Roland Bammer1, Bei Zhang2,
Weiran Deng3, Graham C. Wiggins2, Andy V. Stenger3,
Daniel K. Sodickson2
1Radiology, Stanford University,
Stanford, CA, United States; 2Radiology, New York University
Langone Medical Center, New York, United States; 3JABSOM,
University of Hawaii, Honolulu, HI, United States
Due to the sequential nature of MRI, patient motion affects not only signal reception and encoding but also parallel transmit MRI (pTx). An obvious challenge is when pose changes happen between the measurement of coil sensitivities & the design of the corresponding RF waveforms and the point in time when RF pulses are actually played out on the system (as the patient might be exposed to an entirely different B1+ field). This will ultimately affect ones pTx approach to fully handle unwanted aliasing in the excited region, as well as impair the outcome of pTx-based B1+ mitigation and B1+-shimming approaches. The purpose of this simulation study was to demonstrate pTxs sensitivity to motion and how desired excitation patterns can potentially be degraded by patient motion.