Reliability and Reproducibility of Laser Speckle Contrast Imaging for Assessment of Superficial Perfusion in Patients...

Background/Objectives: Healthy macrovascular and microvascular circulation is essential for wound prevention and healing in high-risk feet. While validated methods of assessing lower limb macrocirculation exist, microcirculation assessment often relies on subjective clinical judgement. This study aimed to determine reliability and reproducibility of laser speckle contrast imaging (LSCI) of superficial circulation in the feet of adults attending a high-risk foot clinic. LSCI was undertaken on seven regions of the foot, and then repeated 3-5 min later. Methods: LSCI measures were compared to health and clinical measures using correlations, t-tests or ANOVA, as appropriate, and intra-class correlation coefficients (ICC) used to analyse reliability measures. In a sample of 31 participants, good test-retest reliability was found (3-5 min apart), with ICC from 0.94 (95% CI 0.76-0.98) to 0.99 (95% CI 0.96-0.99). Results: A sub-group of 10 participants were available to test reproducibility one week later, with Cronbach's alpha ranging from 0.83 to 0.97. Lower LSCI perfusion measures were significantly related to longer ulcer duration, use of a walking aid, and presence of respiratory disease or previous cerebro-vascular accident. Conclusions: These findings support the potential role of LSCI as a non-invasive method to evaluate superficial perfusion in high-risk feet.