Accurate imaging characterization of chronic subdural hemorrhage (cSDH) has clinical and forensic implications, and continues to challenge the radiologist. The MRI characteristics of surgically proven cSDH were retrospectively reviewed in the context of known pathomorphology of the aging SDH. Read More

Meeting name: SPR 2018 Annual Meeting & Postgraduate Course , 2018

Authors: Tutman Jeffrey, Hedlund Gary

Keywords: Non-accidental trauma, Abusive Head Trauma

The purpose of this case report is to familiarize the radiologist with the MR imaging findings of fatal heat stroke. Heat stroke is a severe illness characterized by a core temperature > 40 degrees Celsius, with clinical manifestations of delirium, seizures, and coma, resulting from environmental exposure or physical exertion. This report focuses upon environmental, or classical, fatal heat stroke in the case of a 4 year old male who was left alone for 30 minutes in a vehicle with ambient exterior temperatures of greater than 37.8 degrees Celsius. As a form of hyperthermia, heat stroke ensues from thermoregulatory failure in addition to systemic inflammatory and coagulation phase responses, and conceivably, from modified manifestation of heat shock proteins. Infants and young children comprise a population specifically vulnerable to heat stroke due to their large surface area to volume ratio, underdeveloped thermoregulatory system with small blood volume relative to body size, and decreased sweat production. The CNS is especially susceptible to hyperthermia as cerebral edema and cerebrovascular congestion may lead to increased intracranial pressure, and ischemia or hemorrhage. The cerebellum is the area most sensitive to heat injury, with known direct injury to Purkinje cells, and resultant cerebellar atrophy, often leading to neuronal dysfunction, including ataxia. MR imaging findings in heat stroke are typically multifocal reflecting the complex interplay of direct thermal injury, hypoxic ischemic injury, endothelial damage, cytokine mediated inflammation and coagulopathy. MRI in our case of fatal heat stroke demonstrates diffuse signal abnormality within the peripheral cerebellar hemispheres (eg. Purkinje cell regions). MRI recapitulates the known pathology of fatal heat stroke with injury to Purkinge cells and adjacent Bergmann glia. Other reported heat stroke related MRI findings include T2 prolongation and restricted diffusion involving the paramedian thalamic nuclei, dentate nuclei, basal ganglia, hippocampii, and cerebral cortex particularly the vascular watershed zones. If the health history for heat stroke is uncertain, the imaging differential diagnosis includes other cerebellar syndromes including: toxic - metabolic (eg. opiate toxicity), infectious-autoimmune (eg. Varicellar zoster cerebellitis), histiocytic neoplastic-like (eg. histiocytoses) and neoplastic (eg. leptomeningeal PNET) should be considered in the imaging differential diagnosis. Read More

Meeting name: SPR 2018 Annual Meeting & Postgraduate Course , 2018

Authors: Skelton Hales, Hedlund Gary

Keywords: Hyperthermia, Encephalopathy, Fatal

To familiarize the pediatric radiologist with the important role that the perforin gene plays in lymphocyte cytotoxicity, to discuss the diversity in clinical presentation, and review the scope of neuroimaging abnormalities that may arise in the setting of a missense perforin genetic defect. The brain MRI findings and relevant clinical information of two remotely related children with the same novel missense mutation in the perforin gene represent the basis of this educational poster. Perforin is a glycoprotein (encoded by the PRF-1 gene) involved in several human cellular functions, including, immune response and stored mainly in CD8-positive T-cells as well as natural killer (NK) cells. Normally, T-cells and NK cells are responsible for attacking dead cells. In the clinical setting of perforin deficiency, T-cells and NK cells attack the healthy immune system. This arises from a missense mutation of the PRF-1 gene. Links between perforin deficiency and the autoimmune clinical syndrome of hemophagocytic lymphohistiocytosis (HLH), have been reported. MR imaging abnormalities in patients with perforin gene mutations, are diverse and complex as the defect may occur in the setting of familial hemophagocytic lymphohistiocytosis, primary necrotizing lymphocytic CNS vasculitis or associated with CNS infections such as the Epstein Barr virus. To date, MRI abnormalities that have been reported include mimics of septic cerebral emboli, confluent white matter abnormalities involving the cerebral hemispheres and cerebellum invoking the consideration of diffuse demyelinating disease, and multifocal infratentorial and supratentorial intraaxial lesions with “necrotic-like” character and marginal enhancement. Multifocal sites of perivascular space pathological enhancement has also been reported. Common to many of these reports is cerebellar involvement. The imaging differential diagnosis includes atypical infection, histocytic disorders of the CNS, lymphomatous granulomatosis, neurosarcoidosis, and primary CNS lymphoma. Read More

Meeting name: SPR 2018 Annual Meeting & Postgraduate Course , 2018

Authors: Hedlund Alec, Stern Sara, Bohnsack John, Hedlund Gary

Keywords: Perforin defect, Chronic encephalitis, Necrotizing vasculitis