Pediatric Radiology最新文献

Background: Functional constipation is common in children and accurate diagnostic methods are essential for early diagnosis and effective management. The diagnostic accuracy of transabdominal ultrasound to diagnose functional constipation is unclear.

Objective: To evaluate the diagnostic accuracy of transverse rectal diameter measurement via transabdominal ultrasound in diagnosing children with functional constipation and in identifying fecal impaction.

Materials and methods: Electronic databases were searched from inception to March 2023. Original studies investigating the diagnostic accuracy of measuring transverse rectal diameter via transabdominal ultrasound, including children with and without functional constipation, or with and without fecal impaction were included. Data extraction and quality assessment were performed independently by two reviewers.

Results: Sixteen studies were included (n = 1,801 children, 0-17 years). Thirteen studies investigated the diagnostic accuracy for functional constipation, and five for fecal impaction. High risk of bias was found across the majority of studies mainly due to un-blinded case-control designs. Cut-off transverse rectal diameter values to diagnose functional constipation ranged from 2.4 cm to 3.8 cm. Meta-analysis (seven studies, n = 509 children) estimated mean sensitivity and specificity to diagnose functional constipation were 0.68 (95% confidence interval (CI) 0.55-0.78) and 0.81 (95% CI 0.71-0.88), respectively. Meta-analysis of diagnostic accuracy of identifying fecal impaction was not feasible. Studies reported a sensitivity and specificity ranging between 68-100% and 83-100%, respectively.

Conclusion: Transabdominal ultrasound may be a valuable non-invasive diagnostic tool to diagnose functional constipation by measuring transverse rectal diameter and identifying fecal impaction in children. Heterogeneous study methods and lack of age-dependent normal values impair current clinical recommendations. Future research should focus on separating age groups and developing a standardized protocol.

Pulmonary hypertension is a rare but serious disease in children with potentially poor prognosis in the long term. Direct measurement of increased pressure in the pulmonary circulation requires right-heart catheterisation. Echocardiography is the imaging modality commonly used for suggesting the presence of pulmonary hypertension and estimating its severity. Recognition of structural and haemodynamic signs of increased pulmonary arterial pressure and pressure overload of the right ventricle at magnetic resonance (MR) imaging may contribute to the diagnosis of pulmonary hypertension and management of these patients. In this article, the structural, functional, and haemodynamic cardiovascular MR findings of paediatric pulmonary hypertension are reviewed. Typical diagnostic MR scenarios in children with suspected pulmonary hypertension or in children with disease associated with pulmonary hypertension are presented and discussed.

Four-dimensional phase contrast MRI (4D flow) has emerged as a versatile imaging technique for comprehensive visualization and both qualitative and quantitative assessment of cardiovascular blood flow. 4D flow is a three-dimensional, time-resolved acquisition that is gated to the cardiac cycle. 4D flow provides cardiovascular velocity and flow assessment across the volume of acquisition and yields a multitude of advanced hemodynamic parameters that help to assess the impact of cardiovascular disease on flow and vice versa, guiding the clinical and surgical management of patients with congenital and acquired heart disease. In the past, lengthy scan acquisition and complex post-processing workflows hindered 4D flow adoption into routine clinical practice. Decreasing image acquisition times and improvements in post-processing techniques have made 4D flow a clinically useful tool. The purpose of this communication is to facilitate more widespread adoption of 4D flow by describing its clinical utility, technical acquisition, optimization, and post-processing in pediatric cardiovascular imaging at our center.

Background: Standardized values for esophageal diameter on fluoroscopy have not been established. These values may help in the diagnosis of long-segment and diffuse esophageal narrowing, which can sometimes be subtle and difficult to diagnose.

Objective: Our objective was to establish normal values for esophageal diameter based on age for patients between 1 and 17 years old.

Materials and methods: Our retrospective study included 160 patients separated into eight groups by age with documented normal upper gastrointestinal fluoroscopic examination and normal esophageal biopsy. Three readers measured esophageal diameters in the three locations and two projections. Intra-class correlation coefficients were calculated in order to gauge reader measurement agreement. Student's t-tests were used to evaluate for statistically significant differences between male and female patients. Finally, overall means and 95% confidence intervals were calculated at each esophageal level by age group.

Results: Our readers demonstrated excellent measurement agreement (ICCs > 0.75). Three individual esophageal measurements varied between the biological sexes, but there was no reliable statistically significant difference. There was a linear upward trend in esophageal diameter with age. For each age group, the means, standard deviations, and 95% confidence intervals were calculated for esophageal diameter in each location and projection. Across all included ages, the mean esophageal diameter ranged from 11-21 mm on the anteroposterior projection and 8-17 mm on the lateral.

Conclusion: The provided ranges of normal esophageal diameters at each age and location in the pediatric population are quantitative metrics which can be used in the interpretation of fluoroscopic examinations. New reference values may lead to earlier diagnosis of esophageal pathology in the pediatric population.

Aorto-cardiac tunnels represent uncommon cardiovascular anomalies connecting the ascending aorta to cardiac chambers and are typically characterized by extra-cardiac tubular channels. Among these, the involvement of the left atrium is exceptionally rare, with only a few cases reported in literature. Here, we describe a case of an aorto-left atrial tunnel in a 6-year-old boy with an associated bicuspid aortic valve, a large patent ductus arteriosus, and atrial septal defects. This case highlights the significance of multimodal imaging in the accurate identification and characterization of rare cardiovascular anomalies.

Background: Distal femoral diffusion tensor imaging (DTI) is a predictor of height gain but it is uncertain whether DTI can demonstrate differences in growth potential between the tibia and femur.

Objective: To explore the differences in structure and growth potential of the proximal tibia physeal-metaphyseal complex compared to those of the distal femur through DTI tractographic characterization and DTI metric comparison.

Materials and methods: Prospective cross-sectional study involved 108 healthy children (59 females) aged 8-14 years (females) and 10-16 years (males) around the growth spurt. We acquired knee DTI once at 3 T with b-values of 0 s/mm² and 600 s/mm². Tract parameters including number, length, volume, and fractional anisotropy were measured. Regression analysis with linear and negative binomial models, incorporating bone age-based quadratic fitting, characterized DTI parameter changes in relation to bone age and sex, as well as variations between physes. Femorotibial ratios were calculated based on paired DTI parameter absolute values during peak height gain. The study was approved by the institutional review board of two tertiary pediatric centers in compliance with the Health Insurance Portability and Accountability Act.

Results: Proximal tibial tracts were more numerous in the central physis, whereas distal femoral tracts predominated peripherally. Tract volume rose and fell during adolescence and peaked earlier in females (140-160 months vs. 160-180 months, P=0.02). At maximal height velocity (160 months), tibial tract volume (5.43 cc) was 37.4% of total knee tract volume (14.53 cc). Tibial fractional anisotropy decreased and then increased, both earlier than the femur.

Conclusion: Proximal tibial and distal femoral tract distributions differ. The tibia accounts for 37.4% of total knee tract volume during maximal height velocity. Tract volumes rise and fall, earlier in females. Tibiofemoral ratios of DTI metrics resemble known ratios of growth rates between tibia and femur.

Spinal chondrosarcomas are uncommon malignant bone tumors that are rare in children. The location and imaging features of the lesion help in formulating a differential diagnosis, though in certain instances the lack of typical imaging findings may elude the differential of a chondrosarcoma. There are only a few reported cases in literature and owing to its rarity and lack of specific management protocols in this age group, making treatment decisions can be complex. We report a case of spinal chondrosarcoma in a young girl, where the treatment of choice was primary surgical resection. Transarterial embolization was performed to reduce tumor vascularity and aid the surgery.