Infrared Thermography as a Diagnostic Tool for Peripheral Artery Disease.

Abstract

The prevalence of peripheral arterial disease (PAD) is increasing worldwide. The ankle-brachial index (ABI) is considered the criterion standard of noninvasive screening, but it does have limitations. The present study aimed to clarify the clinical diagnostic potential of infrared thermography (IRT) compared with conventional noninvasive measurements for PAD. Patients were divided into two groups: the healthy control group (n = 93) and the PAD group (n = 164). Control participants had an ABI 0.9 to 1.4 and no former PAD diagnosis. The PAD group was divided into three subgroups based on ABI classifications and two subgroups based on toe pressure measurements. Investigators performed IRT using a standardized protocol with temperature measurements at five different foot sites. Differences in skin temperatures between feet were greater (P < .001) in the PAD group than in healthy controls. In general, mean foot temperatures were lower in the PAD group than in controls but did not differ significantly among PAD subgroups based on ABI classifications or toe pressure measurements. Infrared thermography effectively distinguished temperature differences between feet and thus might be diagnostically useful. However, because normal skin surface temperature varies among individuals, IRT alone cannot be recommended for evaluating PAD. However, it does have potential to provide additional information about circulation, subclinical infections, and the severity of vascular disease.