Validity of laser speckle contrast imaging for predicting wound healing potential in burns: A critical examination

Background: Accurate assessment of burn depth is imperative for the efficacious management of burns. Although clinical assessment is commonly used, its accuracy ranges only between 50 % and 70 %. Laser Doppler imaging (LDI) is considered as a gold standard - with an accuracy exceeding 95 %, - for the objective measurement of Healing Potential (HP), HP being the output of the LDI device, as colour-coded on LDI blood flow images. Despite its proven efficacy, widespread adoption is impeded by practical challenges. Laser Speckle Contrast Imaging (LSCI) emerges as a possible alternative. This study investigated the performance and accuracy of LSCI in comparison with LDI for predicting the HP of burns; LDI was assumed to provide 'ground truth' for the assessment of HP. Methods: Hospitalized burn patients underwent LDI and LSCI scans between day 2 and day 5 postburn. Analysis involved selecting corresponding regions of interest (ROI) in target wounds prioritized by LDI and LSCI perspectives. Results: In 19 patients, 112 ROI within LDI-priority ranges were collected from 50 target wounds. 130 ROI within LSCI-priority ranges were collected from 52 target wounds. Positive predictive values (PPV) were low, at only 50.8 % and 68.2 % for HP14-21 and HP21, respectively, and 86.9 % for HP14. Conclusion: Objective assessment by LSCI for burns is not recommended, as it fails to detect deep dermal blood flow, leading to an overestimation of burn severity and potential inadequacies in therapy.