• The Korean Journal of Nuclear Medicine
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• v.33 no.1
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• pp.57-64
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• 1999

Purpose: The purpose of this study was to evaluate the accuracy of Tc-99m DTPA diuretic renal scans in children with dilated upper urinary tract. Materials and Methods: We reviewed diuretic renal scans of 14 pediatric patients (age range: 3 days to 4 years) with unilateral hydronephrosis diagnosed by ultrasonography. Diuretic renal scan was done using Tc-99m DTPA and standardized protocol. In 3 neonates, diuretic renal scans were performed within 1 week and 3-7 months after birth. Results: Six patients required Pyeloplasty and eight were managed conservatively. All 6 patients requiring Pyeloplasty were diagnosed as having ureteropelvic junction obstruction in the diuretic renal scan. In these 6 patients, post-operative renal scans at 3-12 months after surgery were converted to nonobstructive pattern in 5 and a nonfunctioning pattern in 1. In 3 patients who underwent diuretic renal scan within 1 week after birth, nonobstructive patterns of initial scan were converted to obstructive patterns in the follow-up scan. However, all patients with nonobstructive diuretic renal scans performed after the neonatal period did well on serial ultrasonography and showed favorable clinical outcome without progression to obstruction. Conclusion: Tc-99m DTPA diuretic renal scan with standardized protocol is useful in assessing suspected ureteropelvic junction obstruction in children as an initial diagnostic or post-operative follow-up modality. Nonobstructive or indeterminate scan results in the neonatal period requires follow-up scan to monitor development of the obstructive pattern.

• The Korean Journal of Nuclear Medicine
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• v.17 no.2
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• pp.57-62
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• 1983

Diuretic renal scan, a modified method of conventional radionuclide renography by administration of intravenous furosemide was performed in 54 patients with suspected urinary tract obstruction. Two showed normal responses, 41 showed increased washout patterns, and the remainder 15 revealed no changes in response to the furosemide administration. IVP was done in 34 patients. In comparision to the diuretic renal scan, the following results were obtained. 1) Patients with normal results by the scan, showed normal IVP findings also. 2) 10 patients who showed delayed excretory patterns not influenced by the diuretics administration. 9 patients revealed obstructive lesions and hydronephrotic changes, and CPN was diagnosed for the remainder one and the one patient without obstruction was diagnosed as chronic pyelonephritis. 3) 22 patients showed positive results to the diuretics. Among them 10 patients had positive results in IVP. but, were not related to the speed of decrement of the renal activity after the furosemide administration.

• The Korean Journal of Nuclear Medicine
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• v.29 no.4
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• pp.497-503
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• 1995

We evaluated diagnostic accuracy of diuretic renal scan with standardization in 45 childrens(107 hydronephrotic kidneys) with 91 diuretic assessments. Sensitivity was 100%, specificity was 78%, and accuracy was 84% in 49 hydronephrotic kidneys with standardization. Diuretic renal scan without standardization, sensitivity was 100%, specificity was 38%, and accuracy was 57 % in 58 hydronephrotic kidneys. The false-positive results were observed in 25 cases without standardization, and in 8 cases with standardization. In diuretic renal scans without standardization, the causes of false-positive results were 10 early injection of lasix before mixing of radioactivity in pelvocalyceal system, 4 full bladder, 2 markedly dilated pelvocalyceal systems postpyeloplsty, 6 extrarenal pelvis, and 3 immature kidneys of neonates. In diuretic renal scans with standardization the causes of false-positive results were 2 markedly dilated systems postpyeloplsty, 2 extrarenal pelvis, 1 immature kidney of neonate, and 2 severe venal dysfunction, 1 vesicoureteral reflux. In diuretic renal scan without standardization the false-positive results by inadequate study were common, but false-positive results by inadequate study were not found after standardization. The false-positive results by dilated pelvocalyceal systems postpyeloplsty, extrarenal pelvis, and immature kidneys of neonates were not dissolved after standardization. In conclusion, diagnostic accuracy of diuretic renal scan with standardization was useful in children with renal outflow tract obstruction by improving specificity significantly.

• The Korean Journal of Nuclear Medicine
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• v.36 no.5
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• pp.306-313
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• 2002

Purpose: Diuretic renography (DR) can be false negative in patients with upper urinary tract obstruction due to low compliance of the renal pelvis. Delayed parenchymal transit (DPT) may be a valuable sign in case of false negative DR. We compared the diagnostic values of DR and DPT during Tc-99m MAG3 diuretic scan in adults with suspected unilateral obstructive uropathy. Materials and Methods: Fifty-four patients(male:female=30:24, age: $40.7{\pm}15.5$ yrs) who underwent Tc-99m MAG3 diuretic scan due to suspicious unilateral obstructive uropathy were analyzed. DR with a $T_{1/2}\;of\;>\;15min$ was considered as positive for obstruction. DPT was considered to be present when there was delayed appearance of radioactivity in the renal pelvis and prolonged retention of radioactivity in the renal parenchyma. The renal area ratio was defined as the ratio of pixel number of hydronephrotic kidney over that of normal contralateral at $1{\sim}2min$ images. Definition of obstruction was improved hydronephrosis after intervention, or aggravated hydronephrosis without intervention. Non-obstruction was defined as unchanged hydronephrosis over 6 months. Results: Twenty-six renal units had obstruction and 28 no obstruction. The sensitivities of DR and DPT were 69% (18/26) and 50% (13/26) respectively. Two renal units with DPT but negative DR showed the renal area ratio of <1.1. Among the 20 obstructive renal units with DPT or positive DR, 13 with DPT had lower renal area ratio than 7 renal units without DPT ($0.97{\pm}0.20\;vs\;1.30{\pm}0.41,\;p<0.05$). Differential renal function was not significantly different between these groups. DPT correctly diagnosed all renal units with non-obstruction (specificity 100%), while the specificity of DR was 89% (25/28). Conclusion: DPT during Tc-99m MAG3 diuretic scan may be a valuable sign in diagnosing urinary obstruction especially in patients with false negative DR and early HN.

• 대한핵의학회:학술대회논문집
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• 1988.05a
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• pp.133.2-134
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• 1988

• 대한핵의학회:학술대회논문집
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• 1985.05a
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• pp.176.2-176.2
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• 1985

• Clinical and Experimental Pediatrics
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• v.45 no.2
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• pp.223-231
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• 2002

Purpose : We review our experience with pyeloplasty for unilateral ureteropelvic junction obstruction of moderate to severe hydronephrosis observed by prenatal ultrasonography to assess the appropriate timing of operation for recovery of renal function and obstruction. Methods : We retrospectively reviewed the records of the total 28 patients who underwent pyeloplasty between 1995 and 2001 at Asan Medical Center. We compared pre and postoperative differentials in renal function and diuretic renogram as measured by technetium-99m-mercaptoacetyl-triglycerine scan and the degree of hydronephrosis by renal ultrasonography. Results : In all 28 patients postoperative follow-up renal ultrasonography revealed significant improvement in hydronephrosis. In 10 poorly functioning hydronephrotic kidneys in which relative renal function function was less than 35%, renal function was improved postoperatively in 3 cases, but not improved in 7 cases. In all 28 patients postoperative follow-up diuretic renogram revealed significant improvement. Conclusion : We believe that the early pyeloplasty should be considered when ultrasonography and diuretic renography suggest obstruction because renal function does not improve significantly after pyeloplasty over preoperative value.

• Clinical and Experimental Pediatrics
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• v.49 no.1
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• pp.64-70
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• 2006

Purpose : The natural courses of prenatally diagnosed hydronephrosis(HN) are diverse. Our purpose was to determine if the findings of renal ultrasonography(USG) in patients with prenatal HN at 1 month of age can predict the 1 year follow-up results and determine the guideline of follow-up study. Methods : Among 462 hydronephrotic patients registered between 1996 and 2004, 153 unilateral hydronephrotic renal units were enrolled in this study, bilateral HN, vesicoureteral reflux and other associated anomaly were excluded. These were classified into four groups respectively, according to anterior posterior pelvic diameter(APPD) or Society for Fetal Urology(SFU) grading by USG findings at 1 month after birth. Renal USG and $Tc^{99m}$-mercaptoacetyl triglycerine(MAG3) scan were done according to a set protocol. Results : Most cases improved or remained stationary. No one underwent an operation SFU grade 1,2 groups and only one case of SFU grade 3 group was operated. Thirty two cases(64 percent) were operated on among the 50 cases of SFU grade 4 group. 0/2(0 percent), 5/11(45.5 percent), 11/17(64.7 percent) and 16/20(80 percent) were operated on in each group with APPD <10, 10-19, 20-29, >30 mm, and the operation risk is higher as the APPD is increased. Conclusion : In group with SFU grade below 3 and APPD below 10 mm, we can delay the follow-up study beyond existing set protocol. Operations are recommended immediately if diuretic renogram show the obstructive pattern or decreased renal function in SFU grade 4 group with APPD over 10 mm.