Paradoxical Hyperfunctioning Kidney on the Renal Scan in Patients with Ureteropelvic Junction Obstruction / 대한비뇨기과학회지

PURPOSE: We evaluated whether increased split renal function ratio (%) on the renal scan with Tc-99m diethylenetriamine pinta-acetic acid (DTPA) represent elevated renal function in the obstructed kidney. MATERIALS AND METHODS: From 1994 to 1995, we evaluated 36 patients with unilateral hydronephrosis due to ureteropelvic junction (UPJ) obstruction and split renal function ratios of the affected kidneys were calculated using Tc-99m DTPA renal scan. RESULTS: Of the 36 patients, 7 patients showed that split renal function ratios of the affected kidneys were all over 52%. To assess the significance of the split renal function ratio on the Tc-99m DTPA renal scan, we performed Tc-99m mercaptoacetyltriglycine (MAG3) renal scan with the time interval of 3 days and calculated the split renal function ratios of the affected kidneys on the MAG3 renal scan in all 7 patients. The split renal function ratios of the affected kidneys on the MAG3 renal scan were also higher than those of the normal kidney. And the split renal function ratios of the affected kidneys on the MAG3 renal scan were well correlated with those of DTPA renal scan (r=0.83). CONCLUSIONS: Our results suggest that the increased split renal function ratio in affected kidney due to UPJ obstruction is not an artifact of the DTPA renogram.

Comparison of Tc-99m MAG, and Tc-99m DTPA Renal Scans in Patients with Upper Urinary Tract Obstruction / 대한비뇨기과학회지

Tc-99m mercaptoacetyltriglycine (MAG3) is a new Tc-99m renal agent that is excreted by tubular function. To evaluate the efficacy of Tc-99m MAG3, renal scans with Tc-99m MAG3 and Tc-99m diethylenetriamine penta-acetic acid(DTPA) were performed in patients with upper urinary tract obstruction within the time interval of 3 days. Of the 36 patients 17 had ureteropelvic junction (UPJ) strictures, 5 had renal stones, 10 had ureteral stones, and 4 had ureterovesical junction (UVJ) strictures. The patient ages were ranged from 1 to 72 years and the numbers of male and female were 22 and 14, respectively. Split renal function ratio(%), time parameters and image quality using target to background ratio of the Tc-99m MAG, renal scan were compared with those of Tc-99m DTPA, in terms of age group (less than 16, 16 or more), obstruction site (UPJ or proximal to UPJ, distal to UPJ) and treatment pre-treatment, post-treatment state). The split rena1 function ratio(%) of Tc-99m MAG, was well correlated with that of Tc-99m DTPA (r=0.92). There was no statistically significant difference between time parameters of Tc-99m MAG, and Tc-99m DTPA. The image quality of Tc-99m MAG, was superior to that of Tc-99m DTPA (p<0.05). In conclusion, Tc-99m MAG, renal scan had a superior image quality to that of Tc-99m DTPA and correlated well with other Tc-99m DTPA parameters. Thus, Tc-99m MAG, renal scan may be considered to replace Tc-99m DTPA in the evaluation of patients with upper urinary tract obstruction.