Simulation of light absorption in tumor-embedded uterus filled with strong scattering media by diffused light sources

摘要

Photoacoustic imaging (PAI) is a promising technique to image tumor angiogenesis development and detect endometrial carcinoma in earlier stages. The light absorption distribution of uterine tissue determines the imaging depth and range of PAI. In this work, a 3D triangular meshes tumor-embedded uterine optical model was established by the histological structure of uterus. The model is filled with strong scattering media (undiluted raw and homogenized milk, URHM) and air, respectively. Monte Carlo simulation is implemented based on the molecular optical simulation environment (MOSE) to find the absorption profiles of photons by transcervical laser illumination with cylindrically diffused light source (CDLS) or spherically diffused light source (SDLS) at wavelength 800nm. The results show the media with an extremely high scattering coefficient and an extremely low absorption coefficient like URHM helps the light propagations in a relatively small cavity. CDLS performs better when the tumor happens far from the light source center than the SDLS. On the same time, embedded tumors of the model filled with URHM are easier to detect by the transcervical laser illumination of CDLS than SDLS in the fundus of the uterus. The conclusions are helpful to optimize the laser source and to improve the imaging depth in a photoacoustic imaging system.