First results of a multiple fan-beam approach to analyze bone structure in vivo

Multiple fan-beam CT combines the advantages of fan-beam and cone-beam CT, i.e. the precise reconstructions of the former and the fast (2D) data acquisition of the latter. Two systems had been realized: a 3D-Micro-CT for the examination of bone samples and small laboratory animals with a spatial resolution of 20 mu m, and a 3D-pQCT system for the examination of patients with a spatial resolution of 120 mu m. Both system are able to perform complete 3D examinations within two minutes. In this work we report on pilot studies performed with the 3D-pQCT on the distal radius of patients. First results of longitudinal examinations reveal surprising temporal changes of cortical as well as cancellous bone. Hence it is now possible to base the theoretical models on real data and to consider the consequences of structural changes on the mechanical competence of bone in individual patients.