I Thought I Saw a Retrocaval Ureter; Don't Bite the Fish-Hook Sign So Easily.

Background: During the management of patients with hydronephrosis, a possibility of retrocaval ureter (RCU) may emerge indicated by a fish-hook sign or its mimickers. Owing to infrequent incidence, the proper way to diagnose or exclude an RCU is challenging and has not been discussed previously. Methods: The aim of this study was to retrospectively evaluate the children who were suspected to have an RCU during management for urinary tract dilation. An RCU may be missed or misdiagnosed owing to rare incidence. Results: The children with urinary tract dilation in whom RCU was considered are enrolled in the study (n = 13). The demographics of the patients, findings suggesting RCU, evaluation process, management, and final diagnosis are retrospectively evaluated. The final diagnosis of the patients was RCU (n = 4), ureteropelvic junction obstruction (UPJO) (n = 7), and duplicated collecting system (n = 2). An RCU was confirmed or excluded by ultrasonography (US) while there was a stent in the ureter in 6 patients and by laparoscopic exploration in the other 7 patients. Four underwent correction for RCU, 7 for UPJO, 1 for reflux, and 1 ureterocele puncture. Conclusion: The fish-hook sign is a rare conflicting radiological finding that can be encountered in imaging studies. This uncommon finding needs confirmation or exclusion of a possible RCU as missed cases manifested after failed pyeloplasty or ureteroneocystostomy were reported. Radiological evaluation (by US or cross-sectional studies) while there is a stent in the ureter is the most satisfactory radiological technique to confirm or exclude an RCU. Alternatively, being aware of a possible RCU and performing a more extensive dissection may be necessary during surgery to confirm or exclude it. If available, laparoscopy may provide this goal in a minimally invasive manner with superior visualization.

A Rare Case of "Periportal Cuffing" as an Incidental Finding on 18F-FDG PET/CT.

A 7-year-old boy with known diagnosis of hereditary spherocytosis and ulcerative colitis was referred for 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography after detection of a 28 mm lesion suspicious for malignancy in spleen on upper abdomen magnetic resonance imaging (MRI). As an incidental finding, a moderately increased uptake of 18F-FDG was observed in periportal region with no definable mass. MRI revealed compatible findings with "periportal cuffing" as described on ultrasonography.

Childhood-Onset Sacroiliitis: Causes and Correlation Between Clinical Findings and Magnetic Resonance Imaging.

OBJECTIVE: The aims of this study were to describe disease associations of magnetic resonance imaging (MRI)-confirmed and clinically symptomatic sacroiliitis in pediatric patients with rheumatic diseases and to examine the relationship between patient characteristics and MRI findings of the sacroiliac joint (SIJ). METHODS: Demographic and clinical data were extracted from the electronic medical records of the patients with sacroiliitis followed in the last 5 years. Active inflammatory and structural damage lesions of the SIJ-MRI were examined by the modified Spondyloarthritis Research Consortium of Canada scoring system, and correlation analysis of these results with clinical characteristics was evaluated. RESULTS: A total of 46 symptomatic patients were found to have MRI-proven sacroiliitis of 3 different etiologies: juvenile idiopathic arthritis (JIA) (n = 17), familial Mediterranean fever (FMF) (n = 14), and chronic nonbacterial osteomyelitis (CNO) (n = 8). Seven patients, FMF and JIA (n = 6) and FMF and CNO (n = 1), had a co-diagnosis that might cause sacroiliitis. Although inflammation scores and structural damage lesions did not statistically differ between the groups, capsulitis and enthesitis on the MRI were more frequently detected in the CNO group. There was a negative correlation between symptom onset and inflammation scores of bone marrow edema. Disease composite scores and acute phase reactants were correlated with MRI inflammation scores. CONCLUSIONS: We demonstrated that JIA, FMF, and CNO were the major rheumatic causes of sacroiliitis in children originating from the Mediterranean region. Quantitative MRI scoring tools can be used to assess the inflammation and damage of the SIJ in rheumatic diseases, show discrepancies between them, and have an important correlation with various clinical and laboratory features.

Multisystem inflammatory syndrome in children associated with SARS-CoV-2: extracardiac radiological findings.

OBJECTIVE: Multisystem inflammatory syndrome in children (MIS-C) is seen as a serious delayed complication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The aim of this study was to describe the most common imaging features of MIS-C associated with SARS-CoV-2. METHODS: A retrospective review was made of the medical records and radiological imaging studies of 47 children (26 male, 21 female) in the age range of 25 months-15 years who were diagnosed with MIS-C between August 2020 and March 2021. Chest radiographs were available for all 47 patients, thorax ultrasound for 6, chest CT for 4, abdominal ultrasound for 42, abdomen CT for 9, neck ultrasound for 4, neck CT for 2, brain CT for 1, and brain MRI for 3. RESULTS: The most common finding on chest radiographs was perihilar-peribronchial thickening (46%). The most common findings on abdominal ultrasonography were mesenteric inflammation (42%), and hepatosplenomegaly (38%, 28%). Lymphadenopathy was determined in four patients who underwent neck ultrasound, one of whom had deep neck infection on CT. One patient had restricted diffusion and T2 hyperintensity involving the corpus callosum splenium on brain MRI, and one patient had epididymitis related with MIS-C. CONCLUSION: Pulmonary manifestations are uncommon in MIS-C. In the abdominal imaging, mesenteric inflammation, hepatosplenomegaly, periportal edema, ascites and bowel wall thickening are the most common findings. ADVANCES IN KNOWLEDGE: The imaging findings of MIS-C are non-specific and can mimic many other pathologies. Radiologists should be aware that these findings may indicate the correct diagnosis of MIS-C.

Value of strain-wave sonoelastography as an imaging modality in assessment of benign acute myositis in children

Background/aim: Although sonoelastography is applied in assessment of many organs, studies for evaluation of muscles are very few in number and are mostly limited to adults. With this prospective study, we aimed to evaluate the value of sonoelastography in assessment of influenza related benign acute myositis in children. Materials and methods: This study enrolled 25 patients with a clinical diagnosis of benign acute childhood myositis (BACM) and 25 age and sex-matched healthy controls. All patients presented to our emergency department with the complaint of inability to walk and had increased serum creatine kinase (CK) levels. All patients underwent strain elastography of the gastrocnemius muscle, and an elastography score was assigned to each patient by using a previously published 5 point-color scoring system. The findings were compared with those of the control group. Results: No statistically significant difference was detected regarding age, weight, height, or body mass index (BMI) between patient and control groups. A statistically significant difference was found between the final elastography scores of the patient and control groups, mean values being 4.16 ± 0.75 versus 3.08 ±0.40, respectively (p < 0.001). Sonoelastography yielded a sensitivity of 80%, positive predictive value of 87%, specificity 88%, negative predictive value of 81.5%, and an overall accuracy of 84 %. Conclusion: Sonoelastography proves to be a valuable tool for diagnosis of BACM. It is one of the available ultrasound techniques in a radiology department and may particularly evolve to become a useful routine ancillary technique for investigation and follow-up in these cases.