So-Young Yoo

Neurodevelopmental Outcomes in Preterm Infants: Comparison of Infants with and without Diffuse Excessive High Signal Intensity on MR Images at Near–term-equivalent Age

PURPOSEnTo compare the neurodevelopmental outcomes between preterm infants with diffuse excessive high signal intensity (DEHSI) and those without DEHSI on magnetic resonance (MR) images, in association with other white matter lesions.nnnMATERIALS AND METHODSnThis retrospective study was approved by the institutional review board, and requirement to obtain informed consent was waived. High-risk preterm infants (n = 126) who underwent screening brain MR imaging at near-term-equivalent age were classified into two groups according to the presence of DEHSI. Bayley Scales of Infant Development-II, presence of cerebral palsy, and neurosensory impairment between 18 and 24 months of age were compared between the two groups. The associations of MR findings of other white matter lesions (cystic encephalomalacia, punctate lesions, loss of volume, ventricular dilatation, and delayed myelination) and subsequent outcomes were also analyzed. Outcome data were evaluated by using exact logistic regression analyses and Fisher exact test.nnnRESULTSnDEHSI was present in 75% (95 of 126) of infants. Subsequent neurodevelopmental outcomes did not differ significantly between the two groups. Severe motor delay and cerebral palsy were more common in infants with both DEHSI and other white matter lesions as compared with infants with normal white matter (P = .001 and P < .001, respectively). Among other white matter lesions, cystic encephalomalacia (odds ratio, 19.6; 95% confidence interval: 1.3, 333.3) and punctate lesions (odds ratio, 90.9; 95% confidence interval: 6.4, 1000) were significant predictors of cerebral palsy.nnnCONCLUSIONnAlthough the incidence of DEHSI was high (75%) in preterm infants at near-term-equivalent age MR imaging, DEHSI was not predictive of following adverse outcomes. Cystic encephalomalacia and punctate lesions were more significant predictors of cerebral palsy.

Posttransplantation Lymphoproliferative Disorder in Children: Manifestations in Hematopoietic Cell Recipients in Comparison with Liver Recipients

PURPOSEnTo compare the clinical and imaging features of posttransplantation lymphoproliferative disorder (PTLD) in pediatric patients who underwent hematopoietic cell transplantation with those in pediatric patients who underwent liver transplantation.nnnMATERIALS AND METHODSnThis study was approved by the institutional review board, and the requirement to obtain informed consent was waived. The authors retrospectively reviewed the medical records and images of 552 hematopoietic cell transplant recipients and 195 liver transplant recipients. PTLD was histopathologically confirmed in 17 of the patients who underwent hematopoietic cell transplantation and 27 of the patients who underwent liver transplantation. The overall frequency, clinical course, histopathologic type, and imaging findings of PTLD were compared between the two patient groups by using the Fisher exact test.nnnRESULTSnThe overall frequency of PTLD was 3% (17 of 552 patients) after hematopoietic cell transplantation (12% [nine of 75 patients] after umbilical cord blood transplantation) and 14% (27 of 194 patients) after liver transplantation. PTLD occurred within 6 months of transplantation in 14 of the 17 hematopoietic cell recipients (82%) and 11 of the 27 liver recipients (41%) (P = .012). Histopathologic examination revealed monomorphic disease in 11 of the 17 hematopoietic cell recipients (65%) and eight of the 27 liver recipients (30%) (P = .031). The abdomen was the most common site of involvement in both groups. Extraabdominal PTLD developed in 12 of the 17 hematopoietic cell recipients (71%) and five of the 27 liver recipients (19%) (P = .002). Although 15 of the 17 patients with hematopoietic cell transplantation-related PTLD (88%) exhibited responses after treatment, the overall mortality rate was 35% (six of 17 patients). All 27 patients with PTLD after liver transplantation improved after treatment and remain alive.nnnCONCLUSIONnPTLD after umbilical cord blood transplantation occurred as frequently as liver transplantation-related PTLD. Compared with liver transplantation-related PTLD, PTLD after hematopoietic cell transplantation is characterized by an earlier onset, a higher proportion of malignant monomorphic disease, and a worse outcome.

Pancreatic Metastasis in a Child Suffering with Treated Stage 4 Neuroblastoma

We present here a very rare case of metastatic relapse in the pancreas of a 4-year-old boy who had been treated for stage 4 neuroblastoma. Computed tomography showed multiple metastatic masses in the pancreas with secondary pancreatitis. To the best of our knowledge, this is the first case report of pancreatic metastasis in a child with neuroblastoma.

Sporadic meningioangiomatosis: imaging findings with histopathologic correlations in seven patients

IntroductionMeningioangiomatosis (MA) is a rare benign cerebral lesion. We aimed to evaluate the CT and MR features of sporadic MA, with a focus on the correlation between imaging and histopathologic findings.MethodsCT (nu2009=u20097) and MR (nu2009=u20098) images of eight patients (6 men and 2 women; mean age, 12.8xa0years; range, 4–22xa0years) with pathologically proven MA were retrospectively reviewed. After dividing the MA lesions according to their distribution into cortical and subcortical white matter components, the morphologic characteristics were analyzed and correlated with histopathologic findings in seven patients.ResultsCT and MR images showed cortical (nu2009=u20094, 50xa0%) and subcortical white matter (nu2009=u20097, 88xa0%) components of MA. All four cortical components revealed hyperattenuation on CT scan and T1 isointensity/T2 hypointensity on MR images, whereas subcortical white matter components showed hypoattenuation on CT scan and T1 hypointensity/T2 hyperintensity on MR images. Two cortical components (25xa0%) demonstrated enhancement and one subcortical white matter component demonstrated cystic change. Seven cases were available for imaging-histopathologic correlation. In all seven cases, the cortex was involved by MA and six patients (86xa0%) showed subcortical white matter involvement by MA. There were excellent correlations between the imaging and histopathologic findings in subcortical white matter components, and the accuracy was 100xa0% (seven of seven); whereas there were poor correlations in cortical components, and the accuracy was 43xa0% (three of seven).ConclusionsThe cerebral cortex and subcortical white matter were concomitantly involved by MA. Subcortical white matter components of MA were more apparent than cortical components on CT and MR imaging.

Dynamic MRI Findings and Clinical Features of Benign Hypervascular Hepatic Nodules in Childhood-Cancer Survivors

OBJECTIVEnThe purpose of this study is to investigate the dynamic MRI findings and clinical features of benign hypervascular hepatic nodules in childhood-cancer survivors.nnnMATERIALS AND METHODSnWe reviewed dynamic MRI findings and clinical features in 15 patients who had been treated for childhood malignant solid tumors and in whom hypervascular hepatic nodules were later found on surveillance imaging by either CT or ultrasound (or both). The benign nature of the lesion was based on histologic examination or clinical and radiologic follow-up (or both).nnnRESULTSnTime between initial diagnosis of malignancy and detection of the hepatic nodule ranged from 4.5 to 13.5 years with the majority of the malignancies being neuroblastoma treated by high-dose chemotherapy and hematopoietic stem cell transplantation. A total of 43 nodules were detected, often multiple and small. Most of the lesions were isointense or slightly hyperintense on T2-weighted imaging and isointense or slightly hypointense on T1-weighted imaging. All nodules had intense enhancement on the arterial phase and were isointense or slightly hyperintense on the delayed phase. A central scar was seen in four. Additionally, hepatic hemosiderosis was noted in four patients, in whom all the lesions were hyperintense on both T1- and T2-weighted imaging.nnnCONCLUSIONnBenign hypervascular hepatic nodules in survivors of childhood malignancy occur years after high-dose chemotherapy and hematopoietic stem cell transplantation. Dynamic MRI findings including intense arterial enhancement and absence of washout in the delayed phase are of great value in the differential diagnosis of these hepatic nodules.

Clinical and Imaging Features of Focal Nodular Hyperplasia in Children

OBJECTIVEnThe purpose of this article is to review the clinical and imaging features of focal nodular hyperplasia (FNH) developed in children.nnnMATERIALS AND METHODSnAt a single institution, pediatric patients who underwent imaging studies and who had pathologically proven FNH were studied. Clinical characteristics, including presenting symptoms and signs and the presence of underlying disease, were reviewed from the medical records. Imaging features of FNHs, including the number, size, ultrasound echogenicity and vascularity, CT attenuation, MRI signal intensity and enhancement pattern, and the presence of a central scar, were evaluated.nnnRESULTSnTwenty-five patients (11 boys and 14 girls; median age, 8.6 years) were found to have a solitary (n = 23) or multiple (n = 2) FNH lesions with a mean size of 4.9 cm (range, 1-10 cm). Multiple lesions were associated with small size of the lesions and history of malignancy treated by chemotherapy. Most patients were asymptomatic (n = 22). Biliary atresia was the most common underlying disease (n = 5). On ultrasound, FNHs most commonly appeared to be isoechoic and hypervascular. On dynamic CT and MRI, strong enhancement on the arterial phase and becoming isoattenuated or of isointense signal intensity on the portal or delayed phase was common. A central scar was usually noted in large lesions in about half the cases.nnnCONCLUSIONnPediatric FNH is uncommon and usually is found incidentally in otherwise healthy children. However, it may occur in children who have underlying diseases, including biliary atresia. In addition, it can be encountered during surveillance of childhood cancer survivors with less common imaging features, including lack of a central scar and multiplicity.

Imaging findings of Alagille syndrome in young infants: differentiation from biliary atresia

OBJECTIVEnTo compare the imaging findings using ultrasonography, MR cholangiopancreatography (MRCP), and intraoperative cholangiography (IOC) between Alagille syndrome (AGS) and biliary atresia (BA) in young infants with cholestatic jaundice.nnnMETHODSnThe institutional review board approved this retrospective study. Ultrasonography (n = 55), MRCP (n = 33), and IOC (n = 22) studies were performed in 55 infants (all younger than 3 months) with AGS (n = 7) and BA (n = 48). The ultrasound images were reviewed focusing on gallbladder (GB) abnormalities, triangular cord sign, hepatic artery enlargement and signs of portal hypertension. Visualization of the extrahepatic biliary tree was assessed by MRCP and IOC.nnnRESULTSnSix (86%) AGS patients showed a small GB on ultrasound; this was comparable to that in BA patients (81%, 35/43). The images were negative for triangular cord sign and hepatic artery enlargement in all AGS patients, whereas they were positive in 48% (23/48) (p = 0.034) and 77% (33/43) (p < 0.001) of the BA patients, respectively. Signs of portal hypertension were less common in AGS patients than in BA patients (p = 0.010). Although non-visualization of the extrahepatic biliary tree by MRCP did not differ significantly between patients with AGS and BA, AGS patients showed a higher proportion of visible common bile ducts with IOC, compared to BA patients. The diagnosis of AGS was made in four infants (57%) before ultrasonography, based on extrahepatic manifestations.nnnCONCLUSIONnThe small GB visualized on ultrasonography and non-visualization of extrahepatic biliary tree by MRCP commonly occurred in patients with either AGS or BA. However, triangular cord sign, hepatic artery enlargement and signs of portal hypertension onultrasonography and non-visualized common bile duct with IOC were less frequent in AGS patients than in BA patients. Advances in knowledge: Atypical imaging findings for BA should prompt a meticulous evaluation for the extrahepatic manifestations of AGS to avoid possibly harmful surgery.

Early US findings of biliary atresia in infants younger than 30 days

AbstractPurposeTo investigate and compare ultrasound (US) findings for the diagnosis of biliary atresia (BA) in infants younger than 30 days with those of infants older than 30 days.Materials and MethodsFrom 2000 to 2015, we reviewed hepatobiliary US images in 12 BA infants younger than 30 days (younger BA group) and 62 BA infants older than 30 days (older BA group) before Kasai procedure. Eight (67%) of younger BA group underwent follow-up US examinations before Kasai procedure. Our review of the images focused on triangular cord sign, gallbladder (GB) abnormalities, vascular changes, and signs of portal hypertension.ResultsThe triangular cord sign was present in 17% of younger BA group and in 56% of older BA group (P=.024). GB abnormalities were commonly identified in both groups. The hepatic artery diameter was significantly smaller in younger BA group than in older BA group (P<.001). Signs of portal hypertension were less common in younger BA group (17%) than in older BA group (84%) (P<.001). Follow-up US of two infants in younger BA group showed a new appearance of the triangular cord sign.ConclusionBA infants younger than 30 days showed atypical US findings compared with those older than 30 days.Key Points• BA infants younger than 30 days show atypical US findings.n • GB abnormalities were common in both younger and older BA group.n • Subsequent US examination may be helpful to diagnose BA in young infants.

Pediatric Skeletal Trauma

The unique features of the growing bone result in skeletal injuries that are different from those seen in adults and tend to change with skeletal maturity.

Non-neonatal Gastrointestinal Diseases

Abdominal pain and vomiting are the most common presentation of gastrointestinal tract disorders in children that lead to imaging. According to the suspected disease, the age of the child, and the institutions preferences, various imaging modalities, including radiography, US, barium study, or CT or MR have been used for examining the gastrointestinal tract. After the neonatal period, a different set of disorders involves the gastrointestinal tract in infants and children, sometimes producing acute abdomen. Intussusception is the most common cause of acute abdomen in infants and young children. Hypertrophic pyloric stenosis should be ruled out in a young infant with vomiting. A strangulated inguinal hernia, complicated Meckel’s diverticulum or necrotizing enterocolitis, and malrotation with volvulus are other causes of acute abdomen, both in the neonatal period and infancy. Acute appendicitis is the most common surgically treated condition in older children. Appropriate and judicious use of imaging techniques should be made by paying attention to clinical history and physical findings, which, in conjunction with knowledge of imaging findings of pediatric gastrointestinal disorders, will allow an early diagnosis to be made as well as guiding a proper treatment.