Journal of neuroimaging : official journal of the American Society of Neuroimaging
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The authors evaluate blood flow velocities in the medial cerebral artery (MCA) and the basilar artery using magnetic resonance (MR) phase contrast technique in comparison with transcranial Doppler ultrasound (TCD). Eleven healthy male volunteers were studied. TCD of the MCA (n = 22) and basilar artery (n = 11) was performed. ⋯ The TCD insonation angle differed significantly from the ideal value in the basilar artery (mean value = 32.6 degrees) and the MCA (mean value = 26.5 degrees). The authors find a low correlation between velocities measured with MRI and TCD but similar results with regard to the PIs and RIs. Several sources of error, such as a nonideal TCD insonation angle, were identified.
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The objective of this study was to examine cerebral hemodynamics changes during hypothermic circulatory arrest (HCA) with and without retrograde cerebral perfusion (RCP). Thirteen colony-bred hound dogs were placed on cardiopulmonary bypass (CPB) and cooled to 18 degrees C. Five dogs underwent 2 hours of HCA without RCP and 8 with RCP. ⋯ During hypothermic circulatory arrest, RCP provides CBFV in the MCA comparable to MCA CBFV during CPB. HCA dogs without RCP showed immediate hyperemia on reperfusion. The decreased CBFV and increased PI at 1 hour after postarrest CPB could be an indicator of progressive ischemic injury due to the increased intracranial pressure despite the implementation of RCP.
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Two patients with clinically probable or possible limbic encephalitis (LE) are reported, both cases with typical findings in clinical symptoms (severe neuropsychological deficits and complex partial seizures) and in routine magnetic resonance imaging (MRI) (hyperintense mesiotemporal lesions). Underlying malignancy was identified (rectal carcinoma) in one case but could not be detected in the other patient. ⋯ The authors' findings support FDG-PET coregistered to 3D MRI as a potentially valuable additional tool in the imaging diagnostics of LE. Results are discussed with respect to the clinical symptoms and previously reported imaging findings in the disease.
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Randomized Controlled Trial Multicenter Study Clinical Trial
Temporal changes in brain volume and cognition in a randomized treatment trial of vascular dementia.
To measure changes in brain and ischemic volume over time by magnetic resonance imaging (MRI) as part of a randomized treatment trial of vascular dementia. ⋯ In summary, ventricular volume correlated well with cognitive measures in patients with vascular dementia and was a more sensitive marker for change during the study year than the clinical scales used in this study. This study also points out the practical limitations of brain imaging as a surrogate measure of clinical outcome in multicenter randomized treatment trials of brain disease.
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Review Case Reports
Ganglioneurocytoma mimicking a malignant tumor: case report with a literature review of the MRI appearance of neurocytomas and gangliogliomas.
A 14-year-old girl presented with symptoms of increased intracranial pressure after her head was squeezed at a party. MRI demonstrated a mass that was hypointense to brain on T1WI and heterogeneous in signal on PD and T2WI; compression of the ventricle, midline shift, and mild ventriculomegaly also were present. Contrast enhancement was extensive and heterogeneous, mimicking a malignant tumor. Neuropathology revealed a ganglioneurocytoma.