15,16]. Whereas data acquired fr (...truncated)


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Shifeng Yang, Xia Li, Baoting Chao, Lebin Wu, Zhaoping Cheng, Yanhua Duan, Dawei Wu, Yiqiang Zhan, Jiuhong Chen, Bo Liu, Xiaopeng Ji, Pei Nie, Ximing Wang. Abdominal Aortic Intimal Flap Motion Characterization in Acute Aortic Dissection: Assessed with Retrospective ECG-Gated Thoracoabdominal Aorta Dual-Source CT Angiography, PLOS ONE, 2014, 2, DOI: 10.1371/journal.pone.0087664