AJNR. American journal of neuroradiology
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AJNR Am J Neuroradiol · Nov 2005
Comparative StudyStructural, immunocytochemical, and mr imaging properties of periventricular crossroads of growing cortical pathways in preterm infants.
Periventricular white matter (WM) areas are widely recognized as predilection sites for complex cellular damage after ischemia/reperfusion or inflammatory injury of the perinatal cerebrum. We analyzed histochemical and MR imaging properties of fiber architectonics and extracellular matrix (ECM) of periventricular areas to disclose the potential significance of topographically specific WM lesions for the neurodevelopmental outcome. ⋯ The correlation of MR imaging with histochemical findings demonstrated the presence of periventricular fiber crossroads rich in ECM and axonal guidance molecules. We propose that, in perinatal WM lesions, periventricular WM crossroads represent a hitherto unrecognized and vulnerable cellular and topographic target in which combined damage of association-commissural and projection fibers may explain the complexity of cognitive, sensory, and motor deficit in survivors of periventricular WM lesions.
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AJNR Am J Neuroradiol · Nov 2005
Case ReportsEpidural blood patch at C2: diagnosis and treatment of spontaneous intracranial hypotension.
Spontaneous intracranial hypotension in a 37-year-old man with intractable headaches was diagnosed on MR imaging. A generous CSF leak was identified at C2 on CT myelography. Successful treatment was performed with CT-guided blood patch at the leakage site after the patient had failed 2 lumbar blood patches. Imaging-guided precise placement of the blood patch is safe and recommended when a lumbar blood patch away from the leakage site could be ineffective.
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AJNR Am J Neuroradiol · Nov 2005
Characterization of cerebral aneurysms for assessing risk of rupture by using patient-specific computational hemodynamics models.
Hemodynamic factors are thought to play an important role in the initiation, growth, and rupture of cerebral aneurysms. This report describes a pilot clinical study of the association between intra-aneurysmal hemodynamic characteristics from computational fluid dynamic models and the rupture of cerebral aneurysms. ⋯ Image-based patient-specific numeric models can be constructed in an efficient manner that allows clinical studies of intra-aneurysmal hemodynamics. A simple flow characterization system was proposed, and interesting trends in the association between hemodynamic features and aneurysmal rupture were found. Simple stable patterns, large impingement regions, and jet sizes were more commonly seen with unruptured aneurysms. By contrast, ruptured aneurysms were more likely to have disturbed flow patterns, small impingement regions, and narrow jets.
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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
Intracranial hemorrhage complicating acute stroke: how common is hemorrhagic stroke on initial head CT scan and how often is initial clinical diagnosis of acute stroke eventually confirmed?
Assessment of possible hemorrhage in acute stroke before appropriate therapy remains important. The aim of this study was to determine the frequency with which patients present with clinical stroke and have intracranial hemorrhage on initial noncontrast head CT scan (NCCT). In addition, we sought to determine the frequency with which initial clinical diagnosis acute stroke is confirmed in this group. ⋯ Despite frequent concerns for intracranial hemorrhage complicating acute stroke and treatment, a low percentage of patients had this complication. Moreover, our frequency is much lower than the wide ranges reported elsewhere. The most common type of intracranial hemorrhage in this cohort was intraparenchymal, but subarachnoid and subdural hemorrhages were also diagnosed and must also be considered. Twenty-eight percent of patients with initial suspicion of acute ischemic stroke are eventually given other diagnoses. These results may have implications for use of CT imaging.