Simultaneous Reconstruction and 3d Motion

of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy SIMULTANEOUS RECONSTRUCTION AND 3D MOTION ESTIMATION FOR GATED MYOCARDIAL EMISSION TOMOGRAPHY By Zixiong Cao December 2003 Chair: David Gilland Major Department: Biomedical Engineering A new method for simultaneous image reconstruction and wall-motion estimation in gated myocardial emission tomography (ET) is presented. We implemented the method using simulated phantoms and evaluated the performance of the method. To reduce the blur in the images induced by the heart motion, gated ET uses the patient’s electrocardiogram (ECG) to trigger and acquire a time sequence of image frames, each capturing a particular stage of the cardiac cycle. However, the individual gated image frames reconstructed by conventional image-reconstruction algorithms are very noisy due to the reduced counts of detected gamma rays. Non-rigid deformation of myocardium can be characterized by means of a vector field called the motion field, which describes the relative displacement of each voxel, and thus establishes a voxel-intensity correspondence between two image frames. Previous research incorporated a deformable elastic material model into a motion-estimation algorithm to more accurately describe the deformation of the myocardium. The estimated