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.