Abstrakt: |
A standard computed tomographic (CT) examination provides the observer with a series of cross-sectional images through an area of clinical interest. These images are based on digital information which can then be reformatted in the coronal, sagittal or oblique plane. Both cross-sectional and reformatted CT images are two-dimensional, however, requiring a process of mental integration of multiple sections to be performed by the observer in order to derive three-dimensional information.In areas of complex anatomy it can be difficult even for a skilled radiologist experienced in CT to perceive the third dimension from standard CT sections. Moreover, when reconstructive surgery is planned in such areas, a surgeon may be unable to extract easily the precise anatomical and volumetric detail he requires from conventional CT sections alone.To overcome this problem, computer software has been developed (Marsh & Vannier, 1983a; Udupa, 1983) to enable three-dimensional (3D) images to be produced from a series of standard CT slices. Initial reports suggested that clinically useful images could be created using such programs, particularly in cases of skeletal trauma and craniofacial deformities (Hemmy et al, 1983; Marsh & Vannier, 1983b; Totty & Vannier, 1984). Vannier et al (1984) have reported several illustrative cases representative of their experience in craniofacial deformities in over 300 patients, showing the value of their own 3D computer methods. More recently Burk et al (1985) have described their experience of 3D images in 20 patients with acetubular fractures. |