Time-of-Flight Intracranial MRA at 3 T versus 5 T versus 7 T: Visualization of Distal Small Cerebral Arteries

Zhang Shi; Xueying Zhao; Shuo Zhu; Xiyin Miao; Yunfei Zhang; Shihong Han; Bei Wang; Boyu Zhang; Xiaodan Ye; Yongming Dai; Caizhong Chen; Shengxiang Rao; Jiang Lin; Mengsu Zeng; He Wang

doi:10.1148/radiol.220114

Time-of-Flight Intracranial MRA at 3 T versus 5 T versus 7 T: Visualization of Distal Small Cerebral Arteries

Radiology. 2023 Jan;306(1):207-217. doi: 10.1148/radiol.220114. Epub 2022 Aug 30.

Authors

Zhang Shi^#¹, Xueying Zhao^#¹, Shuo Zhu¹, Xiyin Miao¹, Yunfei Zhang¹, Shihong Han¹, Bei Wang¹, Boyu Zhang¹, Xiaodan Ye¹, Yongming Dai¹, Caizhong Chen¹, Shengxiang Rao¹, Jiang Lin¹, Mengsu Zeng¹, He Wang¹

Affiliation

¹ 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.).

^# Contributed equally.

PMID: 36040333
DOI: 10.1148/radiol.220114

Abstract

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, B₁ 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 P < .001 for distal segments and lenticulostriate artery; median score: 2.0 vs 0, P < .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; P < .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 P > .05) or the quantitative measurements (total length, 5.6 m ± 0.5; P = .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 Online supplemental material is available for this article. An earlier incorrect version appeared online. This article was corrected on September 14, 2022.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cerebral Arteries
Computed Tomography Angiography
Humans
Imaging, Three-Dimensional
Magnetic Resonance Angiography* / methods
Male
Middle Cerebral Artery
Tomography, X-Ray Computed*