%0 Journal Article %A Kalpna Prasad %A Chad Adams %A Eiping Quang %A Derek Stocker %T The Effect of BMI on High versus Low Administered Activity Protocol MPI Scan Time Using a CZT Camera in Clinical Practice %D 2021 %J Journal of Nuclear Medicine %P 1643-1643 %V 62 %N supplement 1 %X 1643Objectives: Cadmium Zinc Telluride (CZT) crystal based myocardial perfusion imaging (MPI) cameras have increased count sensitivity compared to Anger cameras and can be used to lower either the injected activity or the image acquisition time. Institutions adopting CZT cameras need to decide whether to lower the injected activity or imaging time or attempt to lower both with a compromise. The aim of our study was to compare the time required to obtain similar count images using high activity protocol (HAP) versus lower activity protocol (LAP) stratified by body mass index (BMI) and assess the impact on our clinic workflow. Methods: Using a CZT camera, a cohort of 100 consecutive clinical patients imaged with LAP rest-stress MPI with approximately 185 MBq and 555 MBq activity was retrospectively compared to a similar cohort of 100 consecutive clinical patients that had undergone HAP MPI using approximately 370 MBq and 1,110 MBq. Results: Administered activity and BMI both had a statistically significant effect on scan time. HAP scans took an average of 9 minutes longer than LAP scans overall, p<.0001 and larger BMIs took longer than smaller BMIs, p<.0001. There was a steeper slope of increase in scan time as BMI increased in the LAP compared to the HAP. Conclusion: For the same CZT camera, the LAP increased scan time while lowering the radiation effective dose when compared to HAP. The increase in scan time increased proportionally to BMI, and the slope of increase was steeper in the LAP. This increase in time did not have a significant impact on our local workflow, but its implications should be considered in the setting of LAP implementation, especially in obese or high patient volume practices. %U