Correlation of Facial Infrared Thermograph and Carotid Stenosis

Facial temperature distribution is affected by blood flow supply, which is compromised in carotid stenosis. Therefore we conducted a study to compare the parameters of infrared thermograph of face and the result of simultaneous carotid angiography. Totally 26 consecutive patients underwent carotid digital subtraction angiography and the patency of common, external, and internal carotid was measured according to the principle of North American Symptomatic Carotid Endarterectomy Trial . All the stenotic lesions detected were recorded as ECAS for external carotid stenosis, CCAS for common carotid stenosis, and ICAS for internal carotid stenosis. On the other hand, infrared thermograph of bilateral facial sides of the particiants was taken as well. Using a computerized programmatic strategy, the raw image data were processed to calculate the mean temperature and the standard deviation of each side of the 26 patients. In 52 samples (both sides of 26 patients)of this study, there are 29 (55.8%) CCAS, 25 ( 48.1%)ECAS, and 31 ( 59.6%)ICAS. The mean temperature of all 52 samples is 32.72 +/-1.19 degree Celsius, and the average standard deviation of all the samples is 2.01 +/-1.10 degree Celsius. The mean temperature of the ECAS group is significantly lower than that of non-ECAS group (32.33+/-1.03 versus 33.08+/-1.24degC, p=0.022), and the standard deviation of the facial temperature distribution is also lower in the CCAS patients (1.68+/-1.09 versus 2.31+/-1.04degC, p=0.037). In contrast, the ICAS group has the higher mean facial temperature (33.06 +/-1.02 versus 32.22 +/-1.28, p=0.012) (Figure 9), and higher standard deviation of the facial temperature distribution (2.27+/-1.12 versus 1.62+/-0.97, p=0.036) than the non-ICAS patients. The mean temperature and the standard deviation of facial infrared thermograph are significantly associated with carotid stenosis. Such an approach might give a light on the development of the fast screening method of carotid stenosis.