Magnetic resonance imaging apparatus and magnetic resonance imaging method

摘要

The temperature of an MRI gradient magnetic field coil unit is measured at least two times. Shift data indicating a center magnetic resonance frequency of a hydrogen atom in response to variation of the gradient coil temperature is stored in advance. Estimated shift of the center frequency based on the measurement result is determined and the center frequency of an RF NMR excitation pulse is corrected based on the estimated shift.

主权项

1. A magnetic resonance imaging (MRI) apparatus, comprising:
an MRI gradient magnetic field coil unit configured to generate a gradient magnetic field in an imaging space according to a current supplied thereto; at least one temperature sensor configured to measure a temperature of the MRI gradient magnetic field coil unit at least two times at different timings to detect at least one coil unit temperature difference between said different timings; a data store in which shift data have been recorded in advance of measurements by the temperature sensor, the shift data indicating a shift of a center frequency of hydrogen atom nuclear magnetic resonance (NMR) in the imaging space as a function of variation of gradient magnetic field coil unit temperature; a pulse setting unit configured to acquire a measurement result from the temperature sensor, to determine an estimated shift of the hydrogen atom NMR center frequency using the detected variation of temperature and the stored shift data, and to correct an RF pulse center frequency based on the estimated shift; and an imaging unit configured to transmit the corrected RF pulse to receive magnetic resonance signals from an object in the imaging space, and to generate image data of the object based on the received magnetic resonance signals.