PROBLEM TO BE SOLVED: To avoid complication of a device, avoid overrating SAR calculated value without using extended time for processing and execute SAR management exactly.SOLUTION: SAR management is conducted by calculating Q value of each channel of a high-frequency antenna using absolute values of elements on diagonal lines and elements on non-diagonal lines of a reflection matrix of a high-frequency signal; correcting the calculated Q value using the absolute values of elements on non-diagonal lines of the reflection matrix; and calculating power consumed by a subject by using the corrected Q value.SELECTED DRAWING: Figure 3【課題】装置の複雑化を回避し、処理時間を延長させずに、SAR算出値の過剰評価を回避し、延いては、正確にSARマネジメントを行う。【解決手段】高周波信号の反射行列の対角項及び非対角項の絶対値を用いて高周波アンテナの各チャンネルのQ値を算出し、算出したQ値を反射行列の非対角項の絶対値を用いて補正し、補正したQ値を用いて被検体において消費されるパワーを算出し、SARを管理する。【選択図】 図3