Optimization of acquisition parameters of the test of an overall spect/ct system performance

Abstract

The purpose of this study was to present the process of optimizing of acquisition parameters of an overall SPECT/CT system performance test, which could be implemented in each nuclear medicine department. All measurements were performed with the use of Symbia T16 SPECT/CT system. The Jaszczak phantom with cold spheres provided for high-resolution gamma cameras was used. A series of SPECT/CT scans with different acquisition parameters were performed. The influence of the duration of a single projection, the number of projections and the size of acquisition matrix on the quality of the resulting image have been analyzed. All images were subjected to visual evaluation (uniformity and spatial resolution). Quantitative evaluation of image contrast was performed as well. Each SPECT image was evaluated with and without attenuation correction, but always with scatter correction. The proposed process of the evaluation of the parameters, that are crucial for the image quality in nuclear medicine, gave a possibility to identify the optimal acquisition parameters for considered test. Image, indistinguishable from the proposed reference, but acquired in the half of time (decrease from 32 min to 16 min, respectively), was obtained with the following parameters: 30 sec per projection, 64 projections and 128x128 matrix, regardless of the use of attenuation correction or not. Reduction of the duration of a single projection, and especially of the size of the matrix, significantly deteriorated image quality. On the other hand, an increase of the duration of a single projection over 30 sec did not bring any significant improvement of image quality, but increased the duration of the test. The methodology of optimization of acquisition parameters for an overall SPECT/CT system performance test has been presented for Symbia T16 SPECT/CT system in terms of time of a single acquisition and quality of the acquired images.