Dynamic interleaved radial amine CEST and sodium (INTERLACED) at 3T

Motivation: Sodium (23Na) and advanced 1H MRI provides valuable metabolic information but are not routinely used because of the required additional scan time. Goal(s): Employ the idle times in 23Na MRI to perform 1H measurements, reducing total scan time. Approach: An interleaved radial amine CEST and sodium pulse sequence was developed to simultaneously acquire acidity or T2* maps simultaneously with salinity maps in phantoms and in the lower leg during an exercise paradigm. Results: A scan reduction of 46% relative to sequential acquisitions. Dynamic T2*, acidity and sodium changes were successfully tracked and in line with the expected physiological responses. Impact: The achieved scan time reduction could facilitate the inclusion of sodium and advanced 1H imaging in clinical routine. Furthermore, it could benefit functional studies by providing dynamic multinuclear information simultaneously from the same transient state.