Magnetization transfer effects in multislice RARE sequences.

Magnetization transfer effects are demonstrated to be significant in determining the signal intensity from brain tissues on images acquired with multislice rapid acquisition relaxation enhanced (RARE) sequences. We report studies designed to determine how the signal intensities vary with slice number or, equivalently, off-resonance power deposition. The results obtained in fat, gray matter, and white matter are similar in form to those reported in kidney tissues during classic magnetization transfer experiments (J. Eng, T. L. Ceckler, and R. S. Balaban, Magn. Reson. Med. 17, 304 (1991)). Of clinical significance to RARE practitioners is the increase of contrast-to-noise ratios between gray and white matter on proton density-weighted images with increasing slice number.