Optimal coded aperture patterns for improved SNR in nuclear medicine imaging

During a Nuclear Medicine project that called for the optimal design of a coded aperture we found that low-throughput masks do not always provide a Signal-to-Noise Ratio (SNR) advantage. In this paper, we present the simulations of the performance of some coded aperture patterns chosen from different families and compare the results with theoretical predictions. A general expression for the SNR and its particular form for different patterns are provided. The choice of the optimal pattern family is discussed with reference to the characteristics of the object to be imaged and in light of the effect of near-field artifacts. No-Two-Holes-Touching (NTHT) arrays based on Modified Uniformly Redundant Arrays (MURAs) proved to offer the best compromise between SNR performance and practical fabrication constraints.