Point-of-care ultrasound by trained emergency physicians versus radiologists for deep vein thrombosis diagnosis: a prospective blinded study on diagnostic accuracy and time efficiency

OBJECTIVE: This study aimed to evaluate the diagnostic accuracy and time-to-diagnosis of compression ultrasonography performed by emergency physicians compared with radiologist-performed Doppler ultrasonography in patients with suspected deep vein thrombosis (DVT). METHODS: In this prospective blinded study, 309 patients with suspected lower-extremity DVT presenting to a tertiary emergency department between November 2022 and October 2024 were evaluated. All patients underwent compression ultrasonography performed by trained emergency physicians followed by radiologist-performed Doppler ultrasonography as the reference standard. Diagnostic performance was assessed using sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) with 95% CIs. Interobserver agreement was evaluated using Cohen's kappa coefficient. RESULTS: DVT was confirmed in 33/309 patients (10.6%). Emergency physician-performed compression ultrasonography demonstrated a sensitivity of 97.0% (95% CI 84.2 to 99.9) and specificity of 99.3% (95% CI 97.4 to 99.9). The PPV was 94.1% (95% CI 80.3 to 99.3) and the NPV was 99.6% (95% CI 98.0 to 100). Interobserver agreement between emergency physicians and radiologists was excellent across evaluated venous segments, with Cohen's kappa values of 0.926 (95% CI 0.880 to 0.971) for the femoral vein, 0.907 (95% CI 0.855 to 0.958) for the saphenofemoral junction and 0.973 (95% CI 0.947 to 0.999) for the popliteal vein. The median workflow-based time-to-diagnosis was 1 hour (IQR 0.75-1.5) for emergency physician-performed ultrasound and 4 hours (IQR 3-6) for radiologist-performed ultrasound. CONCLUSION: Compression ultrasonography performed by trained emergency physicians demonstrated high diagnostic accuracy and excellent agreement with radiologist-performed Doppler ultrasonography in patients with suspected DVT. Bedside ultrasound was also associated with shorter workflow-based time-to-diagnosis. These findings support further evaluation of whether earlier bedside diagnosis may translate into clinically meaningful outcomes such as reduced emergency department length of stay and improved patient flow.