| 摘要 |
<p>An MRI system using an open type magnet, wherein two coils different in radius for generating gradient magnetic fields in a vertical direction are arranged in the open type magnet for generating a static magnetic field in the vertical direction. Currents are caused to flow through the two coils in directions opposite to each other to improve the degree of uniformity of the magnetic field in the vertical direction, thereby reducing the degradation thereof by equal to or smaller than 2 figures compared with the degree of uniformity of the static magnetic field generated by the existing MRI system. The positional information about a read-out direction is given through the dynamic control for the RF magnetic field to give the positional information about other two axes directions based on the gradient magnetic field having strength much larger than that of nonuniformity of the magnetic field.</p> |
