Magnetic Resonance Imaging Apparatus

A magnetic resonance imaging apparatus, comprising:

• a static magnetic field generation magnet configured to generate a static magnetic field in a space where a subject is arranged;
• a transmission unit configured to transmit a high frequency magnetic field to the subject;
• a reception unit configured to receive a nuclear magnetic resonance signal generated in the subject through transmission of the high frequency magnetic field thereto;
• a gradient magnetic field application unit configured to apply a gradient magnetic field which adds positional information to the nuclear magnetic resonance signal;
• a computer configured to control the transmission unit, the reception unit, and the gradient magnetic field application unit, and configured to process the nuclear magnetic resonance signal;
• and,
• a display unit configured to display an image processed by the computer;
• wherein
• the computer comprises:
• a subject tissue extracting unit configured to compute a subject tissue extraction image for a extracted tissue of the subject tissue, from a complex image composed of the nuclear magnetic resonance signals,
• a phase distribution calculation unit configured to calculate the phase distribution from the complex image,
• a phase wrapping correction unit configured to correct a phase wrapping of the phase distribution,
• an area dividing unit configured to divide the phase distribution after correction into a predetermined area and an area other than the predetermined area of the subject tissue, based on the subject tissue extraction image,
• a background phase distribution calculation unit configured to calculate a background phase distribution of the predetermined area,
• and a local phase distribution calculation unit configured to calculate a local phase distribution in the predetermined area of the subject tissue by combination of the phase distribution after correction and the background phase distribution.