Computed Tomography Angiography "Rim Sign" for Detecting Carotid Intraplaque Hemorrhage: A Computed Tomography Angiography-Magnetic Resonance Imaging-Histology Correlation Study.

BACKGROUND

This study aimed to explore the association between the rim sign and intraplaque hemorrhage (IPH) based on imaging-histology analysis.

METHODS

Patients with carotid plaque were prospectively recruited and underwent computed tomography angiography (CTA) and vessel wall magnetic resonance imaging examination. CTA characteristics were evaluated qualitatively or quantitatively. IPH was determined through vessel wall magnetic resonance imaging assessment. The receiver operating characteristic curve and area under the curve were performed to assess the diagnostic performance of CTA features in the identification of IPH. Additionally, the histological subgroup analysis was performed on plaque specimens obtained from carotid endarterectomy procedures.

RESULTS

In total, 81 patients who underwent unilateral carotid endarterectomy and 143 plaques were included in the analysis. Plaques with IPH exhibited more severe stenosis, greater soft and total plaque thickness, and a higher proportion of rim signs compared with plaques without IPH (P<0.05 for all comparisons). Multivariate logistic regression analysis showed that the rim sign was associated with the presence of IPH. In the subgroup analysis based on histology, the rim sign was independently correlated with the presence of IPH. The rim sign demonstrated diagnostic performance for magnetic resonance imaging-determined IPH, with an area under the curve of 0.85 (95% CI, 0.78-0.92), with a sensitivity of 85.9% and a specificity of 84.1%.

CONCLUSIONS

The rim sign in carotid plaque is associated with the presence of IPH and may be a potential CTA feature for the evaluation of IPH on CTA images. This imaging marker may provide additional value for risk stratification of carotid plaques.