TY - JOUR T1 - Simulating reduced dose PET imaging to determine impacts on diagnostic image quality. JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 172 LP - 172 VL - 62 IS - supplement 1 AU - Robin Schroeder AU - Scott Leonard AU - Michelle Gruchot AU - Ryan Avery AU - Hatice Savas AU - Gary Dillehay Y1 - 2021/05/01 UR - http://jnm.snmjournals.org/content/62/supplement_1/172.abstract N2 - 172Objectives: Using smaller radiopharmaceutical doses for positron emission tomography (PET) imaging would be beneficial in lowering the radiation exposure to patients. However, reducing the given dose could impact the diagnostic quality of the images produced. Therefore, computer software reconstructions can be used to create images that simulate having given reduced radiopharmaceutical PET doses. The purpose of this study was to create PET images that simulate decreased injected doses to determine the effect on image quality and clinical confidence. Methods: Seventeen patients with recent 18F-FDG PET/CT scans were chosen to include in this study. These patients had varying amounts of disease. The patients also ranged in body mass index (BMI) from healthy, overweight, and obese. The patients’ PET data were first reconstructed in the standard manner to create images with 100% of the original dose. The data sets were then reconstructed to simulate having 75% and 50% of the original dose, creating 51 reconstructions in total. Each reconstruction was cleared of patient identifying information and randomly labeled as RD_01, RD_02, etc. The reconstructions were then reviewed by two expert readers. The radiologists scored the reconstructions using a 1 to 5 scale based on general image quality and basic clinical confidence. The scores were then grouped and averaged based on BMI ranges for each dose amount. Results: The overall scores of each BMI group for each reconstruction dose amount are shown in Table 1. The percent decreases from 100% of the dose to 75% and 50% doses for the average scores of each BMI range are shown in Table 2. Conclusions: As anticipated, reducing the simulated dose reduced both scored image quality and clinical confidence, with the largest decrease observed in image quality at the 50% dose level across all BMIs (11.8%). Scores for the 75% dose in the healthy and overweight BMI groups showed only a small reduction in clinical confidence (2.0%), indicating the potential for reducing the injected dose for these populations. The increased score in image quality at 75% of the dose for the overweight BMI group (-4.2%) skews the result of the overall decrease in image quality (1.9%). However, the small reduction in image quality at the 75% dose for the healthy BMI group demonstrates the potential for a decreased injected dose in this population. Additional readers and a larger sample of exams that includes a variety of disease burdens will be needed to refine and clarify these findings before a reduction of clinical 18F-FDG doses can occur. ER -