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

Abstract

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. 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 8days 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 %). 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). 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.