Image reconstruction for diagnosis and prognosis of breast cancer using fluorescence measurements: Phantom studies

摘要

Fluorescence-enhance optical tomography is performed using (ⅰ) point illumination and point collection and (ⅱ) area illumination and area collection geometries in 3D. In both measurement techniques, an image-intensified charge-coupled (ICCD) imaging system is used in the frequency-domain to image near-infrared contrast agents. The experimental measurements are compared to diffusion model predictions in least squares form in the inverse problem. For image recovery for both area and point illumination geometries, an efficient gradient-based optimization technique based on the Penalty/modified barrier function (PMBF) method and the constrained truncated Newton with trust region (CONTN) method is developed. Targets in 3D were reconstructed from experimental data under two conditions of (ⅰ) perfect uptake (1:0, target to background ratio) and (ⅱ) imperfect uptake (100:1, target to background ratio). Parameters of absorption cross section due to fluorophore and lifetimes are reconstructed. The present work demonstrates that 3D fluorescence enhanced optical tomography reconstructions can be successfully performed from both point/area illumination and collection experimental measurements of the time-dependent light propagation on clinically relevant tissue phantoms using a gain-modulated ICCD camera.