Altered Fractional Anisostropy in Early Huntington’s Disease

Huntington's disease (HD) is a dominantly inherited neurodegenerative disease best known for chorea. The disorder includes numerous other clinical features including mood disorder, eye movement abnormalities, cognitive disturbance, pendular knee reflexes, motor impersistence, and postural instability. We describe a mild case of HD early in the disease course with depression and subtle neurological manifestations. In addition, we review MRI and diffusion tensor imaging features in this patient. The bicaudate ratio, a measure of caudate atrophy, was increased. Fractional anisotropy values of the bilateral caudate and putamen were increased, signifying neurodegeneration of these structures in HD

Late-Onset Neurodegeneration with Brain Iron Accumulation with Diffusion Tensor Magnetic Resonance Imaging

Introduction: Neuroferritinopathy is an autosomal dominant neurodegenerative disorder that includes a movement disorder, cognitive decline, and characteristic findings on brain magnetic resonance imaging (MRI) due to abnormal iron deposition. Here, we present a late-onset case, along with diffusion tensor imaging (DTI). Case Presentation: We report the case of a 74-year-old Caucasian female with no significant past medical history who presented for evaluation of orofacial dyskinesia, suspected to be edentulous dyskinesia given her history of ill-fitting dentures. She had also developed slowly progressive dysarthria, dysphagia, visual hallucinations as well as stereotypic movements of her hands and feet. Results: The eye-of-the-tiger sign was demonstrated on T2 MRI. Increased fractional anisotropy and T2 hypointensity were observed in the periphery of the globus pallidus, putamen, substantia nigra, and dentate nucleus. T2 hyperintensity was present in the medial dentate nucleus and central globus pallidus. Discussion: The pallidal MRI findings were more typical of pantothenate kinase-associated neurodegeneration (PKAN), but given additional dentate and putamenal involvement, lack of retinopathy, and advanced age of onset, PKAN was less likely. Although the patient’s ferritin levels were within low normal range, her clinical and imaging features led to a diagnosis of neuroferritinopathy. Conclusion: Neurodegeneration with brain iron accumulation (NBIA) is a rare cause of orofacial dyskinesia. DTI MRI can confirm abnormal iron deposition. The location of abnormal iron deposits helps in differentiating NBIA subtypes. Degeneration of the dentate and globus pallidus may occur via an analogous process given their similar T2 and DTI MRI appearance

Case 271

History An 11-year-old boy taking oral antibiotics for Fusobacterium meningitis diagnosed 3 months earlier presented to the emergency department with a 1-week history of intermittent emesis, dizziness, and vertigo and a 1-day history of wobbly gait and bilateral lower extremity paresthesia without confusion. His metabolic profile was normal. Contrast material-enhanced MRI of the brain was performed, and selected images are shown ( Fig 1 - 4 ). Figure 1a: (a) Axial fluid-attenuated inversion recovery (repetition time msec/echo time msec, 11 000/125) MRI and (b) axial turbo spin-echo T2-weighted (3000/80) MRI of the brain through the cerebellum at presentation. (c) Axial fluid-attenuated inversion recovery (6000/120) MRI and (d) axial turbo spin-echo T2-weighted (5545/100) MRI through the same level of the cerebellum obtained 6 weeks earlier. Figure 1b: (a) Axial fluid-attenuated inversion recovery (repetition time msec/echo time msec, 11 000/125) MRI and (b) axial turbo spin-echo T2-weighted (3000/80) MRI of the brain through the cerebellum at presentation. (c) Axial fluid-attenuated inversion recovery (6000/120) MRI and (d) axial turbo spin-echo T2-weighted (5545/100) MRI through the same level of the cerebellum obtained 6 weeks earlier. Figure 1c: (a) Axial fluid-attenuated inversion recovery (repetition time msec/echo time msec, 11 000/125) MRI and (b) axial turbo spin-echo T2-weighted (3000/80) MRI of the brain through the cerebellum at presentation. (c) Axial fluid-attenuated inversion recovery (6000/120) MRI and (d) axial turbo spin-echo T2-weighted (5545/100) MRI through the same level of the cerebellum obtained 6 weeks earlier. Figure 1d: (a) Axial fluid-attenuated inversion recovery (repetition time msec/echo time msec, 11 000/125) MRI and (b) axial turbo spin-echo T2-weighted (3000/80) MRI of the brain through the cerebellum at presentation. (c) Axial fluid-attenuated inversion recovery (6000/120) MRI and (d) axial turbo spin-echo T2-weighted (5545/100) MRI through the same level of the cerebellum obtained 6 weeks earlier. Figure 2a: (a) Axial fast spin-echo T1-weighted MRI (496/8) and (b) axial reconstruction of three-dimensional fast field-echo T1-weighted contrast-enhanced (7 mL of gadobutrol, Gadavist; Bayer Healthcare Pharmaceuticals, Berlin, Germany) MRI (7.98/3.72) of regions similar to those in Figure 1 . Figure 2b: (a) Axial fast spin-echo T1-weighted MRI (496/8) and (b) axial reconstruction of three-dimensional fast field-echo T1-weighted contrast-enhanced (7 mL of gadobutrol, Gadavist; Bayer Healthcare Pharmaceuticals, Berlin, Germany) MRI (7.98/3.72) of regions similar to those in Figure 1 . Figure 3a: (a) Axial diffusion-weighted MRI (3090/71) and (b) axial apparent diffusion coefficient map (3090/71) of regions similar to those in Figure 1 . Figure 3b: (a) Axial diffusion-weighted MRI (3090/71) and (b) axial apparent diffusion coefficient map (3090/71) of regions similar to those in Figure 1 . Figure 4: Three-dimensional maximum intensity projection image (25/3.45) of the posterior cerebral circulation obtained with MR angiography of the head

Case 271: Metronidazole-Induced Encephalopathy

History: An 11-year-old boy taking oral antibiotics for Fusobacterium meningitis diagnosed 3 months earlier presented to the emergency department with a 1-week history of intermittent emesis, dizziness, and vertigo and a 1-day history of wobbly gait and bilateral lower extremity paresthesia without confusion. His metabolic profile was normal. Contrast material-enhanced MRI of the brain was performed

Differentiation of Hemorrhage from Contrast Enhancement Using Dual-Layer Spectral CT in Patients Transferred for Acute Stroke

Acute stroke patients transferred to thrombectomy capable centers (TCC), undergo a CT head exam upon arrival at the TCC to evaluate for ASPECTS decay and intracranial hemorrhage. In patients who received iodinated contrast prior to transfer, parenchymal enhancement may simulate hemorrhage on this post-transfer CT. We report two cases utilizing CT spectral imaging to differentiate between parenchymal contrast enhancement and hemorrhage in this setting. TCC may consider dual-energy or dual-layer (spectral) imaging for this patient cohort

Dual-Layer Spectral CT Virtual-Non-Contrast Images Aid in Parathyroid Adenoma Analysis and Radiation Dose Reduction: Confirmation of Findings From Dual-Energy CT

4D-parathyroid CT scans have become a mainstay in the evaluation and pre-surgical planning for parathyroid adenomas. Most protocols typically rely on non-contrast images, prior to the arterial and delayed phases. Previous reports with dual-energy CT imaging have highlighted the utility of virtual non-contrast images to help reduce radiation dose while maintaining diagnostic accuracy. Herein, we report two cases of surgically proven parathyroid adenomas diagnosed with 4D-parathyroid CT scans performed on dual-layer spectral scanners, and in retrospect highlight the utility of virtual non-contrast images. To our knowledge, this report provides the first description of virtual non-contrast images from dual-layer spectral CT scanners that could aid in the diagnosis of parathyroid adenomas, confirming similar findings described with dual-energy CT scanners