Tissue characterization by photographic imaging during treatment of chronic venous ulcer: technical note

Abstract

Chronic venous ulcers are a medical challenge with a socioeconomic impact. Tissue characterization was quantified by photographic imaging (p-CATIM) of a leg wound treated with Unna boot for 45 days. Three photographs, taken pre-treatment, post Unna boot and post healing were analyzed. Brightness on a 0-255 gray image was re-scaled with black as 0 and adjacent skin as 200. Gray Scale Median (GSM) and the percentages of pixels in each of 14 brightness intervals were calculated. Open ulcer GSM increased from 110 to 159 post Unna boot treatment, reaching 203 post healing. Predominant brightness intervals for the ulcer were 41-153 pre-treatment, 83% of pixels; 133-196 post Unna boot, 80%; and 175-255 post healing, 97%. The GSM of the subcutaneous wound around the ulcer increased from 117 to 137 post healing; the proportion of pixels in the 91-174 interval increased from 67% to 88% (p<0.001). CATIM quantified photographic changes during venous ulcer healing with comparison to the adjacent skin.