A data processing method for determining a matching transformation for matching a set of one or more images of an anatomical body structure of a patient, referred to as a patient image set, and a set of one or more images of a general anatomical structure, referred to as an atlas image set, wherein the general anatomical structure comprises a plurality of anatomical elements referred to as atlas elements, and each patient image is associated with one of a plurality of different parameter sets, wherein the parameter sets comprise one or more parameters which obtain when the patient images are generated, and the parameters influence representations of anatomical elements in the patient images, the method comprising the following steps performed by a computer: • acquiring atlas data (S110, S120), comprising the sub-steps of - acquiring atlas spatial information which contains spatial information on the general anatomical structure, and - acquiring element representation information which describes a plurality of representation data sets (Table 3) which contain information on representations of the plurality of atlas elements in the atlas images to be determined, wherein the element representation information describes a determination rule for determining respective representation data sets for respective atlas elements in accordance with different respective parameter sets; • acquiring patient data, comprising the sub-steps of - acquiring the patient image set, and - acquiring one or more of the plurality of parameter sets which are respectively associated with the one or more images of the patient image set; • determining, on the basis of the atlas data and the patient data, the set of atlas images which respectively represent at least a part of the general anatomical structure by using (S141b) the spatial information on the general anatomical structure and particular representation data sets which are determined by applying the determination rule in accordance with the one or more associated parameter sets and particular atlas elements acquired (S141a) and referred to as corresponding elements, which are to be matched to corresponding anatomical elements represented in the patient image; • determining the matching transformation (APT; APT1, APT2) which matches the atlas image set and the patient image set, by matching images associated with the same parameter set to each other, wherein the atlas data also comprise spatial flexibility information which describes a flexibility of the position of atlas elements within the general anatomical structure, and characterized in that, the matching transformation is determined on the basis of the spatial flexibility information by using the spatial flexibility information as a constraint for determining the matching transformation, wherein the flexibility information includes a statistical probability for different sizes and/or shapes of the atlas elements. • acquiring atlas data (S110, S120), comprising the sub-steps of - acquiring atlas spatial information which contains spatial information on the general anatomical structure, and - acquiring element representation information which describes a plurality of representation data sets (Table 3) which contain information on representations of the plurality of atlas elements in the atlas images to be determined, wherein the element representation information describes a determination rule for determining respective representation data sets for respective atlas elements in accordance with different respective parameter sets; - acquiring atlas spatial information which contains spatial information on the general anatomical structure, and - acquiring element representation information which describes a plurality of representation data sets (Table 3) which contain information on representations of the plurality of atlas elements in the atlas images to be determined, wherein the element representation information describes a determination rule for determining respective representation data sets for respective atlas elements in accordance with different respective parameter sets; • acquiring patient data, comprising the sub-steps of - acquiring the patient image set, and - acquiring one or more of the plurality of parameter sets which are respectively associated with the one or more images of the patient image set; - acquiring the patient image set, and - acquiring one or more of the plurality of parameter sets which are respectively associated with the one or more images of the patient image set; • determining, on the basis of the atlas data and the patient data, the set of atlas images which respectively represent at least a part of the general anatomical structure by using (S141b) the spatial information on the general anatomical structure and particular representation data sets which are determined by applying the determination rule in accordance with the one or more associated parameter sets and particular atlas elements acquired (S141a) and referred to as corresponding elements, which are to be matched to corresponding anatomical elements represented in the patient image; • determining the matching transformation (APT; APT1, APT2) which matches the atlas image set and the patient image set, by matching images associated with the same parameter set to each other, wherein the atlas data also comprise spatial flexibility information which describes a flexibility of the position of atlas elements within the general anatomical structure, and