Livja Mertiri

Hirayama disease is a rare flexion-induced cervical myelopathy that predominantly affects adolescents and young adults and is frequently overlooked, as its key flexion MRI features are often absent on routine neutral-position MRI. The aim of this study is to raise awareness of this disease and to highlight the diagnostic value of dynamic flexion and extension MRI in establishing Hirayama disease as a differential diagnosis in patients presenting with suspected cervical spinal cord pathology. We retrospectively analyzed three adolescent patients diagnosed with Hirayama disease at a quaternary academic pediatric hospital. Clinical presentation, electrophysiological findings, and cervical spine MRI studies (including neutral, flexion, and extension views) were reviewed. All patients presented clinically with progressive distal upper extremity weakness and electrophysiological findings suggestive of lower cervical cord pathology. Neutral MRI showed insufficient findings to diagnose Hirayama disease, while flexion MRI revealed an imaging pattern characterized by anterior displacement of the posterior dural sac, marked enlargement of the posterior epidural space, and posterior epidural venous plexus prominence. These dynamic changes resulted in flexion-induced spinal cord compression. In this case series, the diagnosis of Hirayama disease relied on flexion MRI, while neutral imaging alone would have been insufficient. Recognition of this characteristic, position-dependent imaging pattern is essential in young patients with unexplained distal upper limb weakness. Early consideration of dynamic imaging in patients clinically suspected of Hirayama disease helps to avoid diagnostic delays.

T2 hyperintensity on fetal brain MRI is frequently observed in fetuses with an open neural tube defect (ONTD) and may reflect edema, impaired CSF circulation, or altered brain maturation. By characterizing the diffusion of water molecules within brain tissue, DWI may help differentiate among these etiologies by assessing water diffusion as a marker of brain microstructure. Our aim was to investigate the relationship between brain T2-hyperintensity and ADC values in fetuses following prenatal ONTD repair. We retrospectively analyzed fetal MRI scans performed 6 weeks after in utero ONTD repair at a single center. T2 hyperintensity was defined as a region with signal intensity subjectively higher than that of the surrounding brain parenchyma. ADC values were measured in the frontal, temporal, parietal, and occipital lobes on axial brain DWI sequences (b=700 s/mm²). Hindbrain herniation was evaluated, and reversal was defined when the cerebellum was seen above the foramen magnum. ADC values were compared between fetuses with and without T2 hyperintensity using the Mann-Whitney U test. A P value < .05 was considered significant. Forty-nine fetuses underwent repair at 25.0 [23.3-26.4] weeks. During the postoperative MRI at 31.2 [29.9-33.3] weeks, T2 hyperintensity was seen in 35/49 (71.4%) fetuses. ADC values were lower in most studied brain regions in fetuses with T2 hyperintensity compared with their counterparts without T2 hyperintensity (right parietal lobe: 2.68 [1.38-7.82] ×10^{-6 mm2/s} versus 3.36 [2.32-7.05] ×10^{-6 mm2/s}, P = .02; left parietal lobe: 2.80 [1.40-7.38] versus 3.45 [1.81-7.58] ×10^{-6 mm2/s}, P = .03; right temporal lobe: 2.75 [1.41-6.63] versus 3.53 [1.87-7.58] ×10^{-6 mm2/s}, P <.01; right occipital lobe: 3.19 [1.20-7.86] versus 4.30 [2.18-7.18], P = .04). Complete hindbrain herniation reversal was more common in those without T2 hyperintensity (100% versus 65.7%, P < .01). After prenatal ONTD repair, the presence of T2 hyperintensity was associated with lower ADC values in most examined brain regions, suggesting altered brain microstructure or delayed myelination.

Background: Cancer predisposition syndromes (CPSs) are inherited disorders that increase the risk of developing cancer from childhood through adulthood. They account for up to 10% of pediatric tumors, making early recognition important for reducing morbidity and mortality. Because these syndromes show variable penetrance and a wide range of clinical presentations even within the same family, identifying affected children can be challenging. Main body: Imaging is an essential tool for diagnosis, surveillance and follow-up of children with cancer predisposition syndromes. In this review we summarize the main clinical and imaging features of Neurofibromatosis type 1, Neurofibromatosis type 2, von Hippel–Lindau disease, PTEN-hamartoma tumor syndrome, Beckwith–Wiedemann syndrome, and multiple endocrine neoplasia. The goal is to help radiologists and clinicians identify these conditions earlier and improve patient care. Conclusion: A clear understanding of the clinical and imaging features of cancer predisposition syndromes can support earlier identification, closer surveillance, and improved outcomes. Radiologists play a crucial role in recognizing characteristic patterns and guiding timely management for affected children and their families.

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. Graphical Abstract

Background and Purpose: Chiari II deformation in open neural tube defect (ONTD) includes hindbrain herniation (HBH) and posterior fossa remodeling. While HBH reversal after prenatal ONTD repair is well described, associated changes in cerebellar morphology, torcular position, and bony configuration remain poorly characterized. This study evaluated longitudinal changes in posterior fossa anatomy following fetal ONTD repair and their associations with HBH reversal and evolving ventriculomegaly. Methods: We retrospectively reviewed 112 fetuses who underwent prenatal ONTD repair at a single center (2011–2023), each with fetal MRI before surgery (median 22.9 [19.1–25.4] weeks) and 6 weeks after surgery (31.4 [28.6–34.0] weeks). Two independent examiners assessed cerebellar and brainstem position, occipital bone outpouching, clivus concavity, torcular position, and preservation of supratentorial subarachnoid space. HBH reversal was defined as cerebellar ascent above the foramen magnum. Severe ventriculomegaly was defined as a mean atrial width ≥15 mm. Associations were tested using Chi‐square or McNemar tests. Results: At referral, 17.9% had severe ventriculomegaly and 79.5% had lesions below L2. After surgery, clivus concavity (97.3% vs 84.1%, p p p <0.01). Severe ventriculomegaly at postoperative MRI (58.9%) was not associated with posterior fossa abnormalities. Conclusions: Prenatal ONTD repair improves HBH and supratentorial CSF space preservation but has limited impact on deeper posterior fossa remodeling, which appears only partially reversible.

Near-drowning is a prevalent cause of hypoxic ischemic injury in children and young adults. Despite its clinical significance, there is a lack of studies e

Neurodegeneration with brain iron accumulation (NBIA) refers to a group of rare genetic disorders characterized by abnormal iron deposition in the basal ganglia and brainstem due to impaired iron homeostasis. Disease severity and manifestations vary according to the underlying genetic mutation and age of presentation; however, most subtypes share progressive neurological features such as dystonia, Parkinsonism, spasticity, cognitive decline, and intellectual disability. In this review, we first outline the physiological role of iron in the central nervous system, emphasizing its importance for neurotransmitter synthesis, myelination, and mitochondrial metabolism, and discuss how disruption of homeostatic mechanisms may lead to ferroptosis and neuronal injury. We then explore the role of neuroimaging in the diagnosis of NBIA, with a focus on MRI as the modality of choice. Finally, we provide an overview of the clinical and imaging features of the major NBIA subtypes, highlighting both shared characteristics and distinctive patterns. Covered NBIA include primary disorders of iron metabolism, such as neuroferritinopathy and aceruloplasminemia, and secondary disorders with disrupted iron regulation, including Pantothenate Kinase‐Associated Neurodegeneration, Phospholipase A2 Group VI‐Associated Neurodegeneration, Mitochondrial Membrane Protein‐Associated Neurodegeneration, Beta‐Propeller Protein‐Associated Neurodegeneration, Fatty Acid Hydroxylase‐Associated Neurodegeneration, Coenzyme A Synthetase Protein‐Associated Neurodegeneration, Woodhouse–Sakati syndrome, and Kufor–Rakeb Disease. By integrating genetics, pathophysiology, and imaging, this review aims to improve recognition of NBIA and support comprehensive clinical management.

Background Prenatal open neural tube defect (ONTD) repair improves motor function and reduces hydrocephalus treatment by ensuring watertight closure of the defect. Hindbrain herniation (HBH) reversal is often observed postoperatively, but its association with postnatal outcomes remains unclear. Objective To assess HBH evolution via fetal MRI following prenatal ONTD repair, and its association with reduced hydrocephalus treatment and absence of cerebrospinal fluid (CSF) leak. Materials and methods This retrospective study included fetuses who underwent prenatal ONTD repair via laparotomy-assisted fetoscopic or open-hysterotomy techniques. Preoperative and 6-week postoperative fetal MRIs were reviewed by two blinded experts using a modified Sutton classification. HBH reversal was categorized as complete (cerebellum above the foramen magnum), partial (improved but still below the foramen magnum), or absent (no change). Associations with hydrocephalus treatment and CSF leak were analyzed using logistic regression, adjusting for potential confounders. A P-value PPPP<0.01). Conclusion Complete HBH reversal occurred in 70.5% after prenatal ONTD repair and was associated with lower risks of CSF leak and hydrocephalus. Fetal MRI at 6 weeks post-surgery is a reliable prognostic indicator for assessing repair integrity and hydrocephalus risk.