Simon Hu1,2, Peder E. Larson1, Adam B. Kerr3, Douglas A. Kelley4, James Tropp4, John M. Pauly3, John Kurhanewicz1,2, Daniel B. Vigneron1,2
1Dept. of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; 2UCSF & UCB Joint Graduate Group in Bioengineering, San Francisco, CA, USA; 3Dept. of Electrical Engineering, Stanford University, Stanford, CA, USA; 4GE Healthcare, San Francisco, CA, USA
In order to develop methods for human studies, we modified a previously reported double spin-echo hyperpolarized 13C spectroscopic imaging sequence by using stretched hyperbolic secant refocusing pulses instead of standard hyperbolic secant pulses. The previous pulses used in animal model studies had a nominal B1 of 1.7 gauss, which was achievable with small coils but not with human coils. We designed new pulses with a nominal B1 of 0.4 gauss, which we validated in simulations, phantom experiments, and in vivo.