Chronic diabetic foot ulcer (DFU) is the most common diabetes related complication which imposes a substantial burden on patients and health care system. Lifetime risk for development of DFU is estimated to be as high as 25% (1, 2). Delayed healing of these ulcers will lead to hospitalization, intervening infection and lower-extremity amputation. Current practice considers 50% or more reduction in ulcer area within the first 4 weeks of ulceration as a robust predictor of the healing by week 12 (3). However, this method is subjective, inaccurate and causes delay of recognising the chronic wounds till week 4.
We report a framework for objective assessment and early prediction of the healing status of Diabetic foot ulcers. We conducted 12-week longitudinal investigation on the thermal images of the Diabetic foot ulcers and identified association of the plantar temperature pattern with healing status of the ulcers. Twenty-six inpatients and outpatients with type-I and II diabetes aged 30 and over who attended Austin-Health, Melbourne, Australia for the management of DFUs, were recruited in this study. Thermal images of neuropathic and neuro-ischemic diabetic foot ulcers were collected over 4 weeks with a follow up in week 12 and segmented into isothermal regions (as shown in Fig 1) to highlight a set of boundaries corresponding to the wound centre and peri-wound regions. Size of these regions were automatically measured and statistically analysed to differentiate between healing and chronic ulcer.
The results show significant association in the reduction of the isothermal area in week 2 with the healing of the ulcers (P=0.036). It was also observed that temperature of the region alone was not a strong predictor of the healing (P>0.05). The outcome of this study can be used for early prediction of the healing of DFUs to avoid further complications.