8: The creation, manipulation, and display of 3-D images for RTP

Three-dimensional surface shaded models have been constructed from contiguous CT scans with slice widths of 5 mm. Interpolation between slices is required to produce satisfactory images and this technique is outlined. The technique removes the necessity to acquire large numbers of narrow (1-2 mm) CT scans. The images generated are acceptable for RTP where tolerances of 2-5 mm are typical. RTP does, however, require the visualisation of multiple structures (skin surface, tumour volume, critical structures, etc.) so a simple surface shading technique has been developed which is used in conjunction with a range of display methods to generate images of multiple structures. 1 reference; 6 figs