Hyperspectral optoacoustic microscopy (OAM) enables obtaining images
with label-free biomolecular contrast, offering excellent perspectives
as a diagnostic tool to assess freshly excised and unprocessed
biological samples. However, time-consuming raster scanning image
formation currently limits the translation potential of OAM into the
clinical setting, for instance, in intraoperative histopathological
assessments, where micrographs of excised tissue need to be taken within
a few minutes for fast clinical decision-making. Here, we present a
non-data-driven computational framework tailored to enable fast OAM by
rapid data acquisition and model-based image reconstruction, termed
Bayesian raster-computed optoacoustic microscopy (BayROM). Unlike
data-driven approaches, BayROM does not require training datasets, but
instead, it uses probabilistic model-based reconstruction to facilitate
fast high-resolution imaging. We show that BayROM enables acquiring
micrographs 10 times faster on average than conventional raster scanning
microscopy and provides sufficient image quality to facilitate the
intraoperative histological assessment of processed fat grafts for
autologous fat transfer.