Assessment of perivascular adipose tissue attenuation using dual-layer spectral-detector CTA for identification of symptomatic carotid plaques.

Purpose: To assess the attenuation of perivascular adipose tissue (PVAT) around carotid plaques on Dual-layer spectral-detector dual-energy computed tomography angiography (DLCTA) and explore its application values for the identification of symptomatic carotid plaques.

Materials and methods: Patients with carotid plaques were enrolled and underwent DLCTA. The PVAT surrounding carotid plaques was outlined and the attenuation was measured on virtual monoenergetic images (40 keV and 70 keV) and polyenergetic imaging (PI). The PVAT attenuation was compared between symptomatic and asymptomatic plaques. The diagnostic performances of PVAT attenuation in differentiating symptomatic plaques were analyzed using receiver operating characteristic (ROC) curves.

Results: A total of 73 patients (65.3 ± 7.9 years, 61 males) were included (symptomatic group, n = 29; asymptomatic group, n = 44). On monoenergetic 40 keV, 70 keV, and PI, PVAT attenuation was found significantly higher in the symptomatic plaques compared to the asymptomatic plaques (P < 0.001, P < 0.001, and P = 0.002 respectively). The area under the curves (AUCs) of PVAT_{40 keV}, PVAT_{70 keV}, and PVAT_PI for distinguishing the symptomatic plaques were 0.864, 0.750, and 0.714 respectively. With the cut-off value of - 86.2 HU, PVAT_{40 keV} showed the best diagnostic performance with a sensitivity of 89.7% and a specificity of 72.7%.

Conclusions: DLCTA-derived PVAT attenuation might serve as a good imaging marker of symptomatic carotid plaques. Including PVAT attenuation on 40 keV images in clinical assessment, may help improve the abilities in the detection and identification of symptomatic carotid plaques.