Multi-slice MRI of rat brain perfusion during amphetamine stimulation using arterial spin labeling.
When a single coil is used to measure perfusion by arterial spin labeling, saturation of macromolecular protons occurs during the labeling period. Induced magnetization transfer contrast (MTC) effects decrease tissue water signal intensity, reducing the sensitivity of the technique. In addition, MTC effects must be properly accounted for in acquiring a control image. This forces the image to a single slice centered between the labeling plane and the control plane. In this work, a two-coil system is presented as a way to avoid saturation of macromolecular spins during arterial spin labeling. The system consists of one small surface coil for labeling the arterial water spins, and a head coil for MRI, actively decoupled from the labeling coil by using PIN diodes. It is shown that no signal loss occurs due to MTC effects when the two-coil system is used for MRI of rat brain perfusion, enabling three-dimensional perfusion imaging. Using the two-coil system, a multi-slice MRI sequence was used to study the regional effects of amphetamine on brain perfusion. Amphetamine causes significant increases in perfusion in many areas of the brain including the cortex, cingulate, and caudate putamen, in agreement with previous results using deoxyglucose uptake to monitor brain activation.
Silva
A C
AC
Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
Zhang
W
W
Williams
D S
DS
Koretsky
A P
AP
D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D001158:Arteries; D001834:Body Water; D001921:Brain / Q000098:blood supply* / Q000187:drug effects* / Q000473:pathology; D002540:Cerebral Cortex / Q000098:blood supply / Q000187:drug effects / Q000473:pathology; D002560:Cerebrovascular Circulation / Q000187:drug effects* / Q000502:physiology*; D006179:Gyrus Cinguli / Q000098:blood supply / Q000187:drug effects / Q000473:pathology; D006935:Hypercapnia / Q000503:physiopathology; D007089:Image Enhancement / Q000295:instrumentation / Q000379:methods; D046911:Macromolecular Substances; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008297:Male; D009833:Olfactory Pathways / Q000098:blood supply / Q000187:drug effects / Q000473:pathology; D011699:Putamen / Q000098:blood supply / Q000187:drug effects / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013113:Spin Labels
D046911:Macromolecular Substances; D013113:Spin Labels; D000661:Amphetamine