Florent Eggenschwiler1,
Rolf Gruetter2, Jos P. Marques3
1EPFL,
Laboratory for Functional and Metabolic Imaging, Lausanne, Vaud, Switzerland;
2Universities of Geneva and Lausanne, cole Polytechnique Fdrale
de Lausanne, Lausanne, Vaud, Switzerland; 3University of Lausanne,
Department of Radiology, Lausanne, Vaud, Switzerland
This work presents a new approach for designing high tip angle kT-point pulses based on a linearization of the Bloch equations and usage of symbolic notation to accelerate the computation when the optimization has to be performed for large number of pixels. Based on the differentiation of the analytic form of the Bloch equations, the kT-point weights and positions were iteratively optimized in order to converge towards a targeted distribution of the magnetization across the brain. The validity of the method was demonstrated by designing high tip angle kT-points excitation and refocusing pulses.