Deep vein thrombosis and diagnostic techniques

It is commonly acknowledged that the signs and symptoms of deep vein thrombosis are non specific and that the clinical diagnosis is unreliable. Many investigators have found that the clinical diagnosis in suspected cases of DVT is correct in only approximateJy 50% of cases. As a result of this, a number of new diagnostic techniques have heen deveJoped. Plethysmography has good result of this diagnosis of DVT. However, DVT confined to calf vessels is not readily detected by this method. Doppler ultrasound technique is similar to plethysmography in that it detects alteration in venous haemodynamics in patients with DVT. False negative have been reported in calf thrombosis but also in the presence of extensive DVT with venous collateralization. In an effort to improve, diagnosis technique in combination have been used. Venous ultrasound of the lower extremities has been shown to be highly accurate for the diagnosis of deep venous thrombosis in the femoropopliteal system. The main disadvantages of this technique are that it requires a skilled technologist who can operate independently from the physician and the relative inability to image veins above the inguinal ligament.