Optimal Brain MRI Protocol for New Neurological Complaint

et al. (2014) Optimal Brain MRI Protocol for New Neurological Complaint. PLoS ONE 9(10): e110803. doi:10.1371/journal.pone.0110803 Optimal Brain MRI Protocol for New Neurological Complaint William A. Mehan Jr. 0 R. Gilberto Gonza lez 0 Bradley R. Buchbinder 0 John W. Chen 0 William A. Copen 0 Rajiv Gupta 0 Joshua A. Hirsch 0 George J. Hunter 0 Scott Hunter 0 Jason M. Johnson 0 Hillary R. Kelly 0 Mykol Larvie 0 Michael H. Lev 0 Stuart R. Pomerantz 0 Otto Rapalino 0 Sandra Rincon 0 Javier M. Romero 0 Pamela W. Schaefer 0 Vinil Shah 0 Jan Kassubek, University of Ulm, Germany 0 Neuroradiology Division, Massachusetts General Hospital, Harvard Medical School , Boston, Massachusetts , United States of America Background/Purpose: Patients with neurologic complaints are imaged with MRI protocols that may include many pulse sequences. It has not been documented which sequences are essential. We assessed the diagnostic accuracy of a limited number of sequences in patients with new neurologic complaints. Methods: 996 consecutive brain MRI studies from patients with new neurological complaints were divided into 2 groups. In group 1, reviewers used a 3-sequence set that included sagittal T1-weighted, axial T2-weighted fluid-attenuated inversion recovery, and axial diffusion-weighted images. Subsequently, another group of studies were reviewed using axial susceptibility-weighted images in addition to the 3 sequences. The reference standard was the study's official report. Discrepancies between the limited sequence review and the reference standard including Level I findings (that may require immediate change in patient management) were identified. Results: There were 84 major findings in 497 studies in group 1 with 21 not identified in the limited sequence evaluations: 12 enhancing lesions and 3 vascular abnormalities identified on MR angiography. The 3-sequence set did not reveal microhemorrhagic foci in 15 of 19 studies. There were 117 major findings in 499 studies in group 2 with 19 not identified on the 4-sequence set: 17 enhancing lesions and 2 vascular lesions identified on angiography. All 87 Level I findings were identified using limited sequence (56 acute infarcts, 16 hemorrhages, and 15 mass lesions). Conclusion: A 4-pulse sequence brain MRI study is sufficient to evaluate patients with a new neurological complaint except when contrast or angiography is indicated. - Diagnostic medical imaging is one of the major driving forces behind rising healthcare expenditures. Between 2000 and 2006, Medicare spending on imaging services more than doubled, increasing to $14 billion1. The volume of brain MR studies performed may continue to rise in the future due to the expansion of health care insurance under the Patient Protection and Affordable Care Act (PPACA) and as a result of an aging population. At our institution, patients with various neurologic complaints are often imaged with MRI protocols that may involve a large number of pulse sequences, resulting in long scan times. There have been major advances in MRI hardware and software technology since the days of the first nuclear magnetic resonance (NMR) images in 1974. These advancements have provided us with an array of available MR sequences to choose from for our neuroimaging protocols. Long scan times related to multiple sequence acquisitions likely result in patient inconvenience and discomfort. It is unclear whether the multiple MR sequences performed are necessary and which of the sequences add value to the interpretation of the study. Optimizing the number of sequences in a routine screening brain MR protocol could improve efficiency as well as increase patient compliance and satisfaction by reducing scan time. Our goal was to investigate the diagnostic accuracy of brain MRI protocols containing a limited number of basic sequences in the evaluation of patients with new neurologic complaints. Patient Selection This retrospective study was approved by the Partners Human Research Committee, our hospitals Institutional Review Board Group 1 (n = 497) Group 2 (n = 499) mean 54.3 (range 0.598) mean 51.3 (range 0.593) Group 2 (n = 28) Table 1. Patient Demographics and MRI Findings Group 1. Posterior reversible encephalopathy syndrome (PRES) Significant MRI Findings Active demyelinating lesions Meningiomas or schwannomas Punctate acute/subacute infarcts Microhemorrhage discrepancies Group 1 (n = 19) * Venous sinus thrombosis, ICA dissection, arterial thrombus, absent vertebrobasilar flow voids, MCA branch thrombosis ** Cerebellar mass, brainstem mass, optic nerve sheath mass, thalamic masses, lobar masses, pituitary/sellar masses, corpus callosal mass, clival mass, colloid cysts ***Included probable metastases, probable primary tumors, inflammatory/demyelinating lesions, and indeterminate punctate enhancing foci doi:10.1371/journal.pone.0110803.t001 (IRB). Consent was not obtained and patient records/information was anonymized and de-identified prior to analysis. We performed a retrospective study of consecutive brain MR examinations performed at our institution, a major urban academic medical center, between February 20, 2010 and April 21, 2010. Studies included patients of all ages who underwent brain MR imaging for the evaluation of new neurologic complaints for which there was no established diagnosis stated on the radiology requisition. We included studies referred from the emergency department, inpatient and outpatient settings. Both intravenous contrast- enhanced and unenhanced studies were included as were studies that contained MR angiogram (MRA) and MR venogram (MRV) sequences. Image review commenced in June 2012, at least 24 months after the examinations were performed. Exclusion criteria were MR studies performed for follow-up evaluation of pre-existing neurological conditions (e.g. serial neuro-oncology studies) and specialized MR protocols (e.g. pituitary, orbits, brainstem and internal auditory canal studies). All MRI examinations were performed on either 1.5T (Tesla) or 3T MR systems (GE Healthcare Clinical Systems, Wauwatosa, WI, USA; Siemens Medical Solutions, Erlangen, Germany). A total of 9 MRI scanners were used during the period that was reviewed. Eight scanners had field strengths of 1.5T. Six were manufactured by General Electric; 3 were located within the hospital and 3 were located at free standing imaging centers. Two 1.5T MRI scanners were manufactured by Siemens and were located within the hospital. Additionally, a single Siemens 3T scanner was located within the hospital. All MR images in the study were reviewed on a PACS system (Agfa Impax 5.3, Agfa Healthcare, Mortsel, Belgium). Study Interpretation The total number of consecutive MRI studies was partitioned into two separate data sets (group 1, MR studies from February 20, 2010 through March 23, 2010; group 2, MR studies from March 24, 2010 through April 21, 2010). The group 1 neuroradiologists reviewed a three-sequence abbreviated im (...truncated)