Nontraumatic Spinal Cord Compression: MRI Primer for Emergency Department Radiologists.

The occurrence of acute myelopathy in a nontrauma setting constitutes a medical emergency for which spinal MRI is frequently ordered as the first step in the patient's workup. The emergency department radiologist should be familiar with the common differential diagnoses of acute myelopathy and be able to differentiate compressive from noncompressive causes. The degree of spinal cord compression and presence of an intramedullary T2-hyperintense signal suggestive of an acute cord edema are critical findings for subsequent urgent care such as surgical decompression. Importantly, a delay in diagnosis may lead to permanent disability. In the spinal canal, compressive myelopathy can be localized to the epidural, intradural extramedullary, or intramedullary anatomic spaces. Effacement of the epidural fat and the lesion's relation to the thecal sac help to distinguish an epidural lesion from an intradural lesion. Noncompressive myelopathy manifests as an intramedullary T2-hyperintense signal without an underlying mass and has a wide range of vascular, metabolic, inflammatory, infectious, and demyelinating causes with seemingly overlapping imaging appearances. The differential diagnosis can be refined by considering the location of the abnormal signal intensity within the cord, the longitudinal extent of the disease, and the clinical history and laboratory findings. Use of a compartmental spinal MRI approach in patients with suspected nontraumatic spinal cord injury helps to localize the abnormality to an epidural, intradural extramedullary, or intramedullary space, and when combined with clinical and laboratory findings, aids in refining the diagnosis and determining the appropriate surgical or nonsurgical management.Online supplemental material is available for this article.©RSNA, 2019.

Imaging in neuro-oncology.

Imaging plays several key roles in managing brain tumors, including diagnosis, prognosis, and treatment response assessment. Ongoing challenges remain as new therapies emerge and there are urgent needs to find accurate and clinically feasible methods to noninvasively evaluate brain tumors before and after treatment. This review aims to provide an overview of several advanced imaging modalities including magnetic resonance imaging and positron emission tomography (PET), including advances in new PET agents, and summarize several key areas of their applications, including improving the accuracy of diagnosis and addressing the challenging clinical problems such as evaluation of pseudoprogression and anti-angiogenic therapy, and rising challenges of imaging with immunotherapy.

False-positive finding of brain metastasis on (18)F-FDG PET imaging due to early subacute ischemic stroke.

An F-FDG PET performed for staging of a left lung mass showed a hypermetabolic focus in the left posterior fossa suggestive for brain metastasis. However, subsequent MRI showed restricted diffusion in the left cerebellum indicating a subacute ischemic stroke. Follow-up PET showed resolution of FDG uptake; MRI showed focal left cerebellar encephalomalacia. This case demonstrates visualization of the hypermetabolic inflammatory phase of a subacute ischemic stroke. The rare possibility of a false-positive result for brain metastasis must be recognized, and because focal neurologic symptoms may overlap in brain metastases and stroke, MRI confirmation of positive brain findings on FDG PET is needed.

Fetal alcohol spectrum disorders: knowledge and screening practices of university hospital medical students and residents.

BACKGROUND: Fetal alcohol spectrum disorder (FASD) is the leading cause of preventable intellectual disabilities in the United States and a significant public health issue. OBJECTIVES: The purpose of this study is to evaluate the knowledge and screening practices of pre-clinical medical students and clinical providers on FAS, FASD, and alcohol consumption. METHODS: A short survey sent to medical students and residents on the campus of a large medical school and university hospital. RESULTS: On the survey of clinical providers, 38% of respondents stated they always survey pregnant women about their alcohol consumption, 34% stated they always screen patients planning to get pregnant, and 9% screen women of childbearing age. There were a significant percentage of providers who never screen women. When questioned regarding safe amounts of alcohol consumption during pregnancy, 69% of pre-clinical medical students and 67% of clinical providers stated there is no safe amount of alcohol consumption. Clinical providers were much more likely to correctly select the facial features necessary for the diagnosis (p-value < 0.01). CONCLUSIONS: Significant differences exist in the knowledge and screening practices of these different healthcare providers and trainees. Future interventions should seek to improve knowledge on FAS, FASD, and alcohol consumption, in order for practitioners to be more consistent with national guidelines and the Surgeon General recommendations.

Gene expression profiling of metastatic brain cancer.

Gene expression profiling of metastatic brain tumors from primary lung adenocarcinoma, using a 17k-expression array, revealed that 1561 genes were consistently altered. Further functional classification placed the genes into seven categories: cell cycle and DNA damage repair, apoptosis, signal transduction molecules, transcription factors, invasion and metastasis, adhesion, and angiogenesis. Genes involved in apoptosis, such as caspase 2 (CASP2), transforming growth factor-beta inducible early gene (TIEG), and neuroprotective heat shock protein 70 (Hsp70) were underexpressed in metastatic brain tumors. Alterations in Rho GTPases (ARHGAP26, ARHGAP1), as well as down-regulation of the metastasis suppressor gene KiSS-1 were noted, which may contribute to tumor aggression. Overexpression of the invasion-related gene neurofibromatosis 1 (NF1), and angiogenesis-related genes vascular endothelial growth factor-B (VEGF-B) and placental growth factor (PGF) was also evidenced. Brain-specific angiogenesis inhibitors 1 and 3 (BAI1 and BAI3) were underexpressed as well. Examination of cell-adhesion and migration-related genes revealed an increased expression of integrins and extracellular matrices collagen and laminin. The study also showed alterations in p53 protein-associated genes, among these increased gene expression of p53, up-regulation of Reprimo or candidate mediator of the p53-dependent G2-arrest, down-regulation of p53-regulated apoptosis-inducing protein 1 (p53AIP1), decreased expression of tumor protein inducible nuclear protein 1 (p53DINP1), and down-regulation of Mdm4 (MDMX). The results demonstrated that genes involved in adhesion, motility, and angiogenesis were consistently up-regulated in metastatic brain tumors, while genes involved in apoptosis, neuroprotection, and suppression of angiogenesis were markedly down-regulated, collectively making these cancer cells prone to metastasis.