Optimal design of fan beam collimation for pixelated breast imaging systems

Abstract

In SPECT the collimator optimization is crucial to obtain a maximized sensitivity for a fixed resolution. In this work we present one approach to optimize convergent collimators for pix elated imaging systems.An optimization algorithm was developed and used to optimize a matched fan beam collimator to image the entire breast and chest wall region. The range of input parameters used to calculate the optimal collimator dimensions was defined using data from patient studies for dual-head scintimammography systems.Results showed that the optimal fan beam collimator thickness is approximately constant from the center to the edge, as well the hole diameter and the septal thickness in both directions.Designed optimal collimators for pixelated breast imaging systems have an increased sensitivity for the upper holes, allowing a good detection in the chest wall region.

Optimization of convergent collimators for pixelated SPECT systems

“…Such collimators generally weigh more than permitted by standard camera gantries, and thus, optimizing collimators for high energy applications has become a well-known challenge in nuclear medicine. 16 In this paper, we extend our previous initial work on low energy convergent collimator optimization 17 and propose an optimization method for high energy applications where the weight limit or the desired septal penetration can be used as input parameters. These high energy collimators could be used to image radioisotopes such as 131 I (364 keV) and positron emitter radioisotopes (511 keV), which are used in tumor quantification studies 18,19 and in simultaneous dualisotope ( 99m Tc and FDG) SPECT imaging, 20, 21 respectively.…”