Thermography and plethysmography, a non‐invasive alternative to venography in the diagnosis of deep vein thrombosis

One plethysmographic and two thermographic methods were evaluated against venography in 102 patients with suspected deep vein thrombosis (DVT). Seventy-one patients had venographically verified DVT, which in 21 cases was restricted to the calf. Plethysmography (PG) gave a sensitivity and specificity of 63% and 94%, respectively. The former was influenced by a limited sensitivity of 14% in the sub-group with distal DVT. The sensitivity and specificity of temperature profiles (TP) were 87% and 39%, respectively, while the corresponding values for thermo-camera (TC) were 83% and 55%, respectively. Using a combined diagnostic approach of PG and TP, additional evaluation of posterior and lateral profiles and pattern recognition, 96% sensitivity and 81% specificity were reached. The combination of PG and TP will be an essential diagnostic complement when venography is not possible or inconclusive, as well as having a role in diagnostic screening in a large number of patients.