Cartesian continuous sampling with unequal gradients

摘要

Example methods and apparatus control ratios between a maximum gradient amplitude (MGA) of a readout lobe (G_READ) in a Cartesian continuous sampling read gradient (CSRG) and an MGA of a dephase lobe (G_DEPHASE) in the CSRG and an MGA of a rephase lobe (G_REPHASE) in the CSRG, where the direction of G_READ is opposite to the direction of G_DEPHASE, and G_REPHASE. One example method includes controlling an MR apparatus to produce a CS gradient where G_READ and G_DEPHASE correspond to the first ratio and where G_READ and G_REPHASE correspond to the second ratio. One example method includes controlling the MR apparatus to acquire an MR signal in response to the CS gradient. The MR signal is acquired during the read lobe and during a portion of the dephase lobe and/or the rephase lobe. The method includes selectively altering the ratios based on an SNR ratio associated with the MR signal.