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.

HistoryAn 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.

The evolution of pituitary cysts in growth hormone-treated children.

OBJECTIVES: We have previously shown that pituitary cysts may affect growth hormone secretion. This study sought to determine cyst evolution during growth hormone treatment in children. METHODS: Forty-nine patients with short stature, a pituitary cyst, and at least two brain MRI scans were included. The percent of the pituitary gland occupied by the cyst (POGO) was calculated, and a cyst with a POGO of ≤15% was considered small, while a POGO >15% was considered large. RESULTS: Thirty-five cysts were small, and 14 were large. Five of the 35 small cysts grew into large cysts, while 6 of the 14 large cysts shrunk into small cysts. Of 4 cysts that fluctuated between large and small, 3 presented as large and 1 as small. Small cysts experienced greater change in cyst volume (CV) (mean=61.5%) than large cysts (mean=-0.4%). However, large cysts had a greater net change in CV (mean=44.2 mm3) than small cysts (mean=21.0 mm3). Older patients had significantly larger mean pituitary volume than younger patients (435.4 mm3 vs. 317.9 mm3) and significantly larger mean CV than younger patients (77.4 mm3 vs. 45.2 mm3), but there was no significant difference in POGO between groups. CONCLUSIONS: Pituitary cyst size can vary greatly over time. Determination of POGO over time is a useful marker for determining the possibility of a pathologic effect on pituitary function since it factors both cyst and gland volume. Large cysts should be monitored closely, given their extreme, erratic behavior.

Brain MRI findings in COVID-19 patients with PRES: A systematic review.

BACKGROUND: Numerous case reports and case series have described brain Magnetic Resonance Imaging (MRI) findings in Coronavirus disease 2019 (COVID-19) patients with concurrent posterior reversible encephalopathy syndrome (PRES). PURPOSE: We aim to compile and analyze brain MRI findings in patients with COVID-19 disease and PRES. METHODS: PubMed and Embase were searched on April 5th, 2021 using the terms "COVID-19", "PRES", "SARS-CoV-2" for peer-reviewed publications describing brain MRI findings in patients 21 years of age or older with evidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and PRES. RESULTS: Twenty manuscripts were included in the analysis, which included descriptions of 30 patients. The average age was 57 years old. Twenty-four patients (80%) required mechanical ventilation. On brain MRI examinations, 15 (50%) and 7 (23%) of patients exhibited superimposed foci of hemorrhage and restricted diffusion respectively. CONCLUSIONS: PRES is a potential neurological complication of COVID-19 related disease. COVID-19 patients with PRES may exhibit similar to mildly greater rates of superimposed hemorrhage compared to non-COVID-19 PRES patients.

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.

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.

Optimization of postoperative computerized tomographic imaging in patients with the implanted responsive neurostimulation system.

The Responsive Neurostimulation System is currently under investigation as a neurosurgical option for medically refractory epilepsy. The device produces significant metallic artifact on conventional axial CT scans, resulting in limited diagnostic imaging options for implanted patients. We have developed a strategy to overcome this technical difficulty utilizing optimized patient positioning, thin-slice image acquisition, and postprocessing image reconstruction with commercially available software. Significant improvements were noted in the severity of device-related metallic streak artifact on reconstructed axial images. In addition, thin-section data were successfully used to generate detailed three-dimensional reconstructions, providing for improved visualization of the stimulator and the intracranial position of attached electrodes.

Retrograde cysto-myelogram: Case Report.

BACKGROUND: In the scenario of blunt trauma with suspected bladder injury, conventional retrograde cystography is the gold standard for accurate diagnosis. CASE DESCRIPTION: The authors report the case of a 54-year-old patient who presented with pelvic and sacral fractures and a ruptured bladder after being hit by a vehicle. A retrograde computed tomography cystogram demonstrated extraperitoneal extravasation of the contrast agent, which traversed violated sacral nerve roots, resulting in contrast entering the subarachnoid space at the left sacral ala predominantly through the left L5 and S1 nerve roots. CONCLUSIONS: This is the first known report of an accidental myelogram imaging performed through a retrograde cystogram.

Early angiographic occlusion of ruptured blister aneurysms of the internal carotid artery using the Pipeline Embolization Device as a primary treatment option.

BACKGROUND: Data on the timing, durability and occlusion rate of treating ruptured blister cerebral aneurysms using the Pipeline Embolization Device (PED) are limited. CLINICAL PRESENTATION: Three patients who presented with subarachnoid hemorrhages from ruptured blister aneurysms of the internal carotid arteries were treated with the PED. RESULTS: Aneurysmal occlusion with reconstruction of the parent vessels occurred angiographically using the PED as a primary treatment modality. All three patients were treated successfully without immediate or delayed complications and remained neurologically intact during the 6-month follow-up period. CONCLUSIONS: Complete occlusion of a ruptured blister aneurysm can occur immediately after PED placement. In ruptured blister aneurysms with contrast stagnation after PED treatment, early angiographic occlusion was confirmed as early as 6 weeks and continued with medium-term durability.

Altered Fractional Anisotropy 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.