Diagnostic accuracy of ultrasonography for lower extremity arterial disease in patients with diabetes

Lower extremity arterial disease (LEAD) is a major macrovascular complication in patients with diabetes mellitus, and accurate noninvasive imaging is essential for early recognition and risk stratification. This retrospective diagnostic accuracy study included 59 adult patients with diabetes who underwent both lower extremity arterial ultrasonography and contrast-enhanced computed tomography angiography (CTA) within a predefined interval of ≤ 30 days. Baseline data showed that patients with CTA-confirmed LEAD were older, had longer diabetes duration, higher glycated hemoglobin (HbA1c), a higher prevalence of hypertension, lower estimated glomerular filtration rate (eGFR), and higher low-density lipoprotein cholesterol (LDL-C) than those without LEAD. CTA revealed a substantial burden of disease with frequent multisegment involvement across iliac–femoral, popliteal, and infrapopliteal segments. Using CTA as the reference standard and a threshold of ≥ 50% diameter stenosis or occlusion, ultrasonography demonstrated a sensitivity of 90.0% and specificity of 75.9% at the patient level, and a sensitivity of 88.5% and specificity of 89.7% at the segment level. Negative predictive values were high at both levels, and agreement between ultrasonography and CTA was acceptable by McNemar’s test. Detection rates increased with lesion severity, with excellent performance for moderate and severe stenoses. These findings indicate that duplex ultrasonography provides robust diagnostic information on clinically significant LEAD in patients with diabetes and can be used as a reliable imaging modality in routine clinical practice.