Non-invasive optoacoustic imaging visualizes exercise-induced dermal revascularization in obese mice

Microcirculatory dysfunction in dermal (dWAT) and subcutaneous white adipose tissue (scWAT) of obese humans may predict cardio-metabolic disease progression. In-vivo visualization and monitoring of microvascular remodeling in these tissues remains challenging. We compared performance of multi-spectral optoacoustic tomography (MSOT) and raster-scanning optoacoustic mesoscopy (RSOM) in visualizing lipid and hemoglobin contrast in scWAT and dWAT of diet-induced obese (DIO) mice undergoing voluntary wheel running. MSOT quantitatively visualized lipid and hemoglobin contrast in fat depots at early stages of DIO. RSOM precisely visualizes microvasculature with quantitative readouts of skin layer thickness and vascular density in dWAT and dermis. Combination of MSOT and RSOM resolved exercise-induced morphological changes in microvasculature density, tissue oxygen saturation, lipid and blood volume content in dWAT and scWAT. Combination of MSOT and RSOM precisely monitor microcirculatory dysfunction and intervention response in dWAT and scWAT of DIO mice. Our findings lay out the foundation for future clinical studies using optoacoustic-derived vascular readouts from adipose tissues as a biomarker for monitoring microcirculatory function in cardio-metabolic disease.