Abstract: A method and apparatus of imaging multiple volumes of the anatomy of interest using a phase-cycled SSFP pulse sequence and a reverse elliptic centric view ordering to sample a first volume and an elliptic centric view ordering to sample a second volume is disclosed. Dummy acquisitions are played out between imaging of the first and second volumes, and the time to play out the dummy acquisitions is used to change the phase-cycling scheme of the RF pulses of the SSFP pulse sequence. Oscillations in signal are reduced as the spins in the anatomy of interest are brought to a new steady-state by gradually ramping the RF pulse phase increment for acquisition from the first volume to the RF pulse phase increment for acquisition from the second volume. The present invention is effective for reducing transient oscillations in MR signals from resonance and off-resonance spins, thus enabling the use of this technique for the reduction of motion artifacts in phase-cycled SSFP.

Abstract: An fMRI scan is performed with an MRI system in which a series of single shot EPI pulse sequences are performed to acquire a series of images. A shim navigator pulse sequence is interleaved with the EPI pulse sequence to acquire data with which the MRI system polarizing magnetic field can be measured. Measured changes in the polarizing field during the scan are employed to calculate corrective changes in the scan parameters that offset phase errors caused by changes in the polarizing field.