Association of Carotid Plaque Gray-scale Median with Plaque Size and Degree of Stenosis

Introduction: Atherosclerosis remains a leading cause of Cardiovascular Disease (CVD) mortality and morbidity. Ultrasound Gray-Scale Median (GSM) of carotid plaques and plaque size have shown potential as markers of vulnerability and predictors of cerebrovascular events. This prospective study investigated the correlation between carotid plaque size, Degree of Stenosis (DoS), and GSM. Materials and Methods: In this study, 32 patients with 43 carotid plaques identified by B-mode ultrasound were recruited. Each B-mode ultrasound image was normalized, and the GSM of carotid plaque echogenicity was quantified using the histogram feature in Adobe Photoshop. GSM data from the thickest plaque area were obtained, and plaque length, thickness, area, and DoS were measured using ImageJ software. Correlations between plaque size, DoS, and GSM were identified and assessed using Spearman’s correlation coefficient. Results: Significant negative correlations were observed between carotid plaque GSM and plaque size (plaque length, r = −0.34, p = 0.02; plaque thickness, r = −0.30, p = 0.04; plaque area, r = −0.40, p = 0.008), with a trend toward significant negative correlation with DoS (r = −0.26, p = 0.08). Discussion: This study identifies an inverse relationship between carotid plaque GSM and plaque size parameters, indicating that hypoechoic plaques, characterized by lower GSM values, are generally larger and potentially more vulnerable to rupture. These findings emphasize the importance of combining structural metrics, such as plaque size and degree of stenosis, with compositional evaluation and their echogenicity for comprehensive cerebrovascular risk assessment. Hypoechoic plaques often correspond to lipid-rich, inflamed lesions with thin fibrous caps, which are histological features associated with an increased risk of cerebrovascular events. The demonstrated associations underscore the clinical relevance of GSM as a noninvasive surrogate biomarker that reflects both local plaque vulnerability and the broader systemic burden of atherosclerosis. Thus, the B-mode ultrasound-derived GSM is a practical and informative tool for enhancing risk stratification and guiding management strategies in patients with carotid artery disease. Conclusion: Our findings reveal significant negative correlations between carotid GSM and plaque size parameters, with a nonsignificant trend for DoS. These findings suggest that hypoechoic plaques, characterized by lower GSM values, are generally larger in size and potentially more vulnerable. Future large-scale longitudinal studies with repeated evaluations are required to validate these findings.