Non invasive medical imaging techniques gets more and more involved in wood quality. This work is a contribution to an EEC project and points out that post processing of CT scans on Norway Spruce logs provides a powerful tool for inner log structure investigation. The CT scanning on fresh Norway spruce was done by Lulea University of Technology (Sweden). Exams were processed with the "C2OOO" software developed by CIRAD. Axial log sections were treated to extract bark, sapwood and heartwood tissues. Specific tools were developed to generate parametric description of these areas. Specific studies were also carried out, mainly using new non linear filtering algorithms for ramification pattern recognition, pith location and ring counting. The 3D reconstruction and visualization were performed on original and processed images. Realistic external shapes as well as internal structures shapes were obtained by merging several viewing techniques. Results gained through this process lead to an accurate geometrical description of bark, sapwood, heartwood, branches boundaries and pedagogic 3D visualizations. Moreover, when including pith location, a wide range of uses is possible from resource evaluation to sawing simulation. It also contributes to define validation tools for external log shape description approaches