Korean Journal of Urology (대한비뇨기과학회지), Vol.42(9) : 889~893, 2001
Purpose: Although ultrasonography and diuretic renography are routinely performed for evaluation of ureteropelvic junction obstruction, no reported studies have systemically investigated the correlation of the two methods. We investigated the correlation and values of the two methods.Materials and Methods: We studied 44 patients who presented with unilateral hydronephrosis due to ureteropelvic junction obstruction from 1994 to 1999. Patients were evaluated with ultrasound and nuclear renograms with furosemide. Hydronephrosis grade on ultrasonography and the severity of obstruction on diuretic renography were in accordance with the SFU (Society for Fetal Urology) system and "The Well Tempered Renogram", respectively.Results: 27 patients showed grade III hydronephrosis and the remaining 17 patients showed grade IV hydronephrosis on ultrasonography. Kidneys of grade IV hydronephrosis had poorer washout patterns on diuretic renography than those of grade III hydronephrosis (p＜0.001). In regard of mean split renal function ratios, there was no statistically significant difference between two groups (p＞0.05). In 37.0% (10/27) and 47.1% (8/17) of patients with grade III and grade IV hydronephrosis, hydronephrotic kidney had a differential function greater than 50%.Conclusions: Our study suggests that diuretic renography is not always indicated in the patients with grade IV hydronephrosis, but, must be performed to confirm the severity of obstruction in the patients with grade III hydronephrosis.