A simplified determination of glomerular filtration rate with 99Tcm-DTPA.

Using 99Tcm-diethylenetriaminepentaacetate (DTPA) an acceptable estimate of glomerular filtration rate (GFR) can be obtained in adult patients by the equation GF (ml/min) = (0.14 x W + 5) x 1000 x k, where W is the 'ideal' body mass (kg) and k the slope determined by two plasma samples. This has been verified in comparison with the results of the Russell (two samples) and Christensen (one sample) methods in 50 patients. The procedure, which does not require determination of the injected dose, could be useful in patients undergoing sequential renal scintigraphy with 99Tcm-DTPA, for example, to check a doubtful value of glomerular filtration obtained by external counting.