Imaging of experimental rat gliomas using a clinical MR scanner.
BACKGROUND
Studies of brain tumor development in experimental animal models have to date mostly been based on post-mortem histological examinations. The use of magnetic resonance imaging (MRI) may provide a non-invasive technique for studying tumor growth and treatment effects in such animal models. However, most of these studies have been performed on purpose-dedicated small bore magnetic resonance (MR) systems, of high cost and limited availability. The purpose of this study was thus to obtain high-resolution images of experimental gliomas in the rat brain, using a clinical 1.5 T MR scanner.


METHODS
Anesthesized rats bearing BT4C brain tumors were positioned into a specially designed immobilizing device, and a small circular coil was positioned onto the skulls. Two T1 weighted series were acquired before and after subcutaneous contrast injections. A T2 weighted series was also obtained. The rats were then sacrified, the brains removed, and the histological tumor volumes were compared to the volumes obtained on MRI.


RESULTS
There were visible tumors in 10 of 13 animals scanned on MR. The rim of the tumors were visualized on T1 weighted series without contrast. On T1 images with contrast, the tumors were seen as high signal intensity areas. The T2 weighted images showed peritumoral edema. No necrosis or cystic parts of the tumors were detected. There was a consistency between the MR and the histology findings, showing a high degree of correlation between the two volume determination methods.


CONCLUSIONS
High-resolution images of experimental rat gliomas can be obtained using a clinical MR scanner and a commercially available RF coil. This MRI technique may also be expanded to extraneural rat tumor models, for studies of tumor development and treatment.
Thorsen
Frits
F
Department of Anatomy and Cell Biology, University of Bergen, Bergen, Norway. frits.thorsen@helse-bergen.no
Ersland
Lars
L
Nordli
Håkon
H
Enger
Per Oyvind
PO
Huszthy
Peter C
PC
Lundervold
Arvid
A
Standnes
Tor
T
Bjerkvig
Rolf
R
Lund-Johansen
Morten
M
D000818:Animals; D001932:Brain Neoplasms / Q000139:chemically induced / Q000175:diagnosis* / Q000473:pathology; D003094:Collagen / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D004195:Disease Models, Animal; D043169:Endostatins; D005038:Ethylnitrosourea; D005260:Female; D005910:Glioma / Q000139:chemically induced / Q000175:diagnosis* / Q000473:pathology; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009374:Neoplasms, Experimental / Q000139:chemically induced / Q000175:diagnosis* / Q000473:pathology; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D014162:Transfection; D014407:Tumor Cells, Cultured / Q000637:transplantation
D043169:Endostatins; D010446:Peptide Fragments; D003094:Collagen; D005038:Ethylnitrosourea