Christof Baltes*1, Simone Bosshard*1,
Thomas Mueggler1,2, Markus Rudin1,3
1Institute for Biomedical Engineering,
University and ETH Zurich, Zurich, Switzerland; 2Pharmaceutical
Research Neuroscience, F. Hoffmann-La Roche Ltd., Basel, Switzerland; 3Institute
of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
BOLD-fMRI
in mice using electrical forepaw stimulation was performed with a cryogenic
transceive RF probe and a room-temperature receive-only surface coil. The
effect of the increased sensitivity of the cryogenic probe on detecting BOLD
responses was analyzed. In fMRI experiments, a gain in image SNR and in
temporal SNR of a factor of 3.10 and 1.77 was found, respectively. As further
optimization parameter adjusting the thermal shield temperature of the
cryogenic probe allows for altering baseline perfusion and accordingly BOLD
responses. Cryogenic cooling reduces BOLD signal variations by a factor of
1.59 and therefore increases the statistical power of fMRI.