AJNR. American journal of neuroradiology
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AJNR Am J Neuroradiol · Oct 2005
Assessing global invasion of newly diagnosed glial tumors with whole-brain proton MR spectroscopy.
Because of their invasive nature, high-grade glial tumors are uniformly fatal. The purpose of this study was to quantify MR imaging-occult, glial tumor infiltration beyond its radiologic margin through its consequent neuronal cell damage, assessed by the global concentration decline of the neuronal marker N-acetylaspartate (NAA). ⋯ The average 26% WBNAA deficit in the patients, which persisted following surgical resection, cannot be explained merely by depletion within the approximately 3% MR imaging-visible tumor volume or an age-dependent effect. Although there could be several possible causes of such widespread decline--perineuronal satellitosis, neuronal deafferentation, Wallerian and retrograde degeneration, vasogenic edema, functional diaschisis, secondary vascular changes--most are a direct or indirect reflection of extensive, MR imaging-occult, microscopic tumor cell infiltration, diffusely throughout the otherwise "normal-appearing" brain.
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AJNR Am J Neuroradiol · Oct 2005
Comparative StudyPostoperative assessment of extracranial-intracranial bypass by time-resolved 3D contrast-enhanced MR angiography using parallel imaging.
Our goals were to assess image quality of time-resolved contrast-enhanced MR angiography (CE MRA), by using 3D data acquisition along with a parallel imaging technique that can improve temporal resolution and to compare this technique with 3D-time-of-flight (TOF) MRA in the postoperative assessment of extracranial (EC)-intracranial (IC) bypass surgery. ⋯ CE MRA by using the parallel imaging technique can increase image acquisition speed with sufficient image quality. This technique is at least equivalent to 3D-TOF MRA to evaluate the postoperative status of EC-IC bypass.
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AJNR Am J Neuroradiol · Oct 2005
Case ReportsSubarachnoid hemorrhage due to isolated spinal artery aneurysm in four patients.
Spinal artery aneurysms are usually found with arteriovenous malformations or other entities that increase hemodynamic stress. Isolated spinal artery aneurysms are rare. ⋯ In all patients, work-up yielded a diagnosis of isolated spinal aneurysm, and operative treatment was successful. In the appropriate clinical setting, spinal aneurysm should be considered as a possible cause of spinal subarachnoid hemorrhage.
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AJNR Am J Neuroradiol · Sep 2005
Prediction of treatment response in head and neck cancer by magnetic resonance spectroscopy.
Poor treatment outcome remains high in patients with squamous cell carcinoma (SCC) of the head and neck region. Treatment of head and neck cancer could be improved and perhaps standardized if reliable markers for tumor progression and poor prognosis could be developed. MR spectroscopy has been used previously to differentiate between malignant and adjacent normal specimen in these cancers. This study explores the capability of MR spectroscopy in providing an indication of the aggressiveness of a tumor and its response to treatment. ⋯ These preliminary results suggest that MR spectroscopy has the potential to contribute to an accurate and early prediction of tumor behavior and response to treatment in squamous cell carcinoma of the head and neck region.