High-Risk Plaque Features in the Non-stenosing Carotid Artery, How Frequently is This Reported? A Retrospective Study.

Background: High-risk features of non-stenosing (ie, <50%) carotid plaques are emerging as a possible source of embolism in patients with embolic stroke of undetermined source (ESUS). However, in the absence of hemodynamically significant stenosis, neuroradiology reports rarely describe these morphological features. Our aim was to determine how often high-risk features of non-stenosing plaques are included in diagnostic imaging reports.

Methods: In this retrospective study, we evaluated computed tomography angiography (CTA) reports associated with the CTA imaging results for a previously published cohort study. Plaque features reporting frequencies were calculated and defined as the number of times specific plaque features were included in the CTA reports (Thickness, ulceration, length, soft component and calcification) divided by the number of occurrences of high-risk plaque features (Thickness >0.3 cm; ulceration; length >1.0 cm), soft component, or calcification identified in the CTA results. We used Fisher exact test to compare the reporting frequencies of the 5 plaque features.

Results: We analyzed 152 CTA reports. The frequency of reporting plaque thickness (0/40; 0%), ulceration (3/37; 8.1%), and length (7/29; 24.1%) was significantly lower than the reporting of plaque calcification (122/122; 100%) and presence of soft component (31/34; 72.1%) when these features were present in CTA imaging results (all P < 0.001).

Conclusion: When carotid plaques are not causing hemodynamically significant stenosis, neuroradiology reports frequency mention plaque density but often exclude other characteristics. Neuroradiologists and neurologists should collaborate to create algorithms, scoring systems and prediction models to accurately determine which plaque features are highly associated with embolism.