Alterations in diffusion and perfusion in the pathogenesis of peritumoral brain edema in meningiomas
| Autor: | Fritz Schick, B. Geist-Barth, Michael Bitzer, Uwe Klose, Matthias Morgalla, Thomas Nägele, Claus D. Claussen, Karsten Voigt |
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| Rok vydání: | 2000 |
| Předmět: |
Adult
Male Pathology medicine.medical_specialty Ischemia Brain Edema Brain Ischemia White matter Edema Parenchyma medicine Effective diffusion coefficient Humans Radiology Nuclear Medicine and imaging Peritumoral Brain Edema Aged business.industry Brain Neoplasms General Medicine Glioma Middle Aged medicine.disease Magnetic Resonance Imaging medicine.anatomical_structure Cerebral blood flow Cerebrovascular Circulation Female Radiology medicine.symptom business Meningioma Perfusion |
| Zdroj: | European radiology. 12(8) |
| ISSN: | 0938-7994 |
| Popis: | Magnetic resonance perfusion and diffusion studies were undertaken to clarify the significance of ischemia in the pathogenesis of peritumoral brain edema in patients with meningiomas. Included in this study were 26 patients with 27 meningiomas and 5 gliomas. Perfusion-weighted imaging (PWI) was performed using a gradient-echo, echo-planar-imaging (EPI) sequence for calculation of the relative regional cerebral blood volume (rrCBV) and the relative regional cerebral blood flow index (rrCBFi). Furthermore, multi-slice spin-echo EPI sequences were applied in order to obtain anisotropic and isotropic diffusion-weighted imaging (DWI). Apparent diffusion coefficient (ADC) values were then calculated for peritumoral brain parenchyma from tumors, with and without edema, using various diffusion sensitivities. Meningiomas without edema demonstrated a minimal increase of perfusion parameters in the peritumoral brain tissue. In contrast, cases with brain edema had highly significant ( p0.0005) lower rrCBV and rrCBFi. The edema index (EI) correlated strongly with the rrCBV. A fitting procedure resulted into the following mathematical relation: EI=0.1/rrCBV(2). The DWI showed a significantly larger ADC value within areas of brain edema, compared with the normal white matter (0.74 x 10(-3) vs 1.55 x 10(-3) mm(2)/s; p0.0001). Increases in EI correlated with increases in ADC values. In 31% of the meningiomas associated with edema, areas with increased signal, probable ischemia, demonstrated significantly lower ADC values, in comparison with the rest of the edematous areas. These areas were confined to tissue immediately adjacent to the tumor. In general, the decrease in rrCBV in brain edema represents a consequence from, rather than a cause of, vasogenic edema. Ischemic alterations can be regarded as secondary, facultative phenomena in the pathogenesis of meningioma-related brain edema. |
| Databáze: | OpenAIRE |
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