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.

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 Renal Size Discrepancy among the Findings of Renal Sonogram in Children with Their First Episode of Pyelonephritis is One of the Useful Parameters to Predict the Presence of Cortical Defects on the Acute DMSA Renal Scan

PURPOSE: We investigated whether a renal size discrepancy on a renal sonogram (US) in children with febrile urinary tract infection (UTI) was correlated with the presence of cortical defects on their dimercaptosuccinic acid (DMSA) renal scan. METHODS: We examined 911 children who were admitted consecutively to our hospital with their first episode of febrile UTI from March 2001 to September 2014. All enrolled children underwent a US and DMSA scan during admission. According to the US findings, including the renal size discrepancy, data were compared between children with positive and negative DMSA scan results. A positive DMSA scan result was defined as reduced or absent tracer localization and indistinct margins that did not deform the renal contour. RESULTS: Mean renal lengths of the right and left kidneys were larger in children with positive DMSA scan results than in children with negative DMSA scan results (63.2±11.3 mm vs. 58.4±7.8 mm, P<0.001; 64.9±11.2 mm vs. 59.9±7.9 mm, P<0.001; respectively). A significant difference was observed in both renal lengths between children with positive and negative DMSA scan results (4.6±3.8 mm vs. 3.3±2.6 mm, P<0.001). A multiple logistic regression analysis, revealed that a small kidney, cortical thinning, and a renal length discrepancy on US findings were significant factors for predicting the presence of cortical defects on an acute DMSA scan [P=0.028, 95% confidence interval (CI) 1.054–2.547; P=0.004, 95% CI 1.354–4.810; P<0.001, 95% CI 1.077–1.190, respectively]. CONCLUSION: In conclusion, a renal size discrepancy on US findings in children with their first episode of febrile UTI was a helpful tool for predicting the presence of cortical defects on an acute DMSA scan.

A Case with Abrupt Progression of Renal Scarring or Abrupt Deterioration of Renal Function Associated with Vesicoureteral Reflux

Abrupt progression of renal scarring associated with vesicoureteral reflux (VUR) is rare in males over 2 years old of age. We report a 5 year old boy with sustained unilateral high grade VUR who experienced abrupt progression of renal scarring; he had a relative renal radionuclide uptake of 38% at 2 years of age that dropped to 8% after three years. Per his parent's wishes, he took prophylactic antibiotics for 25 months after his first febrile urinary tract infection (UTI) at 4 months old without surgical management. One episode of recurrent breakthrough infection occurred at the age of 2 years. This observation reminds us that a recommending surgical management for sustained high grade VUR associated with renal scarring might be needed. Close follow up of DMSA for renal scanning, and long term follow up of patients after the first febrile UTI are important.

Multi-organ visualization in a DMSA renal scan of a nine-year-old male with reflux nephropathy

We present a case of a 9-year-old mole whose follow-up DMSA renal scan showed increased background activity with radio tracer uptake in the liver, cardiac pool, and blood vessels. The possible causes of this unusual finding were discussed. With the patient's medical history, his recent laboratory work-ups and after excluding all other possible causes, we come to a conclusion that the multi-organ visualization in our patient's DMSA renal scan was a result of his medical condition of chronic kidney disease secondary to reflux nephropathy.

(99m)Tc-MAG3 Renal Scan and Ultrasonography in Early Surgical Complications of 203 Renal Transplants / 대한이식학회지

PURPOSE: This study is designed to evaluate the usefulness of (99m)Tc-MAG3 renal scan in the diagnosis of early surgical complication of renal transplantation comparing with that of ultrasonography. METHODS: 203 renal transplantations, from January 2000 to December 2004, were studied retrospectively. (99m)Tc-MAG3 renal scan and ultrasonography were performed routinely for evaluation of allograft kidney at postoperative day 3, 7, 14 and 21 or 28 respectively. RESULTS: Thirteen early surgical complications (6.4%) from 203 recipients were developed during the first one month after transplantation. Six cases of urological complications were noticed. And six cases of hematoma and one case of lymphocele were also developed. (99m)Tc-MAG3 renal scan showed abnormality in ten cases (76.9%) of thirteen early surgical complications. (99m)Tc-MAG3 renal scan revealed all of six urologic complications (100%), and four of six hematomas (66.7%). But one lymphocele was not detected by (99m)Tc-MAG3 renal scan. Ultrasonography showed abnormal findings in eight cases of 13 early surgical complications (61.5%): one of four urine leakage (25%), two of two urinomas (100%), four of six hematomas (66.7%), and one lymphocele (100%). CONCLUSION: (99m)Tc-MAG3 renal scan is more sensitive than ultrasonography in detection of earlysurgical complications of renal transplantation. Then (99m)Tc-MAG3 renal scan is useful test for screening and follow-up of early surgical complications after renal transplantation.

The Decision of Voiding Cystourethrography in Children with Urinary Tract Infection

PURPOSE: We attempted to compare the independent factors such as age, sex, C-reactive protein(CRP), and white blood cell count(WBC) in children with radiologic studies and assess the necessity of performing voiding cystourethrography(VCUG). METHOD: 98 children who have been diagnosed their first time febrile urinary tract infection from Janurary 2002 to Januray 2005 were enrolled. In all patient, the duration of fever which occurred before and after treatment was recorded, and CRP, WBC, (99m)Tc-2,3-dimercaptosuccinic acid((99m)Tc-DMSA) renal scans, renal ultrasound and VCUG were analyzed. RESULTS: Of the 98 children diagnosed with urinary tract infection(UTI), 52 were male and 46 were female. 18 had abnormalities in VCUG, 17 had abnormalities in kidney ultrasound, and 20 had partial defects or diffuse uptake decrease in (99m)Tc-DMSA renal scans. There were no significant relationship between incidence of radiologic abnormalities and age. The risk of renal scar was significantly higher in children who had a longer febrile period before treatment than in those with shorter period. Both CRP and WBC were significantly elevated in children with the radiological abnormalities. A positive of (99m)Tc-DMSA renal scans and renal ultrasound were highly associated with vesicoureteral reflux(VUR). CONCLUSION: If there are abnormalities in the kidney ultrasound and (99m)Tc-DMSA renal scan of a child with initial UTI, a VCUG is recommended. Even in cases without abnormal findings in (99m)Tc-DMSA renal scan and renal ultrasound, clinical data such as CRP and WBC should be assessed, and VCUG should be performed for the undetected VUR.

Voiding cystourethrography in children with an initial episode of febrile urinary tract infection / 소아과

PURPOSE: Because voiding cystourethrography(VCUG) is an invasive method, we studied whether VCUG could be postponed through evaluation of alternative non-invasive tests including renal ultrasonography and (99m)Tc-DMSA renal scan. METHODS: We reviewed the medical records of 175 patients initially diagnosed with febrile urinary tract infection during the one year period of 1999, and compared 3-tests:renal ultrasongraphy, (99m)Tc-DMSA renal scan, and VCUG. RESULTS: Renal ultrasonography didn't contribute to the prognostication of pyelonephritis(photopenic areas) or vesicoureteral reflux(VUR). Presentation of photopenic areas in (99m)Tc-DMSA renal scan was related to VUR. If both findings of renal ultrasonography and (99m)Tc-DMSA renal scans were normal, this condition was closely related to normal results in VCUG. And if both examinations were abnormal, the condition was closely related to VUR. But this state could not always guarantee the normal result from VCUG because of low sensitivity in finding VUR. CONCLUSION: In cases in which acute phyelonephritis is demonstrated by (99m)Tc-DMSA renal scan, VCUG is required. In addition to this, if the conditions of hydronephrosis, vesicoureteral dilatation, increases of renal volume, and changes of echogenesity are shown by renal ultrasonography, VCUG should be performed. If a patient has difficulty undergoing VCUG, temporary postponement of VCUG can be taken into consideration, but only in cases where both examinations of renal ultrasonography and (99m)Tc-DMSA renal scan are normal. Nevertheless, close observation is be advised even in this case.

The Diagnostic Value of Clinical and Radiologic Findings in Children after the First Episode of Acute Pyelonephritis

PURPOSE: Acute pyelonephritis is one of the most common causes of unexplained fever in children. It may lead to the development of progressive renal damage. However, the detection of acute pyelonephritis can be difficult, especially in infants. The objective of this study was to evaluate the diagnostic value of various lab tests and imaging studies for acute renal parenchymal changes in children with APN. We correlated the clinical and laboratory manifestations of acute pyelonephritis with the imaging studies. METHODS: We reviewed the records of 115 children (85 males and 30 females) who were hospitalized during the period of January 1998 to December 2002 with initial clinical symptoms suggestive of pyelonephritis. The patients' age, sex, duration of fever, laboratory findings, and causative organisms were compared with the findings of imaging studies (Technetium-99m dimercaptosuccinic acid renal scan, renal ultrasonography, intravenous pyelography, voiding cystourethrography). RESULTS: No significant relation between the number of febrile days, leukocyte count, causative organism, and the renal abnormalities in the imaging studies were observed. On the other hand, both C-reactive protein and erythrocyte sedimentation rate levels were significantly elevated in children with positive dimercaptosuccinic acid renal scan. Furthermore, females and children older than 1 year presented with significantly higher rate of abnormal dimercaptosuccinic acid renal scan findings and vesicoureteral reflux presented by voiding cystourethrography. CONCLUSION: We recommend females and children older than 1 year who are suspected of acute pyelonephritis be evaluated carefully for renal involvement by performing imaging studies including dimercaptosuccinic acid renal scan and voiding cystourethrography.

The Occurrence of Renal Scarring in Children with Unilateral Vesicoureteral Reflux / 소아과

PURPOSE: We evaluated the occurrence of renal scarring in children with unilateral vesicoureteral reflux (VUR), and the relationships between renal scar formation and risk factors such as VUR, duration of fever, acute-phase reactant, age, and sex. METHODS: We retrospectively analyzed the data of 35 children newly diagnosed with unilateral vesicoureteral reflux after urinary tract infection (UTI) in Wallace Memorial Baptist Hospital between January 1996 and December 2004. Ultrasonography, Erythrocyte sedimentation rate (ESR), and C- reactive protein (CRP) were performed initially. Voiding cystourethrography (VCUG) was performed 1 to 3 weeks after treatment with UTI. (99m) Tc-dimercaptosuccinic acid (DMSA) scan was performed 4 to 6 months after treatment. RESULTS: Scintigraphic renal damage was present in 29 percent of the refluxing and in 3 percent of the nonrefluxing kidneys (P< 0.05). The severity of VUR was significantly correlated with renal scar formation (P< 0.05). The duration of fever before treatmen (5.0+/-1.3 vs 2.6+/-1.3) and prolonged fever of over 5 days were significantly different between renal scar group and non-renal scar group (P< 0.05). ESR (56.3+/-23.8 vs 27.9+/-18.1 mm/hr, P< 0.05) and CRP (12.8+/-7.3 vs 3.9+/-3.8 mg/dL, P< 0.05) at the diagnosis of UTI in the renal scar group were higher, compared to those of the non-renal scar group. There were no significant differences in age and sex between the two groups. CONCLUSION: The presence and grade of VUR, the duration of fever before treatment, prolonged fever over 5 days, ESR, and CRP were risk factors for renal scarring, irrespective of age and sex. Diagnosis and management of VUR, in children with UTI, is important to prevent renal scars.

A Case of Acute Poststreptococcal Glomerulonephritis Accompanied with Acute Pyelonephritis

Acute poststreptococcal glomerulonephritis(APSGN) is the most common form of postinfectious glomerulonephritis, and acute pyelonephritis(APN) is the most severe form of urinary tract infection in childhood. However, the concurrence of two diseases is uncommon in the literature. We describe a case of APSGN accompanied with APN in a 5-year-old female who presented with fever, left flank pain, headache and facial edema. Urinalysis showed pyuria, microscopic hematuria, and mild proteinuira. Serial urine cultures grew Escherichia coli. (99m)Tc-DMSA renal scan revealed a cortical defect in the upper pole of left kidney. She had a history of preceding pharyngitis, in addition, showed high blood pressure, high anti-streptolysin O titer, and low serum complement levels. The patient improved completely with supportive treatment, including antibiotic and antihypertensive therapy. These findings suggested that APSGN and APN could be manifested simultaneously or be superimposed on each other.

Compensatory Glomerular Hypertrophy Is Not a Cause of Supranormal Renographic Differential Renal Function in Patients with Ureteropelvic Junction Obstruction / 대한비뇨기과학회지

PURPOSE: Increasing clinical importance is being placed on the role of differential renal function (DRF) for the management of congenital ureteropelvic junction obstructions. Supranormal DRF of a hydronephrotic kidney, on a renal scan, is hypothesized to be due to an increase in single nephron filtration or nephron volume. However, the etiology of this paradoxical phenomenon still remains to be elucidated. We studied the histopathological changes of hydronephrotic kidneys with a supranormal DRF. MATERIALS AND METHODS: 35 children with unilateral congenital hydronephrosis and supranormal DRF (>55%), on preoperative renal scans, who had undergone pyeloplasty, were retrospectively evaluated. There were 3 female and 32 male patients. The mean age at the time of the operation was 12.6 months, ranging from 0.1 to 144 months. Needle biopsies, from 3 different sites at the lower pole of the kidney, were performed during surgery. To evaluate the presence of glomerular hypertrophy, the maximal planar area of the glomeruli was measured under light microscopy. Tissue samples were obtained in same manner from kidneys with no history of urinary tract disease on autopsy, and used as controls. The mean glomerular areas of the patient and control groups were plotted according to the patient's age. RESULTS: The mean glomerular area in the patient group was smaller than in the control group, with the exception of 4 patients. According to the logistical regression, the probability of larger renal glomeruli increased with decreasing DRF (p=0.1155). CONCLUSIONS: The glomerular area of a hydronephrotic kidney, with a supranormal renal function on a renal scan, was not significantly larger than the normal controls. Therefore, we believe that the theory of increased nephron volume as a cause of a supranormal DRF can be excluded.

Compensatory Glomerular Hypertrophy Is Not a Cause of Supranormal Renographic Differential Renal Function in Patients with Ureteropelvic Junction Obstruction / 대한비뇨기과학회지

PURPOSE: Increasing clinical importance is being placed on the role of differential renal function (DRF) for the management of congenital ureteropelvic junction obstructions. Supranormal DRF of a hydronephrotic kidney, on a renal scan, is hypothesized to be due to an increase in single nephron filtration or nephron volume. However, the etiology of this paradoxical phenomenon still remains to be elucidated. We studied the histopathological changes of hydronephrotic kidneys with a supranormal DRF. MATERIALS AND METHODS: 35 children with unilateral congenital hydronephrosis and supranormal DRF (>55%), on preoperative renal scans, who had undergone pyeloplasty, were retrospectively evaluated. There were 3 female and 32 male patients. The mean age at the time of the operation was 12.6 months, ranging from 0.1 to 144 months. Needle biopsies, from 3 different sites at the lower pole of the kidney, were performed during surgery. To evaluate the presence of glomerular hypertrophy, the maximal planar area of the glomeruli was measured under light microscopy. Tissue samples were obtained in same manner from kidneys with no history of urinary tract disease on autopsy, and used as controls. The mean glomerular areas of the patient and control groups were plotted according to the patient's age. RESULTS: The mean glomerular area in the patient group was smaller than in the control group, with the exception of 4 patients. According to the logistical regression, the probability of larger renal glomeruli increased with decreasing DRF (p=0.1155). CONCLUSIONS: The glomerular area of a hydronephrotic kidney, with a supranormal renal function on a renal scan, was not significantly larger than the normal controls. Therefore, we believe that the theory of increased nephron volume as a cause of a supranormal DRF can be excluded.

Sensitivity of Dimercaptosuccinic Acid(DMSA) Renal Scan in Children with Acute Pyelonephritis

PURPOSE: Accurate diagnosis of acute pyelonephritis(APN) using clinical and laboratory parameters is often difficult in children. Clinical and experimental studies have demonstrated that renal scarring can be prevented or diminished by early diagnosis and aggressive treatment of acute pyelonephritis. dimercaptosuccinic acid(DMSA) renal scan has been reported to be useful in children for confirmation of the diagnosis of acute pyelonephritis. An analysis was undertaken to correlate the clinical and laboratory manifestations of APN with the results of the DMSA renal scan in different age groups. METHODS: We determined the sensitivity of DMSA renal scan in febrile urinary tract infections(UTI) in two groups according to age:group I in less than 2 years; group II in older than 2 years. During the period March 2001 through September 2002, 67 children presented with febrile UTIs. All patients had DMSA renal scan done in the acute period, 55 had voiding cystourethrography(VCUG) and 66 had renal ultrasonogram(RUS) done. RESULTS: There were no significant difference between the two groups in DMSA renal scan (P>0.05). But, in group I sensitivity of DMSA renal scan was 47%; in group II sensitivity of DMSA renal scan was 70%. The grade of reflux correlated with a positive DMSA renal scan. Vesicoureteral reflux did not correlate with age. RUS did not correlate with a positive DMSA renal scan in any age group. Abnormality of RUS did not correlate with age. CONCLUSION: At present, we believe that DMSA renal scan is the prevailing method in differention of the APN. In addition, it is not invasive and less costly. Even though there is no statistical difference in the sensitivity of DMSA renal scan between young and older children, we can observe that in the younger group, the sensitivity of DMSA renal scan seemed to be lower(47%).

Initial 99mTechnetium-dimercaptosuccinic Acid(DMSA) Renal Scan Finding and Vesicoureteral Reflux as Predicting Factor of Renal Scarring

PURPOSE: Acute pyelonephritis in children may result in permanant renal damage which later in life may lead to hypertension and renal failure. The purpose of this study was to evaluate the factors that might be useful for predicting the development of renal scar in children with urinary tract infection(UTI). METHODS: We retrospectively reviewed 442 patients with UTI who were admitted to the Department of Pediatrics of Chonbuk National University Hospital, during the period from April 1992 to March 2002. The patients were divided into two groups according to the presence of renal scar on the follow-up DMSA renal scan, and we compared the factors associated with renal scarring between the two groups. RESULTS: There were no significant differences in sex, causative organism and acute phase reactants between the groups with and without renal scar. The age at diagnosis was significantly higher in the renal scar group compared to that without scar. Of the 60 patients with renal scar, 78% had vesicoureteral reflux(VUR), but 13% of patients without scar had VUR. Furthermore, the severity of VUR was significantly correlated with renal scar formation. 53 % showed multiple cortical defects on the initial DMSA renal scan, compared to 32% in the non-scar group. In addition, 76% of patients showing multiple cortical defects on the initial DMSA renal scan with VUR had renal scar. CONCLUSION: The presence and grade of VUR, and findings on the initial DMSA renal scan would contribute to predict risk of renal scar formation in children with UTI.

The Correlation between Relative Renal Uptake of (99m)Tc-DMSA Renal Scan and Glomerular Filtration Rate in Patients with Reduced Renal Function / 대한신장학회잡지

BACKGROUND: Glomerular filtration rate(GFR) is an important parameter for the evaluation and monitoring of renal function. The aim of this study was to investigate the correlation between the relative 1 hour uptake of (99m)Tc-DMSA renal scan(DMSA- %uptake, TRUR) and GFR which was estimated by (99m)Tc-DTPA, serum creatinine and 24 hour-urinary creatinine excretion. METHODS: Between January 1998 and March 2001, 65 patients had undergone (99m)Tc-DMSA renal scan, (99m)Tc-DTPA renal scan, serum creatinine and 24 hour-urinary creatinine excretion. Of them, 42 patients had moderately or severely reduced renal function(DTPA-GFR 0.05). In group B, TRUR (mean+/-S.D. 16.3+/-7.4%) was significantly correlated with DTPA-GFR(r=0.731, p < 0.01). In both group, serum creatinine, Ccr and C and G Ccr were significantly correlated with TRUR. CONCLUSION: Although the relative 1 hour uptake of the (99m)Tc-DMSA renal scan, as a method of renal cortical image could not estimate the true GFR, it showed a good correlation with GFR in patients with moderately reduced renal function. (99m)Tc-DMSA renal scan seems to be helpful to evaluate the renal function in patients with moderately reduced renal function.

Risk Factors of Renal Scar After Acute Pyelonephritis in Children

PURPOSE: In this study we re-evaluated the known risk factors of pyelonephritic scarring in children. METHODS: A prospective study was performed on 36 acute pyelonephritis(APN) patients who were diagnosed as first acute pyelonephritis on 99mTc-DMSA scan between September 1998 and March 2000 in Masan Samsung Hospital. According to the prescence of remnant lesions on the 99mTc-DMSA scan performed 6 months after the first 99mTc-DMSA scan, the patients were divided into scar(Group A, N=15) and non-scar groups(Group B, N=21). We compared known risk factors of renal scarring between the two groups. RESULTS: There were no differences in age, sex, cultured organisms and CRP level between the two groups. Most of the initial 99mTc-DMSA scan results were not different but bilateral multiple lesions were much more common in group A(40.0% of Group A patients) compared with group B (9.5% of Group B patients). Moderate to high grade vesicoureteral reflux was also much more commonly observed in group A(46.6% of Group A patients) compared with group B(4.8% of Group B patients). CONCLUSION: Bilateral multiple lesion on initial 99mTc-DMSA scan and moderate to high grade vesicoureteral reflux at diagnosis of acute pyelonephritis may be risk factors associated with renal scarring after acute pyelonephritis in children.

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.

Comparison of Split Renal Function on DTPA Renal Scan and Endogenous Creatinine Clearance Ratio in Obstruction of Upper Urinary Tract / 대한비뇨기과학회지

PURPOSE: Split renal function on diuretic renography has been considered to be a good tool for evaluating renal function, selecting treatment modalities and assessing efficacy of surgery in hydronephrosis, especially in ureteropelvic junction(UPJ) obstruction. However, contradictory supranormal function on renography has provided controversy with urologists. Is the phenomenon the result of fact or artifact? The authers thought that contradictory supranormal renal function measured with 99mTc-DTPA Is fundamentally related with a question. How accurately does the split renal function test represent the real renal function, namely, glomerular filtration rate(GFR)? To know relation of split renal function with real renal function(GFR) and to disclose clinical significance of contradictory supranormal renal function on diuretic renal scan, a prospective study was performed. MATERIALS AND METHODS: Diuretic renography was done in 14patients with upper urinary tract obstruction including UPJ obstruction, ureteral stone and lower urethral obstruction. Afer the first diuretic renography using 99mTc-DTPA percutaneous nephrostomy was performed on affected kidney, which was followed by the second diuretic renography. Endogenous creatinine clearance tests were done on the patients. Urine was collected through the nephrostomy tube, self voiding or indwelling Foley catheter, respectively So the endogenous creatinine clearance was determined respectively on both the renal unit. Also the endogenous creatinine clearance ratio of affected kidney was determined to compare with split renal function on renography. RESULTS: In 7patients, ratio of endogenous creatinine clearance on affected kidney was less than 40%. In the other 7patients, the ratio was more than 48%. In patients with less than 40% of endogenous creatinine clearance ratio on affected kidney, split renal function was overestimated by 10.3% to 27.5%(19.5+/-4.9%) comparing to endogenous creatinine clearance ratio. In the other 7patients split renal function had a little difference from endogenous creatinine clearance ratio (4.5+/-2.5%). The endogenous creatinine clearance ratio was not closely related with split renal function(correlation coefficients: 0.65). Split renal function of the first renography was closely related with that of the second renography(correlation coefficients: 0.88). Contradictory supranormal function occurred in 4cases. In 2cases it was real finding, in the other it was not. CONCLUSIONS: It appears that split renal function is overestimated in poor renal function and split renal function is closely related with real renal function in good renal function slate. Supranormal renal function is real finding in part, not in part. Clinical significance of split renal function should be cautiously and basically reevaluated through further study.