1. A method for determining at least one of a position and orientation of an image plane of a plurality of slice image exposures of a vessel region in a magnetic resonance contrast agent bolus examination, comprising the steps of: automatically acquiring a plurality of slice image exposures in respectively different planes of a region encompassing a vessel into which a contrast agent bolus has been administered, said slice image exposures being disposed parallel to each other and substantially orthogonally to the vessel; automatically electronically determining respective image regions, showing said vessel region, in said orthogonal slice image exposures in an image processor; using the determined image regions, automatically electronically determining a spatial position of said vessel region in said image processor; and in said image processor automatically electronically determining at least one of a position and orientation of an image plane, disposed substantially orthogonal to the respective planes of the slice image exposures and traversing said vessel region in longitudinal section, using said spatial position of said vessel region, said image plane being disposed in a center of said vessel region.