RESUMO
<p><b>OBJECTIVE</b>To study the actual glomerular filtration rates (GFR) in patients with nonfunctioning kidneys as shown by intravenous pyelography (IVP) using single photon emission computed tomography (SPECT) dynamic renal scintigraphy and dual-plasma sample clearance method.</p><p><b>METHODS</b>We retrospectively analyzed 107 patients with nonfunctioning kidneys shown by IVP who underwent renal dynamic 99Tcm-DTPA SPECT imaging. GFR was measured by Gates' methods (GFRGates') and dual-plasma sample clearance method (GFRdual-plasma). Based on the dynamic functional images and GFRdual-plasma measurements, the patients were categorized into mild renal impairment (GFRdual-plasma≥30 mL/min), moderate renal impairment group (GFRdual-plasma of 20-30 mL/min), severe renal impairment group (GFRdual-plasma of 10 to 20 mL/min), and nonfunctioning kidney group (GFRdual-plasma≤10 mL/min), and GFRGates' were compared among the groups.</p><p><b>RESULTS</b>According to GFRdual-plasma, the numbers of patients having mild, moderate, and severe renal impairment and nonfunctioning kidneys were 12(11.2%), 33(30.8%), 41(38.3%), and 21(19.6%), respectively. GFRdual-plasma and GFRGates' were not significantly different in mild and moderate renal impairment groups, but in patients with severe renal impairment, GFRdual-plasma was significantly lower than GFRGates' (13.9∓6.2 vs 18.8∓4.2 mL/min; t=-2.73, P=0.03), which was also the case with patients with nonfunctinging kidneys (4.5∓2.1 vs 7.2∓3.2 mL/min; t=-3.81, P=0.005).</p><p><b>CONCLUSION</b>Of the patients with nonfunctinging kidneys shown by IVP, only 58% of them actually have severe renal impairment or worse, and further SPECT dynamic renal scintigraphy is necessary to assess the actual risk of renal function impairment before operation.</p>