Simulation study of ultrasound-modulated optical tomography

Monte-Carlo modeling technique was used to simulate the ultrasound-modulated optical tomography. The difference between absorption and scattering objects was compared. Simulation result indicated that this technique is sensitive to object absorption property, while the scattering properties have less effect on the output AC/DC signal intensity. It was also demonstrated that inhomogeneity and the background optical properties of the scattering medium could change the AC/DC value. The signal-to-noise ratio problem in the experiment is carefully analyzed. The major noise source is the speckle noise caused by the small particle movement within the tissue sample. The decorrelation time of the speckle pattern was measured in the tissue sample. In order to reduce the speckle noise, the data acquisition time must be less than the speckle decorrelation time