Evaluation of Carotid Plaque Vulnerability Using Dual-energy Computed Tomography Angiography: a Prospective Observational Study.

This study aimed to assess the utility of dual-energy computed tomography (DECT) for evaluating carotid plaque vulnerability. This prospective observational study included consecutive patients who underwent DECT for preoperative evaluation of carotid plaques before elective carotid artery stenting between June 2023 and May 2025. DECT parameters-including effective atomic number (Z), electron density (Rho), virtual non-contrast CT value (VNC), fat fraction (FF), and iodine concentration (IC)-were measured. Relative signal intensity (rSI) was calculated on T1-weighted magnetic resonance images as the ratio of plaque to adjacent sternocleidomastoid muscle signal. A total of 46 carotid plaques, asymptomatic (n = 27) and symptomatic (n = 19), were analyzed. Both Rho and VNC were significantly lower in symptomatic compared to asymptomatic lesions (Rho, 29.6 [IQR, 26.5-33.6] vs 37.4 [IQR, 30.4-42.7], p < 0.05; VNC, 25.0 [IQR, 19.5-30.9] vs 31.2 [IQR, 21.9-41.4], p < 0.05), and FF was significantly higher in symptomatic compared to asymptomatic ones (21.5 [IQR, 17.4-23.3] vs 15.1 [IQR, 11.6-20.1], p < 0.05). No significant correlation was observed between the rSI and any of the DECT parameters. Multivariate logistic regression analysis showed that FF was significantly associated with symptomatic lesions in a model including rSI and VNC (OR, 1.39 [95% CI, 1.03-1.99], p < 0.05). Receiver operating characteristic analysis showed that adding FF to rSI improved discrimination of symptomatic plaques compared with rSI alone (AUC, 0.792 vs 0.560, p < 0.05). In this exploratory study, DECT-derived FF was associated with symptomatic carotid plaques and may provide complementary information beyond MRI-based plaque assessment in patients with moderate-to-severe carotid artery stenosis.