Frequency scouting for cardiac imaging with SSFP at 3 Tesla

Steady-state free precision techniques are often used in cine cardiac MRI, but are highly susceptible to off-resonance artifacts. In this article, we review the types and prevalence of off-resonance artifacts in the left ventricle on a 3 T MR scanner and describe the implementation of a technique to mitigate these artifacts. A group of 16 healthy children underwent SSFP cine imaging in the short axis. The synthesizer frequency was adjusted after scouting for the optimal frequency in a series of SSFP images with different frequency shifts. A total of 136 short-axis slices were examined for artifacts after the frequency adjustment. A significant number of slices in the apex region contained dark bands, flow artifacts and/or bright out-of-plane coherent artifacts. However, only five slices (3.6%) had artifacts that were detrimental to the accurate detection of myocardial boundaries. This technique offers a fast and easy way to suppress off-resonance artifacts in SSFP imaging at 3 T.