| 摘要 |
PURPOSE:To make small the rising and falling periods in generation of pulse magnetic field and improve S/N of picture by providing permanent magnets and magnetic pole segments, which are magnetically coupled with such permanent magnet and generate magnetic field to the gap, opposed to each other and then defining specific resistance thereof in a nuclear magnetic resonance diagnostic apparatus for medical use (MRI). CONSTITUTION:Uniform intensified magnetic field is generated within a gap with a permanent magnet 1, magnetic pole segments 2 and iron powder 3. An inclined magnetic field coil 4 is provided in the vicinity of magnetic pole segmetns 2 and a plse current is applied to generate the inclined magnetic field. In this case, the rising and falling period can be reduced to 2 m sec or less by setting the specific resistance of magnetic pole segments to 20 muOMEGA-cm or more. |
