An image processing apparatus includes an image acquisition unit, a setting unit, an image derivation unit, a luminance condition derivation unit and a display unit. The image acquisition unit acquires a first diffusion-weighted image of a first b value and a second diffusion-weighted image of a second b value. The setting unit sets a target diffusion coefficient and a third b value. The image derivation unit derives a virtual diffusion-weighted image of the third b value based on the target diffusion coefficient, the first diffusion-weighted image and the second diffusion-weighted image. The luminance condition derivation unit derives a luminance condition for displaying the virtual diffusion-weighted image based on the target diffusion coefficient and the third b value. The display unit displays the virtual diffusion-weighted image according to the luminance condition derived by the luminance condition derivation unit.
