Role of perfusion-weighted imaging at 3 Tesla in the assessment of malignancy of cerebral gliomas.
OBJECTIVE
This study was performed to clarify the role of perfusion-weighted imaging (PWI) at 3 Tesla in the characterisation of haemodynamic heterogeneity within gliomas and surrounding tissues and in the differentiation of high-grade from low-grade gliomas.


METHODS
We examined 36 patients with histologically verified gliomas (25 with high-grade and 11 with low-grade gliomas). PWI was performed by first-pass gadopentetate dimeglumine T2*-weighted echo-planar images, and cerebral blood volume (CBV) maps were computed with a nondiffusible tracer model. Relative CBV (rCBV) was calculated by dividing CBV in pathological areas by that in contralateral white matter.


RESULTS
In high-grade gliomas, rCBV were markedly increased in mass [mean+/-standard deviation (SD), 4.3+/-1.2] and margins (4.0+/-1.1) and reduced in necrotic areas (0.3+/-0.3). Oedematous-appearing areas were divided in two groups according to signal intensity on T2-weighted images: tumour with lower (nearly isointense to grey matter) and oedema with higher (scarcely isointense to cerebrospinal fluid) signal intensity. Tumour showed significantly higher rCBV than did oedema (1.8+/-0.5 vs. 0.5+/-0.2; p<0.001) areas. In low-grade gliomas, mass (2.0+/-1.5) and margin (2.2+/-1.2) rCBV were significantly lower than in high-grade gliomas (p<0.001).


CONCLUSIONS
Three-Tesla PWI helps to distinguish necrosis from tumour mass, infiltrating tumour from oedema and high-grade from low-grade gliomas. It enhances the magnetic resonance (MR) assessment of cerebral gliomas and provides useful information for planning surgical and radiation treatment.
Di Costanzo
A
A
Dipartimento di Scienze per la Salute, Università degli Studi del Molise, Via Giovanni Paolo II, 86100 Campobasso, Italy. alfonso.dicostanzo@unimol.it
Pollice
S
S
Trojsi
F
F
Giannatempo
G M
GM
Popolizio
T
T
Canalis
L
L
Armillotta
M
M
Maggialetti
A
A
Carriero
A
A
Tedeschi
G
G
Scarabino
T
T
D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000175:diagnosis; D001810:Blood Volume / Q000502:physiology; D001929:Brain Edema / Q000175:diagnosis; D001932:Brain Neoplasms / Q000175:diagnosis*; D002560:Cerebrovascular Circulation / Q000502:physiology; D003287:Contrast Media; D003937:Diagnosis, Differential; D017352:Echo-Planar Imaging / Q000379:methods; D005260:Female; D019786:Gadolinium DTPA; D018303:Ganglioglioma / Q000175:diagnosis; D005909:Glioblastoma / Q000175:diagnosis; D005910:Glioma / Q000175:diagnosis*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D009837:Oligodendroglioma / Q000175:diagnosis; D012189:Retrospective Studies
D003287:Contrast Media; D019786:Gadolinium DTPA