Multicontrast black-blood MRI of carotid arteries: Comparison between 1.5 and 3 Tesla magnetic field strengths

Purpose: To compare black-blood multicontrast carotid imaging at 3T and 1.5T and assess compatibility between morphological measurements of carotid arteries at 1.5T and 3T. Materials and Methods: Five healthy sub jects and two atherosclerosis patients were scanned in 1.5T and 3T scanners with a similar protocol providing transverse T-1-, T-2-, and proton density (PD)-weight:ed black-blood images using a fast spin-echo sequence with single- (T-1 -weighted) or multislice (PD-/T-2-weighted) double inversion recovery (DIR) preparation. Wall and lumen signal-to-noise ratio (SNR) and wall/lumen contrast-to-noise ratio (CNR) were cornpared in 44 artery cross-sections by paired t-test. Interscanner variability of the lumen area (LA), wall area (WA), and mean wall thickness (MWT) was assessed using Bland-Altman analysis. Results: Wall SNR and lumen/wall CNR significantly increased (P < 0.0001) at 3T with a.1.5-fold gain for T-1-weighted images and a 1.7/1.8-fold gain for PD-/T-2-weighted images. Lumen SNR did not differ for singleslice DIRT1-weighted images (P = 0.2). but was larger at 3T for multislice DIR PD-/T-2-weighted images (P = 0.01/0.03). The LA, WA, and MVVT demonstrated good agreement with no significant bias (P 0.5), a coefficient of variation (CV) of < 10%, and intraclass correlation coefficient (ICC) of > 0.95. Conclusion: This study demonstrated significant improvement in SNR, CNR, and image quality for high-resolution black-blood imaging of carotid arteries at 3T. Mor-phologic measurements are compatible between 1.5T and 3T.