Abstract:
PURPOSE:Time-of-flight (ToF) and phase contrast (PC) magnetic resonance angiographies (MRAs) are noninvasive applications to depict the cerebral arteries. Both approaches can image the cerebral vasculature without the administration of intravenous contrast. Therefore, it is used in routine clinical evaluation of cerebrovascular diseases, e.g., aneurysm and arteriovenous malformations. However, subtle microvascular disease usually cannot be resolved with standard, clinical-field-strength MRA. The purpose of this study was to compare the ability of ToF and PC MRA to visualize the cerebral arteries at increasing field strengths. MATERIALS AND METHODS:The Institutional Review Board-approved study included eight healthy volunteers (age: 36 ± 10 years; three female, five male). All subjects provided written informed consent. ToF and PC MRAs were obtained at 1.5, 3 and 7T. Signal intensities of the large, primary vessels of the Circle of Willis were measured, and signal-to-noise ratios were calculated. Visualization of smaller first- and second-order branch arteries of the Circle of Willis was also evaluated. RESULTS:The results show that both ToF and PC MRAs allow the depiction of the large primary vessels of the Circle of Willis at all field strengths. Ultrahigh field (7T) provides only small increases in the signal-to-noise ratio in these primary vessels due to the smaller voxel size acquired. However, ultrahigh-field MRA provides better visualization of the first- and second-order branch arteries with both ToF and PC approaches. Therefore, ultrahigh-field MRA may become an important tool in future neuroradiology research and clinical care.
journal_name
Magn Reson Imagingjournal_title
Magnetic resonance imagingauthors
Stamm AC,Wright CL,Knopp MV,Schmalbrock P,Heverhagen JTdoi
10.1016/j.mri.2012.10.023subject
Has Abstractpub_date
2013-05-01 00:00:00pages
545-9issue
4eissn
0730-725Xissn
1873-5894pii
S0730-725X(12)00422-5journal_volume
31pub_type
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