Improving gamma camera imaging using parallel jagged hole collimator

Abstract

Single photon imaging still remains the most commonly used imaging method in nuclear medicine to date, usually employing a gamma camera furnished with a parallel hole (PH) collimator. Using this type of collimator implies that both the size of the field of view (FOV) and the sensitivity are invariant with the distance from the object plane. Otherwise, the spatial resolution is inversely proportional to the distance from the object plane.In the present study, a modified parallel hole design, i.e., the parallel jagged hole (PJH), is introduced with the aim to improve the relationship between the spatial resolution and the sensitivity of a standard PH collimator.Quantitative characteristics of three PJH test samples were assessed experimentally as well as by applying simulation with the help of the MCNP5 code and using analytical approximation. In addition, the overall qualitative imaging performance was evaluated with the help of a custom-built planar phantom. While the sensitivity of one of the PJH test samples was very close to that of the corresponding PH design, its spatial resolution appeared to be superior by some 5–12%. Another test sample that exhibited nearly identical spatial resolution to its reference PH design was found to have approximately 35% higher sensitivity.So far, the experimental results as well as the outcomes obtained by simulation and by analytical approximation were found to be in good agreement among them what suggests that proposed PJH design could improve the imaging quality beyond that of the standard PH collimator.