| 摘要 |
<p>The purpose of the present invention is to stabilize the magnetic field strength of the superconductive magnet in driven mode operation and achieve improvement of MRI image quality. A magnetism locking sample (122) is disposed at a position where a magnetic field generated by the superconductive coil (105) is applied and which does not physically interfere with the subject (101). A magnetic field locking unit (123) irradiates a high frequency magnetic field on the magnetic field locking sample (122), detects the NMR signal (B) generated by the magnetic field locking sample (122), and adjusts the strength of the static magnetic field according to the detection results to make the static magnetic field constant. Preferably the magnetic field locking sample comprises an atomic nuclide that generates a nuclear magnetic resonance signal (B) of a magnetic resonance frequency differing from the magnetic resonance frequency of the nuclear magnetic resonance signal (A) detected by the measurement unit.</p> |
