| 摘要 |
A uniplanar gradient coil assembly (40) generates substantially linear gradient magnetic fields through an examination region (14). The gradient coil assembly (40) includes at least a pair of primary uniplanar gradient coil sets (40a, 40b) and a pair of shield coil sets (41a, 41b) which are disposed in an overlapping relationship. One gradient coil set is displaced relative to the other gradient coil set such that the mutual inductance between the two is minimized. Preferably, the coil sets (40a, 40b, 41a, 41b) are symmetric, such that the sweet spot of each coil is coincident with the geometric center of each coil. One primary uniplanar gradient coil set (40a) is a high efficiency, high switching speed coil to enhance performance of ultrafast magnetic resonance sequences, while the second primary uniplanar gradient coil set (40b) is a low efficiency coil which generates a high quality gradient magnetic field, but with slower switching speeds. By displacing one gradient coil set relative to the other, mutual inductance is minimized, which maximizes peak gradient, rise time, and slew rate, while dB/dt levels are minimized. In one embodiment, the uniplanar gradient coil assembly (40) is housed within an interior of a couch (30).
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