Patent ID: 9541623
Date: 2017-01-10
CPC Classifications: G01R

Claim:
1. A magnetic resonance imaging apparatus comprising: static magnetic field generating unit configured to generate a static magnetic field; gradient magnetic field application unit configured to apply a gradient magnetic field to an object to be examined that is placed in the static magnetic field; high-frequency magnetic field application unit configured to apply a high-frequency field magnetic pulse for exciting magnetization of the object at a predetermined flip angle; signal receiving unit configured to receive echo signals emitted from the object by nuclear magnetic resonance; image reconstruction unit configured to reconstruct an image from the received echo signal; control unit configured to control the gradient magnetic field application unit, high-frequency magnetic field application unit, signal receiving unit and image reconstruction unit in accordance with an imaging sequence; and input receiving unit configured to receive input of imaging conditions to be used by the control unit, wherein: wherein the flip angle determining unit changes each flip angle of the plural refocus high-frequency magnetic field pulses so that a calculated echo time which determines the contrast of a reconstruction image which can be obtained by the flip angles from the signal intensity of echo signals which can be acquired by the respective flip angles of the plural refocus high-frequency magnetic field pulses falls within the effective range of a desired echo time which determines the desired contrast wherein the flip angle determining unit, as the result of comparing the calculated echo time and the desired echo time, makes the change of flip angles of stabilization pulses among the plural refocus high-frequency magnetic field pulses gradual when the calculated echo time is shorter than the desired echo time, and makes the change of flip angles of the stabilization pulses steep when the calculated echo time is longer than the desired echo time.