Comparison of platelet scintigraphy, impedance plethysmography gray scale and color flow duplex ultrasound and venography for the diagnosis of venous thrombosis.

The several techniques available for the diagnosis of venous thrombosis have not been directly compared in the same patient population. Thus color and gray scale duplex ultrasound (U), impedance plethysmography (IPG), 3-4 hr platelet imaging (PS) were compared to venography (V), in 104 consecutive patients (in hospital and out). PS and V were read by two, and IPG and U by one, blinded reader. Comparisons were made for the calf (CA), popliteal (Pop) and femoral (Fem) vessels. Reproducibility of V and PS was 84 and 87%. (table; see text) We conclude that PS, while having a very high specificity, has an unacceptably low sensitivity. However, while both impedance plethysmography and color flow ultrasound have excellent and similar diagnostic accuracy in the femoral, these techniques have either a low sensitivity or low technical success rate in the calf or popliteal veins.