ABSTRACTS PRESENTADOS AL 11th INTERNATIONAL SYMPOSIUM "RADIONUCLIDES IN NEPHRO-UROLOGY", REALIZADO EN MONTEREY, CALIFORNIA, 13-17 MAYO 2001.

SH Kim. YA Chung. IR Yoo, EN Kim, YH Park, SY Lee, HS Sohn, SK Chung

Department of Nuclear Medicine. The Catholic Unversity of Korea, Seoul, Korea

sghnk@cmc.cuk.ac.kr

The aim was to assess how the background site affects the Gates' glomerular filtration rate (GFR) measurement using Tc-99m-DTPA in correlation with GFR by 1-125-lothalamate method. The study populations were 63 adults with 39 men and 24 women aged from 20 to 59 yrs (mean = 37.9 yrs). The following five background regions of interest (ROI) were used in Gates' measurement of GFR: 1) ROIs drawn on lower of each kidney (subrenal R0I), 2) circumferential ROIs drawn around each kidney, 3) ROIs drawn on upper of each kidney (suprarenal ROIs). 4) semilunar ROIs drawn on the lateral side of each kidney (lateral ROI). 5) a single ROI drawn between the two kidneys (inter-renal). We also measured GFR using I-125-Iothalamate in each subject. The two studies were separated by 1 to 3 weeks. The subjects were divided into two groups by renal depth (RD). Group 1 with RD < 7 cm and group 2 with RD > 7 cm. We analyzed the correlation and differences between Gates' GFR and lothalamate GFR. The mean and standard deviation of the GFR measured by two studies are shows in Table I.

Table I.

Significant differences, *P<0.01. + P< 0.05 vs Iothalamate GFR

In correlating Gates' GFR to lothalamate GFR, the correlation coefficients in group I, range from 0.495 (P<0.01, subrenal ROI) to 0.570 (P<0.01, suprarenal R0I), in group 2, from 0.210 (P = 0.25, lateral R0I) to 0.288 (P = 0.11, intrerenal) in total, from 0.420 (P<0.01, lateral ROI) to 0.462 (P< 0.01, suprarenal ROI.

The results indicated that Gates' GFR measured by subrenal background correction overestimates the GFR measured by lothalamate, while the others underestimate lothalamate GFR. In the Gates' GFR measured by suprarenal background correction, the values were consistently lower than the others, and the best correlation with lothalamate GFR was obtained. The correlation between Gates' GFR and lothalamate GFR was found to be better in group 1.