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


RESULTS
ADC mapping showed higher values of peritumoral edema in patients with glioblastoma (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 x10(-3)mm(2)/s). The higher ADC values in the peritumoral zone were associated with lower 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.
Guzman
R
R
Department of Neurosurgery, Inselspital, University of Berne, Berne, Switzerland.
Altrichter
S
S
El-Koussy
M
M
Gralla
J
J
Weis
J
J
Barth
A
A
Seiler
R W
RW
Schroth
G
G
Lövblad
K O
KO
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001929:Brain Edema / Q000473:pathology; D001932:Brain Neoplasms / Q000473:pathology*; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
D003287:Contrast Media; D019786:Gadolinium DTPA