Fig. 2.

Multi-planar reformations: transversal (left), coronal (center) and sagittal (right). Top CT dataset with segmented periosteal/articular surface (red) and analysis VOIs (blue); for the CT reconstruction, the high-resolution kernel U70u was applied. Bottom HR-pQCT dataset of the same knee (repositioned) with periosteal/articular surface registered (red) and analysis VOIs (blue) transferred from the CT dataset. The names of the analyses VOIs are only indicated in the femur (top, center) but apply to the tibia as well. For the purpose of illustration, the HR-pQCT was downsampled to the same size as the CT dataset. Each CT image has 512 × 512 pixels with a size of 254 × 254 μm² each, while the HR-pQCT image consists of 1352 × 1484 pixels with a size of 82 × 82 μm². Navigation lines were added to every image in order to indicate the relative positions of the reformed slices. cort cortical, mid-epi mid-epiphyseal, sub epi subchondral epiphyseal