Reproducibility of Thermal Images: Some Healthy Examples

Thirty participants with healthy feet were imaged in the same way on two separate occasions (an average of 4 weeks apart). Overall, feet were found to be thermally symmetric although absolute temperature could vary considerably between visits. Temperature differences at specific sites on the foot sometimes exceeded the threshold of 2.2 °C regarded as clinically significant when looking for evidence of inflammation prior to skin breakdown in diabetes. At least one site exceeded this threshold in nine (30%) participants (the same figure for both visits). However, when looking for significant thermal asymmetry it is important to rule out transient changes by repeated imaging and to refer to baseline images.