Leg temperature profiles with a simplified thermographic technique in the diagnosis of acute venous thromboses

Abstract

A simplified thermographic technique has been developed to provide continuous leg temperature profiles by manual scanning with a noncontactile infrared radiation transducer connected to a linear potentiometer for determination of the transducer position. The clinical value of the technique in the diagnosis of acute venous thromboses has been estimated in seventy patients and thirty controls, using plethysmography and phlebography as methods of reference. The thermographic diagnosis was based on side differences in temperature levels within different segments of the limbs, as calculated from the temperature profiles by means of planimetric technique. Standardized temperature profiles from the medial side of the limbs were found to demonstrate a side difference above the reference level in fifty-seven of fifty-nine patients with acute venous thromboses, which means a diagnostic sensitivity corresponding to that of conventional thermography. Skin temperature profiles were superior to plethysmography, particularly in the diagnosis of thromboses located distally. Falsely positive results were obtained, as expected, in some cases of varicose veins or acute arthritis and skin infections. The presented type of thermography has obvious qualifications as a screening method in the early diagnosis of acute venous thromboses, being far less expensive but never the less more suited for objective numerical analyses and evaluation than conventional thermography with scanning cameras.

Key Words:

• phlebography
• plethysmography
• skin temperature
• thermography
• venous thrombosis