Reassessing the Carotid Artery Plaque "Rim Sign" on CTA: A New Analysis with Histopathologic Confirmation.

Area of Science:

• Vascular imaging and pathology
• Carotid artery disease research
• Biomarker discovery in atherosclerosis

Background:

• The "rim sign" on computed tomography angiography (CTA) is a proposed imaging marker for intraplaque hemorrhage in carotid plaques.
• Histopathologic confirmation is essential to validate imaging markers for carotid plaque characterization.

Purpose of the Study:

• To investigate the association between the CTA "rim sign" and intraplaque hemorrhage.
• To determine the diagnostic accuracy of the rim sign for identifying intraplaque hemorrhage using histopathology.

Main Methods:

• CTA neck imaging was performed on patients undergoing carotid endarterectomy.
• Plaque features including stenosis, calcification, thickness, and ulcerations were assessed.
• The "rim sign" was defined by specific calcification and soft-tissue plaque characteristics.
• Carotid endarterectomy specimens were analyzed for lipid content, intraplaque hemorrhage, and calcification.

Main Results:

• Sixty-seven patients were included; 38.3% had the rim sign.
• Intraplaque hemorrhage was present in 77.6% of plaques.
• The rim sign was not significantly associated with the presence of intraplaque hemorrhage (P=.11).
• The rim sign was associated with a greater proportion of intraplaque hemorrhage (P=.049).
• Sensitivity and specificity for intraplaque hemorrhage were 61.5% and 60.0%.

Conclusions:

• The CTA "rim sign" is not directly associated with the presence of intraplaque hemorrhage.
• The rim sign may indicate a higher proportion of hemorrhage within a plaque.
• It could serve as a biomarker for more severe intraplaque hemorrhage when present.