Visualization of carotid vessel wall and atherosclerotic plaque: T1-SPACE vs. compressed sensing T1-SPACE.

OBJECTIVES: To compare visualization of carotid plaques and vessel walls between 3D T1-fast spin echo imaging with conventional SPACE (T1-SPACE) and with a prototype compressed sensing T1-SPACE (CS-T1-SPACE) METHODS: This retrospective study was approved by the institutional review board. Participants comprised 43 patients (36 males, 7 females; mean age, 71 years) who underwent carotid MRI including T1-SPACE and CS-T1-SPACE. The quality of visualization for carotid plaques and vessel walls was evaluated using a 5-point scale, and signal intensity ratios (SRs) of the carotid plaques were measured and normalized to the adjacent sternomastoid muscle. Scores for the quality of visualization were compared between T1-SPACE and CS-T1-SPACE using the Wilcoxon signed-rank test. Statistical differences between SRs of plaques with T1-SPACE and CS-T1-SPACE were also evaluated using the Wilcoxon signed-rank test, and Spearman's correlation coefficient was calculated to investigate correlations.

RESULTS: Visualization scores were significantly higher for CS-T1-SPACE than for T1-SPACE when evaluating carotid plaques (p = 0.0212) and vessel walls (p < 0.001). The SR of plaques did not differ significantly between T1-SPACE and CS-T1-SPACE (p = 0.5971). Spearman's correlation coefficient was significant (0.884; p < 0.0001).

CONCLUSIONS: CS-T1-SPACE allowed better visualization scores and sharpness compared with T1-SPACE in evaluating carotid plaques and vessel walls, with a 2.5-fold accelerated scan time with comparable image quality. CS-T1-SPACE appears promising as a method for investigating carotid vessel walls, offering better image quality with a shorter acquisition time.

KEY POINTS: • CS-T1-SPACE allowed better visualization compared with T1-SPACE in evaluating carotid plaques and vessel walls, with a 2.5-fold accelerated scan time with comparable image quality. • CS-T1-SPACE offers a promising method for investigating carotid vessel walls due to the better image quality with shorter acquisition time. • Physiological movements such as swallowing, arterial pulsations, and breathing induce motion artifacts in vessel wall imaging, and a shorter acquisition time can reduce artifacts from physiological movements.