filters effect on image quality of 177lu-dotatate spect images for neuro-endocrine tumors canning

Purpose: the quality of the image in spect scans depends on the imaging parameters which are determined experimentally in the field of nuclear medicine. designing a dedicated scanning parameter for 177lu-dotatate spect images is required to optimize reconstruction. therefore, this study aims to evaluate the effect of different filters on image quality for bone spect scanning using 177lu-dotatate.materials and methods: the filtered back-projection reconstruction method was used in neuro-endocrine tumor scanning using 177lu-dotatate. three hours after injection of 177lu-dotatate, spect scans from 177lu-dotatate for 30 patients were acquired using a dual-head evoexel detector system. seven parameters were considered, including the contrast/noise ratio, injection activity, uptake duration, acquisition time per injection, frame time, measuring time, and type of filters.results: in all cases, the application of different filters increased contrast to noise ratio (cnr) (9.1%, 1.8%, 10.9%, 61.8%, 23.6%, 29.1%, and 58.2% for wiener, butterworth, parzen, metz, ramp, shepp-logan, and hamming filters, respectively). the percentage of increase in signal-to-noise ratio (snr) was 3.3%, 1.7%, -24%, 21.7%, 9.8%, 11.9%, and 20.6%.conclusion: based on the quantitative analysis of the results, the application of the metz filter (power 2) and hamming filter (with 0.27, 0.47, and 0.67 cut-off frequencies) on spect scans of neuro-endocrine tumors is recommended because of their capacity to provide high-quality images.