Day-to-day variability in cutaneous microcirculation measured with multi-exposure laser speckle contrast imaging and...

Dysfunctional microcirculation is associated with cardiovascular risk factors, chronic disease such as diabetes and acute conditions like septic shock. The non-invasive optical techniques laser Doppler flowmetry (LDF) and diffuse reflectance spectroscopy (DRS) are often used to measure perfusion and oxygen saturation, but are limited to single-point measurements making them sensitive to spatial variations. The imaging modalities multi-exposure laser speckle contrast imaging (MELSCI) and multi-spectral imaging (MSI) overcome this limitation by capturing the parameters in a larger skin area.

To assess the day-to-day variability of speed-resolved perfusion and oxygen saturation in the forearm and plantar foot at baseline and peak response following arterial occlusion-release, while also evaluating sex and age influences.

MELSCI and MSI were used on 48 participants (12 males and 12 females aged 20-30, and 12 males and 12 females aged 50-60) across two measurements within a week. Each measurement lasted 60 min, with perfusion and oxygen saturation being measured at baseline (10 min), during occlusion (5 min), and post-occlusion (5 min) as spatial averages over the entire imaged tissue area.

Older age was associated with higher foot perfusion at peak (p = 0.006). Variability (CV) ranged from 1.4 % to 19 %, with foot low-speed perfusion showing a sex- and age-related difference at peak (p = 0.007).

Age and sex influenced microcirculatory parameters, aligning with prior research. MELSCI and MSI demonstrated low day-to-day variability, making them promising techniques for clinical disease monitoring. The variability of MELSCI perfusion was lower than previously reported for laser speckle contrast imaging (LSCI) perfusion.