An image processing apparatus for diagnostic imaging and which allows easy verification of a spatial position ON an arbitrary cross section is provided. An image processing apparatus 1 includes a basic position calculating unit 2 configured to calculate a position of a basic cross section from an image data, an auxiliary position calculating unit 3 configured to calculate a position of an auxiliary cross section, a generating unit 4 configured to generate a basic cross-sectional image using the image data and the position of the basic cross section and generate an auxiliary cross-sectional image using the image data and the position of the auxiliary cross section and a relationship calculating unit 5 configured to calculate information ON a positional relationship indicating the relative positional relationship between the position of the basic cross section and the position of the auxiliary cross sectionAnd a combining unit 6 configured to combine the information ON the positional relationship with the basic cross-sectional image or the auxiliary cross-sectional image respectively and a display unit 9 configured to display the combined image.
