A medical image data processing method for determining a set of medical image data to be displayed, the data processing method being constituted to be executed by a computer and comprising the following steps: a) acquiring medical image data comprising three-dimensional medical image information describing an anatomical structure, and displaying the medical image information; b) acquiring navigation display feature data comprising navigation display feature information describing at least one graphical navigation feature; c) displaying the navigation display information simultaneously with the medical image information; d) acquiring viewing direction data comprising viewing direction information describing a spatial relationship of a viewing direction of a user relative to the position of the at least one graphical navigation feature; e) determining, based on the viewing direction data, image information subset data comprising image data subset information describing a subset of the medical image information to be selected for display.