Determination of glomerular filtration rate using a dual-detector gamma camera and the geometric mean of renal activity: Correlation with the Tc-99m DTPA plasma clearance method

Purpose: In this study, the authors studied the use of a dual-detector gamma camera to measure the glomerular filtration rate (GFR). Methods: Thirty-three patients with a wide range of renal function participated in this study. The GFR was measured using a dual-detector gamma camera by calculating the geometric mean of activity from each kidney and using an outline background. These results were compared with the GFR estimates obtained from Tc-99m DTPA plasma clearance using a multiple blood sample method. Results: Correlation was excellent between GFR estimated using the dual-detector gamma camera and GFR measured using the plasma clearance of Tc- 99m DTPA with multiple blood samples (r = 0.89). The correlation was especially strong in children younger than 13 years (r = 0.94). Conclusion: Measuring the GFR using a dual-detector gamma camera and calculating the geometric mean of renal activity yields relatively accurate results.