Pediatric Radiology最新文献

Background: Little is known about the impact of spinal cord microstructural alterations after prenatal myelomeningocele (MMC) repair and their associations with neurological clinical assessments.

Objective: To assess spinal cord diffusivity using diffusion-weighted imaging (DWI) obtained between 10 months and 30 months of age in children who underwent prenatal MMC repair, and to explore associations with neurological clinical assessments.

Materials and methods: This retrospective cohort study included children who underwent prenatal MMC repair from November 2011 to May 2023. All children met the Management Of Myelomeningocele Study (MOMS) inclusion criteria. DWI (b=0 s/mm² and 800 s/mm²) was performed between 10 months and 30 months of age, and apparent diffusion coefficient (ADC) values were obtained at the level of the spinal lesion. Neurological clinical assessments included intact S1 motor and sensory level, need for anticholinergic therapy or clean intermittent catheterization at the evaluation closest to 12 months, and ambulatory status at the evaluation closest to 30 months. Associations between ADC values (expressed as median [interquartile range]) and neurological clinical assessments were evaluated using the Mann-Whitney U test. A P-value <0.05 was considered significant.

Results: Thirty-six children were included (23 fetoscopic, 13 open-hysterotomy repairs). ADC values were significantly higher in children with intact S1 motor function (1.25 [1.00-1.89] vs 1.19 [1.00-1.30]×10^-3 mm²/s, P=0.01), intact S1 sensory level (1.36 [1.12-1.74] vs 1.21 [1.04-1.38]×10^-3 mm²/s, P=0.02), no anticholinergic therapy (1.31 [1.13-1.70] vs 1.22 [1.04-1.40]×10^-3 mm²/s, P=0.04), no catheterization (1.33 [1.04-1.74] vs 1.21 [1.12-1.32]×10^-3 mm²/s, P=0.04), and independent ambulation (1.36 [1.04-1.89] vs 1.19 [1.00-1.46]×10^-3 mm²/s, P=0.02).

Conclusion: Lower ADC values at the lesion level were associated with worse neurological and urological clinical assessments in children after prenatal MMC repair, suggesting that DWI may provide imaging biomarkers of spinal cord integrity.

Background: Most commercially available artificial intelligence (AI) tools in radiology are trained and approved for adult use, creating an access gap for pediatric patients. Intracranial hemorrhage (ICH) detection is a common adult AI application without pediatric FDA clearance.

Objective: To evaluate the performance of an FDA-cleared, adult-trained AI tool for ICH detection on non-contrast head CT (NCHCT) in pediatric patients aged 6-17 years.

Materials and methods: This retrospective, multi-institution study analyzed consecutive pediatric NCHCTs performed between January 2017 and November 2022 across 21 sites. Inclusion criteria were patient age 6-17 years and adequate imaging quality. Radiology reports were classified as ICH-positive or ICH-negative using a validated natural language processing (NLP) tool. The AI tool analyzed DICOM images independently. Discordant AI-NLP cases underwent blinded adjudication by three radiologists to establish ground truth. Performance metrics includingsensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were calculated with Wilson 95% confidence intervals (CIs).

Results: The cohort included 1,996 NCHCTs (768 females, 1,223 males, 5 unknown). ICH prevalence was 8.6% (172/1,996). Compared with ground truth, AI achieved 94.2% sensitivity (162/172, 95% CI, 89.6-97.2%), 94.7% specificity (1,727/1,824, 95% CI, 93.6-95.7%), 94.6% accuracy (1,889/1,996, 95% CI, 93.6-95.6%), 62.5% PPV (162/259, 95% CI, 57.8-67.0%), and 99.4% NPV (1,727/1,737, 95% CI, 99.0-99.7%). AI correctly identified ICH in cases missed by radiologists, but false positives were common, most often due to streak artifact (21.6%) and misclassified anatomy (18.6%). Interrater agreement for ground truth adjudication was substantial (κ=0.683).

Conclusion: An adult-trained AI tool demonstrated high sensitivity, specificity, and accuracy for ICH detection in pediatric patients aged 6-17 years, comparable to its adult performance. Selective adaptation of adult-trained AI tools could expand access to AI-assisted triage for certain pediatric populations, potentially reducing delays in critical imaging interpretation. However, prospective validation is required before clinical deployment.

Background: Radiation dose reduction is essential in paediatric lung computed tomography (CT). Advances in energy-integrating detector CT and deep-learning reconstruction may enable ultra-low-dose imaging comparable to photon-counting CT.

Objective: To evaluate the radiation dose and performance of an ultra-low-dose lung CT protocol using a wide-detector energy-integrating CT system in paediatric patients, focusing on effective radiation dose and diagnostic image quality.

Materials and methods: A total of 277 low-dose lung CT scans from 106 paediatric patients (age range, 113 days to 17.85 years) were retrospectively analysed. All scans were acquired in axial mode using a 256-slice-multidetector CT scanner with deep learning image reconstruction and attenuation-based Auto Prescription. Radiation dose parameters, including volume CT dose index, dose-length product, size-specific dose estimate, and effective dose, were calculated. Signal-to-noise ratio and contrast-to-noise ratio were assessed in standardised anatomical regions. Patients were stratified by age, and statistical analysis was conducted to evaluate dose trends and image quality metrics.

Results: There were significant differences between all age groups for all dose parameters (Kruskal-Wallis test, P<0.05). The median effective dose increased with age, ranging from 0.12 mSv (interquartile range (IQR) 0.09-0.14 mSv) in the 0-5-year group to 0.23 mSv (IQR 0.21-0.25 mSv) in adolescents aged 15 years to <18 years. Contrast-to-noise ratio and signal-to-noise ratio exhibited age-dependent variation with a small increase in older age groups. One-sided non-inferiority testing demonstrated that the signal-to-noise ratio and contrast-to-noise ratio in the youngest age group (0-5 years) were not significantly inferior to those in the ≥15-year group (P<0.05). All examinations were deemed diagnostically sufficient by board-certified paediatric radiologists. Non-disruptive artefacts such as cardiac motion and step artefacts occurred frequently but did not impair interpretation.

Conclusions: Ultra-low-dose lung CT using wide-detector energy-integrating CT with deep-learning image reconstruction allows for routine diagnostic imaging in children at radiation doses ranging from 0.12 mSv to 0.23 mSv, comparable to those reported for newer photon-counting CT systems. This approach provides a robust, clinically viable strategy for minimizing radiation exposure while maintaining diagnostic image quality.

Background: Childhood obesity is rising worldwide, leading to an increased prevalence of metabolic dysfunction-associated steatotic liver disease, the most common pediatric liver disease. Ultrasound-derived fat fraction (UDFF) is a recently developed technique for quantifying hepatic fat that has been validated in children, providing a rapid, reliable, and non-invasive alternative to conventional imaging.

Objective: To evaluate the association between weight status, expressed as body mass index (BMI) z-score, and UDFF in a pediatric population without underlying liver disease.

Materials and methods: Abdominal ultrasounds including a UDFF measurement in patients without liver disease were retrospectively evaluated. We calculated the BMI z-score for all patients and classified them as normal weight (zBMI) or overweight (zBMI≥1). UDFF values were compared across zBMI categories, sex and ethnicity (Hispanic/Latino or non-Hispanic/non-Latino), using chi-square tests (P<0.05). Pearson's correlation was used to assess the relationship between continuous UDFF values and zBMI. Logistic regression analyses were performed to assess associations between elevated UDFF (>6%) and adiposity markers (zBMI and ultrasound-measured abdominal wall thickness (AWT)), as well as ethnicity.

Results: Of 223 subjects, 93 (41 males/52 females, mean age of 8.2 years) met the inclusion criteria. In the normal-weight population (n=46), 41 (89.1%) had normal UDFF, and 5 (10.9%) had elevated UDFF. In the overweight group (n =47), 29 (61.7%) had normal UDFF and 18 (38.3%) had elevated UDFF. UDFF values showed a positive correlation with zBMI, and higher zBMI increased the odds of elevated UDFF. In the multivariable model including zBMI, AWT, and ethnicity, ultrasound-measured abdominal wall thickness was the strongest predictor of elevated UDFF.

Conclusion: BMI z-score was positively associated with hepatic fat content and with higher odds of elevated UDFF. When multiple factors were considered together, ultrasound-measured abdominal wall thickness showed the strongest independent association with elevated UDFF supporting the central role of adiposity in pediatric hepatic fat accumulation. UDFF may serve as a valuable complement to routine clinical markers, using zBMI, for early identification of children with hepatic steatosis. Larger prospective studies are needed to define its role in clinical practice.

Background: The main pulmonary artery (MPA) and branch pulmonary arteries (PAs) are commonly affected in congenital heart diseases, with residual postoperative abnormalities, a leading cause of reintervention.

Objective: To establish normative mean diameters, area and corresponding Z-scores for the MPA and branch PAs in teenagers, utilizing respiratory-navigated non-contrast ECG-gated 3D balanced steady-state free precession (3D bSSFP) magnetic resonance imaging (MRI) in systole.

Materials and methods: This retrospective study included patients with pectus excavatum deformity who underwent cardiac MRI between January and August 2023, excluding patients with aortopathies. Measurements of the PAs were obtained from non-contrast multiplanar reformatted 3D bSSFP datasets. Mean diameters and cross-sectional areas were calculated. Relationships between each vascular measurement and patient characteristics (age, height, and body surface area (BSA)) were assessed individually using weighted linear regression with inverse-density-based weights to account for data distribution. Additionally, Z-scores were calculated.

Results: The study included 112 patients (91 males [81%]; mean age, 14.3±1.7 years; mean BSA, 1.63±0.2 m²). All vessel measurements showed a positive trend with body size (height and BSA). Across categorical age groups, however, they did not exhibit a monotonic increase with age. Across all models, BSA was a statistically significant independent predictor of PA dimensions (p<0.01), with stronger associations observed for cross-sectional area than for diameter. Height contributed minimally and was not an independent predictor. Branch PA measurements-particularly right pulmonary artery, and to a lesser extent left pulmonary artery-exhibited slightly better model fit than the MPA.

Conclusion: We report normative reference values for mean diameters and cross-sectional areas of the MPA and branch PAs in children 10-18 years, obtained using respiratory-navigated ECG-gated non-contrast-enhanced 3D bSSFP MRI technique in systole.

MR angiography with ferumoxytol expands the toolset for imaging the pediatric abdominal vasculature. As an iron-based blood pool contrast agent, ferumoxytol allows for high-resolution imaging of the abdominal vessels that is not dependent on precise timing of contrast phases and can be used in patients with a contraindication to gadolinium-based contrast agents. At our institution, it has proven useful for abdominal indications including vascular mapping in the settings of portal hypertension, portosystemic shunts, and abdominal transplant evaluation, as well as for investigation of vascular malformations and vasculitis. Others have demonstrated its utility in tumor imaging, especially with hepatic tumors. In this review, we describe our protocol for ferumoxytol-enhanced MR angiography and discuss its various pediatric abdominal applications.

Background: Workload among pediatric radiologists is rising, driven by staff shortages, case complexity, and call demands. Higher imaging volumes are linked to diagnostic errors and job dissatisfaction, affecting patient care and radiologists' retention and recruitment. Technological advances may have increased the number of images generated per study, contributing a hidden workload not captured by study counts alone.

Objective: To determine the increase in the number of images per study in pediatric ultrasound (US), computed tomography (CT), and magnetic resonance (MR) at a pediatric tertiary care hospital between 2004 and 2023.

Materials and methods: A single-center retrospective review was conducted on the number of images acquired in select US, CT, and MR studies for patients under 18 years during the week of June 1-7, from 2004 to 2023. Trends were assessed with linear regression, with statistical significance at a P-value of <0.05.

Results: A total of 1,751 studies were reviewed and 749,152 total images were analyzed. The average number of US images per study increased from 38.67 to 165.24, MR from 185.62 to 1,292.00, and CT from 42.53 to 266.00. Regression analysis indicated statistically significant increases in all modalities: US by 7.41 images per year, MR by 51.60, and CT by 22.27 (P<0.0001 for all). Stratification based on study subtype was also performed.

Conclusion: The number of images per study has significantly increased over the two decades, adding hidden strain on pediatric radiologists' workload. Imaging protocols should be reviewed to optimize the number of acquired images without losing diagnostic accuracy.

Background: Cerebral magnetic resonance imaging (MRI) at term-equivalent age can provide prognostic information for extremely preterm infants; however, MRI-based reference values for ventricular size at term-equivalent age are sparse.

Objective: To present supratentorial ventricular size around term-equivalent age using MRI-based linear- and approximate volumetric measurements in extremely premature infants with and without germinal matrix-intraventricular haemorrhages, to assess whether ventricular size increases with haemorrhage presence and severity, and to determine which linear measurement best predicts volume of the lateral ventricles.

Materials and methods: In total, 119 infants born before 28 gestational weeks (mean chronological age at MRI 14.6 weeks) were prospectively included and categorised as having either no haemorrhage or germinal matrix-intraventricular haemorrhages based on cerebral ultrasound findings in the neonatal period. Brain MRI was performed around term-equivalent age. Linear measurements and approximate volumetric measurements of ventricular size were obtained.

Results: Infants with germinal matrix-intraventricular haemorrhages grade 4 had significantly larger supratentorial ventricular systems compared to those with no haemorrhage or grade 1, including both linear measurements and approximate volumetric measurements. No differences were observed between infants with no haemorrhage and grades 1 or 2. Bilateral haemorrhages resulted in larger ventricular sizes than unilateral haemorrhages. Frontal horn depth and thalamo-occipital distance demonstrated the strongest correlations with lateral ventricle volume.

Conclusion: Supratentorial ventricular size around term-equivalent age varies with severity and laterality of neonatal germinal matrix-intraventricular haemorrhages, with grade 4 associated with the largest ventricles. Frontal horn depth and thalamo-occipital distance were the best linear predictors of lateral ventricular volume.