Optimization of alternating TR-SSFP for fat-suppression in abdominal images at 3T.

Magnetic resonance imaging is widely used in the work-up and monitoring of patients with Crohn's disease. Balanced steady-state free precession sequences are an important part of the imaging protocol and until now primarily 1.5T scanners have been used in daily clinical practice. This is largely because running balanced steady-state free precession sequences in 3T magnets has technical problems related to increased B(0) inhomogeneity and specific absorption rate (SAR) deposition. A modified form of alternating repetition time steady-state free precession sequence is presented to acquire 3D-isotropic abdominal images with fat-suppression at 3T within a breath-hold. The modifications include an adjusted radiofrequency pulse shape, suitable phase-cycling scheme and TR(1)/TR(2) ratio. Results show that the proposed sequence is successful in obtaining high contrast 3D-isotropic abdominal images within a breath-hold. Furthermore, the proposed methodology is easy to implement in a clinical setting and does not require any postprocessing steps.