1. Technical Field
The present invention relates to a magnetic resonance imaging apparatus that images an inside of a subject by using magnetic resonance phenomenon.
2. Related Art
Conventionally, a magnetic resonance imaging apparatus is an apparatus that reconstructs an image from a magnetic resonance signal generated along with excitation by magnetically exciting a nuclear spin of a subject placed in a static magnetic field with a radio-frequency signal at a Larmor frequency appropriate to the nucleus.
Such magnetic resonance imaging apparatus sometimes uses a receiving coil in which a plurality of element coils each configured to receive a magnetic resonance signal emitted from a subject is arranged, in some cases. Such receiving coil is also called an array coil.
A method known as a technology related to a receiving coil in which a plurality of element coils is arranged is a method of measuring the positions of element coils by placing a receiving coil onto a subject, for example, as shown in FIG. 15, then actually detecting a magnetic resonance signal, and using data created from the detected magnetic resonance signal (for example, see JP-A 10-179551 (KOKAI), or U.S. Pat. No. 6,794,872).
However, if the positions of individual coils are determined from a single measurement result, measurement errors are not sufficiently reduced. The reason for this is because, for example, when a coil is located at a position off the center of magnetic field, an error is produced due to degradation in uniformity of a magnetic field, degradation in linearity of a gradient magnetic field and/or signal variation from the body tissues.