| 摘要 |
The MRI apparatus of the present invention executes a non-imaging mode 501 for obtaining a steady state of magnetization and an imaging mode 502 for measuring echoes for images. In the non-imaging mode 501 and the imaging mode 502, imaging is performed by using a GrE type pulse sequence. In the imaging, RF pulses are irradiated while flip angle of nuclear magnetization in the imaging mode 502 is changed in a range of values not larger than a certain value determined by flip angle of nuclear magnetization used in the non-imaging mode 502 is irradiated. This certain value is, for example, the maximum value of flip angle of nuclear magnetization used in the non-imaging mode, or flip angle provided by an RF pulse used at the end of the non-imaging mode. SAR observed with use of a GrE type pulse sequence can be thereby reduced without degrading image contrast, and thus influence on human bodies can be reduced.
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