Perfusion-sensitive MRI of pilocytic astrocytomas: initial results.
OBJECTIVE
To present the imaging and perfusion data obtained in nine patients with pilocytic astrocytomas (PA) and to discuss the original functional issues of this technique.


METHODS
Nine patients with pathologically proven PA underwent conventional and perfusion MR imaging. Various areas of relative cerebral blood volume (rCBV) within the tumors were obtained. The maximum rCBV ratios were identified and considered as representative of the tumor. The results were compared with the pathological findings.


RESULTS
In all patients, rCBV was <1.5 (mean 1) and the signal intensity curve overshot the baseline.


CONCLUSIONS
PA tend to have low rCBV values and a first-pass curve that crosses the baseline. These characteristics may be explained by the histological profile of the tumoral vascularity and are of relevance in the identification of these rare tumors.
Grand
Sylvie D
SD
Neuroradiology, Hôpital Michallon, Grenoble, France. SGrand@chu-grenoble.fr
Kremer
Stéphane
S
Tropres
Irène M
IM
Hoffmann
Dominique M
DM
Chabardes
Stephan J
SJ
Lefournier
Virginie
V
Berger
François R
FR
Pasteris
Caroline
C
Krainik
Alexandre
A
Pasquier
Basile M
BM
Peoch
Michel
M
Le Bas
Jean François
JF
D000293:Adolescent; D000328:Adult; D001254:Astrocytoma / Q000175:diagnosis* / Q000503:physiopathology*; D001810:Blood Volume; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology; D002648:Child; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D012189:Retrospective Studies
D003287:Contrast Media; D019786:Gadolinium DTPA