The present invention relates to a method, a device and a computer program product for evaluating medical image data sets, which consists of two-dimensional section images, in particular MR images, wherein a plurality of two-dimensional cross-sections (K1, K2, . . . Kn) and at least one two-dimensional longitudinal section (L1) of a target region (1) of a human or animal body are recorded and stored, a longitudinal axis (5) and points of intersection (6) are determined at the points at which the longitudinal axis (5) extends through the plurality of two-dimensional cross-sections (K1, K2 . . . Kn) and a reduced data volume (7) is generated, which is composed of partial cross-sections (k1, k2, . . . kn), which are generated by means of the points of intersection (6) and scaling factors (a1, a2, b1, b2) from the plurality of two-dimensional cross-sections (K1, K2, . . . Kn).