An image processing apparatus includes a storage unit, a specifying unit, a calculation unit and a display unit. The storage unit stores diffusion weighted image data. The specifying unit specifies a calculation target region on the diffusion weighted image data. The calculation unit calculates at least one of a diffusion coefficient and a fractional anisotropy serving an index of diffusion anisotropy with regard to the calculation target region based on the diffusion weighted image data. The display unit displays at least one of the diffusion coefficient and the fractional anisotropy calculated by the calculation unit.
Diffusion-weighted MRI