Brain magnetic resonance imaging (MRI) provides detailed anatomical and functional information about the brain without radiation exposure. One of the biggest challenges in pediatric brain MRI is to successfully acquire high-quality diagnostic images. As water content in brain tissues is higher and brain myelination is less mature in newborns and infants compared with older children and adults, specific scan parameters are required in sequences that are designed according to the age of the child. In addition, younger children often need to be sedated to enable them to hold still adequately during the long acquisition time. The recently published “Joint recommendations for sedation during MRI” provides valuable advice for improving safety in pediatric MRI. In this paper, practical tips and tricks for pediatric brain MRI are reviewed and safety issues in pediatric sedation are discussed.

Ultrasonography still plays an important role in pediatric abdominal diagnostic imaging even now that CT and MRI are currently the primary modalities in diagnostic imaging. The greatest advantage of abdominal ultrasonography is that it can be performed repeatedly at the bedside without radiation exposure. Its disadvantage is that the quality of the examination is greatly influenced by the skill of the examiner. One of the best and fastest ways to improve ultrasonography skills is through experience. Establishing and routinely performing your own abdominal ultrasonography screening procedures should make it easier to notice abnormal findings. This article provides some tips on screening procedures for pediatric abdominal ultrasonography.

Computed tomography (CT) is a valuable tool because of its excellent diagnostic accuracy, wide availability, and short acquisition time. However, because children are more radiosensitive than adults, the indications for pediatric CT should be considered carefully. Non-essential radiation exposure can be avoided by prior discussion between clinicians and diagnostic radiologists to evaluate justification of the scan and the need for contrast agent, pre-contrast imaging, and dynamic scanning.

Contrast agent is essential for evaluating internal organs, vascular systems, and the extent of tumors because it increases the conspicuity of targeted tissues and improves the diagnostic value. However, it is difficult to determine appropriate infusion rates and scan delay times due to the wide variations in body size and circulatory dynamics in the pediatric population. Because pediatric contrast-enhanced CT protocols are not fully established, it is important to share experiences among institutions. In this article, we suggest tips for performing pediatric contrast-enhanced CT appropriately based on the experience of our institution.

The diagnostic approach to childhood intussusception in most cases involves ultrasonography and fluoroscopy. However, controversy remains regarding which type of enema is most efficacious, and methods differ between facilities. This article reviews the imaging diagnosis of intussusception with ultrasonography and enema examination, and presents the method of enema reduction used in our hospital.

Pneumatosis cystoides intestinalis (PCI), a condition in which small cystic emphysema forms in the intestinal wall, is rarely reported in children. This article describes the case of a 9-year-old girl with spinal muscular atrophy type I, who was found to have PCI due to persistent mucous blood in her stool. She responded well to hyperbaric oxygen therapy. Had we known the characteristic imaging findings, we could have identified the PCI earlier.

Axial spondylometaphyseal dysplasia (axial SMD) is an autosomal recessive disorder characterized by dysplasia of the axial skeleton and retinal degeneration. A 5-year-old girl, born of consanguineous parents, presented with thoracic deformities that were first noticed at the age of 1 year. Physical and radiological evaluations showed short stature (−2.7 SD), marked symmetrical deformity of the anterior thorax with a normal sternum, hollowing of the shortened ribs in the mid-parasternal region, flaring of the lower costal margins, and irregular sclerotic lesions at the proximal femoral metaphyses. No other long or short bone metaphyses or epiphyses were affected. On ophthalmological examination, retinal degeneration was seen bilaterally, leading to a clinical diagnosis of axial SMD. DNA analysis of the CFAP410 gene identified biallelic mutations in exon 4 (c.322 C>T, p.Arg108Cys). Understanding the basic processes of bone formation and membranous and endochondral ossification is important for identifying pathognomonic skeletal changes in the radiological diagnosis of skeletal dysplasia.

A 10-month-old female patient with Todani Type IV-A congenital biliary dilatation underwent extrahepatic bile duct resection and intrahepatic cholangiojejunostomy. Multiple intrahepatic cysts were observed in her liver, and cholangiography during surgery showed them to be cystic dilatations of the peripheral bile ducts connecting to the main bile ducts. At the age of 11 years, she visited our hospital for fever and epigastric pain. Abdominal ultrasonography showed a 20-mm tumor containing solid cyst components and a posterior echo in the left lobe of her liver. Abdominal contrast-enhanced computed tomography showed that the tumor was not enhanced, and that the surrounding area was deeply stained in the early arterial phase. A hepatic abscess was diagnosed due to preoperative intrahepatic bile duct dilatation. She was admitted and treated with antibiotics. Her symptoms resolved, and she was discharged after 21 days with a remnant cystic lesion at the abscess site. She and her family refused surgical lobectomy. She was followed conservatively for 3 years and 5 months; there was no relapse of cholangitis or liver abscess. Postoperative patients with congenital biliary dilatation require careful follow-up for complications for a long period of time.