Incremental value of pericarotid adipose tissue radiomics in predicting in-stent restenosis after carotid artery stenting

OBJECTIVE: To evaluate the potential of pericarotid adipose tissue radiomics to improve the prediction of in-stent restenosis (ISR) after carotid artery stenting (CAS). METHODS: This retrospective study included 191 patients who underwent carotid CT angiography (CTA) and CAS within 1 week at two centers from September 2019 to December 2023. ISR was defined as ≥50% stenosis on follow-up Doppler ultrasound or CTA. Three predictive models were developed and defined as follows: Model A (Clinical), Model B (Clinical + Imaging), and Model C (Clinical + Imaging + Radiomics) using receiver operating characteristic (ROC) analysis, calibration curves, and decision curve analysis. RESULTS: ISR occurred in 44 patients with a mean time interval of 11.3 months. Multivariate Cox regression analyses identified diabetes, fibrinogen, systolic blood pressure, calcified plaque volume, and pericarotid adipose tissue radiomics as independent predictors of ISR. The radiomics score, derived from 15 significant characteristics, outperformed conventional imaging markers. In the training set, Model C (AUC=0.881) significantly outperformed Model A (AUC=0.664) and Model B (AUC=0.840), with statistically significant differences (Model A vs Model C: P=0.001; Model B vs Model C: P=0.0246). This trend was consistent in the validation sets. Calibration curves showed good agreement between predicted and actual ISR probabilities, and decision curve analysis indicated that Model C provided greater net benefits. CONCLUSION: The radiomic characteristics of pericarotid adipose tissue provide incremental value in predicting ISR after CAS and serve as a valuable biomarker for restenosis risk assessment.