| 摘要 |
PURPOSE:To forcibly bring magnetization to thermal equlibrium, by a method wherein an object to be inspected is excited by a specific angle pulse at the beginging of repeated inspection sequence and the specific angle pulse is again applied at the point of time when the echo signal at the end of sequence becomes max. CONSTITUTION:Gradient magnetic fields in three axis directions crossed at right angles, that is, in an x-, a y- and a z-axes are controlled through a gradient magnetic field control circuit 4 and the applications of various kinds of pulses for exciting an object to be inspected through a gate circuit 61 are controlled by a controller 60. In this case, after an object to be inspected is excited by a 90 deg. pulse at the begining of repeated inspection sequence, an echo signal due to nuclear magnetic resonance is formed by a predetermined gradient magnetic field and an exciting pulse. When the 90 deg. pulse is again applied at the point of time when the echo signal becomes max., the direction of magnetization is forcibly directed to the direction for bring said direction to thermal equilibrium state and rapidly returned to the good initial state for starting the next sequence to form a tomographic image having high S/N and high resolving power. |
