| 摘要 |
PURPOSE:To reduce the distortion of an image to drift by detecting the drift from variation in time when a spin echo signal obtained by the inversion of an inclined magntic field has a peak and controlling a power source for an inclined magnetic field coil. CONSTITUTION:A body 2 to be measured is placed in a uniform static magnetic field produced by a magnet 1 and an electromagnetic wave is applied to the body 2 to be measured from the transmission part of a transmitter receiver 4 through a high-frequency coil 3. Then when the irradiation of the electromagnetic wave is stopped, an electromagnetic wave emitted from an atomic nucleus in the object body 2 is detected by the reception part of the transmitter receiver 4 through the high-frequency coil 3 and the static magnetic field is given a slope by the inclined magnetix field coil 5 to decide on the position, which is displayed on an image display device 9. On the other hand, high-frequency pulses 10 and the inclined magnetic field 11 are applied during drift correction to measure times tau1, and tau2 when the spin echo signal 12 has a peak. Then, a drift correcting signal is sent from a control circuit 17 to the power source for the inclined magnetic field coil so that the time difference is reduced, thereby correcting the drift of the output current of the power source 6. |
