Imaging of adult astrocytic brain tumours with 7 T MRI: preliminary results.
OBJECTIVE
In this study tumour vascularity and necrosis of intracranial astrocytomas were compared using 7 T and 1.5 T magnetic resonance imaging (MRI).


METHODS
Fifteen patients with histologically proven astrocytomas (WHO grades II-IV) were prospectively examined at 1.5 T (Magnetom Espree or Sonata) and 7 T (Magnetom 7 T, Siemens, Erlangen, Germany) with T2*-w (weighted), T1-w with (only a subset of five patients at 7 T) and without contrast medium, T2-w and proton-density (PD)-w MRI. Clinically used 1.5 T sequences were adapted to 7 T. Histological findings and T2*-w MR images at both field strengths were compared for the presence of assumed tumour microvascularity and necrosis. Two diffusely infiltrating astrocytomas, four anaplastic astrocytomas and nine glioblastomas were included.


RESULTS
T2*-w images depicted susceptibility patterns representing presumed tumour microvascularity in 8 out of 15 (53%) gliomas at 7 T compared with 5 out of 15 (33%) gliomas at 1.5 T. Compared with 1.5 T MRI three additional necrotic tumour areas were depicted only on 7 T T2- and T2*-w images of one glioblastoma. On T1-w MR images, contrast enhancement of five out of five glioblastomas was similar at both field strengths.


CONCLUSIONS
7 T gradient-echo sequences provide excellent image contrast of presumed microvasculature and necrosis in astrocytomas.
Moenninghoff
Christoph
C
Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Hufelandstrasse 55, 45147 Essen, Germany. christoph.moenninghoff@uk-essen.de
Maderwald
Stefan
S
Theysohn
Jens M
JM
Kraff
Oliver
O
Ladd
Mark E
ME
El Hindy
Nicolai
N
van de Nes
Johannes
J
Forsting
Michael
M
Wanke
Isabel
I
D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000098:blood supply / Q000473:pathology*; D001932:Brain Neoplasms / Q000098:blood supply / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000473:pathology*; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity