| 摘要 |
PURPOSE:To correct the attenuation of a magnetic field automatically and to produce a static magnetic field with high uniformity by providing a control means which the controls the excitation of a correcting coil which corrects the static magnetic field established by a main coil on the basis of a magnetic field detecting means. CONSTITUTION:An MR (magnetic resonance) phenomenon is caused at the expected tomographic surface part of an object body P arranged in an uniform static magnetic field produced by the main coil 1 and a shim coil and an induced MR signal is detected to obtain projection information. Then,a the magnetic field sensor consisting of a detection part 11, coupling support rod 12, and rotary driving device 13 is fitted in a groove 10 for magnetic sensor storage formed in the internal surface of the transmitting and receiving coil container 4 of a high-frequency transmitter and receiver 4. The device 13, on the other hand, incorporates a storage position sensor 14 and a measurement position detection sensor 15 which detect the position of the magnetic sensor, and the detection part 11 is coupled electrically; with the magnetic field sensor transmitting and receiving device 16. Further, a controller 17 which controls the correction of the attenuation of the magnetic field, the device 16, the device 13, and a Zo shim coil power unit 7a are coupled electrically with one another. |
