1. A method of creating and simultaneously displaying medical scan images, from each of: (i) a first ( 780 ) medical scan dataset, obtained by scanning a 3-dimensional (3-D) object with a first scanning modality; and (ii) a second ( 530 ) medical scan dataset, obtained by scanning the 3-dimensional (3-D) object with a second scanning modality; the method comprising: deriving a first image ( 410 ) from the first ( 780 ) medical scan dataset, the first image lying in a first plane, the first plane corresponding to an acquisition plane of the first ( 780 ) medical scan dataset; obtaining a second image ( 420 ) from the second medical scan dataset ( 530 ), the second image lying in the first plane; displaying the first image ( 410 ) and the second image ( 420 ) simultaneously.