[en] For the assessment of renal functional status, DTPA renography is widely used. Split function provides excellent information, but it has certain shortcomings especially in bilateral renal disease or in solitary kidney. This study demonstrates the importance of kidney to liver ratio as a functional parameter. In 65 patients, a total of 123 kidney were studied. Renographic studies were done after a bolus of Tc-99m DTPA. The kidney to liver ratios was calculated at 3 minutes (K3/L3). The ratios and renography curve patterns correlated well in 101 (82%) kidneys, both normal in 42 and both abnormal in 59 kidneys. Only 22 (18%) kidneys had discrepancies and among them 12 showed abnormal ratios but having normal renogram curves. The findings display the usefulness of K3/L3 ratio. The authors advocate that it is a good parameter for renal studies. (author) 9 refs., 3 tabs