Search

Human adenoviruses typically cause self-limited respiratory, gastrointestinal, and conjunctival infections in healthy children. In late 2021 and early 2022, several previously healthy children were identified with acute hepatitis and human adenovirus viremia.We usedA total of 15 children were identified with acute hepatitis - 6 (40%) who had hepatitis with an identified cause and 9 (60%) who had hepatitis without a known cause. Eight (89%) of the patients with hepatitis of unknown cause tested positive for human adenovirus. These 8 patients plus 1 additional patient referred to this facility for follow-up were included in this case series (median age, 2 years 11 months; age range, 1 year 1 month to 6 years 5 months). Liver biopsies indicated mild-to-moderate active hepatitis in 6 children, some with and some without cholestasis, but did not show evidence of human adenovirus on immunohistochemical examination or electron microscopy. PCR testing of liver tissue for human adenovirus was positive in 3 children (50%). Sequencing of specimens from 5 children showed three distinct human adenovirus type 41 hexon variants. Two children underwent liver transplantation; all the others recovered with supportive care.Human adenovirus viremia was present in the majority of children with acute hepatitis of unknown cause admitted to Children's of Alabama from October 1, 2021, to February 28, 2022, but whether human adenovirus was causative remains unclear. Sequencing results suggest that if human adenovirus was causative, this was not an outbreak driven by a single strain. (Funded in part by the Centers for Disease Control and Prevention.).

Background Human adenoviruses (HAdV) are a common cause of respiratory and gastrointestinal infections but rarely cause end-organ disease in children. From October 2021 to February 2022, several previously healthy children admitted to a single center for significant hepatitis also tested positive for HAdV. The aim of this investigation is to describe characteristics of these children. Methods Children admitted to Children’s of Alabama (COA) from October 2021 to February 2022 with hepatitis who tested positive for HAdV by whole blood RT-PCR were included. Demographic, clinical, laboratory and treatment data were collected from medical records. Residual blood specimens were sent for adenovirus typing. Results Nine pediatric patients with hepatitis and HAdV infection were identified (78% female; median age 3.0 years; IQR 1.7-3.0). Before admission, six reported diarrhea and three had respiratory symptoms. At presentation, eight had scleral icterus, six had jaundice, seven had hepatomegaly, and one was encephalopathic. All patients had elevated transaminases (AST range: 447-4000 U/L, ALT range: 784-4695 U/L); initial total bilirubin varied [range 0.23-13.5 mg/dL]). All had confirmed HAdV by RT-PCR on whole blood (initial qPCR range: 991-70,680 copies/mL). Notably, two children who transferred to another facility were negative for HAdV by RT-PCR when plasma was tested (instead of whole blood). Six children underwent liver biopsy showing varying degrees of hepatitis with no adenovirus detected on immunohistochemistry stains. Five children had HAdV type 41 confirmed. Three children presented or progressed to acute liver failure, two children were treated with cidofovir, and two underwent successful liver transplantation. No known epidemiologic links between patients were identified and all were from geographically distinct parts of Alabama. Conclusion HAdV is a potentially underrecognized cause of hepatitis. Whole blood specimens may be preferred over plasma for HAdV RT-PCR testing. HAdV type 41 was identified in all patients with typing results available. Improved type-based surveillance may help determine HAdV patterns of circulation and inform future diagnostic testing. Disclosures William Britt, MD, First Energy Corporation: Stocks/Bonds|Hookipa Pharma: Advisor/Consultant|Kroger Care: Stocks/Bonds|MDU Resources Group: Stocks/Bonds|PG&E Corporation: Stocks/Bonds.

Background Diagnoses of thalamic atrophy in children are based on experts’ judgments. No normative measures exist for aiding objective diagnoses. Our aim was to determine normative two-dimensions(2D) and volume measurements of the thalamus in normally developing children. Methods MRI images of 245 patients were retrospectively collected. Only participants with normal brain MRIs were included in this cross-sectional study. Anterior-posterior (AP), transverse (T), and craniocaudal (C) diameters were measured. Volumetric masks of the thalamus were manually drawn, whereas volumetric measurements of the brain were automated. Results 124 patients were male (50.6%). We tabulated our measurements from birth until 18 years old. No significant differences in the thalamus measurements are found between the two hemispheres nor between sexes. The most remarkable increase in the thalamus volume and AP dimension is noted in the first four years of life, following which the values seem to stabilize. Craniocaudal diameters seem to increase in the first year of life, whereas transverse diameters increase until the age of 14 before plateauing. Conclusion We report normative values of the thalamus in 2D and 3D from birth until 18 years of age. A rapid increase in the thalamic size is noted during the first four years of life followed by stabilization.

Gadolinium-based contrast agent (GBCA) effect on automated segmentation algorithms of subcortical gray matter (GM) is not fully known. The aim of this study is to determine gadolinium effect on the segmentation of the thalamus and whole brain tissue using different automated segmentation techniques. Eighty-four multiple sclerosis (MS) patients underwent an MRI acquisition of two 3DT1-weighted sequences with and without gadolinium injection among which 10 were excluded after image quality check. Manual thalamic segmentation considered as gold standard was performed on unenhanced T1 images. volBrain and FSL-Anat were used to automatically segment the thalamus on both enhanced and unenhanced T1 and the degree of similitude (DICE) values were compared between manual and automatic segmentations. Whole brain tissue segmentation (GM, white matter (WM), and lateral ventricles (LV)) was also performed using SIENAX. A paired samples t test was applied to test the significance of DICE value differences between the thalamic manual and automatic segmentations of both enhanced and unenhanced T1 images. Significant differences (FSL-Anat 1.474% p

The anatomical structure of the thalamus renders its segmentation on 3DT1 images harder due to its low tissue contrast, and not well-defined boundaries. We aimed to investigate the differences in the precision of publicly available segmentation techniques on 3DT1 images acquired at 1.5 T and 3 T machines compared to the thalamic manual segmentation in a pediatric population. Sixty-eight subjects were recruited between the ages of one and 18 years. Manual segmentation of the thalamus was done by three junior raters, and then corrected by an experienced rater. Automated segmentation was then performed with FSL Anat, FIRST, FreeSurfer, MRICloud, and volBrain. A mask of the intersections between the manual and automated segmentation was created for each algorithm to measure the degree of similitude (DICE) with the manual segmentation. The DICE score was shown to be highest using volBrain in all subjects (0.873 ± 0.036), as well as in the 1.5 T (0.871 ± 0.037), and the 3 T (0.875 ± 0.036) groups. FSL-Anat and FIRST came in second and third. MRICloud was shown to have the lowest DICE values. When comparing 1.5 T to 3 T groups, no significant differences were observed in all segmentation methods, except for FIRST (p = 0.038). Age was not a significant predictor of DICE in any of the measurements. When using automated segmentation, the best option in both field strengths would be the use of volBrain. This will achieve results closest to the manual segmentation while reducing the amount of time and computing power needed by researchers.

Diagnoses of thalamic atrophy in children are based on experts' judgments. No normative measures exist for aiding objective diagnoses. Our aim was to determine normative two-dimensions(2D) and volume measurements of the thalamus in normally developing children.MRI images of 245 patients were retrospectively collected. Only participants with normal brain MRIs were included in this cross-sectional study. Anterior-posterior (AP), transverse (T), and craniocaudal (C) diameters were measured. Volumetric masks of the thalamus were manually drawn, whereas volumetric measurements of the brain were automated.124 patients were male (50.6%). We tabulated our measurements from birth until 18 years old. No significant differences in the thalamus measurements are found between the two hemispheres nor between sexes. The most remarkable increase in the thalamus volume and AP dimension is noted in the first four years of life, following which the values seem to stabilize. Craniocaudal diameters seem to increase in the first year of life, whereas transverse diameters increase until the age of 14 before plateauing.We report normative values of the thalamus in 2D and 3D from birth until 18 years of age. A rapid increase in the thalamic size is noted during the first four years of life followed by stabilization.

BACKGROUND AND PURPOSE: Few articles in the literature have looked at the diameter of the optic nerve on MR imaging, especially in children, in whom observations are subjective and no normative data exist. The aim of this study was to establish a data base for optic nerve diameter measurements on MR imaging in the pediatric population. MATERIALS AND METHODS: This was a retrospective study on the MR imaging of pediatric subjects (younger than 18 years of age) at the Department of Diagnostic Radiology at the American University of Beirut Medical Center, Beirut, Lebanon. The optic nerve measurements were obtained by 3 raters on axial and coronal sections at 3 mm (retrobulbar) and 7 mm (intraorbital) posterior to the lamina cribrosa. RESULTS: Of 211 scans of patients (422 optic nerves), 377 optic nerves were measured and included. Ninety-four patients were female (45%) and the median age at MR imaging was 8.6 years (interquartile range, 3.9–13.3 years). Optic nerves were divided into 5 age groups: 0–6 months ( n = 18), 6 months–2 years ( n = 44), 2–6 years ( n = 86), 6–12 years ( n = 120), and 12–18 years ( n = 109). An increase in optic nerve diameter was observed with age, especially in the first 2 years of life. Measurements did not differ with eye laterality or sex. CONCLUSIONS: We report normative values of optic nerve diameter measured on MR imaging in children from birth to 18 years of age. A rapid increase in optic nerve diameter was demonstrated during the first 2 years of life, followed by a slower increase. This was independent of sex or eye laterality.