Acquisition of Priori Tissue Optical Structure Based on Non-rigid Image Registration

Shape-parameterized diffuse optical tomography (DOT), which is based on a priori that assumes the uniform distribution of the optical properties in the each region, shows the effectiveness of complex biological tissue optical heterogeneities reconstruction. The priori tissue optical structure could be acquired with the assistance of anatomical imaging methods such as X-ray computed tomography (XCT) which suffers from low-contrast for soft tissues including different optical characteristic regions. For the mouse model, a feasible strategy of a priori tissue optical structure acquisition is proposed based on a non-rigid image registration algorithm. During registration, a mapping matrix is calculated to elastically align the XCT image of reference mouse to the XCT image of target mouse. Applying the matrix to the reference atlas which is a detailed mesh of organs/tissues in reference mouse, registered atlas can be obtained as the anatomical structure of target mouse. By assigning the literature published optical parameters of each organ to the corresponding anatomical structure, optical structure of the target organism can be obtained as a priori information for DOT reconstruction algorithm. By applying the non-rigid image registration algorithm to a target mouse which is transformed from the reference mouse, the results show that the minimum correlation coefficient can be improved from 0.2781 (before registration) to 0.9032 (after fine registration), and the maximum average Euclid distances can be decreased from 12.80mm (before registration) to 1.02mm (after fine registration), which has verified the effectiveness of the algorithm.