A method for determining an optimal trajectory for 3-dimensional rotational X-ray coronary angiography for a C-arm X-ray system that has at least two degrees of freedom, where the C-arm X-ray system is defined by a rotational movement of the C-arm expressed in a left/right coronary artery oblique angle, and a roll motion of the C-arm expressed in a caudal/cranial angle. The method includes generating of a 3-dimensional representation of a center-line of a body vessel in a region of interest. generating at least one optimal view map. Further, an optimal trajectory for the X-ray system within the optimal view map is determined, where an optimal trajectory is at least determined by movements of the C-arm within its two degrees of freedom allowing image projections with minimal foreshortening and/or overlap while minimizing an exposure to X-rays.