Three-Dimensional T2-Weighted MRI of the Human Femoral Arterial Vessel Wall at 3.0 Tesla

Abstract

OBJECTIVES-To evaluate the potential use of a novel 3D turbo spin-echo (TSE) T2-weighted (T2w) technique for assessing the vessel wall in the superficial femoral artery at 3.0T.BACKGROUND-Magnetic resonance imaging (MRI) can be used for the noninvasive assessment of atherosclerotic plaque burden in the peripheral circulation. While black-blood 2D TSE techniques have been used for femoral arterial wall imaging, these techniques require prolonged imaging time to cover a large field of view required to cover the leg. Recently, variable-flip-angle 3D TSE T2w (SPACE) has been introduced as a fast vessel wall imaging technique with submillimeter spatial resolution. A systematic investigation of the application of this technique to femoral arterial wall imaging has yet to be performed.

Intracranial arterial wall imaging using three‐dimensional high isotropic resolution black blood MRI at 3.0 Tesla

“…3D images (0.5-mm isotropic resolution) were reconstructed to match the voxel dimensions of the 2D sequence (0.5 Â 0.5 Â 2 mm skull base), particularly at high fields such as 3.0T. In contrast, a 3D TSE technique with a dedicated refocusing sweep and a long echo train (e.g., VISTA) is less sensitive to these field inhomogeneities (19,20). Our study is the first application of the VISTA sequence for intracranial vessel wall imaging.…”

“…Because of the inhomogeneous noise distribution encountered in parallel imaging, we measured noise from an ROI of 25 mm 2 manually placed in the adjacent white matter (20,25) instead of using the air. The contrast-to-noise ratio (CNR) of wall versus lumen (CNR wall-lumen ) was calculated as CNR wall-lumen ¼ SNR wall -SNR lumen .…”

“…The CNR efficiency (CNR eff ) was determined to account for differences in scan times between 2D and 3D techniques to enable a fair comparison. CNR eff was calculated as: CNR eff ¼ CNR/(VOXEL(TA slice ) 1/2 ), where VOXEL is the voxel volume (in mm 3 ) and TA slice is the scan time per slice (in minute) (20).…”

“…A 3D variable flip-angle refocusing pulse sequence has been used to image carotid (19) and peripheral (20) arterial walls. However, one cannot intuit the successful application of this technique to intracranial wall imaging because these vessels are structurally unique.…”

Fast plaque burden assessment of the femoral artery using 3D black-blood MRI and automated segmentation

“…8 In femoral arteries, however, 3D acquisitions have been found to yield improved signal-to-noise ratios (SNR), extended coverage and higher resolution without increasing imaging time over 2D acquisitions. 9,10 The use of 3D imaging has specifically benefitted from the introduction of blood suppression techniques, such as motion-sensitized driven equilibrium (MSDE), which depends on the flow velocity of blood and not on the outflow volume for black-blood imaging. 11 This blood suppression technique has been integrated into the 3D black-blood sequence called 3D MSDE prepared rapid gradient echo sequence (3D MERGE) Ref.…”