Markus Nikola Streicher1, Andreas Schfer1, Dirk Mller1, Carsten Kgler1, Enrico Reimer1, Bibek Dhital1, Robert Trampel1, Debra Rivera1, Andr Pampel1, Dimo Ivanov1, Robert Turner1
Institute for Human Cognitive & Brain Sciences,
The proton resonance frequency shift MR thermometry method is inherently very sensitive to magnetic field perturbations in time. We simulated and tested a new referenced spin-echo (SE) EPI sequence which solves these problems reliably, efficiently and quickly. Frequency-selectivity of the SE sequence is achieved by using different slice-select gradient amplitudes for excitation and refocusing, making it easy to image water and a reference substance separately. The sequence alternately images each species, and thereby allows fast voxel-wise correction for magnetic field changes in a working range of 1ppm and excitation flip angles from 0 to 130.