PROBLEM TO BE SOLVED: To provide a magnetic resonance imaging apparatus having high safety.SOLUTION: A magnetic resonance imaging apparatus includes: a magnetic field generation system which gives a subject a static magnetic field and a gradient magnetic field a multi-channel transmission system with at least 2 channels which applies high frequency magnetic fields for making atomic nuclei constituting the subjects organic systems cause the magnetic nuclear resonance a reception system which detects nuclear magnetic resonance signals discharged by the nuclear magnetic resonance a signal processing system which makes image reconstruction operation using the nuclear magnetic resonance signals detected by the reception system and a CPU which controls the entire system operation. The magnetic resonance imaging apparatus measures an irradiation power value and a reflection power value for each channel by preliminarily performing high-frequency magnetic field irradiation for channels one by one before measuring the subject, and calculates an absorbed power value and the reflection power value of the subject on the basis of the irradiation power value to the subject, and the irradiation power value and the reflection power value preliminarily measured for each channel, when measuring the subject.SELECTED DRAWING: Figure 5COPYRIGHT: (C)2016,JPO&INPIT【課題】安全性の高い磁気共鳴イメージング装置を提供する。【解決手段】被検体に静磁場および傾斜磁場を与える磁場発生系と、前記被検体の生体組織を構成する原子核に核磁気共鳴を起こさせるための高周波磁場を照射する少なくとも2チャンネル以上の多チャンネル送信系と、当該核磁気共鳴により放出される核磁気共鳴信号を検出する受信系と、前記受信系で検出された核磁気共鳴信号を用いて画像再構成演算をおこなう信号処理系と、装置全体の動作を制御する中央処理装置と、を備えた磁気共鳴イメージング装置であって、前記磁気共鳴イメージング装置は、前記被検体の計測前に、予め1チャンネルずつ高周波磁場照射を行うことによりチャンネル毎の照射電力値と反射電力値を測定し、前記被検体の計測時に、前記被検体に対する照射電力値および予め測定したチャンネル毎の照射電力値と反射電力値に基づき前記被検体の吸収電力値および反射電力値を算出する。【選択図】図5
