Nuclide renal dynamic imaging for evaluating renal function in hydronephrotic kidneys with no image on intravenous urography and its significance

Objective To explore clinical value of dynamic renal imaging in evaluating renal function of obstructively hydronephrotic kidney with no image on intravenous urography (IVU) by technetium-99m diethylenetriaminepentaacetic acid (99Tcm-DTPA). Methods A total of 48 patients with unilateral chronic severely obstructive hydronephrosis with no image on IVU and with normal renal function in the other side were enrolled in this study. All of them were undergone 99Tcm-DTPA dynamic renal imaging to evaluate the function of the sick kidney before and one to two weeks after percutaneous renal puncture (nephrostomy) and 24-hour drainage. And, data were compared with chi-square test. Results Before nephrostomy, only 13 of 48 (27%) hydronephrotic kidneys had function, with an average glomerular filtration rate (GFR) of (47±6) ml/min. Thirty-five of 48 (73%) hydronephrotic kidneys had no function, with an average GFR of (17±5) ml/min. But, after nephrostomy, 19 of them (40%) had function, with an average GFR of (56±5) ml/min, and 29 had no function with an average GFR of (17±5) ml/min. Function of the 19 functioning kidneys obviously recovered to varied extent six to 12 months after treatment with conservative operation. Conclusions 99Tcm-DTPA dynamic renal imaging should be used to evaluate the function of severely obstructive hydronephrotic kidneys with no image on IVU, which can reflect its objective function, especially one to two weeks after nephrostomy in hypertonic hydronephrostic kidneys, and is better than IVU. Key words: Kidney function test;  Radionuclide imaging;  Urography;  Glomerular filtration rate;  Hydronephrosis