Optimal design of fan beam collimation for pixelated breast imaging systems

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 pixelated 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.