P15 - Microvascular alterations in autoimmune thyroid disease: insights from subtraction ultra-micro angiography

Background/Introduction Altered vascularity is a key feature of autoimmune thyroid disorders, often reflecting both the degree of inflammation and hormonal imbalance. Subtraction Ultra-Micro Angiography (sUMA) is an advanced Doppler- based technique that enhances the visualization of low-flow microvascular networks by eliminating background tissue signals. Purpose This study explores the utility of sUMA in identifying perfusion patterns associated with autoimmune thyroid disease compared to healthy thyroid tissue. Methods In this prospective, single-center study, 62 subjects were enrolled: 15 healthy controls, 37 with chronic autoimmune thyroiditis (CAT), and 10 with Graves’ disease (GD). All participants underwent multiparametric ultrasound, followed by sUMA imaging for thyroid microvascular assessment. Vascularity was expressed using the color pixel percentage (CPP). The median CPP values were calculated for each group and compared, and correlations with clinical and laboratory parameters were explored. Results All groups had comparable mean ages (46.1–50.2 years), with a predominance of female participants (70%–80%). The median CPP was significantly lower in the healthy control group (28.7; 95% CI [23.8–32.2]) compared to CAT (50.6; 95% CI [42.6–58.3]) and GD (46.55; 95% CI [39.2–65.9]; p < 0.0001). Among healthy controls, a moderate inverse correlation was observed between CPP and BMI (r = -0.535, p = 0.039). In the CAT group, CPP showed moderate positive correlations with TSH (r = 0.498, p = 0.002) and thyroid volume (r = 0.419, p = 0.009). Conclusion(s) sUMA reveals distinct vascular patterns in autoimmune thyroid disease and may serve as a quantitative, noninvasive tool for diagnosis, prognosis, and monitoring treatment response.