Journal of neuroimaging : official journal of the American Society of Neuroimaging
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A 21-year-old man was troubled with a subacute history of brainstem involvement and a leukocyte pleocytosis in the cerebrospinal fluid. Magnetic resonance imaging (MRI) demonstrated a massive lesion with Gd enhancement in the pons. ⋯ Over 4 years no recurrence has been recognized, so this case was diagnosed to be an unusual case of acute disseminated encephalomyelitis (ADEM). ADEM must be included in the differential diagnosis for a brainstem mass in MRI.
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The benefits and limits of a magnetic sensor-based 3-dimensional (3D) intraoperative ultrasound technique during surgery of vascular malformations and supratentorial tumors were evaluated. Twenty patients with 11 vascular malformations and 9 supratentorial tumors undergoing microsurgical resection or clipping were investigated with an interactive magnetic sensor data acquisition system allowing freehand scanning. An ultrasound probe with a mounted sensor was used after craniotomies to localize lesions, outline tumors or malformation margins, and identify supplying vessels. ⋯ The spatial relation between aneurysm sac and surrounding vessels or the skull base could be enhanced in 3 out of 6 aneurysms with 3D intraoperative ultrasound. Perforating arteries were visible in 3 cases only by using 3D imaging. 3D ultrasound provides a promising imaging technique, offering the neurosurgeon an intraoperative spatial orientation of the lesion and its vascular relationships. Thereby, it may improve safety of surgery and understanding of 2D ultrasound images.
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Case Reports
Pitfall of electron beam computed tomography angiography in diagnosis of subclavian steal syndrome.
A patient presented with vertebrobasilar insufficiency during exertion. Vertebral duplex and transcranial Doppler ultrasonography showed reversal of flow in both intracranial and extracranial vertebral and basilar arteries, suggesting bilateral subclavian and vertebrobasilar steal. ⋯ This false-negative finding on CTA in detection of subclavian steal syndrome (SSS) is due to inappropriate contrast administration technique and postprocessing method, inability to differentiate flow direction, and lack of hemodynamic time sequences. This study demonstrates a pitfall of CTA in diagnosis of SSS compared to more reliable hemodynamic information obtained by duplex and transcranial Doppler ultrasonography, and digital subtraction angiography.
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Case Reports
Flumazenil responsive ornithine transcarbamylase deficiency encephalopathy: clinical and radiographic features.
A 22-year-old woman with a negative urine drug screen and somnolence rapidly reversed by intravenous flumazenil was found to have elevated ammonia levels and punctate calcifications of the subcortical frontal white matter. Abnormally high levels of orotic acid were found in serum and urine, confirming the diagnosis of ornithine transcarbamylase deficiency. Although computed tomography findings are non-specific, young patients with unexplained hyperammonemic states of somnolence reversed by flumazenil should be screened for this X-linked recessive metabolic disorder.
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Septum pellucidum agenesis is frequently associated with other cerebral malformations. Its isolated agenesis is quite rare. In the literature, all reported cases were diagnosed in early childhood. The authors present an unusual case of isolated septum pellucidum agenesis detected in adulthood with computed tomography and magnetic resonance imaging.