Objective Quantification of the Continuous-Wave Venous Doppler Examination

Abstract

Objective: To develop a quantitative, objective method to diagnose deep venous thrombosis (DVT) with the continuous-wave (CW) Doppler system. Design: Case control study. Setting: Vascular Laboratory of the Surgical Services, Veteran's Affairs Medical Center, La Jolla, California, USA. Patients, participants: Thirty-five control subjects and the limbs of 50 patients with suspected DVT were examined. Main outcome measures: Phlebography, CW Doppler ultrasound. CW Doppler output was recorded from the popliteal, superficial femoral and common femoral veins. The response to standardized calf compression was analysed. Results: The most useful information included the Doppler velocity increase, decay time and deceleration. Because the determination of decay time does not require calibration of the Doppler system, it is the preferred parameter. Conclusions: A decay time longer than 1.05 s is a very good discriminant between normal control and DVT limbs.