Simultaneous Visualization of the Carotid and Subclavian Arteries Using Non-Contrast-Enhanced MR Angiography With a 3D Fast Field Echo Sequence and Time-Spatial Labeling Inversion Pulse: A Comparison With 3D Time-of-Flight MR Angiography.

Abstract

Background: Carotid artery stenosis is a major cause of stroke. Non-contrast MR angiography (MRA) using time-spatial labeling inversion pulse (Time-SLIP) may offer potential advantages over 3D time-of-flight (TOF)-MRA for simultaneous visualization of carotid, vertebral, and subclavian arteries, but remains uninvestigated.

Purpose: To determine optimal black blood inversion time (TI) for visualizing the carotid and subclavian arteries using three-dimensional (3D) fast field echo (FFE) Time-SLIP MRA, and to compare its image quality with 3D TOF-MRA.

Study type: Prospective.

Subjects: 11 healthy adults (23-57 years, five females) and 4 patients (76-93 years, three females) with cervical vascular abnormalities. All patients had ICA stenosis. One patient exhibited ECA stenosis.

Field strength/sequence: 3-T, 3D FFE with Time-SLIP using four TIs (1200-1800 ms) for healthy, 3D balanced steady-state free precession (bSSFP) with Time-SLIP using TI = 1600 for patients, and 3D TOF-MRA for all subjects, covering the cervical and subclavian arteries.

Assessment: For healthy subjects, relative signal intensity (SI) was measured using ROI for both sides of the carotid, vertebral, and subclavian arteries. For the same locations, vessel visibility was independently scored by three board-certified radiologists. Patient images were qualitatively assessed for vessel visibility, abnormality, and artifacts.

Statistical tests: Friedman and Wilcoxon signed-rank tests for pairwise comparisons of vessel visibility. A Bonferroni-corrected significance threshold of p < 0.005 (= 0.05/10) was used.

Results: In volunteer scans, relative SI for TI = 1600 was highest, while TI = 1800 showed the best visibility scores. 3D TOF-MRA showed limitations in subclavian and brachiocephalic arteries due to low vessel-to-background contrast. In patients, FFE-based Time-SLIP provided better subclavian artery depiction than bSSFP-based Time-SLIP.

Data conclusion: 3D FFE with Time-SLIP may enable high-quality simultaneous visualization of the carotid and subclavian arteries when compared to 3D TOF-MRA. In patients with vascular abnormalities, 3D FFE may provide superior subclavian artery depiction compared to 3D TOF-MRA and 3D bSSFP.

Evidence level: 2.

Technical efficacy: Stage 2.