Quantitative photoacoustic tomography of blood oxygenation enhanced by Monte Carlo modeling

We present a Monte Carlo-enhanced photoacoustic tomography (MC-PAT) system for quantitative three-dimensional mapping of tissue optical properties and blood oxygenation. Combining Monte Carlo light transport with finite-element acoustic inversion, the system achieved accurate absorption coefficient quantification (0.44 ± 0.02 mm−1, 1.85% deviation) and high spatial resolution (250 μm). In vivo pilot studies (n = 3) demonstrated reliable measurements (0.42 ± 0.02 mm−1, 2.78% deviation) and clear arteriovenous differentiation (arterial: 97.8 ± 0.8% sO2; venous: 74.5 ± 1.3% sO2) with 0.8% error vs pulse oximetry. MC-PAT shows potential for functional vascular studies and future clinical translation.