Atypical and Fibrous Meningioma with Differential Cerebral Blood Volume on Magnetic Resonance Imaging: A Case Report

Abstract OBJECTIVE: Glucocorticoid analogues are often administered to patients with intracranial space-occupying lesions. Clinical response can be dramatic, but the neurophysiological response is not well documented. This study sought to investigate the blood-lesion barrier, blood-brain barrier, and cerebral perfusion characteristics of patients who have undergone such therapy using magnetic resonance imaging. METHODS: Seventeen patients with intracranial mass-enhancing lesions underwent magnetic resonance imaging before and after 3 days of high-dose dexamethasone therapy. Assessments of blood-lesion barrier and blood-brain barrier integrity were based on a dynamic T1-weighted exogenous contrast technique that yielded the normalized maximal change in contrast uptake (T1-uptake). Perfusion was assessed using a dynamic T2*-weighted exogenous contrast technique to yield relative regional cerebral blood volume and first-moment mean transit time. Comparisons were made in T1-uptake, regional cerebral blood volume, and first-moment mean transit time of both enhancing lesion and contralateral normal-appearing white matter (CNAWM) obtained before and after dexamethasone. RESULTS: Significant reduction in T1-uptake was observed (19% decrease, P < 0.005) within enhancing pathological tissue, whereas no significant alteration was detected in CNAWM. Regional cerebral blood volume was significantly reduced in both enhancing tissue (28% decrease, P < 0.005) and in CNAWM (20% decrease, P < 0.001). Bolus first-moment mean transit time significantly increased (2.0 s prolongation, P < 0.05) in CNAWM, whereas there was no significant change (1.4 s prolongation, P > 0.05) within enhancing tissue. CONCLUSION: Glucocorticoid-analogue therapy not only affects the permeability of the blood-lesion barrier and lesion blood volume but also affects blood flow within normal-appearing contralateral parenchyma. There is a need for controls in steroid therapy in magnetic resonance imaging studies, which involve assessments of cerebrovascular function.

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Cerebral Hemodynamics in Human Acute Ischemic Stroke: A Study with Diffusion- and Perfusion-Weighted Magnetic Resonance Imaging and SPECT

Journal of Cerebral Blood Flow & Metabolism ◽

10.1097/00004647-200006000-00003 ◽

2000 ◽

Vol 20 (6) ◽

pp. 910-920 ◽

Cited By ~ 63

Author(s):

Yawu Liu ◽

Jari O. Karonen ◽

Ritva L. Vanninen ◽

Leif Østergaard ◽

Reina Roivainen ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Ischemic Stroke ◽

Magnetic Resonance ◽

Acute Ischemic Stroke ◽

Blood Volume ◽

Cerebral Blood Volume ◽

Acute Stage ◽

Resonance Imaging ◽

Relative Cerebral Blood Volume ◽

Ischemic Tissue

Nineteen patients with acute ischemic stroke (<24 hours) underwent diffusion-weighted and perfusion-weighted (PWI) magnetic resonance imaging at the acute stage and 1 week later. Eleven patients also underwent technetium-99m ethyl cysteinate dimer single-photon emission computed tomography (SPECT) at the acute stage. Relative (ischemic vs. contralateral control) cerebral blood flow (relCBF), relative cerebral blood volume, and relative mean transit time were measured in the ischemic core, in the area of infarct growth, and in the eventually viable ischemic tissue on PWI maps. The relCBF was also measured from SPECT. There was a curvilinear relationship between the relCBF measured from PWI and SPECT ( r = 0.854; P < 0.001). The tissue proceeding to infarction during the follow-up had significantly lower initial CBF and cerebral blood volume values on PWI maps ( P < 0.001) than the eventually viable ischemic tissue had. The best value for discriminating the area of infarct growth from the eventually viable ischemic tissue was 48% for PWI relCBF and 87% for PWI relative cerebral blood volume. Combined diffusion and perfusion-weighted imaging enables one to detect hemodynamically different subregions inside the initial perfusion abnormality. Tissue survival may be different in these subregions and may be predicted.

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