Contribution of the apparent diffusion coefficient in perilesional edema for the assessment of brain tumors

Objectives. - Diffusion-weighted MRI is sensitive to molecular motion and has been applied to the diagnosis of stroke. Our intention was to investigate its usefulness in patients with brain tumor and, in particular, in the peritesionat edema. Methods. - We performed MRI of the brain, including diffusion-weighted imaging and mapping of the apparent diffusion coefficient (ADC), in 16 patients with brain tumors (glioblastomas, low-grade gliomas and metastases). ADC values were determined by the use of regions of interest positioned in areas of high signal intensities as seen on T2-weighted images and ADC maps. Measurements were taken in the tumor itself, in the area of perilesional edema and in the healthy contrataterat brain. Results. - ADC mapping showed higher values of periturnorat edema in patients with gtiobtastoma (1.75 x 10(-3) mm(2)/s) and metastatic lesions (1.61 x 10(-3) mm(2)/S) compared with those who had low-grade glioma (1.40 x 10(-3) mm(2)/s). The higher ADC values in the periturnorat zone were associated with tower ADC values in the tumor itself. Conclusions. - The higher ADC values in the more malignant tumors probably reflect vasogenic edema, thereby allowing their differentiation from other lesions. (C) 2008 Elsevier Masson SAS. All rights reserved.