RADIAL GRADIENT MAGNETIC FIELD COIL FOR MAGNETIC RESONANCE IMAGING

摘要

PURPOSE:To enhance linearity by reducing a third order (odd number) derivative component, by arranging four saddle-shaped coils each having the same arrangement as a fundamental saddle-shaped coil in a state divided into 2N layers and setting the circular arc angle of both coils to a predetermined angle. CONSTITUTION:Four first layer fundamental saddle-shaped coils 1 are symmetrically arranged not only in a shape but also in the direction of a current with respect to an X-Y plane and arranged so as to be symmetric in a shape but asymmetric in the direction of a current with respect to a Y-Z plane. Four second layer saddle-shaped coils arranged symmetrically in a shape and the direction of a current with respect to the X-Y plane and arranged symmetrically in a shape but asymmetrically in the direction of a current with respect to the Y-X plane in the same way as the coils 1. A Y inclined magnetic field coil is realized by rotating an X inclined magnetic field coil by 90 deg. with respect to a Z-axis. Because coil winding is wound in a divided state as mentioned above, winding becomes easy and the generation of third order (odd number) derivative component is reduced and linearity can be enhanced.