Pediatric Radiology最新文献

Background: Hindbrain herniation is part of Chiari II deformation and serves as an inclusion criterion for prenatal open neural tube defect (ONTD) repair. Its assessment on fetal MRI remains challenging, due to limited spatial resolution, fetal motion and difficulty obtaining a true mid-sagittal plane.

Objective: We aimed to evaluate the reproducibility of the Hindbrain herniation severity classification, based on repeated consensus readings by two evaluators.

Methods: We retrospectively reviewed fetuses who underwent prenatal ONTD repair at a single center (2011-2024), with pre- and 6 week post-operative T2-weighted fetal brain MRI scans. Hindbrain herniation was graded as: 0 = normal; 1 = effacement of the 4th ventricle and/or cisterna magna without Hindbrain herniation; 2 = Hindbrain herniation above the C1 posterior arch; 3 = Hindbrain herniation bellow C1 posterior arch. Two experienced fetal imaging specialists independently assessed all scans, resolved discrepancies by consensus, and repeated the evaluation two months later, blinded to initial grading. Reproducibility was assessed with weighted Cohen's Kappa overall and separately for pre- and post-operative scans.

Results: 121 fetuses were included. Postoperative MRI was available in 113 (93.4%). Overall reproducibility was excellent (κ = 0.87). Agreement was lower for pre-operative (κ = 0.57) than post-operative (κ = 0.74) scans (p < 0.01).

Conclusion: Hindbrain herniation grading on fetal MRI shows excellent overall reliability. The moderate agreement in preoperative scans reflects the difficulty of assessing Hindbrain herniation before prenatal repair and highlights the need for more standardized imaging criteria, when accurate assessment is necessary for surgical eligibility and parental counseling.

We report a case of Lemierre syndrome complicated by multiple pulmonary artery pseudoaneurysms. A previously healthy 11-year-old girl presented with pansinusitis complicated by internal jugular vein thrombosis consistent with a diagnosis of Lemierre syndrome. She presented an episode of massive hemoptysis secondary to pseudoaneurysm rupture requiring radiologically guided embolization. Blood cultures isolated Streptococcus constellatus. Prolonged antibiotic therapy was administered. The patient was discharged from hospital 1 month later and recovered uneventfully.

Background: Federal regulations require an audible alarm for each passage of 5 min of cumulative x-ray irradiation time during a diagnostic fluoroscopy procedure. In contrast to United States federal requirements, regulations vary amongst individual states.

Objective: Determine whether a shortened fluoroscopy time alarm reduces pediatric patient ionizing radiation exposure for modified barium swallow studies (MBSS).

Materials and methods: Fluoroscopy time alarms were changed from the passage of every 5 min to 2 min. A retrospective analysis of MBSS compared patient reference point air kerma and fluoroscopy time before and after the alarm time was shortened.

Results: A total of 3,875 MBSS performed on patients under the age of 18 years were analyzed. Reductions of 14.9% and 19.6% for average and median reference point air kerma (P<0.001) and 15.5% and 16.2% for average and median fluoroscopy time (P<0.001) were observed at the main campus for MBSS performed before and after changing the fluoroscopy time alarm from 5 min to 2 min. Reductions of 14.3% and 9.1% for average and median reference point air kerma (P<0.001) and 13.9% and 8.3% for average and median fluoroscopy time (P<0.001) were observed at the satellite locations for MBSS performed before and after changing the fluoroscopy time alarm.

Conclusion: This retrospective study suggests a shortened fluoroscopy time alarm can significantly lower pediatric patient dose and fluoroscopy time in MBSS. State and federal regulations should consider establishing flexible fluoroscopic alarm settings, especially when used for the pediatric population.

This case report describes a unique case of hemiconvulsion-hemiplegia-epilepsy syndrome in a paediatric patient with an underlying hypomyelinating leukodystrophy. We present the clinical, neuroimaging and genetic findings of a 3-year-old girl with a myelin deposition disorder who presented with a prolonged febrile status epilepticus, followed by persistent left hemiplegia. Brain magnetic resonance imaging (MRI) revealed a pattern consistent with hemiconvulsion-hemiplegia-epilepsy syndrome, with unilateral cytotoxic oedema and increased cerebral blood flow in the right cerebral hemisphere cortex. The girl was treated with corticosteroid therapy and levetiracetam. Follow-up imaging showed cerebral atrophy ipsilateral to the seizure focus. Incomplete myelination pattern remained unchanged. No prior cases associating hypomyelinating leukodystrophy with hemiconvulsion-hemiplegia-epilepsy syndrome have been reported. This case expands the phenotypic spectrum of hypomyelinating disorders and raises the hypothesis that an underlying white matter vulnerability may predispose to or modify the course of hemiconvulsion-hemiplegia-epilepsy syndrome. Recognition of such associations may have implications for prognosis and management, including seizure control strategies and neurorehabilitation. Further reports are needed to determine the role of myelination in the development of epileptic syndromes.

Background: Magnetic resonance imaging (MRI) plays an important role in the diagnosis and treatment of hippocampal sclerosis. However, this exam presents challenges due to long scan times and image quality variability in pediatric patients.

Objective: This study aims to compare conventional reconstructed MRI and accelerated sequences with and without deep learning-based reconstruction (DLR) with regard to image quality and diagnostic performance in pediatric hippocampal sclerosis patients.

Materials and methods: A total of 68 pediatric patients proven or suspected to have temporal lobe epilepsy with hippocampal sclerosis who underwent recommended epilepsy structural MRI were included in this study. MRI examination included standard sequences and accelerated sequences with and without DLR. Standard sequences were reconstructed using the conventional pipeline, while accelerated sequences were reconstructed using both the conventional pipeline and DLR pipeline. Two experienced pediatric radiologists independently evaluated the following parameters of three reconstructed image sets on a 5-point scale: image quality, anatomic structure visibility, motion artifact, truncation artifact, image noise, and detectability of hippocampal abnormalities. Signal-to-noise ratio (SNR) measurements of the hippocampus were performed in all sequences and compared between the three sets of images. Inter-reader agreement and agreement between image sets for detecting hippocampal abnormalities were assessed using Cohen's kappa.

Results: Images reconstructed with DLR received significantly higher scores of overall image quality, presence of lesion, and image noise than with conventional or original accelerated reconstructions (all P<0.05), while there was no statistical difference of artifacts between the three groups (all P>0.05). The SNR for all sequences with DLR was significantly higher than conventional or original reconstructions without DLR (all P<0.001). Inter-reader agreement showed almost perfect agreement (κ=0.803-0.963) of the imaging manifestations, while agreement between image sets showed substantial agreement to almost perfect agreement (κ=0.778-0.965) of the imaging manifestations.

Conclusion: Accelerated sequences with DLR provide a 44% scan time reduction with similar subjective image quality, artifacts, and diagnostic performance to conventional reconstruction sequences.

Background: Neonatal hypoxic-ischemic encephalopathy (HIE) diagnosis is confounded by heterogeneous neural injury and metabolic dysfunction. Multi-pool chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) uniquely quantifies amide proton transfer, nuclear Overhauser enhancement, and magnetization transfer signals, providing multi-parametric assessment of HIE pathophysiology.

Objective: To investigate whether multi-pool CEST MRI can serve as a molecular-specific biomarker for histopathological alterations in HIE and assess its efficacy in grading disease severity.

Materials and methods: This prospective study included 20 neonates with HIE and 42 age-matched controls undergoing 3.0-T CEST MRI. Imaging data were spatially normalized to a neonatal atlas for region-specific analysis (caudate, putamen, thalamus, pallidum, amygdala, hippocampus). Group differences in CEST signals (amide proton transfer, nuclear Overhauser enhancement, magnetization transfer) were analyzed via Wilcoxon tests, with diagnostic performance evaluated through receiver operating characteristic analysis.

Results: Compared to controls, HIE neonates showed significant reductions in amide proton transfer (bilateral putamen, right hippocampus/pallidum/amygdala, left thalamus/caudate), nuclear Overhauser enhancement (left thalamus/caudate/putamen), and magnetization transfer signals (bilateral thalamus/pallidum/putamen, left caudate; all P<0.05). Subgroup analysis revealed progressive metabolic decline: moderate-to-severe HIE exhibited further amide proton transfer reduction in the right thalamus, nuclear Overhauser enhancement decreases in bilateral hippocampus, and magnetization transfer decreases in left hippocampus/thalamus compared to mild cases (all P<0.05). Notably, conventional amide proton transfer-weighted imaging showed no significant changes, as the reduction in amide proton transfer signal was offset by a concurrent decrease in the nuclear Overhauser enhancement, highlighting the superiority of multi-pool analysis. Left hippocampal nuclear Overhauser enhancement demonstrated exceptional severity discrimination (area under curve (AUC)=0.96), while a multi-region integrated model achieved perfect staging accuracy (AUC=1.00).

Conclusion: Multi-pool CEST MRI effectively captures histopathological changes in neonatal HIE, with left hippocampal nuclear Overhauser enhancement emerging as a precise biomarker for severity stratification. The combined dynamics of amide proton transfer, nuclear Overhauser enhancement, and magnetization transfer signals provide noninvasive insights into metabolic-pathological correlations, highlighting its transformative potential for early diagnosis and targeted therapeutic monitoring.

Background: The rising prevalence of paediatric liver disease, including metabolic dysfunction- associated steatotic liver disease, highlights the need for reliable, non-invasive diagnostic tools. Advanced ultrasound techniques such as shear wave elastography (SWE), shear wave dispersion (SWD), and attenuation imaging (ATI) offer promising alternatives to biopsy or magnetic resonance imaging, but normative paediatric values remain limited.

Objective: This study aimed to establish age-specific reference values for SWE, SWD, and ATI in healthy children and to assess potential influencing factors such as age, sex, body mass index (BMI), and fasting duration.

Materials and methods: In this retrospective study, 264 children (135 female, median age 11.5 years) without known liver disease were selected from a cohort of 734. Each child underwent liver ultrasound using a standardized protocol with five ATI and ten SWE/SWD measurements. Only high-quality data were included. Statistical analyses examined correlations between imaging parameters and patient characteristics.

Results: The median ATI was 0.54 dB/cm/MHz [interquartile range (IQR):0.50-0.58], SWE was 1.24 m/s (IQR:1.14-1.33) and SWD was 11.70 (m/s)/kHz (IQR:10.84-12.13). ATI and SWD values showed significant negative correlations with age (P < 0.001 and P = 0.0048, respectively). SWD also correlated negatively with BMI z-score (P < 0.001) and was significantly lower in females (P = 0.001). SWE showed only a weak positive correlation with measurement depth (P = 0.0261). Fasting duration had no significant impact on any measurement.

Conclusion: This study provides reference values for SWE, SWD, and ATI in children. Age and sex influence SWD and ATI values, underscoring the importance of age-specific interpretation in paediatric liver ultrasound.