Extralobar pulmonary sequestration in neonates: The natural course and predictive factors associated with spontaneous regression.

PURPOSE: To describe the natural course of extralobar pulmonary sequestration (EPS) and identify factors associated with spontaneous regression of EPS. MATERIALS AND METHODS: We retrospectively searched for patients diagnosed with EPS on initial contrast CT scan within 1 month after birth and had a follow-up CT scan without treatment. Spontaneous regression of EPS was assessed by percentage decrease in volume (PDV) and percentage decrease in sum of the diameter of systemic feeding arteries (PDD) by comparing initial and follow-up CT scans. Clinical and CT features were analysed to determine factors associated with PDV and PDD rates. RESULTS: Fifty-one neonates were included. The cumulative proportions of patients reaching PDV > 50 % and PDD > 50 % were 93.0 % and 73.3 % at 4 years, respectively. Tissue attenuation was significantly associated with PDV rate (B = -21.78, P < .001). The tissue attenuation (B = -22.62, P = .001) and diameter of the largest systemic feeding arteries (B = -48.31, P = .011) were significant factors associated with PDD rate. CONCLUSION: The volume and diameter of systemic feeding arteries of EPS spontaneously decreased within 4 years without treatment. EPSs showing a low tissue attenuation and small diameter of the largest systemic feeding arteries on initial contrast-enhanced CT scans were likely to regress spontaneously. KEY POINTS: • Extralobar pulmonary sequestration (EPS) could show spontaneous regression. • Initial CT features may predict spontaneous regression of EPS. • The tissue attenuation and diameter of systemic feeding artery are important factors.

Cranial Nerve Disorders in Children: MR Imaging Findings.

Cranial nerve disorders are uncommon disease conditions encountered in pediatric patients, and can be categorized as congenital, inflammatory, traumatic, or tumorous conditions that involve the cranial nerve itself or propagation of the disorder from adjacent organs. However, determination of the normal course, as well as abnormalities, of cranial nerves in pediatric patients is challenging because of the small caliber of the cranial nerve, as well as the small intracranial and skull base structures. With the help of recently developed magnetic resonance (MR) imaging techniques that provide higher spatial resolution and fast imaging techniques including three-dimensional MR images with or without the use of gadolinium contrast agent, radiologists can more easily diagnose disease conditions that involve the small cranial nerves, such as the oculomotor, abducens, facial, and hypoglossal nerves, as well as normal radiologic anatomy, even in very young children. If cranial nerve involvement is suspected, careful evaluation of the cranial nerves should include specific MR imaging protocols. Localization is an important consideration in cranial nerve imaging, and should cover entire pathways and target organs as much as possible. Therefore, radiologists should be familiar not only with the various diseases that cause cranial nerve dysfunction, and the entire course of each cranial nerve including the intra-axial nuclei and fibers, but also the technical considerations for optimal imaging of pediatric cranial nerves. In this article, we briefly review normal cranial nerve anatomy and imaging findings of various pediatric cranial nerve dysfunctions, as well as the technical considerations of pediatric cranial nerve imaging. Online supplemental material is available for this article. (©)RSNA, 2016.

Humidifier disinfectant-associated children's interstitial lung disease: Computed tomographic features, histopathologic correlation and comparison between survivors and non-survivors.

OBJECTIVES: To report radiologic findings with histopathologic correlations of humidifier disinfectant-associated children's interstitial lung disease (HD-chILD) and to compare computed tomography (CT) findings between survivors and non-survivors. METHODS: Forty-seven children with HD-chILD (27.4 ± 12.4 months old) were categorized as survivors (n = 25) and non-survivors (n = 22). The patterns, distributions, and chronological changes in lung lesions at follow-up CT were investigated. Histopathologic correlations were performed in 23 patients. RESULTS: CT features were characterized by chronological changes, from consolidation to centrilobular opacities, and lesions eventually became faint centrilobular nodules. Histopathologic features were bronchocentric-distributed fibro-inflammatory lesions, which were more profound in the advanced stage than the early stage. Consolidation ≥ 30 % [hazard ratio (HR), 2.932], centrilobular opacities ≥ 60 % of the total lung volume (TLV; HR, 0.206) and spontaneous air leaks (HR, 3.457) were significant factors associated with patient survival, as per univariate analysis. Consolidation ≥ 30 % (HR, 3.519), centrilobular opacities ≥ 60 % (HR, 0.205) and diffuse ground glass opacity (GGO) ≥ 70 % of the TLV (HR, 3.521) were significant factors associated with patient survival, as determined via multivariate analysis. CONCLUSION: Distinctive chronological CT features were observed in the HD-chILD images. Spontaneous air leaks, consolidation, GGO, and centrilobular opacities were prognostic factors. KEY POINTS: Chemical disinfectants can induce severe inhalation lung injury. Lung injury caused by inhaled disinfectants demonstrates chronologic changes in radiologic findings. Understanding of radiological characteristics is important to predict outcomes in chemical pneumonitis. Physicians should be aware of the potential risk of environmental chemicals.

Cholangiographic characteristics of common bile duct dilatation in children.

AIM: To investigate whether children with congenital common bile duct dilatation (CBDD) differ from children with obstructive CBDD in cholangiographic characteristics. METHODS: In this retrospective cohort study, the baseline data and the results of imaging analyses were reviewed among children who had endoscopic retrograde cholangiopancreatography (ERCP) due to CBDD. ERCP was performed on all pediatric patients by experienced pediatric endoscopists. The maximal transverse diameter of the common bile duct (CBD) was measured on ERCP. To assess whether age-adjusted CBDD could be used for differential diagnosis, a CBDD severity index (SI) was calculated by dividing the measured CBD diameter by the age-corrected maximal diameter of a normal CBD. RESULTS: A retrospective medical chart review revealed that 85 consecutive children under 16 years of age with hepatobiliary disease and CBDD were referred to Seoul Asan Medical Center. Fifty-five (64.7%) children had congenital CBDD and 30 (35.3%) had obstructive CBDD. The two groups did not differ significantly in terms of clinical characteristics except for sex. The congenital and obstructive CBDD groups did not differ significantly in terms of mean CBD diameter (19.3 ± 9.6 mm vs 12.2 ± 4.1 mm, P > 0.05). However, congenital CBDD cases had a significantly higher mean SI than obstructive CBDD cases (3.62 ± 1.64 vs 1.98 ± 0.71, P = 0.01). In multivariate analysis, an SI value ≥ 2.32 and comorbidity with anomalous union of pancreaticobiliary duct (APBDU) in ERCP independently predicted congenital CBDD. CONCLUSION: Measuring the CBD may aid the differential diagnosis of both CBDD and APBDU in children.

Transperineal ultrasonography for evaluation of the perianal fistula and abscess in pediatric Crohn disease: preliminary study.

PURPOSE: To assess the feasibility and effectiveness of transperineal ultrasonography (TPUS) for the evaluation of perianal Crohn disease (PCD) in pediatric patients. METHODS: Between September 2010 and August 2013, 64 TPUS examinations were performed in 43 patients (34 males and 9 females; mean age±standard deviation, 13.3±2.4 years; age range, 6 to 17 years) to evaluate PCD. The pain severity, location, and activity of perianal fistula, the presence of an abscess, and anal canal hyperemia were retrospectively evaluated. Spearman rank correlation analysis was performed to assess the relationship between the severity of the pain and the fistula activity, the presence of an abscess, and anal canal hyperemia. RESULTS: All examinations were successfully performed. Thirty-nine examinations (60.9%) were performed without any pain experienced by the patient, 19 examinations (29.7%) with mild pain, five examinations (7.8%) with moderate pain, and one examination (1.6%) with severe pain. The pain severity was correlated with the fistula activity (P<0.01). An anterior fistula location was more common than a posterior location. Active fistulas and abscesses were identified during 30 examinations (46.9%) and 12 examinations (18.8%), respectively. Anal canal hyperemia was identified in 31 examinations (48.4%). CONCLUSION: TPUS with a color Doppler study is useful for visualizing a perianal fistula or abscess and for assessing its inflammatory activity in pediatric Crohn patients.

Improved outcomes in liver transplantation in children with acute liver failure.

OBJECTIVE: The aim of our study was to review the experiences of a living donor-dominant transplantation program for children with acute liver failure (ALF). METHODS: Data were derived from the retrospective chart review of 50 children with ALF in a major liver center in the Republic of Korea. RESULTS: A total of 50 children with ALF underwent 47 (94%) primary living donor liver transplantations and 3 (6%) cadaveric liver transplantations. The cumulative survival rates of the grafts at 1 and 5 years were 81.9% and 79.2%, respectively. The overall retransplantation rate was 12%. The cumulative survival rates of these patients at 1 and 5 years were all 87.9%. Most incidents of mortality followed the failure of the preceding graft. We observed no mortalities among donors. Based on multivariate analysis, children who had pretransplant thrombocytopenia or had to use the molecular adsorbent recycling system preoperatively were related to the graft loss. Age younger than 2 years and a hyperacute onset (within 7 days) of hepatic encephalopathy were associated with pretransplant thrombocytopenia. CONCLUSIONS: Living donor-dominant transplantation program in the present study demonstrates tolerable achievements in terms of clinical outcomes of recipients and donors; however, putative factors, such as pretransplant thrombocytopenia, seem to play unclear roles in a poor prognosis following transplantation.

A case of campomelic dysplasia without sex reversal.

Campomelic dysplasia (CD; OMIM #114290), a rare form of congenital short-limbed dwarfism, is due to mutations in SOX9, a member of the SOX (SRY-related HMG box) gene family. Multiparous mother at 38 weeks' gestation delivered a 3,272 g baby boy with characteristic phenotypes including bowing of the lower limbs, a narrow thoracic cage, 11 pairs of ribs, hypoplastic scapulae, macrocephaly, flattened supraorbital ridges and nasal bridge, cleft palate, and micrognathia. He underwent a tracheostomy at the age of three months for severe laryngomalacia after a number of repeated hospitalizations due to respiratory problems and died at the age of four months from progressive respiratory failure. He was diagnosed as having CD based on a novel frameshift mutation (p.Gln458ArgfsX12) in the SOX9 gene, the mutation which has not yet been reported in Korea.

An 18-year experience of tracheoesophageal fistula and esophageal atresia.

PURPOSE: To determine the clinical manifestations and outcomes of patients with tracheoesophageal fistula (TEF) and esophageal atresia (EA) born at a single neonatal intensive care unit. METHODS: A retrospective analysis was conducted for 97 patients with confirmed TEF and EA who were admitted to the neonatal intensive care unit between 1990 and 2007. RESULTS: The rate of prenatal diagnosis was 12%. The average gestational age and birth weight were 37(+2) weeks and 2.5±0.7 kg, respectively. Thirty-one infants were born prematurely (32%). Type C was the most common. The mean gap between the proximal and distal esophagus was 2 cm. Esophago-esophagostomy was performed in 72 patients at a mean age of 4 days after birth; gastrostomy or duodenostomy were performed in 8 patients. Forty patients exhibited vertebral, anorectal, cardiac, tracheoesophageal, renal, limb (VACTERL) association with at least 2 combined anomalies, and cardiac anomaly was the most common. The most common post-operative complications were esophageal stricture followed by gastroesophageal reflux. Balloon dilatation was performed for 1.3 times in 26 patients at a mean age of 3 months. The mortality and morbidity rates were 24% and 67%, respectively, and the most common cause of death was sepsis. The weight of approximately 40% patients was below the 10th percentile at 2 years of age. CONCLUSION: Mortality and morbidity rates of patients with TEF and EA are high as compared to those of infants with other neonatal surgical diseases. Further efforts must be taken to reduce mortality and morbidity and improve growth retardation.

Long-term outcomes of pediatric living donor liver transplantation at a single institution.

There have only been a few studies on the long-term outcomes and prognostic factors after pediatric LDLT. We conducted a retrospective, single-center assessment of the outcomes as well as the demographic and clinical factors that influenced the poor outcomes in 113 children aged <16 (median age 21 months; 6 months-15.5 yr) who underwent 115 LDLTs, predominantly for biliary atresia (60.9%) and FHF (14.8%), between 1994 and 2006 at Asan Medical Center. Left lateral segment or left lobe grafts were implanted into most of these children (86.9%) according to routine procedures. The overall rates of graft survival at one, five, and 10 yr were 89.6%, 83.0%, and 81.5%, respectively, and the overall rates of patient survival were 92.9%, 86.3%, and 84.8%, respectively. Virus-related disease (41.2%) and chronic rejection (29.4%) were the major causes of mortality. On multivariate analysis, UNOS status 1a and 1b and chronic rejection were significant risk factors for both graft and patient loss, whereas the PELD score >25 was a significant risk factor for graft loss. Patient and graft survival may be related not only to post-operative complications, but also to the patient's preoperative clinical condition.

Endoscopic retrograde cholangiopancreatography in pancreatic and biliary tract disease in Korean children.

AIM: To assess the indications, findings, therapeutic procedures, safety, and complications of endoscopic retrograde cholangiopancreatography (ERCP) performed in Korean children. METHODS: The demographic characteristics, indications for ERCP, findings, therapeutic procedures, and complications of 122 pediatric patients who underwent 245 ERCPs in the Asan Medical Center between June 1994 and March 2008 were investigated. RESULTS: The mean age of the 122 patients was 8.0 +/- 4.2 years. Indications were biliary pathology in 78 (64.0%), pancreatic pathology in 43 (35.2%), and chronic abdominal pain in one. Biliary indications included choledochal cysts in 40, choledocholithiasis in 24, suspected sclerosing cholangitis in 8, trauma in 2, and other conditions in 4. Pancreatic indications included acute pancreatitis in 7, acute recurrent pancreatitis in 11, chronic pancreatitis in 20, trauma in 3, and pancreatic mass in 2. Of the 245 ERCPs, success rate was 98.4% and 190 (77.6%) were for therapeutic purposes, including endoscopic nasal drainage (51.8%), biliary sphincterotomy (38.0%), pancreatic sphincterotomy (23.3%), stent insertion (15.1%), stone extraction (18.8%), and balloon dilatation (11.0%). Complications were post-ERCP pancreatitis in 16 (6.5%), ileus in 23 (9.4%), hemorrhage in 2 (0.8%), perforation in 2 (0.8%), sepsis in 1 (0.4%), and impacted basket in 1 (0.4%). There were no procedure-related deaths, and most complications improved under supportive care. CONCLUSION: This study showed that there is a high incidence of choledochal cyst and diagnostic and therapeutic ERCP for the management of various biliary and pancreatic diseases was safe and effective in Korean children.

Characteristics and trends in the incidence of inflammatory bowel disease in Korean children: a single-center experience.

BACKGROUND: Inflammatory bowel disease (IBD) is rare in Asian children and few reports on pediatric IBD have appeared. AIMS: We, therefore, investigated the incidence trends and clinical characteristics of pediatric IBD in Korea. METHODS: We enrolled 48 children with Crohn's disease (CD) and 14 children with ulcerative colitis (UC) from 1996 to 2007. Trends in annual enrollment and clinical characteristics were retrospectively evaluated by medical record review. RESULTS: During the 12 years of observation, the number of new enrollments gradually increased. CD showed male predominance (33 boys, 15 girls), but more females presented with UC (4 boys, 10 girls). A relevant family history was observed in 3 (4.9%) of the 61 unrelated families. The most common presenting symptom was abdominal pain (67%) in CD and hematochezia (93%) in UC. Growth delay was observed in 10% of CD patients, but not in any of the UC patients. In CD, colonic involvement occurred in 87% of patients, ileal involvement in 87%, and both the small bowel and colon were affected in 75%. With UC, pancolitis occurred in 43% of patients, left-sided colitis in 36%, and proctitis in 21%, including all three patients with appendiceal orifice inflammation. The most frequent disease behavior was inflammatory in 85% of patients, but perianal fistula was noted in 50% of CD patients. CONCLUSION: This study showed that the incidence of pediatric IBD has been rapidly increasing in Korea in recent years. Relevant family history is less prevalent and phenotypic expression differs from what is seen in Western countries.

Neonatal pulmonary sequestration: clinical experience with transumbilical arterial embolization.

Pulmonary sequestration (PS) is a rare congenital malformation of the lower respiratory tract. The exact natural course of PS is not well understood and there are no well-established treatment guidelines for antenatally diagnosed PS. The aim of this study was to describe clinical outcomes in neonates with PS and to evaluate the efficacy of transumbilical arterial embolization (TUE). From 1998 to 2006, total 30 neonatal cases were included. Serial antenatal ultrasound in 26 cases found 6 (23%) regressed lesions, all of which were demonstrated on postnatal chest CT. Six (20%) cases were classified as mixed-type (combined cystic) lesions. Surgery was performed early (during initial hospitalization) in two cases and lately (after the neonatal period) in four cases. TUE was performed for 17 (57%) cases of intrapulmonary PS. Follow-up images obtained a median of 19 months (range, 4-51) after TUE demonstrated complete (9, 53%), partial (5, 29%), and no (3, 18%) regression. The regression rate was significantly higher in solid-type lesions (13/13, 100%) than in mixed-type (1/4, 25%) (P = 0.006). Complications included transient hypertension (two cases, 12%), post-embolization fever (two cases, 12%) and migration of a microcoil (one case, 6%), without long-term morbidities. Natural courses could be observed in 10 cases of extralobar PS and regression was observed in 2 cases (20%) during a median follow-up of 12 months (range, 6-45). A well-designed comparative study is warranted to evaluate the long-term efficacy and safety of TUE.

Comparison of the clinical manifestations, brain MRI and prognosis between neuroBeçhet's disease and neuropsychiatric lupus.

BACKGROUND: Neuropsychiatric systemic lupus erythematosus (NPSLE) shows some similarities to neuroBeçhet disease (NBD) in that both conditions have some analogous clinical features and they are both pathologically associated cerebral vasculopathy. This study compared the clinical manifestations, brain MRI findings and prognosis of NPSLE and NBD patients. METHODS: Forty three patients with NPSLE (n = 25) or NBD (n = 18), who were monitored at a single center, were enrolled in this study. We retrospectively analyzed the clinical and brain MRI data. The neuropsychiatric manifestations were classified in both groups according to the new American College of Rheumatology nomenclature for NPSLE. RESULTS: The diffuse symptoms that included mood disorders, psychosis, confusion, cognitive dysfunctions, generalized seizures and headaches other than migraine or cluster headaches were more commonly observed in the NPSLE patients, while the frequency of focal diseases such as cranial neuropathy tended to be higher in the NBD patients. The brain MRI revealed that the NBD patients had more abnormalities in the brain stem than did the NPSLE patients. Most of the patients improved, at least partially, after being treated with glucocorticoid and/or immune suppressants. However, the disease course differed significantly between the two groups. There were more episodic cases in the NPSLE group of patients, while there were more remittent cases in the NBD group of patients. CONCLUSION: NPSLE had a tendency to cause diffuse neuropsychiatric manifestations, and it has a different predilection of brain lesions compared with NBD. The NBD patients showed a poorer outcome than did the NPSLE patients, suggesting that different therapeutic strategies for the two diseases need to be considered.

Cytomegalovirus retinitis in a patient with dermatomyositis.

Cytomegalovirus (CMV) retinitis rarely occurs in patients with connective tissue disease. We present a rare case of CMV retinitis in a patient with dermatomyositis. A 38-year-old man was admitted due to blurred vision and floaters of right eye. He had been diagnosed with dermatomyositis and taken prednisolone and immunosuppressive agents for 10 months. He was diagnosed as having CMV retinitis based upon ophthalmologic examination, decreased CD4+T cell count, and positive IgM anti-CMV antibody. Intravenous ganciclovir was administrated with cessation of immunosuppressive agents for 40 days and the lesion did not progress. This is the first report of a CMV retinitis that developed in a patient with dermatomyositis.

Implication of genetic variations in congenital obstructive nephropathy.

The renin-angiotensin system (RAS) has long been implicated in kidney development, and it has been reported that disruption of angiotensin type 2 receptor (AGTR2) results in a wide range of congenital anomalies of the kidney and urinary tract. We investigated the allele frequencies of the AGTR2 and other RAS genes in Korean patients with ureteropelvic junction obstruction, multicystic dysplastic kidney (MCDK), and unilateral renal agenesis (RA). Fifty-three Korean children were enrolled: 37 boys and 16 girls, 27 with hydronephrosis, 23 with MCDK, and 3 with RA. Among 100 healthy Koreans, the frequencies of A and G alleles at the A-G transition site of intron 1 of the AGTR2 gene were 70% (140/200) and 30% (60/200), respectively. In the patient group, the A allele frequency was 57% (60/106) and the G allele frequency was 43% (46/106), significantly higher than in the general population (P=0.024). There was no significant difference of allele frequency between boys and girls. Angiotensin-converting enzyme insertion/deletion, angiotensinogen M235T, and the angiotensin 2 type 1 receptor A1166C genotype distribution showed no difference from those of the control subjects. These findings indicate that the AGTR2 gene may play a major role in the development of congenital obstructive nephropathy.

Multi-slice spiral CT of living-related liver transplantation in children: pictorial essay.

In pediatric living-related liver transplantation, preoperative evaluation of the recipient is important for surgical planning, while the accurate diagnosis of postoperative complications is essential for graft salvage. Multiplanar and three-dimensional imaging using multi-slice spiral CT can be used for preoperative vascular imaging, as well as for evaluating postoperative complications. In this essay, we describe the usefulness of multi-slice CT, combined with a variety of different reconstruction techniques, for the preoperative evaluation of transplant recipients. In addition, we demonstrate the multi-slice CT findings of postoperative complications, including vascular stenosis or thrombosis, bile duct leak or stricture, and extrahepatic fluid collection.

Congenital intrahepatic arterioportal and portosystemic venous fistulae with jejunal arteriovenous malformation depicted on multislice spiral CT.

We report a symptomatic infant with very rare congenital arterioportal and portosystemic venous fistulae in the liver. Multislice CT after partial transcatheter embolisation revealed not only the complicated vascular architecture of the lesion, but also an incidental jejunal arteriovenous malformation which explained the patient's melena. The patient underwent ligation of the hepatic artery and resection of the jejunal arteriovenous malformation. Postoperative multislice CT clearly demonstrated the success of the treatment.

CT of congenital heart disease: normal anatomy and typical pathologic conditions.

Computed tomography (CT) plays an important supplementary role in the evaluation of patients with congenital heart disease (CHD). Fast multisection spiral CT can be used to obtain isotropic volume data, and high-quality two- and three-dimensional multiplanar reformatted images can be created to accurately and systematically delineate the normal and pathologic morphologic features of the cardiovascular system. CT may be technically challenging and demanding in uncooperative young children. However, it can be used to systematically evaluate the aorta, pulmonary artery, pulmonary vein, cardiac chambers and ventriculoarterial connection, relationship between the upper lobe bronchi and pulmonary arteries, coronary artery, valves, systemic veins (superior vena cava, inferior vena cava, hepatic veins), and visceral situs with a step-by-step approach. This approach may be helpful in understanding the anatomy of the cardiovascular system in CHD patients. CT has both advantages and disadvantages in evaluating patients with CHD. Nevertheless, it is useful in this setting, and radiologists who perform CT in young children with CHD should be familiar with the advantages and disadvantages of CT and with the normal anatomy and typical pathologic conditions in affected patients.

Acute pancreatitis associated with biliary disease in children.

BACKGROUND AND AIMS: Biliary disease is one of the most common causes of acute pancreatitis in adults; however, this cause and outcome in children have rarely been described in the literature. Therefore, the present study was conducted to evaluate the role of biliary disease as a cause of acute pancreatitis in children. METHODS: The present study included 56 children with acute pancreatitis, of which 16 (29%) cases were associated with biliary disease. The 16 cases consisted of four boys and 12 girls ranging in age from 2 to 13 years. The underlying causes of the biliary disease were evaluated, as well as its clinical presentations, management modalities, and outcomes. RESULTS: The causes of biliary disease in the 16 children included choledochal cyst in seven, biliary sludge in six, gallstone in two, and anomalous pancreaticobiliary junction in one. Acute pancreatitis with biliary disease showed increased presentation of jaundice and abnormalities in a liver-function test. Therapeutic interventions were performed more frequently in acute pancreatitis associated with biliary disease. All seven children with choledochal cysts needed hepaticojejunostomy. Of eight children with biliary sludge or gallstones, five children remained free of and two suffered from repeated attacks of pancreatitis after endoscopic papillotomy. Mortality did not occur. CONCLUSION: The present study suggests that biliary disease can be one of the causes of acute pancreatitis in children and has the clinical characteristics of jaundice and/or abnormalities in a liver-function test. Appropriate therapeutic interventions should be considered as the treatment modality.

Value of supranormal function and renogram patterns on 99mTc-mercaptoacetyltriglycine scintigraphy in relation to the extent of hydronephrosis for predicting ureteropelvic junction obstruction in the newborn.

UNLABELLED: We investigated the value of supranormal function and renogram patterns on (99m)Tc-mercaptoacetyltriglycine ((99m)Tc-MAG3) scintigraphy in relation to the extent of hydronephrosis for predicting ureteropelvic junction (UPJ) obstruction in the newborn. METHODS: We studied 48 patients with prenatally diagnosed unilateral hydronephrosis that was confirmed on postnatal ultrasonography. The anteroposterior pelvic diameter (APPD) and the Society for Fetal Urology (SFU) grade were measured on 1-mo ultrasonography to assess the extent of hydronephrosis. Neonates with an APPD of or=55%) and renogram grades (1, not obstructive; 2, indeterminate; 3, obstructive; and 4, prolonged parenchymal transit) were determined on 1-mo (99m)Tc-MAG3 renography. Multivariate logistic regression analysis was performed to predict the presence of obstruction. RESULTS: Of the 48 kidneys with hydronephrosis, 19 were diagnosed as having UPJ obstruction. Twenty-nine kidneys were classified as having nonobstructive hydronephrosis. The APPD of the 19 kidneys with obstruction (24.3 +/- 9.2 mm) was significantly larger than that of the 29 kidneys without obstruction (17.5 +/- 11.2 mm; P < 0.05). The SFU grades of UPJ obstruction (2 with grade 3, 17 with grade 4) were also significantly higher than those without UPJ obstruction (grades 1-4 in 1, 6, 10, and 12 kidneys, respectively; P < 0.01). Supranormal function was present in 4 kidneys with UPJ obstruction but in none without obstruction (P < 0.001). (99m)Tc-MAG3 renography of the 19 obstructions showed grades 2, 3, and 4 renograms in 4, 8, and 7 patients, respectively. The 29 without obstruction revealed significantly lower grades (grades 1-4 in 10, 13, 5, and 1 patient, respectively; P < 0.001). Multivariate logistic regression analysis revealed that the addition of supranormal function or renogram grade in the model significantly increased the likelihood ratio in comparison with that of the SFU grade only (chi(2) = 7.73 and 9.99, respectively; P < 0.01). Of the 29 neonates with SFU grade 4, supranormal function or renogram >or= grade 4 had a positive predictive value of 90% (9/10). CONCLUSION: (99m)Tc-MAG3 renography at 1 mo after birth has a significant additive value in relation to the degree of hydronephrosis in predicting UPJ obstruction in patients with prenatally diagnosed unilateral hydronephrosis with normal function.