Right Ventricular Outflow Tract Obstruction by an Aneurysm of the Ventricular Membranous Septum: A Systematic Review of Case Reports.

We performed a literature search to identify the details of patients with right ventricular outflow tract obstruction caused by an aneurysm of the ventricular membranous septum in a perimembranous ventricular septal defect. Thirty-one cases with a median age of 29 years (range, 1-69 years) were studied. A right ventricle-pulmonary artery systolic pressure gradient ranged from 35 to 107 mm Hg (mean 69 mm Hg). An interventricular shunt was absent in eight patients: two children and six adults. It is necessary to monitor the size of an aneurysm of the ventricular membranous septum, whether or not an interventricular shunt is present.

Real-world efficacy and safety of glecaprevir/pibrentasvir in Japanese adolescents with chronic hepatitis C: a prospective multicenter study.

BACKGROUND: Part 1 of the DORA study, a 2019 international clinical trial of glecaprevir and pibrentasvir (G/P) treatment in adolescents with chronic hepatitis C virus (HCV) infection, demonstrated high efficacy and safety. However, few reports have considered real-world experience with G/P treatment in adolescents with chronic HCV. The present prospective multicenter study assessed real-world efficacy and safety of G/P treatment in Japanese adolescents with chronic HCV. METHODS: Subjects between 12 and 17 years old who were treatment-naïve or previously managed with interferon-based regimens were prospectively enrolled and treated with G/P (300 mg/120 mg) once daily for 8 or 12 weeks. The primary efficacy endpoint was sustained virologic response at 12 weeks after treatment completion (SVR12). Adverse effects and laboratory abnormalities were assessed. RESULTS: Twenty-five Japanese patients (15 female) were enrolled from 13 pediatric centers in Japan. Median age was 13 years (range 12-17). Numbers of patients with genotypes 1b, 2a, 2b, and 2b/1b were 6, 12, 6, and 1, respectively. Twenty-two were treatment-naïve, while three had experienced interferon-based treatments. All patients completed G/P treatment (24 for 8 weeks and 1 for 12). Twenty-four achieved SVR12 (96%). Most adverse events were mild. None were serious. G/P significantly decreased serum alanine aminotransferase, γ-glutamyltransferase, and Wisteria floribunda agglutinin-positive Mac-2-binding protein concentrations. No negative effects on growth or maturation were apparent at 12 weeks. CONCLUSIONS: Under real-world conditions, G/P treatment of Japanese adolescents with chronic HCV was highly efficacious and well tolerated.

Quadricuspid Pulmonary Valve: Case Report and the Comparison with Quadricuspid Aortic Valve.

BACKGROUND: Quadricuspid pulmonary valve (QPV) is a rare congenital anomaly. Simple QPV had been mainly diagnosed at the time of autopsy before 2000, and the frequency rates of QPV are approximately 0.02%-0.41%. QPV was initially diagnosed using transthoracic echocardiography (TTE) after 2000 and with contrast computed tomography (CT) or cardiac magnetic resonance imaging (CMR) after 2009. Obtaining the cross-sectional view of the pulmonary valve using TTE is difficult. We aimed to review the papers regarding the incidence, embryology, diagnosis, associated congenital heart anomalies, and prognosis in patients with QPV, and furthermore to compare with those in patients with quadricuspid aortic valve (QAV). CASE PRESENTATION: We diagnosed QPV with mild stenosis in a 12-month-old infant. With a slight angulation of the transducer superiorly from the left high parasternal short-axis view, a short-axis view of QPV was obtained. RESULTS: In QPV cases diagnosed at autopsy, Hurwitz's type-b with three equal cusps and one smaller cusp is dominant, whereas Hurwitz's type-a with four equal cusps is dominant in clinically diagnosed cases. Congenital heart anomaly and valvular stenosis are more frequent in patients with QPV than in patients with QAV. Coronary artery anomalies and infectious endocarditis are more frequent in patients with QAV than in patients with QPV. The incidence of PR is more common in type-a QPV than in type-b QPV. There is no difference between type-a QAV and type-b QAV with respect to the incidence of aortic regurgitation (AR). It is assumed that QPV is a risk factor for a Ross operation. However, QPVs have been used as autografts in certain patients. CONCLUSION: Between QPV and QAV, various differences were found in frequency rates, diagnostic methods, valve morphology, valve function, associated congenital heart diseases, and frequencies of infectious endocarditis.

Assessing liver stiffness with conventional cut-off values overestimates liver fibrosis staging in patients who received the Fontan procedure.

AIM: Patients who undergo the Fontan procedure for complex congenital heart disease are prone to liver cirrhosis. Liver stiffness (LS) reflects liver fibrosis stage in patients with chronic viral hepatitis; however, its accuracy in predicting liver fibrosis stage in Fontan patients is controversial. We aimed to clarify the correlation between LS and liver fibrosis stage in Fontan patients. METHODS: Fifty-eight Fontan patients were prospectively measured for LS with transient elastography. We undertook liver biopsy, cardiac catheterization, and laboratory tests in 22 of these patients (median age, 14.7 years; range, 9.9-32.1 years) with LS > 11.0 kPa (median, 19.2 kPa; range, 12.2-39.8 kPa); these elevated LS values suggest liver cirrhosis. RESULTS: Histologically, all patients showed mild-to-severe portal and sinusoidal fibrosis but no cirrhosis. Statistically, LS did not predict histological liver fibrosis scores (p = 0.175). Liver stiffness was not correlated with central venous pressure (p = 0.456) or with the hepatic venous pressure gradient (HVPG; p = 0.062), although the p value for HVPG was only slightly above the threshold for significance. CONCLUSIONS: Fontan patients are prone to developing both portal and sinusoidal fibrosis. Liver stiffness could be influenced by HVPG, and using the conventional cut-off values for LS overestimates and overtreats liver fibrosis in these patients.

Policy statement of enteral nutrition for preterm and very low birthweight infants.

For preterm and very low birthweight infants, the mother's own milk is the best nutrition. Based on the latest information for mothers who give birth to preterm and very low birthweight infants, medical staff should encourage and assist mothers to pump or express and provide their own milk whenever possible. If the supply of maternal milk is insufficient even though they receive adequate support, or the mother's own milk cannot be given to her infant for any reason, donor human milk should be used. Donors who donate their breast milk need to meet the Guideline of the Japan Human Milk Bank Association. Donor human milk should be provided according to the medical needs of preterm and very low birthweight infants, regardless of their family's financial status. In the future, it will be necessary to create a system to supply an exclusive human milk-based diet (EHMD), consisting of human milk with the addition of a human milk-derived human milk fortifier, to preterm and very low birthweight infants.

Clinical Features, Molecular Genetics, and Long-Term Outcome in Congenital Chloride Diarrhea: A Nationwide Study in Japan.

OBJECTIVE: To clarify clinical and genetic features of Japanese children with congenital chloride diarrhea (CCD). STUDY DESIGN: This was a multi-institutional, retrospective survey of 616 pediatric centers in Japan with identified patients with CCD between 2014 and 2018. Mutations involving SLC26A3 were detected by Sanger sequencing. RESULTS: Thirteen patients met all entry criteria including mutations in SLC26A3, and 14 patients satisfied clinical diagnostic criteria. Homozygous or compound heterozygous mutations in SLC26A3, including 6 novel mutations, were identified in 13 of these 14 patients (93%). The most common (detected in 7 of 13) was c.2063-1g>t. Median age at diagnosis was 1 day. Nine of the patients meeting all criteria were diagnosed as neonates (69%). Median follow-up duration was 10 years. When studied, 8 patients had <5 stools daily (62%), and all had fewer than in infancy. Only 1 patient had nephrocalcinosis, and 3 (23%) had mild chronic kidney disease. Neurodevelopment was generally good; only 1 patient required special education. Five patients (38%) received long-term sodium, potassium, and chloride supplementation. CONCLUSIONS: Early fetal ultrasound diagnosis and prompt long-term sodium, potassium, and chloride supplementation were common management features. Genetic analysis of SLC26A3 provided definitive diagnosis of CCD. In contrast with previously reported localities, c.2063-1g>t might be a founder mutation in East Asia.

A case of coronary-pulmonary artery fistula with coronary artery aneurysm detected for Kawasaki disease remote phase.

Follow-up echocardiography showed two coronary-pulmonary artery fistulae and a coronary artery aneurysm in a 12-year-old boy who had been diagnosed with Kawasaki disease without persistent coronary artery lesion at the acute phase when he was 6-months-old. Left coronary arteriogram confirmed the fistulae and the 4.3 × 6.3 mm aneurysm. Results show that the fistula is associated with Kawasaki disease.

Shwachman-Diamond syndrome: Nationwide survey and systematic review in Japan.

BACKGROUND: Shwachman-Diamond syndrome (SDS) is a rare multisystem disorder associated with exocrine pancreatic insufficiency. The present study reports the results of a nationwide survey and a systematic review on SDS to develop consensus guidelines for intractable diarrhea including SDS. METHODS: Questionnaires were sent to 616 departments of pediatrics or of pediatric surgery in Japan in a nationwide survey. A second questionnaire was sent to doctors who had treated SDS patients and included questions on clinical information. Additionally, a systematic review was performed using digital literature databases to assess the influence of medical (i.e. non-surgical) treatment on SDS prognosis. RESULTS: Answers were received from 529 institutions (85.9%), which included information on 24 patients with SDS (median age, 10.4 years; male, n = 15) treated from January 2005 to December 2014. Although 75% of patients received pancreatic enzyme replacement therapy, there was no significant association between treatment and prognosis. Systematic review identified one clinical practice guideline, two case series, eight case reports and 26 reviews. Patient information from those studies was insufficient for meta-analysis. CONCLUSIONS: The rarity of SDS makes it difficult to establish evidence-based treatment for SDS. According to the limited information from patients and published reports, medical treatment for malabsorption due to SDS should be performed to improve fat absorption and stool condition, but it is not clear whether this treatment improves the prognosis of malabsorption.

Rab11a is required for apical protein localisation in the intestine.

The small GTPase Rab11 plays an important role in the recycling of proteins to the plasma membrane as well as in polarised transport in epithelial cells and neurons. We generated conditional knockout mice deficient in Rab11a. Rab11a-deficient mice are embryonic lethal, and brain-specific Rab11a knockout mice show no overt abnormalities in brain architecture. In contrast, intestine-specific Rab11a knockout mice begin dying approximately 1 week after birth. Apical proteins in the intestines of knockout mice accumulate in the cytoplasm and mislocalise to the basolateral plasma membrane, whereas the localisation of basolateral proteins is unaffected. Shorter microvilli and microvillus inclusion bodies are also observed in the knockout mice. Elevation of a serum starvation marker was also observed, likely caused by the mislocalisation of apical proteins and reduced nutrient uptake. In addition, Rab8a is mislocalised in Rab11a knockout mice. Conversely, Rab11a is mislocalised in Rab8a knockout mice and in a microvillus atrophy patient, which has a mutation in the myosin Vb gene. Our data show an essential role for Rab11a in the localisation of apical proteins in the intestine and demonstrate functional relationships between Rab11a, Rab8a and myosin Vb in vivo.

Pediatric chronic intestinal pseudo-obstruction is a rare, serious, and intractable disease: a report of a nationwide survey in Japan.

BACKGROUND/PURPOSE: A nationwide survey was conducted to identify the clinical presentation of pediatric chronic intestinal pseudo-obstruction (CIPO) in Japan. METHODS: Data were collected via a questionnaire, ensuring patient anonymity, from facilities that treat pediatric gastrointestinal diseases in Japan. RESULTS: Ninety-two responses were collected from forty-seven facilities. Sixty-two patients (28 males, 34 females) met formal diagnostic criteria for CIPO. The estimated pediatric prevalence was 3.7 in 1 million individuals. More than half the children (56.5%) developed CIPO in the neonatal period. Full-thickness intestinal specimens were available for histopathology assessment in forty-five patients (72.6%). Forty-one (91.1%) had no pathological abnormalities and were considered to be idiopathic. Patients were treated according to the local protocol of each facility. Forty-one patients (66.1%) had restricted oral intake of ordinary diets, and twenty-nine (46.8%) depended on parenteral nutrition. No therapeutic intervention, including medication and surgery, successfully improved oral food intake or obstructive symptoms. Only three patients (4.8%) died from enteritis or sepsis. CONCLUSIONS: In Japan, pediatric CIPO is a rare, serious, and intractable disease. The prognosis with respect to survival is good, but unsatisfactory because of the need for prolonged parenteral nutrition and associated potential for restricted quality of life.

Sodium-coupled neutral amino acid transporter 4 functions as a regulator of protein synthesis during liver development.

AIM: The molecular mechanisms by which hepatocyte nuclear factor (HNF)4α regulates fetal liver development have not been fully elucidated. We screened the downstream molecules of HNF4α during liver development and identified sodium-coupled neutral amino acid transporter (SNAT)4. The aim of this study is to investigate the regulation of SNAT4 by HNF4α and to clarify its roles in differentiating hepatocytes. METHODS: HNF4α was overexpressed in cultured liver buds using adenovirus, and suppression subtractive hybridization screening was performed. Temporal and spatial expression of SNAT4 during liver development was investigated. Regulation of SNAT4 by HNF4α was examined by promoter analyses and electrophoretic mobility shift assays (EMSA). Metabolic labeling and western blotting were carried out using primary hepatoblasts with SNAT4 overexpression. RESULTS: The expression of Slc38a4 encoding SNAT4 showed a marked perinatal increase, and was predominant among system A amino acid transporters. It was first detected in embryonic day 18.5 liver, and found in most hepatocytes after birth. Three alternative first exons were found in the SNAT4 gene. Promoter analyses using approximately 3-kb fragments corresponding to each first exon (AP1, AP2, AP3) revealed that AP1 and AP2 exhibited strong promoter activity in mouse hepatoblasts with endogenous HNF4α. Transactivation of AP2 was upregulated by HNF4α in HeLa cells without endogenous HNF4α. EMSA has demonstrated that HNF4α directly binds to cis-elements in AP2. Overexpression of SNAT4 facilitated amino acid uptake and de novo protein synthesis in primary hepatoblasts. CONCLUSION: SNAT4 functions downstream of HNF4α and plays significant roles in liver development through mechanisms of amino acid uptake and protein synthesis.

Fatigue and quality of life in citrin deficiency during adaptation and compensation stage.

Citrin-deficient children and adolescents between adult-onset type II citrullinemia and neonatal intrahepatic cholestasis by citrin deficiency do not have clear clinical features except for unusual diet of high-fat, high-protein, and low-carbohydrate food. The aims of the present study are to characterize fatigue and quality of life (QOL) in citrin-deficient patients during adaptation and compensation stage, and to define the relationship between fatigue and QOL. The study subjects were 55 citrin-deficient patients aged 1-22years (29 males) and 54 guardians. Fatigue was evaluated by self-reports and proxy-reports of the PedsQL Multidimensional Fatigue Scale. QOL was evaluated by the PedsQL Generic Core Scales. Both scale scores were significantly lower in child self-reports (p<0.01 and p<0.05, respectively) and parent proxy-reports (p<0.01 and p<0.01, respectively) than those of healthy children. Citrin-deficient patients with scores of 50 percentile or less of healthy children constituted 67.5% of the sample for the Fatigue Scale and 68.4% for the Generic Core Scales. The PedsQL Fatigue Scale correlated with the Generic Core Scales for both the patients (r=0.56) and parents reports (r=0.71). Assessments by the patients and their parents showed moderate agreement. Parents assessed the condition of children more favorably than their children. The study identified severe fatigue and impaired QOL in citrin-deficient patients during the silent period, and that such children perceive worse fatigue and poorer QOL than those estimated by their parents. The results stress the need for active involvement of parents and medical staff in the management of citrin-deficient patients during the silent period.

Humoral immunity is involved in the development of pericentral fibrosis after pediatric live donor liver transplantation.

Although LT can be successful for treating end-stage liver disease in children, some patients develop fibrosis around the central vein area (PCF). This raises the possibility that PCF could lead to later cirrhosis and graft failure. Here, we report a retrospective immunohistochemical study of 28 patients who received a live donor liver transplant. We assessed the incidence and etiology of PCF using CD3, CD20, HLA-DR, and C4d-specific antibodies. Histological evidence of PCF was found in 13 cases (46.4%), of which 11 (84.6%) had experienced ACR and/or CP events post-transplant. Immunohistochemical evaluation revealed significantly stronger staining with these antibodies in the central vein area in PCF, especially for CD20 and C4d. This implies humoral immunopathology and suggests involvement of humoral immunity in the development of PCF. These results further imply that suppression of cellular immunity alone is insufficient to prevent PCF. We therefore suggest that suppression of both humoral and cellular immunity in combination would be required for prevention of PCF.

Graft fibrosis in patients with biliary atresia after pediatric living-related liver transplantation.

Although an LDLT can successfully treat biliary atresia (BA), some patients develop liver fibrosis or inflammation. To study the incidence and risk factors associated with these complications, we performed serial protocol biopsies. Twenty-four patients with BA who received a pediatric LDLT underwent protocol biopsies. All patients received standard tacrolimus-based immunosuppression and steroids. The last available biopsies were assessed. The mean age at the time of transplant was 4.8yr and the follow-up period ranged from 1.2 to 12.3yr. The GRWR ranged from 0.8% to 4.5%. The mean time from transplantation to the latest biopsy was 4.7yr. No complications occurred with the biopsy protocol. The last available biopsies for 13 (54%) and 4 (17%) patients indicated grade 1 and grade 2 portal fibrosis, respectively, and 14 patients (54%) had inflammation. No ductopenia was detected. A younger age at LDLT was significantly correlated with graft fibrosis (p=0.036). These results indicate that biopsy-proven fibrosis can be detected in patients with BA after LDLT, even in the context of normal liver function blood tests. Therefore, a serial biopsy is a safe and effective follow-up procedure for pediatric LDLT.

Major role of apolipoprotein B in cycloheximide-induced acute hepatic steatosis in mice.

AIM: Hepatic steatosis accompanied by impaired protein synthesis is often observed in hepatic dysfunction. To assess whether protein synthesis inhibition directly induces hepatic steatosis, we investigated the molecular mechanisms of cycloheximide (CHX)-induced fatty liver mice. METHODS: C57/BL6CR mice were i.p. administrated CHX (20 mg/kg) three times every 4 h to induce hepatic steatosis. Hepatic lipid secretion, fatty acid oxidation, hepatic lipogenesis and hepatic lipid uptake were evaluated. RESULTS: Twenty-four hours after the first CHX injection, hepatic lipid levels increased in CHX-treated mice to 1.8-fold of that in controls but returned to normal within 48 h. The hepatic triglyceride (TG) secretion rate decreased significantly to 22% of controls, and the apolipoprotein B (apoB) protein level, but not microsomal TG transfer protein, decreased in CHX-treated mice. The apob gene expression was not significantly different between controls and CHX-treated mice. On the other hand, plasma free fatty acid and lipogenic protein levels did not increase and plasma ß-hydroxybutyrate level remained stable, suggesting that the coordinated balance between fatty acid oxidation, hepatic lipid uptake and lipogenesis was not disrupted in this model. Cellular lipid accumulation and decreased cellular and secreted apoB were also observed in CHX-treated HepG2 cells. Knockdown of apoB in HepG2 cells also resulted in the cellular TG accumulation. CONCLUSION: We demonstrated that decreased hepatic lipid secretion due to acute apoB reduction is involved in the pathogenesis of CHX-induced liver steatosis.

Histological findings in the livers of patients with neonatal intrahepatic cholestasis caused by citrin deficiency.

AIM: To characterize the histological features of the livers of patients with neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD), we studied specimens from 30 patients diagnosed with NICCD by genetically analyzing the SLC25A13 gene. METHODS: Liver biopsy specimens were subjected to hematoxylin-eosin, Azan, and Berlin-blue staining. RESULTS: Most specimens showed varying degrees of fibrosis. The degree of inflammation varied among the specimens, with half showing moderate or severe inflammatory changes. Fat deposition in hepatocytes was observed in almost all of the specimens, and severe fatty liver was noted in 20 (67%) of them. There was a mixture of two types of hepatocytes with macrovesicular or microvesicular fat droplets, and cholestasis was observed at a rate of 77%. Hemosiderin deposition, mostly mild and localized in periportal hepatocytes and macrophages in portal areas, was observed in 57% of the specimens. CONCLUSION: A combination of mixed macrovesicular and microvesicular fatty hepatocytes and the above-described findings, such as fatty liver, cholestasis, necroinflammatory reaction and iron deposition, are almost never observed in other liver diseases in infants and adults. We believe that NICCD is a disease with characteristic hepatopathological features.

Increased type 3 iodothyronine deiodinase activity in a regrown hepatic hemangioma with consumptive hypothyroidism.

INTRODUCTION: Infantile hepatic hemangioma with consumptive hypothyroidism is a rare condition. CASE REPORT: A 4-month-old girl presented with diffuse hepatic hemangiomas during treatment of congenital hypothyroidism. Serum reverse triiodothyronine was elevated, and her hypothyroidism improved concomitant with involution of the hemangioma following prednisolone and interferon-alpha administration. At 20 months of age, 7 months after discontinuing prednisolone and interferon-alpha, a focal hemangioma regrew from one of the previous lesions and was surgically resected. The expression and activity of type 3 iodothyronine deiodinase (D3) were elevated in the resected tumor tissue compared with placenta. DISCUSSION: Here, we describe a patient with consumptive hypothyroidism and diffuse infantile hepatic hemangiomas, one of which regrew after involution following pharmacotherapy. The etiology of elevated D3 activity is also discussed. CONCLUSION: It is important to identify infantile hepatic hemangioma in patients with hypothyroidism refractory to hormone replacement therapy, who have low free triiodothyronine despite high thyrotropin and normal free thyroxine levels, and long-term follow-up will be needed for these patients.

A case of pediatric virilizing adrenocortical tumor resulting in hypothalamic-pituitary activation and central precocious puberty following surgical removal.

We present a 6-year-old boy with a virilizing adrenocortical tumor who initially presented with peripheral precocious puberty. Development of facial acne, pubic hair and a growth spurt were noted at the age of five. A low-pitched voice as well as maturation of external genitalia was noted at the age of six. Both serum and urinary levels of adrenal androgens were elevated. Abdominal computed tomography revealed a large right suprarenal mass and he underwent surgical resection without any complications. The histological diagnosis was adrenocortical carcinoma according to the criteria of Weiss. Following surgical removal of the androgen-producing tumor, the patient subsequently developed hypothalamic-pituitary activation and demonstrated central precocious puberty. He was treated with a gonadotropin-releasing hormone agonist in order to delay further pubertal progression. Clinical follow-up of potential secondary effects of excess hormone secretion after removal is important in some pediatric patients with virilizing adrenocortical tumor.

Endocrinological analysis of 122 Japanese childhood cancer survivors in a single hospital.

With recent improvements in the diagnosis and treatment of cancer, the number of childhood cancer survivors (CCSs) has been increasing in Japan. The importance of quality of life during the lifetime of CCSs has now been recognized, and the late effects of cancer treatments are essential and important issues. In this study we analyzed the endocrinological abnormalities of CCSs by retrospectively evaluating 122 outpatients (62 males and 60 females) who had been referred from pediatric oncologists to our follow-up clinic among 151 CCSs attending our hospital more than two years after their cancer treatment. Follow-up duration varied from 2 to 30 (median 8.0) years. Their average age was 17.3 (range 4-36, median 17.0) years, and 38 patients (31.1%) reached adulthood. Endocrinological abnormalities were found in 82 (67%) of 122 survivors. Gonadal dysfunction was observed in 60 patients (49%). Thirty-nine patients (32%) were short or grew at a slower rate. Twenty-six patients (21%) showed thyroid dysfunction. Other abnormalities were as follows: obesity in 20 patients (16%), leanness in 10 (8%), central diabetes insipidus in 11 (9%) and adrenocortical dysfunction in 9 (7%). Low bone mineral density was observed in 41 (42%) of 98 patients evaluated. These endocrinological abnormalities were caused by the combined effects of cancer itself and various treatments (chemotherapy, radiation therapy, surgery, and hematopoietic stem cell transplantation). Lifetime medical surveillance and continuous follow-up are necessary for CCSs, because treatment-related complications may occur during childhood and many years after the therapy as well. Endocrinologists should participate in long-term follow-up of these survivors in collaboration with pediatric oncologists.

Abnormal computed tomography findings among children with viral gastroenteritis and symptoms mimicking acute appendicitis.

OBJECTIVE: To evaluate computed tomography (CT) findings in pediatric patients with viral gastroenteritis who presented with clinical features of acute abdomen. PATIENTS AND METHODS: During 2 seasons of viral gastroenteritis from 2005 to 2007, 302 children with acute gastrointestinal symptoms were admitted to our center for treatment of dehydration and associated complications. Stool specimens obtained from 130 of the 302 were tested for norovirus with the reverse transcriptase-polymerase chain reaction method. RESULTS: Among the 130 patients, 44 tested positive for norovirus, 34 for rotavirus, and 1 for adenovirus. In the remaining 51, except one with Campylobacter jejuni, no viral or bacterial pathogen was detectable. An abdominal CT scan was performed in 4 patients with norovirus and in 1 with rotavirus for suspected acute abdomen including acute appendicitis. Computed tomography (CT) findings were similar among the 5 patients, including thickening of the bowel wall and fluid-filled bowel loops in the small intestine with no pathological findings in the stomach, appendix, or colon. CONCLUSIONS: Anatomical changes in the small intestine were shown by CT in 5 children with viral gastroenteritis who presented with acute abdomen. These imaging features of viral gastroenteritis may be useful in differential diagnosis of acute abdomen to avoid unnecessary surgery.