Patent ID: 8614574
Filing Date: 2013-12-24
Classification: A61B,G01R

Abstract:
1. A nuclear magnetic resonance imaging apparatus comprising, a static magnetic field a application part for applying a static magnetic field to a subject, a gradient magnetic field application part for applying a gradient magnetic field to the subject, a radio frequency pulse irradiator for irradiating the subject with a radio frequency pulse, a detector for detecting a nuclear magnetic resonance signal from the subject, and a controller for controlling the radio frequency pulse irradiator, the gradient magnetic field application part, and the detector, to execute an imaging pulse sequence being predetermined, wherein, the controller executes one or more sequence groups, as the imaging pulse sequence, including irradiation of multiple radio frequency pulses and application of multiple gradient magnetic fields for providing multiple types of phase encoding amount, and sets a flip angle to the radio frequency pulse as to each of the one or more sequence groups, two or more sequence groups are provided, and the controller sets a maximum value flip angle to the sequence group which executes the phase encoding of an amount having a minimum absolute value, among the two or more sequence groups, and sets a value smaller than the maximum value as the flip angle to the other sequence group, the controller calculates a specific absorption rate of the imaging pulse sequence as a whole, and determines a value of the flip angle to be set to the other sequence group so that the specific absorption rate being obtained becomes equal to or less than a predetermined safety level value.