Pediatric Radiology最新文献

Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS), also known as Berdon syndrome, is a rare genetic congenital disorder of impaired smooth muscle contractility, resulting in functional obstruction of the bladder and bowel. Historically associated with a poor prognosis, recent advances in the use of total parenteral nutrition (TPN), intestinal rehabilitation, and multi-visceral transplantation have led to improvements in survival in patients with MMIHS, with patients now living into the second decade of life. The radiologist plays a key role in the initial workup of these patients and is often the first to suggest the diagnosis. Furthermore, with patients living longer, the radiologist's role now includes the following: (1) identifying complications on follow-up imaging, such as distinguishing mechanical obstruction from dysmotility; (2) following findings of chronic kidney disease; and (3) recognizing cholestatic TPN-related liver disease. With expedient diagnosis and management, survival can be extended, and quality of life can be improved. This pictorial essay aims to demonstrate the spectrum of imaging findings in the prenatal stage, the neonatal period, and later childhood in confirmed cases. Clinical findings, management, and outcomes of MMIHS, as well as imaging features that differentiate MMIHS from similar conditions, will be discussed.

Background: Most artificial intelligence (AI) research in radiology has focused on adults. Understanding macro-level trends in pediatric radiology AI can help guide, streamline, and bolster future research.

Objective: To detail the current landscape of published AI research in pediatric radiology, filling a key research gap, as most radiology AI research has focused on adults.

Materials and methods: We conducted a scoping review, with a comprehensive literature search of Medline, Embase, Web of Science, and Cochrane Library from 2005 to 2024. Literature included for review were (1) original articles, (2) investigations that focused on pediatric populations (<18 years of age), and (3) articles with direct applications to clinical radiology and AI. We extracted each article's study information, clinical application of focus, imaging modality, and the use of AI. We used descriptive frequencies to analyze summary statistics, and Chi-square testing to determine differences between categories.

Results: In total, we found 4,376 articles and included 789 articles in the review. The top three countries most active in scholarship related to AI in pediatric radiology were China (220, 27.9%), the USA (200, 25.4%), and Canada (51, 6.5%) (P<0.001). The most common imaging modalities were radiography (298, 37.8%), MRI (260, 33.0%), and ultrasonography (114, 14.4%) (P<0.001). The most common subspecialties represented were musculoskeletal (260, 33.0%), neurological (227, 28.8%), and chest imaging (130, 16.5%) (P<0.001). The top two image analysis tasks discussed were image interpretation/diagnosis (719, 91.1%), and artifact and motion reduction/enhancing image quality (44, 5.6%) (P<0.001).

Conclusion: Most pediatric radiology AI research originated from China and the USA, and focused on image interpretation/diagnosis. Thematic imbalances, particularly underrepresentation in research on communication, education, policy, and stakeholder perspectives, offer a guide for pediatric radiology AI development. There is a need for improved global collaboration and improved patient representativeness in datasets for pediatric radiology AI research to reduce bias with AI algorithms. The results from this scoping review offer a practical roadmap to inform future research and funding priorities in pediatric radiology AI.

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.

Background: Fetal abdominopelvic cysts are relatively common, but distinguishing ovarian from non-ovarian cysts prenatally remains challenging because morphologic features overlap, and no imaging marker has been validated.

Objective: To evaluate fetal endometrial thickness and cyst volume as imaging markers for the prenatal diagnosis of ovarian cysts.

Materials and methods: We conducted a single-center, retrospective study of female fetuses with abdominopelvic cysts diagnosed on prenatal ultrasound and/or magnetic resonance imaging (MRI) between January 2010 and December 2024. Two blinded pediatric radiologists independently measured endometrial thickness and cyst volume, with discrepancies resolved by consensus. Postnatal confirmation of diagnosis was obtained through imaging, surgical pathology, or clinical follow-up. Statistical analyses included regression models adjusted for gestational age and receiver operating characteristic (ROC) analysis.

Results: A total of 63 fetuses met inclusion criteria (40 ovarian cysts, 23 non-ovarian cysts) between 21 weeks and 40 weeks of gestation. Fetuses with ovarian cysts underwent ultrasound at later gestational ages than those with non-ovarian cysts (median, 35.0 weeks vs. 27.9 weeks; P<0.001), and MRI showed a similar difference (median, 34.4 weeks vs. 27.9 weeks; P<0.001). Ovarian cysts were associated with significantly greater endometrial thickness on ultrasound (median 3.2 mm vs. 1.3 mm, P<0.001) and MRI (2.2 mm vs. 1.2 mm, P<0.001). Cyst volumes were larger in ovarian cysts (median, 45.4 mL vs. 2.8 mL; P<0.001), although volume was not independently associated with ovarian cyst diagnosis after adjustment for gestational age (P=0.36). Endometrial thickness remained independently associated with ovarian cysts after adjustment for gestational age (ultrasound coefficient, 1.56 [95% CI, 0.84-2.26]; MRI coefficient, 0.81 [95% CI, 0.41-1.21]). ROC analysis demonstrated excellent diagnostic performance, with an ultrasound threshold of 1.9 mm yielding 100% sensitivity and specificity (AUC, 1.00 [95% CI, 1.00-1.00]). In contrast, cyst volume showed only moderate discriminatory ability (AUC, 0.82 [95% CI, 0.71-0.93]).

Conclusion: Fetal endometrial thickness is a robust imaging marker for the prenatal diagnosis of ovarian cysts. Incorporating this parameter into routine prenatal imaging may enhance diagnostic accuracy, guide counseling, and improve perinatal management.

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.

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: The migration index (MI) is a quantitative measurement of femoral head extrusion used to help risk stratify neuromuscular hip dysplasia. However, MI relies upon the radiographically visible ossified capital femoral epiphysis which is only partially ossified in young children and therefore may potentially underestimate hip extrusion.

Objective: To compare proof-of-concept accuracy of using a metaphyseal and traditional MI to measure femoral head extrusion in children compared with an MRI-based anatomic reference standard.

Materials and methods: We reviewed 205 normal hips, each by MRI and x-ray, in patients aged 6 months - 6 years old. Three femoral head MI measurements were performed: (1) MRI-MI: percentage of the cartilaginous femoral head uncovered by the osseous acetabulum (anatomic reference standard); (2) traditional MI (TMI) x-ray: percentage of osseous capital femoral head uncovered by the osseous acetabulum; (3) metaphyseal MI x-ray (MeMI): percentage of the femoral head uncovered by the osseous acetabulum, using the metaphyseal vertex used as a surrogate for lateral margin of the cartilaginous femoral head. Statistical analysis of the three measurement techniques was performed using paired t-tests. Intraclass correlation coefficient was calculated.

Results: There was a statistically significant underestimation of femoral head extrusion using TMI and MeMI (P<0.05) when compared with MRI-MI, but MeMI more closely approximated the MRI-MI. Inter-reader reliability showed excellent agreement.

Conclusion: The MeMI better approximates the MRI anatomic landmarks for measuring the true degree of femoral head extrusion in children 6 months - 5 years of age. Its usage should be considered in lieu of the TMI in children under 5 years of age for radiographically determining MI.

Background: While single-energy hand computed tomography angiography (CTA) often yields suboptimal visualization of distal vessels, dual-energy computed tomography (CT) with low-keV virtual monoenergetic image (VMI) reconstruction enhances small-vessel conspicuity.

Objective: To evaluate the value of dual-energy CT VMIs in pediatric hand CTA.

Materials and methods: This retrospective study included 49 pediatric patients. Seven image series per patient were generated from dual-energy data: an M_0.5 image (50% 70 kVp+50% tin-filtered 150 kVp), a 70-kVp image, and five VMIs at 40-80 keV (10-keV increments). Objective metrics (attenuation, vessel noise, signal-to-noise ratio, contrast-to-noise ratio) and subjective scores were assessed for five vessels: the radial artery, the ulnar artery, the common palmar digital artery, and the proximal and distal parts of the proper palmar digital artery. Subjective image quality was independently evaluated by two radiologists using a 4-point Likert scale.

Results: The 40-keV VMIs provided the highest vascular attenuation across all vessels, albeit with the highest noise. Subjective scores for the radial, ulnar, and common palmar digital arteries showed no significant differences among the 40-keV, 50-keV, and 70-kVp series. However, for the small distal proper palmar digital arteries and total image quality, the 40-keV series was rated superior to the other series. No significant differences in image quality existed between the 70-kVp and 50-keV images.

Conclusion: For pediatric hand CTA, 40-keV VMIs provide optimal vascular conspicuity for small distal vessels, yielding the highest diagnostic confidence and total image quality score, and this benefit outweighs the associated increase in vessel noise.

Artificial intelligence (AI) holds immense promise in guiding clinical decision making in pediatric radiology, but its implementation in resource-constrained healthcare systems is limited by several significant challenges. The common AI methods, specifically deep learning models, used for image synthesis, reconstruction and segmentation require high-performance computers (HPC) and large memory capacities, which are often unavailable in low- and middle-income countries, especially in Sub-Saharan Africa. Long reconstruction times, inadequate hardware, and reliance on expensive commercial software further hinder adoption. These issues are compounded by the scarcity of annotated pediatric datasets, variability in imaging protocols, and limited data-sharing infrastructure, all of which widen the AI divide, particularly in pediatric imaging. Even when advanced AI models are developed, deploying them into clinical workflows remains difficult due to poor integration with existing picture archiving and communication systems (PACS) and the limited internet infrastructure for cloud-based solutions and data storage. Addressing these barriers will require intentional efforts to provide affordable high-performance computing resources, open-source pediatric datasets, federated learning approaches, and seamless workflow integration backed by robust region-specific AI regulations. This review sheds light on these barriers and highlights opportunities for AI-enabled solutions to become routine in pediatric radiology on the African continent.