Craniofacial phenotyping with fetal MRI: a feasibility study of 3D visualisation, segmentation, surface-rendered and physical models.

This study explores the potential of 3D Slice-to-Volume Registration (SVR) motion-corrected fetal MRI for craniofacial assessment, traditionally used only for fetal brain analysis. In addition, we present the first description of an automated pipeline based on 3D Attention UNet trained for 3D fetal MRI craniofacial segmentation, followed by surface refinement. Results of 3D printing of selected models are also presented.Qualitative analysis of multiplanar volumes, based on the SVR output and surface segmentations outputs, were assessed with computer and printed models, using standardised protocols that we developed for evaluating image quality and visibility of diagnostic craniofacial features. A test set of 25, postnatally confirmed, Trisomy 21 fetal cases (24-36 weeks gestational age), revealed that 3D reconstructed T2 SVR images provided 66-100% visibility of relevant craniofacial and head structures in the SVR output, and 20-100% and 60-90% anatomical visibility was seen for the baseline and refined 3D computer surface model outputs respectively. Furthermore, 12 of 25 cases, 48%, of refined surface models demonstrated good or excellent overall quality with a further 9 cases, 36%, demonstrating moderate quality to include facial, scalp and external ears. Additional 3D printing of 12 physical real-size models (20-36 weeks gestational age) revealed good/excellent overall quality in all cases and distinguishable features between healthy control cases and cases with confirmed anomalies, with only minor manual adjustments required before 3D printing.Despite varying image quality and data heterogeneity, 3D T2w SVR reconstructions and models provided sufficient resolution for the subjective characterisation of subtle craniofacial features. We also contributed a publicly accessible online 3D T2w MRI atlas of the fetal head, validated for accurate representation of normal fetal anatomy.Future research will focus on quantitative analysis, optimizing the pipeline, and exploring diagnostic, counselling, and educational applications in fetal craniofacial assessment.

Bulging Anterior Fontanelle Caused by Severe Acute Respiratory Syndrome Coronavirus-2.

Neurologic manifestations of the 2019 novel coronavirus disease in children are varied. We present the case of a 9-month-old child with bulging anterior fontanelle caused by severe acute respiratory syndrome coronavirus-2.

Thanatophoric dysplasia type 1 with tectal plate dysplasia and aqueductal stenosis.

INTRODUCTION: Skeletal dysplasias are a heterogeneous group of disorders comprising of more than 300 entities, many of which manifest in the prenatal period, emphasizing the importance of accurate prenatal diagnosis. Detection of a lethal skeletal dysplasia via prenatal ultrasound is often straightforward. However, establishing the specific diagnosis and detailed evaluation of intracranial anomalies are often challenging. Fetal magnetic resonance imaging (MRI) is superior to ultrasound in the detection of abnormal sulcation pattern, corpus callosal agenesis, and posterior fossa anomalies. Hence, it has the potential of delineating neuroimaging features that may not be fully elucidated by ultrasound. The objective of this article is to describe an unusual case of thanatophoric dysplasia (TD) with dysplastic tectal plate and resultant aqueductal stenosis diagnosed on fetal MRI. To the best of our knowledge, this has never been reported before in the literature. A comprehensive review of literature pertaining to TD-associated CNS abnormalities will also be included. CONCLUSIONS: Our reported case adds to the current limited knowledge of this rare entity and emphasizes the crucial role of fetal MRI in expanding the neuroimaging phenotypes of TD.

Orbital lymphoma: imaging features and differential diagnosis.

PURPOSE: Patterns of orbital lymphoma at diagnosis and follow-up are described. We also discuss differential diagnosis of orbital masses. MATERIALS AND METHODS: This pictorial review contains 19 cases of orbital lymphoma before and after treatment. Superior-lateral quadrant and extra-conal location were observed predominantly. Effective response after treatment was presented on follow-up imaging, although few local relapses were found. Further follow-up showed no changes of residual images. DISCUSSION: Location of orbital masses can help in the differential diagnosis. Moreover, imaging features of lymphoma at diagnosis can be useful in planning surgical biopsy. Pattern of follow-up described may be relevant on monitoring imaging. TEACHING POINTS : • Orbital lymphoma involves mainly superior-lateral quadrant and the orbital structures inside. • Location of retrobulbar mass-like lesions are useful information in the differential diagnosis. • Satisfactory response is detected after treatment, however relapse is noted, so follow-up is needed.