Design and Emulation of a Multiple-Camera SPECT Breast Imager

摘要

The purpose of this study has been to design and emulate a multiple- camera dedicated SPECT breast imager. The scope of this study involved characterizing radioactivity within a human breast, building breast phantoms for imaging, modeling mean detector responses, optimizing the system geometry, collecting planar projection data, measuring detector performance for the task of detecting signals in random backgrounds, emulating the system point response function, and generating three-dimensional reconstructions of the radioactivity distribution within the breast phantoms. Major results have included estimated percentage of total injected activity taken up by one breast of average mass (0. 08%), estimated activity per unit mass of normal breast tissue (43 decays/ second), and estimated maximum relative uptake ratio (6:1). Human breast and torso phantoms were constructed. Camera responses were measured and accurately modeled, and the camera model was used to help design a prototype camera. Planar projection data of a breast phantom was collected, and the performance of a camera for the task of detecting lesions as a function of diameter and depth was measured, indicating that 1 O-mm diameter lesions were reliably detected at depths up to 6 cm. A significant problem was the failure of an essential computer system in Year 2.