IMAGING CHARACTERISTICS OF SCINTIMAMMOGRAPHY USING PARALLEL-HOLE AND PINHOLE COLLIMATORS

The purpose of the study is to investigate the imaging characteristics of scintimammography (SM) using parallel-hole (PR) and pinhole (PN) c ollimators in a clinical setting. Experimental data were acquired from a phantom that models the breast with small lesions using a low energ y high resolution (LEHR) PR and a PN collimator. At close distances, t he PN collimator provides better spatial resolution and higher detecti on efficiency than the PR collimator, at the expense of a smaller fiel d-of-view (FOV). Detection of small breast lesions can be further enha nced by noise smoothing, field uniformity correction, scatter subtract ion and resolution recovery filtering. Monte Carlo (MC) simulation dat a were generated from the 3D MCAT phantom that realistically models th e Tc-99m sestamibi uptake and attenuation distributions in an average female patient. For both PR and PN collimation, the scatter to primary ratio (S/P) decreases from the base of the breast to the nipple and i s higher in the left than right breast due to scatter of photons from the heart. Results from the study add to understanding of the imaging characteristics of SM using PR and PN collimators and assist in the de sign of data acquisition and image processing methods to enhance the d etection of breast lesions using SM.