The use of thermography in early detection of tissue perfusion disorders in rats

INTRODUCTION: Tissue perfusion disorders can be present in various diseases and progress in the form of arterial ischemia or venous stasis with accompanying local changes in temperature. AIM: To use of thermography in the diagnostics of early periods of tissue perfusion disorders before the clinical symptoms occur. MATERIAL AND METHODS: Thirty-two male rats were used. After anesthesia the skin on lower limbs was shaved and femoral vessels of both sides were exposed. In 10 rats the left femoral artery was ligated, in 12 rats the left femoral vein was ligated and in the 10 remaining rats both left femoral vessels were ligated. Thermography of the limbs was performed before the vessels were ligated and after a period of 24 h. The pictures were taken every 5 s during 3 min. Before the measurement, the tissues were cooled down for 20 s with a 5°C water compress. The rate of temperature return to the limbs was evaluated. RESULTS: Statistically significant differences were observed after the 24-hour period on the thigh after the ligation of the vein, and on the shank and the foot after ligation of the artery. After the ligature of both vessels, statistically significant differences occurred immediately after their ligature within the thigh and shank and after 24 h on the foot. CONCLUSIONS: The results show that cameras with an accuracy of 0.05°C can be used to detect tissue perfusion disorders. The special diagnostic value is the ability to detect perfusion disorders before clinical symptoms occur.