Can Thermal Imaging Technique be Used to Predict the Healing Status of a Venous Leg Ulcer?

Venous leg ulcers (VLUs) are the most common chronic wound types in older populations, with many wounds not healing in the normal trajectory. Many older people with wounds are treated in their homes, currently assessed by monitoring the wound area over weeks to ascertain the potential for healing. A noncontact method using thermal imaging has been shown to predict the healing trajectory of diabetes-related foot ulcers, although has not been tested in VLU or the home setting. This project investigated the effectiveness of using thermal imaging to predict VLU healing in the homes of participants. Images of 78 ulcers were collected weekly using a thermal camera from 67 participants in their homes, at 5 consecutive time points. Final follow-up calls were undertaken at 12 weeks to ascertain healing status (healed/unhealed). Images were preprocessed and segmented and the area of the region of the wound was extracted. Kruskal-Wallis tests were performed to test the association of the change of areas over the 5 consecutive weeks with the healing status of the ulcers at 12 weeks. The 95% confidence interval plots were obtained to study the distribution of the area in the healed and unhealed cases. This study found that the difference in the imaged areas between unhealed ulcers at 12 weeks did not reach statistical significance using thermal imaging. Therefore, thermal images could not predict healing progression in VLUs when the images were taken in the homes of participants. Future research to improve the prediction of venous leg ulcer healing should include developing a protocol to standardize conditions, improve imaging process methods, and use machine learning.

Thermal imaging potential and limitations to predict healing of venous leg ulcers.

Area analysis of thermal images can detect delayed healing in diabetes foot ulcers, but not venous leg ulcers (VLU) assessed in the home environment. This study proposes using textural analysis of thermal images to predict the healing trajectory of venous leg ulcers assessed in home settings. Participants with VLU were followed over twelve weeks. Digital images, thermal images and planimetry of wound tracings of the ulcers of 60 older participants was recorded in their homes by nurses. Participants were labelled as healed or unhealed based on status of the wound at the 12th week follow up. The weekly change in textural features was computed and the first two principal components were obtained. 60 participants (aged 80.53 ± 11.94 years) with 72 wounds (mean area 21.32 ± 51.28cm2) were included in the study. The first PCA of the change in textural features in week 2 with respect to week 0 were statistically significant for differentiating between healed and unhealed cases. Textural analysis of thermal images is an effective method to predict in week 2 which venous leg ulcers will not heal by week 12 among older people whose wounds are being managed in their homes.

The impact of providing product funding for compression bandaging and medical footwear on compression use, wound healing and quality of life.

A study conducted in an Australian home nursing service sought to ascertain whether the provision of funding for compression bandaging and medical footwear would impact on compression therapy use, wound healing and quality of life (QoL) among people with venous leg ulcers. Clients (n = 120) were randomly allocated to evaluation funded or not evaluation funded groups, the former provided funding for compression bandaging and medical footwear. Outcome measures included the number of wounds healed, healing rate, compression use and QoL. Analysis included ttests and Kaplan-Meier Survival Analysis. An alpha level of 0·05 classified findings as significant. There were no significant differences between groups for rate or time to healing, wounds healed or compression use. The evaluation funded group were significantly more likely to receive medical footwear. Those with confirmed diagnosis and who received multilayer bandaging, irrespective of group, achieved healing rates significantly higher than those who wore other compression therapy. Factors other than cost intervened with the capacity to evaluate the impact of wound product subsidisation. Further exploration of how to best promote evidence-based practice and future research to evaluate clinically and cost-effective wound treatments in a range of health care settings is required.