Anzalone Nicoletta, Scomazzoni Francesco, Cirillo Mario, Cadioli Marcello, Iadanza Antonella, Kirchin Miles A, Scotti Giuseppe
Department of Neuroradiology, Ospedale San Raffaele, Milan, Italy; and daggerBracco Imaging SpA, Milan, Italy.
Invest Radiol. 2008 Aug;43(8):559-67. doi: 10.1097/RLI.0b013e31817e9b0b.
To compare three-dimensional (3D) time-of-flight (TOF)-magnetic resonance angiography (MRA) at 3 T with 3D TOF-MRA and ultrafast contrast-enhanced (CE)-MRA at 1.5 T and to determine the optimum MRA sequence for follow-up of cerebral aneurysms treated with Guglielmi detachable coils (GDCs).
Twenty-eight patients treated with GDCs for 29 cerebral aneurysms underwent MRA at 3 T and 1.5 T within 24 hours (during the same session for outpatients). All imaging was performed using a sensitivity-encoding head coil (SENSE factor = 2). Unenhanced axial 3D TOF-MRA at 3 T was performed with repetition time (TR)/echo time (TE) = 16/2.9. At 1.5 T, axial 3D TOF-MRA (TR/TE = 23/4) was performed first, followed by axial 3D ultrafast gradient echo MRA (TR/TE = 6/2) enhanced with 0.1 mmol/kg gadobenate dimeglumine (MultiHance). Source images and maximum intensity projection and shaded surface display reconstructions for each acquisition sequence were evaluated for quality of visualization of residual aneurysm patency and scored for visualization preference.
Residual aneurysm was detected in 15/29 cases on CE-MRA at 1.5 T and TOF-MRA at 3 T but in only 11/29 cases on TOF-MRA at 1.5 T. CE-MRA at 1.5 T was preferred to TOF-MRA at 1.5 T in 13 cases (P = 0.004) and to TOF-MRA at 3 T in 3 cases. TOF-MRA at 3 T was preferred to TOF-MRA at 1.5 T in 11 cases (P = 0.04) but was not preferred to CE-MRA at 1.5 T in any case. The parent artery was identifiable in all 29 cases after TOF-MRA at 3 T and CE-MRA at 1.5 T but in only 27 cases after 3D TOF-MRA at 1.5 T.
TOF-MRA follow-up of coiled aneurysms is better at 3 T than at 1.5 T; nevertheless, greater definition of residual patency is achieved with ultrafast CE-MRA at 1.5 T.
比较3T场强下的三维（3D）时间飞跃（TOF）磁共振血管造影（MRA）与1.5T场强下的3D TOF-MRA及超快对比增强（CE）-MRA，并确定用于随访经 Guglielmi 可脱性弹簧圈（GDC）治疗的脑动脉瘤的最佳MRA序列。
28例因29个脑动脉瘤接受GDC治疗的患者在24小时内（门诊患者在同一时间段内）分别于3T和1.5T场强下接受MRA检查。所有成像均使用灵敏度编码头线圈（灵敏度编码因子=2）。3T场强下未增强的轴向3D TOF-MRA的重复时间（TR）/回波时间（TE）为16/2.9。在1.5T场强下，先进行轴向3D TOF-MRA（TR/TE=23/4），随后进行用0.1mmol/kg钆贝葡胺（MultiHance）增强的轴向3D超快梯度回波MRA（TR/TE=6/2）。对每个采集序列的源图像、最大密度投影和表面阴影显示重建进行评估，以观察残余动脉瘤通畅情况的可视化质量，并对可视化偏好进行评分。
1.5T场强下的CE-MRA及3T场强下的TOF-MRA在29例中有15例检测到残余动脉瘤，而1.5T场强下的TOF-MRA仅在29例中的11例检测到残余动脉瘤。1.5T场强下的CE-MRA在13例中优于1.5T场强下的TOF-MRA（P=0.004），在3例中优于3T场强下的TOF-MRA。3T场强下的TOF-MRA在11例中优于1.5T场强下的TOF-MRA（P=0.04），但在任何情况下均不优于1.5T场强下的CE-MRA。在3T场强下的TOF-MRA及1.5T场强下的CE-MRA后，29例中所有病例的载瘤动脉均可识别，而在1.5T场强下的3D TOF-MRA后仅27例可识别。
3T场强下对栓塞后动脉瘤的TOF-MRA随访效果优于1.5T场强；然而，1.5T场强下的超快CE-MRA对残余通畅情况的显示更清晰。
