COMMON K-SPACE ACQUISITION - A METHOD TO IMPROVE MYOCARDIAL GRID-TAG CONTRAST

A current limitation of many myocardial fag acquisitions employing SPA MM encoding is the relatively rapid loss of tag contrast over the card iac cycle. Acquisition schemes that apply line tags produce prolonged tag contrast compared with directly excited grid tags. However, a grid -tag series can be generated by combining two orthogonal line-fag seri es. To be time efficient, each line-tag series can be acquired with th e read gradient oriented perpendicular to the line-tag direction, Ther e are several disadvantages associated with this approach, including t he requirement to avoid signal fold-over and that fat shift artifacts appear in different directions in each line-fag series, Presented here is a method of applying separate line tags that does not require inte rchanging the read and phase encoding gradients and does not extend th e scan time compared with a conventional grid-tag acquisition, Additio nally, the means of generating grid tags results in a doubling of the tag contrast to noise ratio compared a line-tag set, Computer simulati ons are presented along with phantom and volunteer scans.