Markus Nikola Streicher1, Andreas Schfer1, Dimo Ivanov1, Laurentius Huber1, Bibek Dhital1, Enrico Reimer1, Dirk Mller1, Andre Pampel1, Robert Trampel1, Robert Turner1
1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
The proton resonance frequency shift MR-thermometry method is inherently very sensitive to magnetic field perturbations in time. We show an improved referenced spin-echo EPI sequence which enables paired water and fat image acquisition in 100 ms, and allows correction for almost all causes of in-vivo field drift, such as breathing. Frequency-selectivity of the spin-echo sequence is achieved by using reversed gradient amplitudes for excitation and refocusing. With an appropriate choice of parameters, the technique provides not only fat and water separation, but immediate acquisition of the reference map at the same slice position and with maximum signal amplitude.