Evaluation of a method for medical exposure optimization studies in nuclear medicine

Nuclear medicine (NM) diagnostic procedures use ionizing radiation and it is necessary to ensure that the amount of prescribed activity is as low as reasonably achievable. Optimizing these procedures, one of the greatest challenges facing Nuclear Medicine today, is based on achieving a balance between image quality and radiation dose. The objective of this article is to establish and validate a method for optimization studies of medical exposure in NM simulating different levels of activity that can be applied in patients without violating the ethical and radiological protection principles. The method is based on the recombination of data obtained in gated acquisitions to simulate activity levels. For this, measurements were made using different phantoms and a signal generator. A Python code was developed that allows the different activity levels to be simulated automatically from a single gated acquisition and returns the studies in the same dicom format to be reconstructed in the registered processing program provided by the manufacturer. To validate our method, the linear dependence of the number of total counts with the simulated activity levels was demonstrated and the quality of the reconstructed images vs the simulated activity levels was qualitatively evaluated. This method constitutes a valid and applicable proposal in the majority of nuclear medicine services in the country to implement optimization procedures for SPECT studies, contributing to a reduction in population exposure to radiation, due to high-tech diagnostic tests.