3D Fast Spin Echo using Frequency-Modulated RF Pulses for MRI in Highly Inhomogeneous Magnetic Fields

3D Fast spin echo (FSE) with frequency-modulated (FM) pulses has been introduced for MRI in highly inhomogeneous fields. B1 dependent phase in FM pulse excitation and refocus was adjusted in the FM-FSE pulse sequence. Refocus flip angles in FM-FSE were determined with prospective extended phase graph (EPG). Proposed flip angle and phase in FM-FSE were validated in EPG simulation and experiments at 3T by introducing a linear inhomogeneous field. Finally, in vivo human brain imaging with T1- and T2-weighting was performed using the proposed 3D FM-FSE sequence.