High-frequency coil and magnetic resonance imaging device employing same

摘要

A technique is provided to reserve large examination space in the tunnel type MRI apparatus, without increasing production cost nor reducing significantly irradiation efficiency and homogeneity in an irradiation distribution within an imaging region. The present invention provides an RF coil unit in which four partial cylindrical coils are placed with a gap therebetween in the circumferential direction inside a cylindrical RF shield, in such a manner that two pairs of the partial cylindrical coils are opposed to each other, and magnetic fields produced by the individual partial cylindrical coils are combined, thereby producing a circularly polarized wave field or an elliptically polarized wave field. The partial cylindrical coil is provided with a partial cylindrical conductor, multiple first conductors substantially parallel with the central axis of the RF shield, multiple capacitors connecting both ends of the first conductors with the partial cylindrical conductor, and a second conductor adjacent to at least one of the ends of the first conductor. The partial cylindrical coils are respectively provided with high frequency signals having a desired amplitude ratio and phase difference, while a reference frequency thereof being identical.

主权项

1. A high frequency coil comprising:
a cylindrical RF shield, a first high frequency coil, and a second high frequency coil, the first high frequency coil and the second high frequency coil being placed with a gap therebetween in a circumferential direction inside the RF shield, each of the first high frequency coil and the second high frequency coil being provided with two sheet-like partial cylindrical coils opposed to each other placing a central axis of the RF shield therebetween, and each of the sheet-like partial cylindrical coils comprising:
a sheet-like partial cylindrical conductor sharing the central axis,multiple first conductors being placed inside the sheet-like partial cylindrical conductor and substantially parallel to the central axis,multiple first capacitors connecting both ends of the first conductors with the sheet-like partial cylindrical conductor, andat least one second conductor establishing a short-circuit between at least one end of the first conductor and one end of an adjacent first conductor.