Thomas K.F. Foo1, Louis Frigo2, Myung-Ho In3, Nastaren Abad1, Vincent B Ho4, and Matt A Bernstein3
1GE Research, Niskayuna, NY, United States, 2GE Healthcare, Waukesha, WI, United States, 3Mayo Clinic, Rochester, MN, United States, 4Uniformed Services University of the Health Sciences, Bethesda, MD, United States
1GE Research, Niskayuna, NY, United States, 2GE Healthcare, Waukesha, WI, United States, 3Mayo Clinic, Rochester, MN, United States, 4Uniformed Services University of the Health Sciences, Bethesda, MD, United States
A single-sided
bipolar encoding, phase difference method was used to calculate the transverse
gradient offsets for asymmetric gradient coils by fitting the measured phase
values. This was used for pre-emphasis compensation for the zeroth and first
order concomitant gradient fields.
Figure 2: Phase
error from a single-sided encoding experiment for (a) MAGNUS unit#2, and (b)
the C3T system. The difference between the measured and the EM-derived nominal
offset of 12 cm is shown.
Figure 4: Phase
difference images for the single-sided encoding experiment with g3
= 71 mT/m (a) before applying the zeroth order frequency correction (ROI phase
= 4.2$$$\pm$$$0.1 radians), and (b) after correction (ROI phase = 0.1$$$\pm$$$0.1
radians). A zero phase is expected for the phase difference in the stationary
phantom.
