High-resolution functional magnetic resonance imaging of the rat brain: mapping changes in cerebral blood volume using iron oxide contrast media.
Contrast-enhanced magnetic resonance imaging was used to produce high-resolution activation maps reflecting local changes in cerebral blood volume after a simple sensory stimulus. Activation of the forelimb region of the somatosensory cortex was performed in alpha-chloralose-anaesthetized rats with an electrical stimulus (5 V, 3 Hz) delivered through needle electrodes placed subcutaneously on the left forelimb. A gradient echo magnetic resonance imaging sequence, sensitive to changes in the relative amount of deoxyhemoglobin within the cerebral vasculature, produced a 4.05%+/-1.69% increase in signal intensity. This effect was enhanced with an injection of an intravascular iron oxide contrast agent (Combidex, Advanced Magnetics), resulting in a 9.11%+/-1.52% decrease in signal intensity.
van Bruggen
N
N
Department of Neuroscience, Genentech, Inc., South San Francisco, California 94080, USA.
Busch
E
E
Palmer
J T
JT
Williams
S P
SP
de Crespigny
A J
AJ
D000818:Animals; D001810:Blood Volume; D001921:Brain / Q000098:blood supply / Q000502:physiology*; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003287:Contrast Media; D004558:Electric Stimulation; D005290:Ferric Compounds; D005552:Forelimb; D006454:Hemoglobins / Q000378:metabolism; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
D003287:Contrast Media; D005290:Ferric Compounds; D006454:Hemoglobins; C000499:ferric oxide; C100003:deoxyhemoglobin