MR perfusion, diffusion and BOLD imaging of methotrexate-exposed swine brain.
OBJECTIVE
To evaluate the methotrexate (MTX)-exposed swine brain, functional magnetic resonance imaging (MRI), including perfusion, diffusion, and blood-oxygen-level-dependent (BOLD) contrast imaging, was used.


METHODS
Juvenile pigs received either 2 x 5 g/m(2), or 5 x 2 g/m(2) MTX intravenously within one month. MRI was performed (sedative: propofol) before (14-17 kg, N = 6) and after (21-27 kg, N = 4) the MTX exposure. Also, age-matched controls (22-27 kg, N = 4) were imaged.


RESULTS
After the MTX exposure, reduced (from 2%-4% to 0%-1%) or negative (-2% to -3%) BOLD responses were detected; apparent diffusion coefficient (ADC) or relative perfusion values did not change.


CONCLUSIONS
This study suggests that MTX-related changes in the brain may be detected as changes in flow-metabolism coupling as reduced or negative response (for somatosensory activation) in the BOLD contrast MRI. The contrast agent perfusion MRI, without absolute quantification, may not show global damage in brain perfusion related to the MTX exposure in the swine model used. ADC (in one direction) may not indicate MTX-related changes in the brain.
Mäkiranta
Minna J
MJ
Department of Diagnostic Radiology, University of Oulu, Oulu, Finland. Minna.Makiranta@oulu.fi
Lehtinen
Satu
S
Jauhiainen
Jukka P T
JP
Oikarinen
Jarkko T
JT
Pyhtinen
Juhani
J
Tervonen
Osmo
O
D000818:Animals; D001921:Brain / Q000098:blood supply / Q000187:drug effects / Q000378:metabolism*; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000187:drug effects; D004058:Diffusion; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008727:Methotrexate / Q000378:metabolism*; D010477:Perfusion; D013552:Swine
D008727:Methotrexate