Prevalence of Incidentally Detected Spondylolysis in Children

Purpose@#To assess the prevalence of incidentally detected lumbar spondylolysis in children. @*Materials and Methods@#We retrospectively reviewed the data of 809 patients under the age of 11 years (mean age, 7.0 ± 2.7 years; boys:girls = 479:330) who underwent abdominal and pelvic CT between March 2014 and December 2018. We recorded the presence, level, and laterality (unilateral or bilateral) of spondylolysis. Patients were divided into two groups based on the presence of spondylolysis: the spondylolysis (SP) and non-SP groups. @*Results@#In total, 21 cases of spondylolysis were detected in 20 patients (20/809, 2.5%). The mean age of the SP group was higher than that of the non-SP group (7.8 ± 1.8 vs. 6.9 ± 2.7 years, p > 0.05). The prevalence of spondylolysis in boys was higher than that in girls (15/479 [3.1%] vs. 5/330 [1.5%], p > 0.05). The prevalence of spondylolysis in school-age children (6–10 year olds) was higher than that in preschool-age children (0–5 year olds) (17/538 [3.2%] vs. 3/271 [1.1%], p > 0.05). L5 was the most common level of spondylolysis (76.2%); one 8-year-old boy had twolevel spondylolysis. One case of isthmic spondylolisthesis was detected in a 10-year-old boy (1/809, 0.1%). There were 11 unilateral spondylolysis cases (11/21, 52.4%). @*Conclusion@#In our study, the prevalence of spondylolysis in children under the age of 11 was 2.5%. The prevalence was higher in boys than in girls and in school-age than in preschool-age children, despite the lack of any statistically significant differences.

Kleefstra syndrome combined with vesicoureteral reflux and rectourethral fistula: a case report and literature review

Kleefstra syndrome is a rare genetic disease characterized by mental retardation, hypotonia, and a characteristic facial appearance. Furthermore, in some cases, Kleefstra syndrome is associated with various anorectal and genitourinary complications, including imperforated anus, vesicoureteral reflux, hydronephrosis, and chronic kidney disease. Herein, we present a case of Kleefstra syndrome with recurrent urinary tract infections associated with vesicoureteral reflux and rectourethral fistula, which was treated by a multidisciplinary approach.

Feasibility of Pediatric Low-Dose Facial CT Reconstructed with Filtered Back Projection Using Adequate Kernels

Purpose@#To evaluate the feasibility of pediatric low-dose facial CT reconstructed with filtered back projection (FBP) using adequate kernels. @*Materials and Methods@#We retrospectively reviewed the clinical and imaging data of children aged 0.05). Group A showed a 76.9% reduction in radiation dose compared to Group B (3.2 ± 0.2 mGy vs. 81.9 ± 11.1 mGy; p < 0.001). @*Conclusion@#The addition of a soft tissue kernel image to conventional CT reconstructed with FBP enables the use of pediatric low-dose facial CT protocol while maintaining image quality.

Incidentally Detected Asymptomatic Perianal Abscess in an Adolescent during Crohn's Disease Diagnosis: Is Routine Pelvic Imaging Required in Korean Pediatric Patients at Diagnosis? / 대한소아소화기영양학회지

Perianal fistulizing diseases, namely perianal fistulas and/or abscesses, are well-known complications of Crohn's disease (CD). These are known to develop more frequently in Asian children with CD, especially in the early stages of the disease course. Approximately half of the pediatric CD cases in Korea present with perianal fistulizing diseases at diagnosis. We report a rare case of a 12-year-old boy with CD with an incidental discovery of a perianal abscess on pelvic magnetic resonance imaging during CD diagnosis. No symptoms or signs of perianal fistulizing disease were identified. The early diagnosis of the perianal abscess enabled timely and effective treatment. Considering the high incidence of concomitant perianal CD in Korean children at diagnosis, perianal imaging may be useful and should be considered during diagnostic evaluation, even in patients with no subjective or objective findings indicating perianal CD.

Establishment of Local Diagnostic Reference Levels of Pediatric Abdominopelvic and Chest CT Examinations Based on the Body Weight and Size in Korea

Objective@#The purposes of this study were to analyze the radiation doses for pediatric abdominopelvic and chest CT examinations from university hospitals in Korea and to establish the local diagnostic reference levels (DRLs) based on the body weight and size. @*Materials and Methods@#At seven university hospitals in Korea, 2494 CT examinations of patients aged 15 years or younger (1625 abdominopelvic and 869 chest CT examinations) between January and December 2017 were analyzed in this study. CT scans were transferred to commercial automated dose management software for the analysis after being de-identified. DRLs were calculated after grouping the patients according to the body weight and effective diameter. DRLs were set at the 75th percentile of the distribution of each institution’s typical values. @*Results@#For body weights of 5, 15, 30, 50, and 80 kg, DRLs (volume CT dose index [CTDIvol]) were 1.4, 2.2, 2.7, 4.0, and 4.7 mGy, respectively, for abdominopelvic CT and 1.2, 1.5, 2.3, 3.7, and 5.8 mGy, respectively, for chest CT. For effective diameters of 24 cm, DRLs (size-specific dose estimates [SSDE]) were 4.1, 5.0, 5.7, 7.1, and 7.2 mGy, respectively, for abdominopelvic CT and 2.8, 4.6, 4.3, 5.3, and 7.5 mGy, respectively, for chest CT.SSDE was greater than CTDIvol in all age groups. Overall, the local DRL was lower than DRLs in previously conducted dose surveys and other countries. @*Conclusion@#Our study set local DRLs in pediatric abdominopelvic and chest CT examinations for the body weight and size.Further research involving more facilities and CT examinations is required to develop national DRLs and update the current DRLs.

Establishment of Local Diagnostic Reference Levels of Pediatric Abdominopelvic and Chest CT Examinations Based on the Body Weight and Size in Korea

Objective@#The purposes of this study were to analyze the radiation doses for pediatric abdominopelvic and chest CT examinations from university hospitals in Korea and to establish the local diagnostic reference levels (DRLs) based on the body weight and size. @*Materials and Methods@#At seven university hospitals in Korea, 2494 CT examinations of patients aged 15 years or younger (1625 abdominopelvic and 869 chest CT examinations) between January and December 2017 were analyzed in this study. CT scans were transferred to commercial automated dose management software for the analysis after being de-identified. DRLs were calculated after grouping the patients according to the body weight and effective diameter. DRLs were set at the 75th percentile of the distribution of each institution’s typical values. @*Results@#For body weights of 5, 15, 30, 50, and 80 kg, DRLs (volume CT dose index [CTDIvol]) were 1.4, 2.2, 2.7, 4.0, and 4.7 mGy, respectively, for abdominopelvic CT and 1.2, 1.5, 2.3, 3.7, and 5.8 mGy, respectively, for chest CT. For effective diameters of 24 cm, DRLs (size-specific dose estimates [SSDE]) were 4.1, 5.0, 5.7, 7.1, and 7.2 mGy, respectively, for abdominopelvic CT and 2.8, 4.6, 4.3, 5.3, and 7.5 mGy, respectively, for chest CT.SSDE was greater than CTDIvol in all age groups. Overall, the local DRL was lower than DRLs in previously conducted dose surveys and other countries. @*Conclusion@#Our study set local DRLs in pediatric abdominopelvic and chest CT examinations for the body weight and size.Further research involving more facilities and CT examinations is required to develop national DRLs and update the current DRLs.

Gastrointestinal Emergencies in Neonates: What We Should Know

Newborn gastrointestinal tract emergency diseases include various disorders that occur anywhere along the digestive tract. Most of them are congenital malformations, not acquired diseases. Many of them cannot be confirmed on prenatal examination, and consequently, postnatal evaluation is required. Unlike adults, in newborn babies, detailed evaluations with computed tomography (CT) and magnetic resonance imaging (MRI) are often limited, so making the diagnosis based on early abdominal radiography is most important. Therefore, it is necessary to be familiar with the radiologic findings that may be seen on imaging studies. In addition, it is important to understand abdominal ultrasound and fluoroscopy findings, which can be used in addition to simple radiography and indications that can be used for further diagnosis and appropriate treatment. Therefore, this study describes and organizes the various imaging findings that may occur in neonatal gastrointestinal emergencies.

Clinical Characteristics of Ureteral Duplication in Children

PURPOSE: Ureteral duplication is a relatively common congenital urinary tract abnormality that can be associated with various clinical problems such as vesicoureteral reflux (VUR), hydronephrosis, and ectopic ureters. The purpose of this study was to analyze the clinical characteristics of pediatric patients with recently diagnosed ureteral duplication and to identify any differences from those described in previous reports.METHODS: We retrospectively reviewed the clinical characteristics and course of pediatric patients who were diagnosed with ureteral duplication between January 2008 and June 2017.RESULTS: A total of 32 pediatric patients were diagnosed with ureteral duplication during the study period. The male to female ratio was 1:2.2. Twenty-seven patients (84.4%) were first diagnosed with ureteral duplication at less than 3 months of age, and 26 (81.3%) were first diagnosed by prenatal ultrasonography. Four of the 32 patients were diagnosed with bilateral ureteral duplication, for a total of 36 occurrences of ureteral duplication. In 17 occurrences of complete ureteral duplication (47.2%), other urinary tract anomalies were also found; namely, ureterocele (7), VUR (11), and ectopic ureter (5). However, none of the patients with incomplete ureteral duplication had ureterocele or VUR.CONCLUSION: With the advent of routine prenatal ultrasound, ureteral duplication is being diagnosed earlier than was previously possible, enabling timely treatment of the various accompanying urinary tract anomalies. Multicenter studies are needed to establish guidelines for standardized evaluation and treatment of ureteral duplication.

Susceptibility of the Index Urinary Tract Infection to Prophylactic Antibiotics Is a Predictive Factor of Breakthrough Urinary Tract Infection in Children with Primary Vesicoureteral Reflux Receiving Continuous Antibiotic Prophylaxis

BACKGROUND: Few studies have reported on breakthrough urinary tract infection (UTI) associated with the susceptibility of index UTI to prophylactic antibiotics in children with primary vesicoureteral reflux (VUR) receiving continuous antibiotic prophylaxis (CAP). We assessed the impact of the susceptibility of index UTI to prophylactic antibiotics in breakthrough UTIs in children with primary VUR receiving CAP. METHODS: We retrospectively reviewed the medical records of 81 children with primary VUR who were diagnosed after febrile or symptomatic UTI and subsequently received trimethoprim-sulfamethoxazole (TMP-SMX) as CAP between January 2010 and December 2013. We allocated children to a susceptible group or a resistant group based on the susceptibility of index UTI to TMP-SMX. We evaluated patient demographics and clinical outcomes after CAP according to the susceptibility of index UTI to TMP-SMX. Multivariate analysis was used to identify the predictive factors for breakthrough UTI. RESULTS: Of the 81 children, 42 were classified into the susceptible group and 39 into the resistant group. The proportion of breakthrough UTI was 31.0% (13/42) in the susceptible group and 53.8% (21/39) in the resistant group (P = 0.037). Progression of renal scarring was observed in 0% of children in the susceptible group and 15% in the resistant group (P = 0.053). Multivariate analysis showed that TMP-SMX resistance and initial renal scarring were significant predictors of breakthrough UTI. CONCLUSION: Susceptibility of index UTI to prophylactic antibiotics is a risk factor of breakthrough UTI and is associated with poor clinical outcomes in children with primary VUR receiving CAP.

Incidentally detected gallbladder agenesis in a child: the importance of identifying anatomic structure

The absence of a gallbladder is a very rare anomaly. While it is usually asymptomatic, it can cause biliary colic symptoms. For these reasons, gallbladder agenesis can be misdiagnosed as a hepatobiliary disease and is diagnosed correctly after surgery. This condition may also be detected through an autopsy for other causative diseases. Abdominal ultrasonography is used as a diagnostic method to detect gallbladder agenesis. Hepatobiliary scintigraphy, magnetic resonance cholangiopancreatography, and endoscopic cholangiopancreatography are also used to make a more accurate diagnosis. In the emergency room, however, gallbladder agenesis can still be misdiagnosed as acute or chronic cholecystitis, leading to the detection of gallbladder agenesis in the operating room. Although some cases of gallbladder agenesis detected in adults during surgery have been reported in Korea, there are no reports of gallbladder agenesis in pediatric patients to date. This paper reports a case of gallbladder agenesis in a symptomatic child that was detected incidentally by a radiographic examination.

Comparison between 3-dimensional cranial ultrasonography and conventional 2-dimensional cranial ultrasonography in neonates: impact on reinterpretation

PURPOSE: The aim of this study was to evaluate impact of 3-dimensional cranial ultrasonography (3DUS) on reinterpretation of cranial ultrasonography images in neonates in comparison with 2-dimensional cranial ultrasonography (2DUS). METHODS: We retrospectively enrolled 50 young infants who simultaneously underwent both 2DUS and 3DUS scanning from February to March 2015. Two pediatric radiologists independently reviewed both scans for overall image quality on a 5-point scale. Five features were evaluated in both scans: the presence of germinal matrix hemorrhage (GMH), intraventricular hemorrhage (IVH), ventriculomegaly (VM), abnormality of periventricular echogenicity (PVE), and focal parenchymal lesions (FL). The concordance rate between the two scanning modes was calculated. The confidence level for each finding on a 3-point scale and the scanning time were compared between the two scanning modes. Interobserver agreement was evaluated using kappa statistics. RESULTS: Both scans demonstrated similar overall image quality in terms of reinterpretation (mean scores for 2DUS and 3DUS, 4.0±0.5 and 4.0±0.7 in reviewer 1, 3.9±0.6 and 4.0±0.8 in reviewer 2, respectively). GMH, IVH, VM, and FL showed perfect concordance, while PVE showed a concordance rate of 91.4% between the two modes by both reviewers. 3DUS was associated with a higher diagnostic confidence in the evaluation of GMH, IVH, and FL than 2DUS (P < 0.05) for both reviewers. For PVE, 3DUS received a significantly higher confidence score than 2DUS from one of the reviewers. The mean scanning time for 2DUS and 3DUS was 92.75 seconds and 36 seconds, respectively. Interobserver agreement for qualitative scoring was almost perfect. CONCLUSION: In reinterpretation, 3DUS showed very high concordance with 2DUS and a similar image quality. 3DUS also increased diagnostic confidence for several image findings and significantly decreased scan time.

Reversible Metronidazole-induced Encephalopathy in a Patient with Acute Lymphoblastic Leukemia during Chemotherapy / 임상소아혈액종양

We describe our experience regarding metronidazole-induced encephalopathy in a patient with acute lymphoblastic leukemia during chemotherapy. A 17-year-old girl was admitted to our institution with complaints of abdominal pain and mucoid stools. She was diagnosed with acute lymphoblastic leukemia and had been undergoing intensified chemotherapy protocol. During the fifth week of interim maintenance-1 therapy, she developed a fever and complained of chills. On stool examination, stool occult blood was positive and Clostridium difficile toxin A/B test was positive. She was started on metronidazole treatment for possible Clostridium difficile infection and other inflammatory gastrointestinal diseases. Ten days later, the patient complained of dizziness and nausea. A brain MRI was performed to make a differential diagnosis of any chemotherapy- induced CNS complication such as necrotizing leukoencephalopathy. The brain MRI showed features of metronidazole-induced encephalopathy. Metronidazole was discontinued and symptoms started to subside four days after. A follow-up brain MRI performed at four weeks showed that lesions of the dentate nucleus had disappeared.

Reversible Metronidazole-induced Encephalopathy in a Patient with Acute Lymphoblastic Leukemia during Chemotherapy / 임상소아혈액종양

We describe our experience regarding metronidazole-induced encephalopathy in a patient with acute lymphoblastic leukemia during chemotherapy. A 17-year-old girl was admitted to our institution with complaints of abdominal pain and mucoid stools. She was diagnosed with acute lymphoblastic leukemia and had been undergoing intensified chemotherapy protocol. During the fifth week of interim maintenance-1 therapy, she developed a fever and complained of chills. On stool examination, stool occult blood was positive and Clostridium difficile toxin A/B test was positive. She was started on metronidazole treatment for possible Clostridium difficile infection and other inflammatory gastrointestinal diseases. Ten days later, the patient complained of dizziness and nausea. A brain MRI was performed to make a differential diagnosis of any chemotherapy- induced CNS complication such as necrotizing leukoencephalopathy. The brain MRI showed features of metronidazole-induced encephalopathy. Metronidazole was discontinued and symptoms started to subside four days after. A follow-up brain MRI performed at four weeks showed that lesions of the dentate nucleus had disappeared.

Xanthogranulomatous Pancreatitis Mimicking a Pancreatic Cancer on CT and MRI: a Case Report and Literature Review

Xanthogranulomatous inflammation is a rare benign condition involving various organs. However, its pancreas involvement is very rare. To the best of our knowledge, only 17 cases have been described in the literature. Interestingly, all reported 17 cases due to various causes underwent surgical resection. Here, we present a case of xanthogranulomatous pancreatitis in a 63-year-old man. He presented with epigastric pain and solid mass mimicking ductal adenocarcinoma in the body and tail of pancreas on magnetic resonance imaging. The patient was diagnosed as xanthogranulomatous pancreatitis via endoscopic ultrasound-guided fine needle aspiration. After that, he was followed up and monitored without any surgical treatment. Here, we show imaging findings and serial image changes of xanthogranulomatous pancreatitis for this case.

Erratum: Ultrasonographic Diagnosis of Biliary Atresia Based on a Decision-Making Tree Model

On page 1364, the fifth author's name has been incorrectly spelled.

Pediatric Magnetic Resonance Enterography: Focused on Crohn's Disease / 대한소아소화기영양학회지

Crohn's disease is a chronic idiopathic inflammatory disease of the intestines characterized by frequent relapse and remission. It often develops in children and adolescents, who are vulnerable to repeated exposure to ionizing radiations. Magnetic resonance enterography (MRE) is an increasingly important radiation-free imaging modality that is used to evaluate pediatric patients with Crohn's disease. MRE can evaluate extraluminal and extraintestinal abnormalities as well as the status of the bowel wall. In addition, MRE has an advantage in the evaluation of the small bowel involvement. MRE can be used for the initial diagnosis of Crohn's disease, and can aid in the assessment of disease activity and complications such as penetrating and fibrostenotic diseases. The aims of this article are to review the MRE technique for obtaining diagnostic and high-quality images and to discuss interpretations of imaging findings in patients with Crohn's disease.

Lack of Myelination in the Anterior Limbs of the Internal Capsule Associated with Cri-du-Chat Syndrome: Case Report

A 21-month-old girl with cri-du-chat syndrome in conjunction with developmental delay underwent brain magnetic resonance imaging (MRI). The MRI showed hypoplasia of the brain stem, a normal cerebellum, thinning of the corpus callosum, and a lack of myelination in both anterior limbs of the internal capsule. She also had neonatal bilateral subependymal cysts. We believe that the symmetrical lack of myelination in both anterior limbs of the internal capsule could be a diagnostic clue of cri-du-chat syndrome.

Quantitative Analysis of the Facial Nerve Using Contrast-Enhanced Three Dimensional FLAIR-VISTA Imaging in Pediatric Bell's Palsy

PURPOSE: To evaluate the usefulness of quantitative analysis of the facial nerve using contrast-enhanced three-dimensional (CE 3D) fluid-attenuated inversion recovery-volume isotopic turbo spin echo acquisition (FLAIR-VISTA) for the diagnosis of Bell's palsy in pediatric patients. MATERIALS AND METHODS: Twelve patients (24 nerves) with unilateral acute facial nerve palsy underwent MRI from March 2014 through March 2015. The unaffected sides were included as a control group. First, for quantitative analysis, the signal intensity (SI) and relative SI (RSI) for canalicular, labyrinthine, geniculate ganglion, tympanic, and mastoid segments of the facial nerve on CE 3D FLAIR images were measured using regions of interest (ROI). Second, CE 3D FLAIR and CE T1-SE images were analyzed to compare their diagnostic performance by visual assessment (VA). The sensitivity, specificity, and accuracy of RSI measurement and VA were compared. RESULTS: The absolute SI of canalicular and mastoid segments and the sum of the five mean SI (total SI) were higher in the palsy group than in the control group, but with no significant differences. The RSI of the canalicular segment and the total SI were significantly correlated with the symptomatic side (P = 0.028 and 0.015). In 11/12 (91.6%) patients, the RSI of total SI resulted in accurate detection of the affected side. The sensitivity, specificity, and accuracy for detecting Bell's palsy were higher with RSI measurement than with VA of CE 3D FLAIR images, while those with VA of CE T1-SE images were higher than those with VA of CE 3D FLAIR images. CONCLUSION: Quantitative analysis of the facial nerve using CE 3D FLAIR imaging can be useful for increasing the diagnostic performance in children with Bell's palsy when difficult to diagnose using VA alone. With regard to VA, the diagnostic performance of CE T1-SE imaging is superior to that of CE 3D FLAIR imaging in children. Further studies including larger populations are necessary.

Ultrasonographic Diagnosis of Biliary Atresia Based on a Decision-Making Tree Model

OBJECTIVE: To assess the diagnostic value of various ultrasound (US) findings and to make a decision-tree model for US diagnosis of biliary atresia (BA). MATERIALS AND METHODS: From March 2008 to January 2014, the following US findings were retrospectively evaluated in 100 infants with cholestatic jaundice (BA, n = 46; non-BA, n = 54): length and morphology of the gallbladder, triangular cord thickness, hepatic artery and portal vein diameters, and visualization of the common bile duct. Logistic regression analyses were performed to determine the features that would be useful in predicting BA. Conditional inference tree analysis was used to generate a decision-making tree for classifying patients into the BA or non-BA groups. RESULTS: Multivariate logistic regression analysis showed that abnormal gallbladder morphology and greater triangular cord thickness were significant predictors of BA (p = 0.003 and 0.001; adjusted odds ratio: 345.6 and 65.6, respectively). In the decision-making tree using conditional inference tree analysis, gallbladder morphology and triangular cord thickness (optimal cutoff value of triangular cord thickness, 3.4 mm) were also selected as significant discriminators for differential diagnosis of BA, and gallbladder morphology was the first discriminator. The diagnostic performance of the decision-making tree was excellent, with sensitivity of 100% (46/46), specificity of 94.4% (51/54), and overall accuracy of 97% (97/100). CONCLUSION: Abnormal gallbladder morphology and greater triangular cord thickness (> 3.4 mm) were the most useful predictors of BA on US. We suggest that the gallbladder morphology should be evaluated first and that triangular cord thickness should be evaluated subsequently in cases with normal gallbladder morphology.

Role of MRI in Diagnostic Evaluation of Papillary Lesions of the Breast

PURPOSE: To evaluate the role of magnetic resonance imaging (MRI) in the diagnosis of papillary lesions of the breast. MATERIALS AND METHODS: Among 45 papillary lesions diagnosed at ultrasonography-guided core biopsy (USCB), 27 benign papillary lesions in 22 patients who underwent breast MRI were reviewed. The excsional biopsy was performed in 1-10 days after MRI was done. In MRI findings, lesions were considered suspicious if they show irregular, rim enhancement, or linear enhancement in morphologic evaluation, or washout enhancement pattern of delayed phase in dynamic enhancement characteristics. Diffusion-weighted images were analyzed according to visibility of lesions. MRI findings were correlated with pathologic results at excisional biopsy. RESULTS: At excisional biopsy, two lesions (9%) were diagnosed malignant in 22 benign papillary lesions without atypia by USCB and 4 (80%) were malignant in 5 benign papillary lesions with atypia by USCB. Among 18 lesions detected on MRI, 16 lesions showed suspicious findings on MRI, 11 lesions (69%) were diagnosed as benign and 5 (31%) were malignant. Among 12 lesions detected on diffusion weighted imaging, 10 lesions were diagnosed as benign and 2 were malignant. MRI findings were not significantly correlated with pathologic results at excisional biopsy. CONCLUSION: MRI findings were not useful to predict malignancy in benign papillary lesions diagnosed at USCB, because MRI findings of these were mostly suspicious (88.9%, 16/18). The benign papillary lesion should be included in the false positive lesion on breast MRI.