Clinical application of normalized residual activity as a semiquantitative adjunct in assessing renal emptying in pediatric diuretic scans

Background@#The most recent pediatric diuretic imaging guidelines recommend the use of normalized residual activity (NORA) as a semiquantitative index of renal tracer drainage. It is defined as the ratio of post-void renal counts to 1-2 minute post-injection renal counts, with values less than 1 indicative of good drainage. We present two instances where NORA calculation was adjunctive in the evaluation of obstructive uropathy. @*Case Presentation@#The first patient was a 3-month-old male with left-sided congenital hydronephrosis. On dynamic imaging, the diseased kidney showed adequate perfusion and parenchymal extraction; moderate to severe pelvicalyceal tracer retention exhibited good response to diuretic. The pre-diuretic NORA of 1.62 declined to 0.28 after furosemide challenge, concordant with imaging findings that were negative for obstruction. The second patient was a 7-week-old male, also with congenital hydronephrosis of the left kidney. Dynamic images showed the diseased kidney with diminished perfusion and function, as well as pelvicalyceal tracer retention which became more severe after the diuretic was given. The pre-diuretic NORA was 1.81, which became 1.18 post-diuretic. This inadequate decline supplemented imaging findings pointing to significant obstruction. Other semiquantitative parameters have preceded NORA; however, clearance half-time is not validated as a marker of obstructive uropathy in infants and children, and output efficiency requires specialized software to calculate. Standardization of NORA determination is largely provided for by the guidelines recommending a perirenal background region of interest, as well as minimizing the interval between starting camera acquisition and injecting the tracer. @*Conclusion@#Semiquantitative analysis through NORA calculation gives relevant supporting information in the reporting of renal tracer drainage among pediatric patients. Further studies are needed to ascertain its applicability among adults and its diagnostic value in a larger sample of affected Filipino children.

Initial observational management of hydronephrosis in infants with reduced differential renal function and non-obstructive drainage parameters.

INTRODUCTION: Hydronephrosis secondary to ureteropelvic junction (UPJ) obstruction is a common finding in infants with prenatally-diagnosed hydronephrosis and often results in pyeloplasty due to obstructive drainage parameters and/or renal function compromise. However, little is known regarding the natural history of hydronephrosis with reduced differential renal function (DRF) but non-obstructive drainage. OBJECTIVE: We sought to explore our experience with initial observational management of these patients. STUDY DESIGN: A retrospective review of our institutional database of all diuretic MAG-3 renal scans obtained between 2000 and 2016 was performed. We included patients with antenatally-detected unilateral hydronephrosis ≥ SFU grade 2, first MAG-3 scan prior to 18months of age, DRF <40% and post-furosemide half-time (T1/2) <20 min. Exclusion criteria were: hydroureter, VUR, solitary kidney, duplication anomalies. Outcomes of interest were a progression of T1/2 ≥ 20 min and/or further decline in DRF >5%. RESULTS: Of 704 patients with unilateral hydronephrosis, 91 had DRF≤40%, of which 29 (18 boys, 11 girls) met our inclusion criteria and were followed for a mean of 2.8 years (1.4 months-6.6 years). Mean age at first sonogram was 2.3 months. 2 patients had SFU grade 2, 16 had grade 3, and 9 had grade 4 hydronephrosis, and 2 unknown grade. Median half-time on initial MAG-3 scan across all patients was 10 min (3-20 min). Initial MAG3 scan was performed at a median of 2.3 months of age (0.3-17 months). 22/29 patients had >1 MAG3 scan. Of the 7 remaining, 5 were lost to follow-up and 2 demonstrated improvement in hydronephrosis. Worsening drainage occurred in 10/22(45%), median final T1/2 was 45.5 min 8 of these underwent pyeloplasty and 2 were lost to follow up. 4/22 patients (18%) had progressive decline in DRF (mean 8.3%, range 6-10%). 3/4 maintained non-obstructive drainage patterns and stable/improved hydronephrosis, and 1 underwent pyeloplasty. 13/18 remaining patients had stable DRF and 5 had improvement in DRF. 7(39%) of these underwent surgery for worsening drainage (Summary Figure). Overall, 7/29(24%) patients had sufficient resolution of hydronephrosis to be discharged from our care, 8(28%) are under continued observation, 9(31%) underwent pyeloplasty, and 5(17%) were lost to follow-up. In the observational group [median follow-up 4.5 years (3.7-6.6 years)], all 8 demonstrated improved non-obstructive drainage (T1/2 <20 minutes) and/or improvement in hydronephrosis. 4/10(40%) with DRF <35% underwent pyeloplasty versus 5/19(26%) with DRF 35-40%(p=0.67). CONCLUSION: Initial observational management of unilateral hydronephrosis with reduced DRF and nonobstructive drainage is recommended as most kidneys maintain nonobstructive drainage and do not demonstrate further decline in DRF. Even when DRF decreases, the majority remain non-obstructive. Worsening drainage over time more often leads to the decision for pyeloplasty rather than change in DRF.

Diuretic Enhanced Ultrasonography in the Diagnosis of Pyeloureteral Obstruction.

Background and Objectives: To determine the value of diuretic ultrasonography for the diagnosis of obstructive hydronephrosis. Materials and Methods: Diuretic enhanced ultrasonography was used routinely as a part of examination of patients with hydronephrosis in our Department. There were 72 patients (42 males, 30 females; aged 2 months to 17 years; median age 7.07 years) with a sonoscopic diagnosis of hydronephrosis included from January 2006 until October 2011. The anteroposterior diameter (AD) of renal pelvis was measured sonoscopically before and at sixty minutes after furosemide injection. A weight-adjusted dose of 1 mg/kg of furosemide was administered intravenously. Results: Patients were operated on if pyeloureteral obstruction was suspected because of low or deteriorating differential renal function, increasing hydronephrosis or symptoms thereof. Hydronephrosis was unilateral in 61 (84.7%) and bilateral in 11 (15.3%) patients. The median AD of pelvis before furosemide injection was 22 mm in operated and 17 mm in non-operated patients (p = 0.005). Sixty minutes after furosemide injection, the AD of pelvis in operated patients was 35.5 mm and 25.8 mm in non-operated-25.8 mm (p < 0.001). Logistic regression model demonstrated that significant factors for surgery were: AD 60 min after furosemide infection and ultrasonographic parenchymal sclerosis. Conclusion: Ultrasound measurement of the AD of renal pelvis 1 h after the injection of furosemide used as an additional investigation can help in predicting obstructive hydronephrosis.

Analysis of long-term follow-up results of conservative treatment of children with unilateral UPJO / 中华泌尿外科杂志

Objective This study was a retrospective analysis of the efficacy of conservative treatment of unilateral renal pelvic ureteral junction obstruction with good renal function at the time of initial diagnosis.Methods The clinical data of 101 children with unilateral pelvic ureteral junction obstruction from January 2008 to December 2017 was analyzed retrospectively.All the patients underwent non-surgical treatment.There were 67 males and 34 females.The age range is from 10 days to 10 years old,with an average age of 3.4 years.52 cases got left side obstruction and 49 cases got the right side obstrction.14 children had abdominal pain symptoms.Among the 37 neonates:21 male,16 female.15 were left,22 were right.10 cases were found during prenatal pregnancy,and 27 were dignosed postpartum.The indication for conservative treatment is no hydronephrosis-related symptoms or normal renal function at the initial diagnosis.The hydronephrosis did not affect the child's breathing,growth and development.The B-ultrasound was done every 1 to 6 months which depended on the different grades of hydronephrosis during a conservative observation period.The diuretic radionuclide imaging was done every 6 to 12 months.The end point of follow-up was surgery or disappear of the hydronephrosis in the affected side.Surgical indications are symptoms of hydronephrosis during follow-up which affecting growth and development,renal function reduction ＞ 10％,hydronephrosis SFU,UTDP grade progressive increase.Among them,3 cases were raised from SFU2 to SFU3,17 cases were raised from SFU3 to SFU4;4 cases of neonatal UTDP2 progressed to grade 3 hydronephrosis and UTDP3 increased in 5 cases.Regression of hydronephrosis test three consecutive urinary renal ultrasound was defined as no hydronephrosis in.Results Continuous follow-up ranged from 1 year to 5 years,a median follow-up is 37 months.Of the 101 patients,41 (40.5％) required surgery,and 60 (59.5％) kept conservative follow up.2 cases of SFU1 children with hydronephrosis spontaneously disappeared.Of the 26 SFU class 2 children,15 (69.2％) spontaneously resolved,7 (30.7％) improved,and 4 underwent surgery.Of the 50 children with SFU grade 3 hydronephrosis,11 (22.0％) spontaneously resolved,19 improved or remained unchanged,and 20 patients eventually underwent surgery.Of the 23 patients with SFU grade 4 hydronephrosis,6 (26.0％) improved (to SFU 2) and 17 (73.9％) underwent surgery.37 of the 101 children were enrolled in the neonatal group for SFU grading while performing UTDP grading.Twenty-seven (70.2％) of the 37 neonates underwent conservative treat ment,including 8 (100.0％) UTDP grade 1 hydronephrosis,8(66.7％) UTDP grade 2 hydronephrosis,and UTDP grade 3 10 cases (58.8％) of hydronephrosis were effective for conservative treatment.There was a statistically significant difference between the level of hydronephrosis at the time of initial diagnosis of hydronephrosis and the efficacy of conservative treatment.Conclusion Conservative treatment of unilateral ureteral pelvic and ureteral junction obstruction is safe and effective.Severe hydronephrosis is unlikely to spontaneously resolve,often accompanied by early loss of renal function,and should be followed closely by ultrasound.

Analysis of long-term follow-up results of conservative treatment of children with unilateral UPJO / 中华泌尿外科杂志

Objective@#This study was a retrospective analysis of the efficacy of conservative treatment of unilateral renal pelvic ureteral junction obstruction with good renal function at the time of initial diagnosis.@*Methods@#The clinical data of 101 children with unilateral pelvic ureteral junction obstruction from January 2008 to December 2017 was analyzed retrospectively. All the patients underwent non-surgical treatment. There were 67 males and 34 females. The age range is from 10 days to 10 years old, with an average age of 3.4 years. 52 cases got left side obstruction and 49 cases got the right side obstrction. 14 children had abdominal pain symptoms. Among the 37 neonates: 21 male, 16 female. 15 were left, 22 were right. 10 cases were found during prenatal pregnancy, and 27 were dignosed postpartum. The indication for conservative treatment is no hydronephrosis-related symptoms or normal renal function at the initial diagnosis. The hydronephrosis did not affect the child's breathing, growth and development. The B-ultrasound was done every 1 to 6 months which depended on the different grades of hydronephrosis during a conservative observation period. The diuretic radionuclide imaging was done every 6 to 12 months. The end point of follow-up was surgery or disappear of the hydronephrosis in the affected side. Surgical indications are symptoms of hydronephrosis during follow-up which affecting growth and development, renal function reduction >10%, hydronephrosis SFU, UTDP grade progressive increase. Among them, 3 cases were raised from SFU2 to SFU3, 17 cases were raised from SFU3 to SFU4; 4 cases of neonatal UTDP2 progressed to grade 3 hydronephrosis and UTDP3 increased in 5 cases. Regression of hydronephrosis test three consecutive urinary renal ultrasound was defined as no hydronephrosis in.@*Results@#Continuous follow-up ranged from 1 year to 5 years, a median follow-up is 37 months. Of the 101 patients, 41 (40.5%) required surgery, and 60 (59.5%) kept conservative follow up. 2 cases of SFU1 children with hydronephrosis spontaneously disappeared. Of the 26 SFU class 2 children, 15 (69.2%) spontaneously resolved, 7(30.7%) improved, and 4 underwent surgery. Of the 50 children with SFU grade 3 hydronephrosis, 11(22.0%) spontaneously resolved, 19 improved or remained unchanged, and 20 patients eventually underwent surgery. Of the 23 patients with SFU grade 4 hydronephrosis, 6(26.0%) improved (to SFU 2) and 17(73.9%) underwent surgery. 37 of the 101 children were enrolled in the neonatal group for SFU grading while performing UTDP grading. Twenty-seven (70.2%) of the 37 neonates underwent conservative treat ment, including 8(100.0%) UTDP grade 1 hydronephrosis, 8(66.7%) UTDP grade 2 hydronephrosis, and UTDP grade 3 10 cases (58.8%) of hydronephrosis were effective for conservative treatment. There was a statistically significant difference between the level of hydronephrosis at the time of initial diagnosis of hydronephrosis and the efficacy of conservative treatment.@*Conclusion@#Conservative treatment of unilateral ureteral pelvic and ureteral junction obstruction is safe and effective. Severe hydronephrosis is unlikely to spontaneously resolve, often accompanied by early loss of renal function, and should be followed closely by ultrasound.

A long-term follow-up in conservative management of unilateral ureteropelvic junction obstruction with poor drainage and good renal function.

The aim of the study was to retrospectively review the outcome of neonatal ureteropelvic junction obstruction with a good renal function and a poor drainage at a first diuretic renal scan, in cases where surgery was recommended on the basis of a loss of renal function, worsening of hydronephrosis or occurrence of clinical symptoms. Hydronephrosis was graded from 1 to 4 or as ureteral tract dilatation (UTD) P1 to UTD P3. During follow-up, 15 out of 38 patients (34.2%) required surgery while 25 out of 38 (65.8%) could have been managed conservatively. In patients with grade 2, 3, and 4 hydronephrosis, the ureteropelvic junction obstruction resolved or improved spontaneously in 100%, 63%, and 33% of cases (in 100% of UTD P1, 67% of UTD P2, and 50% of UTD P3), respectively. The median of follow-up was 14 years. Chi-square test showed a significant relationship between initial grade of hydronephrosis or UTD and the possibility of an efficient conservative management (p = 0.0088 and p = 0.0460).Conclusion: Conservative management can be safely achieved in ureteropelvic junction obstruction with poor drainage. Scheduled controls are needed for early discovery of functional renal deterioration. High-grade hydronephrosis is unlikely to resolve spontaneously and is often accompanied by a loss of renal function during the first years of life. What is Known: • There is controversy about which management should be adopted in infants with unilateral ureteropelvic junction obstruction with poor drainage but good differential renal function. What is New: • Long-term follow-up suggests that conservative management can be safely achieved also in unilateral ureteropelvic junction obstruction with poor drainage in more than 60% of cases, even if high-grade hydronephrosis is unlikely to resolve spontaneously and it is often accompanied by a loss of renal function during the first years of life. In our experience, surgical intervention was required in more than 50% of cases before 1 year of life and in all cases before 3 years of life.

The Value of Tc-99m DTPA Diuretic Renography for Assessment of Dilated Upper Urinary Tract in Children / 대한핵의학회잡지

PURPOSE: The purpose of this study was to evaluate the accuracy of Tc-99m DTPA diuretic renal scans in children 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 nonobstructive patterns in 1. In 3 patients who underwent diuretic renal scan within 1 week after birth., nonobstructive patterns of initial scan were coverted 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 standarized 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 effect of dismembered pyeloplasty on renal function in patients with ureteropelvic junction obstruction / 대한비뇨기과학회지

To elucidate whether dismembered pyeloplasty improves renal function, the authors studied 37 patients with ureteropelvic junction obstruction. Changes in various renal parameters pre-and postoperatively by 99mTc-DTPA diuretic renal scintigraphy(DTPA scan) and intravenous urography were evaluated. Subjects included 24 pediatric(mean age 9.7 years) and 13 adult(mean age 33 years) patients. Postoperative split renal function was improved in 79 % (l9/24) of pediatric patients and in 69%(9/13) of adult ones. While, the excretory slope was improved in 71%(17/24) of pediatric patients and in 77%( 10/13) of adult ones. Hydronephrosis on intravenous urogram was improved in 58% (14/24) and 54% (7/13), respectively between pediatric and adult patients. There was no statistically significant differences of improvement in split renal function and renographic washout curve between pediatric and adult patients. In summary, renal function was improved by dismembered pyeloplasty in both pediatric and adult patients.