Reproducibility of high-resolution laser speckle contrast imaging to assess cutaneous microcirculation for wound healing monitoring in mice.

OBJECTIVE:Laser speckle contrast imaging (LSCI) combines an excellent spatial and temporal resolution, with excellent reproducibility in humans. Recently, high-resolution LSCI (LSCI-HR), coupled or not with oximetry, have been marketed. They are promising approaches to assess wound healing, especially in rodents. However, their reproducibility and performance against a reference technique remain unknown. METHODS:Healthy skin perfusion was evaluated at day 0 and repeated at day 2, using LSCI-HR, high-resolution LSCI with oximetry by reflectance spectrometry (LSCI-OX), compared with laser Doppler imaging (LDI) as a reference. In a second experiment, cutaneous perfusion was measured daily during 8 days after wounding at two different sites. The reproducibility of haemoglobin oxygenation with LSCI-OX was also assessed in the two experiments. Reproducibility was expressed as within-subject coefficients of variation (CV, in %). RESULTS:The inter-day reproducibility of healthy skin perfusion was better when assessed with LSCI-HR and LSCI-OX, compared to LDI (CVs between 12 and 17% and between 26 and 29%, respectively). Inter-site reproducibility of perfusion during wound healing was also better with LSCI-HR compared to LDI (CV = 12% and 23%, respectively). Finally, we observed a good, positive correlation between perfusion measured with LDI and LSCI-HR on the periulcer area (average r = 0.77 ± 0.24). CONCLUSION:Recently developed high-resolution LSCI devices provide good reproducibility to assess healthy and wounded skin perfusion in mice. However, the reproducibility of haemoglobin oxygenation is poor.