Effect of different kind of background correction on glomerular filtration rate measured by dynamic renal imaging with ~(99m)Tc-DTPA

Dynamic renal imaging studies were performed in 132 patients using 99m Tc DTPA and 131 I OIH. Effective renal plasma flow(ERPF) and glomerular filtration rate(GFR) was obtained. GFRs were calculated with 2 background regions of interest(ROI),conventional subrenal areas(SB) and suprarenal areas(SP). The relative renal functions(RR) obtained by GFRs determination was significantly higer compared with that by ERPF. These results suggested that the RR of impaired kidney determined by GFR(SB) was obviously higher than that assessed by ERPF. Higher coefficient( r value) was gotten with GFR(SP) than with GFR(SB).Results suggested that the GFR obtained with conventional subrenal background ROI might overestimate individual renal function of the poorly functional kidney and the GFR estimated by suprarenal background ROI might be more accurate.