From the Departments of Radiology (Z.S., S.Z., X.M., X.Y., C.C., S.R., J.L., M.Z.) and Neurology (H.W.), Zhongshan Hospital, Fudan University, No. 180 Fenglin Rd, Xuhui District, Shanghai 200032, China; Shanghai Institute of Medical Imaging, Shanghai, China (Z.S., S.Z., Y.Z., X.Y., C.C., S.R., J.L., M.Z.); Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, China (X.Z., B.W., B.Z., H.W.); Central Research Institute, United Imaging Healthcare, Shanghai, China (Y.Z., Y.D.); Shanghai United Imaging Healthcare, Shanghai, China (S.H.).
Radiology. 2023 Jan;306(1):207-217. doi: 10.1148/radiol.220114. Epub 2022 Aug 30.
Background Three-dimensional (3D) time-of-flight (TOF) MR angiography (MRA) at 7 T has been reported to have high image quality for visualizing small perforating vessels. However, B inhomogeneity and more physiologic considerations limit its applications. Angiography at 5 T may provide another choice for intracranial vascular imaging. Purpose To evaluate the image quality and cerebrovascular visualization of 5-T 3D TOF MRA for visualizing intracranial small branch arteries. Materials and Methods Participants (healthy volunteers or participants with a history of ischemic stroke undergoing intracranial CT angiography or MRA for identifying steno-occlusive disease) were prospectively included from September 2021 to November 2021. Each participant underwent 3-T, 5-T, and 7-T 3D TOF MRA with use of customized MR protocols within 48 hours. Radiologist scoring from 0 (invisible) to 3 (excellent) and quantitative assessment were obtained to evaluate the image quality. The Friedman test was used for comparison of characteristics derived from 3 T, 5 T, and 7 T. Results A total of 12 participants (mean age ± SD, 38 years ± 9; nine men) were included. Visualizations of the distal arteries and small vessels at 5-T TOF MRA were significantly higher than those at 3 T (median score: 3.0 vs 2.0, all < .001 for distal segments and lenticulostriate artery; median score: 2.0 vs 0, < .001 for pontine artery). The total length of small vessel branches detected at 5 T was larger than that at 3 T (5.1 m ± 0.7 vs 1.9 m ± 0.4; < .001). However, there was no evidence of a significant difference compared with 7 T in either the depiction of distal segments and small vessel branches (average median score, 2.5; all > .05) or the quantitative measurements (total length, 5.6 m ± 0.5; = .41). Conclusion Three-dimensional time-of-flight MR angiography at 5 T presented the capability to provide superior visualization of distal large arteries and small vessel branches (in terms of subjective and quantitative assessment) to 3 T and had image quality similar to 7 T. © RSNA, 2022
背景 7T 下的三维（3D）时间飞跃（TOF）磁共振血管成像（MRA）已被报道具有较高的可视化小穿支血管的图像质量。然而，B 不均匀性和更多的生理因素限制了其应用。5T 下的血管造影可能为颅内血管成像提供另一种选择。目的 评估 5T 3D TOF MRA 用于可视化颅内小分支动脉的图像质量和脑血管可视化效果。材料与方法 参与者（健康志愿者或因疑似狭窄闭塞性疾病而行颅内 CT 血管造影或 MRA 检查的缺血性脑卒中患者）于 2021 年 9 月至 11 月前瞻性纳入。每位参与者在 48 小时内分别使用定制的 MR 方案行 3T、5T 和 7T 3D TOF MRA。采用 0（不可见）至 3（极好）的放射科评分和定量评估来评估图像质量。采用 Friedman 检验比较 3T、5T 和 7T 得出的特征。结果 共纳入 12 名参与者（平均年龄±标准差，38 岁±9；9 名男性）。5T TOF MRA 对远端动脉和小血管的显示明显高于 3T（远端节段和纹状体动脉的中位数评分：3.0 比 2.0，均<.001；脑桥动脉的中位数评分：2.0 比 0，<.001）。5T 检测到的小血管分支总长度大于 3T（5.1m±0.7 比 1.9m±0.4；<.001）。然而，与 7T 相比，远端节段和小血管分支的显示（平均中位数评分，2.5；均>.05）或定量测量（总长度，5.6m±0.5；=.41）均无明显差异。结论 5T 3D TOF MRA 能够在主观和定量评估方面提供优于 3T 的远端大动脉和小血管分支可视化效果，且图像质量与 7T 相似。 ©RSNA，2022
