Performance Assessment of a Channel Multi-pinhole Collimator for Myocardial Perfusion Imaging with SPECT: A Monte Carlo Simulation

While conventional parallel-hole collimators are widely used in myocardial perfusion imaging (MPI) with SPECT, they are suboptimal in balancing the existing sensitivity-resolution compromise. Therefore, multi-pinhole collimation has been proposed to address the problem. In the present study, a channel multi-pinhole collimated SPECT scanner is modeled and then simulated using GATE Monte Carlo simulation. The multi-pinhole collimator comprises eight apertures. The material, diameter, and height of the apertures were assumed to be varying. A comparison with a conventional single-pinhole was also conducted. The results show that increasing the hole diameter leads to degraded spatial resolution for the multi-pinhole collimator. Compared to single-pinhole collimators, multi-pinhole collimators suffer from projection overlapping and thus deteriorated spatial resolution. The findings confirm that the channel multi-pinhole collimators outperform the single-pinhole apertures by providing much higher sensitivity at the expense of slightly lower spatial resolution and therefore would be the collimator of choice for MPI with SPECT.