TY - JOUR T1 - Vascular Wall Imaging of Unruptured Cerebral Aneurysms with a Hybrid of Opposite-Contrast MR Angiography JF - American Journal of Neuroradiology JO - Am. J. Neuroradiol. SP - 1507 LP - 1511 DO - 10.3174/ajnr.A4318 VL - 36 IS - 8 AU - T. Matsushige AU - Y. Akiyama AU - T. Okazaki AU - K. Shinagawa AU - N. Ichinose AU - K. Awai AU - K. Kurisu Y1 - 2015/08/01 UR - http://www.ajnr.org/content/36/8/1507.abstract N2 - BACKGROUND AND PURPOSE: Inflammation and degeneration of the intracranial saccular aneurysm wall play a major role in aneurysm formation, development and subsequent rupture. The aim of this study was to characterize the walls of unruptured intracranial aneurysms by using a hybrid of opposite-contrast MRA at 3T.MATERIALS AND METHODS: Fourteen consecutive patients with 17 unruptured intracranial aneurysms who initially underwent clipping surgery were prospectively evaluated. All aneurysms were scanned preoperatively by using a hybrid of opposite-contrast MRA in 3T high-resolution MR imaging. We classified intraoperative findings of atherosclerotic plaques in the aneurysms into 3 grades: grade A (major plaques), grade B (minor plaques), and grade C (no plaques). The contrast ratio of the high-intensity area was also measured relative to the background low-intensity area inside the carotid artery.RESULTS: Findings from preoperative plaque imaging of the aneurysm corresponded to the intraoperative findings in 15 of 16 aneurysms (excluding 1 that was impossible to visualize in its entirety due to anatomic reasons). Overall sensitivity and specificity of the hybrid of opposite-contrast MRA were 88.9% and 100%, respectively. During the operation, 4 aneurysms were classified as grade A; 5, as grade B; and 7, as grade C. The means of the contrast ratio for grades A, B, and C were 0.72 ± 0.03, 0.34 ± 0.30, and −0.02 ± 0.09, respectively.CONCLUSIONS: The hybrid of opposite-contrast MRA can detect visible atherosclerotic plaques in the unruptured aneurysm wall, and the contrast ratio in intracranial aneurysms correlated with their presence and extent. A study including a larger series is needed to validate the diagnostic potential of this imaging technique.AcomAanterior communicating arteryFSBBflow-sensitive black-bloodHOP-MRAhybrid of opposite-contrast MR angiographyWVCRwall-vessel lumen contrast ratio ER -