PROBLEM TO BE SOLVED: To provide a technology to calculate oxygen intake rate distribution in the brain including the brain parenchyma by simple processing without imposing a load such as caffeine administration on a subject in calculating oxygen intake rate distribution using an MRI.SOLUTION: A complex image of a nuclear magnetic-resonance signal is measured, and physical property value distribution for calculating a physical property value image reflecting an oxygen intake rate is calculated from the measured complex image. The calculated physical property value distribution is separated into the physical property value distributions (tissue separation images) of every at least two kinds or more of tissues. After one of the tissue separation images is converted to the oxygen intake rate, the oxygen intake rate distribution is estimated based on the condition that a pixel value of an arbitrary pixel and an average value of the peripheral pixels are roughly equal.SELECTED DRAWING: Figure 6【課題】ＭＲＩを用いて酸素摂取率分布を算出するにあたり、被験者に対してカフェイン投与などの負荷を与えず簡易な処理で脳実質を含む脳内の酸素摂取率分布を算出する技術を提供する。【解決手段】核磁気共鳴信号の複素画像を計測し、計測した複素画像から、酸素摂取率を反映した物性値画像を算出する物性値分布を算出する。そして、算出した物性値分布を少なくとも２種類以上の組織毎の物性値分布（組織分離画像）に分離する。組織分離画像のいずれかを酸素摂取率に換算したのち、任意の画素の画素値とその周囲の画素の平均値が略等しいという条件に基づいて酸素摂取率分布を推定する。【選択図】図６
