Following the diagnosis of upper urinary tract infection (UTI) in infants, a radiographic workup is necessary to identify susceptibility to renal damage. However, there is incomplete agreement regarding whether the emphasis should be on the presence of acute parenchymal damage versus the presence of vesicoureteral reflux (VUR). Voiding cystourethrography (VCUG) was historically used to detect high-risk patients. This method is now referred to as the bottom-up approach (BUA), and relies on VCUG to identify lower urinary tract abnormalities and VUR. Only those patients diagnosed with VUR then undergo ^99mTc-DMSA renal scan to assess renal scarring at the convalescent phase. As an alternative method, the top-down approach (TDA) targets the kidney with a ^99mTc-DMSA renal scan to diagnose acute renal parenchymal involvement at the acute phase of the upper UTI. Patients with photon defects are subsequently referred for VCUG to assess VUR in addition to a late ^99mTc-DMSA renal scan (at 3–6 months) to assess for permanent renal scarring. As each strategy carries advantages and disadvantages, it is difficult to declare the winner between BUA and TDA. Given the unavailability of ^99mTc-DMSA renal scans at most local medical institutions in Japan, where infants with upper UTI are managed, the author considers that BUA is more practical for infants with upper UTI.

In multicenter clinical trials for hepatoblastoma, accurate PRETEXT is critical for assigning patients to the correct risk groups and providing appropriate treatment. Accurate imaging is also necessary to determine the optimal surgical treatment. Thus, quality-assured radiological diagnoses based on state-of-the-art imaging studies are mandatory for the success of clinical trials. To ensure accurate risk classification and evaluation of response, the JCCG Liver Tumor Committee has recently adopted a teleradiology system for central radiologic diagnosis of all patients. Surgical therapy consultation based on this imaging information is also being undertaken. These efforts are world-leading and will be indispensable in future international collaborative clinical studies in which standardization of diagnostic imaging and surgical treatment is required.

Coronary aneurysms and dilated lesions associated with patients with Kawasaki disease show various changes over time, including calcification of the aneurysm wall, intimal thickening, development of mural thrombi, development of collateral vessels, and asymptomatic thrombotic occlusion followed by subsequent post-occlusive recanalization. Both morphological and functional evaluations are necessary for their diagnosis and management.

Coronary CT angiography (CCTA) has recently superseded selective coronary angiography for morphological evaluation, whereas myocardial scintigraphy is used in myocardial perfusion imaging (MPI) for functional assessment. In recent years, semiconductor SPECT has shortened imaging times and enabled imaging to be performed in the sitting position, thus making the examination less invasive and more tolerable for younger patients.

Various novel imaging modalities might be applied in the future for the evaluation of coronary artery lesions associated with Kawasaki disease.

Interventional radiology (IVR) procedures are classified as vascular (vascular intervention) and non-vascular (non-vascular intervention). IVR can deliver targeted treatment for a wide variety of conditions and diseases, including hemorrhage, tumors, and vascular malformations. Of the two types, vascular intervention is performed more frequently in daily clinical practice, whereas non-vascular intervention is performed depending on the target site and disease, and some procedures may be a combination of both. IVR is generally less invasive than surgery and is preferred over surgery in the treatment of children.

In this article, we discuss abdominal and pelvic procedures that are frequently performed in our daily clinical practice, present example cases, and describe our own experiences.

Wolman disease is a metabolic disorder with a poor prognosis. It has an autosomal recessive form of inheritance that causes death in early infancy due to a deficiency of lysosomal acid lipase. Before the availability of enzyme replacement therapy with recombinant human lysosomal acid lipase, the disease usually resulted in death within the first six months of life. We experienced two cases of Wolman disease in siblings who were diagnosed prior to the approval of enzyme replacement therapy. The (older) brother gradually developed abdominal distention and limb emaciation from 2 weeks of age, and died of unknown causes at 51 days of age. The (younger) sister developed abdominal distention and vomiting from 3 weeks of age. Abdominal CT scan taken at 76 weeks of age revealed adrenal calcification, leading to a diagnosis of Wolman disease, but she died at 4 months of age due to multiple organ failure. As adrenal calcification had been found in the brother, it was assumed that he also had Wolman disease. Although only one case has been diagnosed in Japan in the past 20 years, it is important to raise awareness of Wolman disease to enable early diagnosis now that treatment is available.

In June 2017, the Japanese Society of Emergency Pediatrics published its “Guidelines for the Management of Acute Appendicitis in Children.” In these guidelines, ultrasonography was recommended as the preferred diagnostic imaging modality for children with acute appendicitis. Computed tomography, specifically contrast-enhanced computed tomography, was recommended as the second choice. This study investigated choices made with respect to diagnostic imaging for pediatric patients with suspected acute appendicitis and admitted to our hospital from 2013 to 2021. Participants comprised 280 patients, with 115 admitted before June 2017 and 165 admitted after. The number of patients for whom ultrasonography was selected as the preferred imaging method was significantly higher after June 2017 (12% vs 25%; p < 0.05), but the frequency of selecting contrast-enhanced computed tomography remained low (25% vs 18%; p = 0.48). With respect to selection of diagnostic imaging modalities, we cannot conclude that guidelines were recognized in actual clinical settings. Additional efforts appear necessary to effectively reduce childhood exposures to radiation.

Syngnathia is an extremely rare congenital anomaly involving bony or soft tissue adhesion between the maxilla and mandible. We report herein the case of a 2-year-old girl clinically diagnosed with Dobrow syndrome due to multiple anomalies, including maxillomandibular fusion. She was born at a gestational age of 38 weeks and 3 days, weighing 2334 g. At birth, mouth opening was limited due to severe microstomia. Nasal intubation was performed on the day of admission, and tracheoscopy was performed on day 107. Physical features included right coloboma lobuli, right choanal atresia, cervical fistula, hypoplasia of the left auricle, maxillomandibular fusion, and micrognathia. Craniofacial and thoracic three-dimensional computed tomography demonstrated maxillomandibular bony syngnathia, middle ear abnormalities, and vertebral bone and rib anomalies at multiple levels. Callosal hypoplasia and delayed myelination in the left anterior lobe were evident on magnetic resonance imaging of the brain. Severe intellectual retardation was also identified after birth gradually. Given the presence of maxillomandibular bony fusion and multiple other anomalies, Dobrow syndrome was clinically diagnosed. Differential diagnoses for multiple anomalies with syngnathia cover a wide range. Vertebral bone and rib anomalies are specific for Dobrow syndrome and also affect prognosis, so careful radiological examination is recommended.

Sternal fractures are considered among the most specific signs of child abuse, along with the classical metaphyseal lesions of the long tubular bones and rib fractures, but are less frequently reported in the literature. Most sternal fractures in infants and young children show manubriosternal segmental dislocation/fracture between the manubrium and the body of the sternum. Skeletal survey may not adequately depict sternal lesions due to overlap with the upper extremities or inappropriate radiographic coverage. Lateral images of the spine with the upper limbs elevated are useful for clear sternal visualization, or lateral target imaging of the sternum can be added. Chest Computed Tomography (CT) is excellent in detecting fractures in both the acute and chronic phases. Considering the serious consequences of missing signs of possible abuse, we consider that aggressive use of chest CT is justified in cases where abuse is clinically suspected but not confirmed from radiographs. The 2021 guidelines from the Japan Radiological Society Imaging weakly recommend using chest CT with appropriate dose settings to detect rib fractures in situations of suspected abuse.