Determining the Optimal Dose of Radioactivity for Measuring Glomerular Filtration using Gate’s Method and Obtaining Renogram

Objectives: Measuring Glomerular Filtration (GFR) using Gate’s method gives low radioactivity of approximately 74~111 MBq to a patient. Such low counts on image acquisition degrade image quality. The objective of this study was to limit the amount of radioactivity needed to acquire high-quality dynamic renal images when measuring GFR. Methods/Statistical Analysis: We performed experiments with different radio activities at matrix size of 128 x 128 or other matrix sizes to check overflow phenomenon of gammaray. Findings: Ideal total count was at radioactivity of approximately 37 MBq. However, measured total counts from acquire images showed certain counting loss. The average margin of error was –1.88 ± 1.61%. The mean value of GFR according to the radioactivity at more than 370 MBq was –2.91 ± 1.19 %. We could calculate GFR by substituting these results in GFR formula under the same condition. The mean GFR value was –1.89 ± 1.62% at radioactivity of 37 MBq and –2.93±1.2 % at radioactivity of more than 370 MBq. Conclusion: High-quality functional image could be acquired at the same time by increasing radioactivity to 370 MBq with higher matrix size. Improvements/Applications: With these results, we can improve diagnostic ability and make more accurate evaluation of renal function.