The following text is largely excerpted from the article: Three-dimensional Volume Rendering of Spiral CT Data: Theory and Method. Calhoun PS, Kuszyk BS, David G. Heath DG, et al. (Radiographics. 1999;19:745-764.)
A 3D Maximum Intensity Projection (MIP) image of a normal dog's thorax.
Over the years, 3D rendering techniques have been compared on the basis of a wide range of criteria. Initially, SSD and MIP clearly had advantages over 3D volume rendering in terms of rendering speed and hardware costs, which were often seen as prohibitive in a clinical setting. Several generations of computers have come and gone since the introduction of volume rendering, and now it is legitimate to focus on the accuracy of each of the rendering techniques in clinical applications. This is clearly the research agenda seen in the literature: Of the more than 500 articles that present the merits of SSD, MIP, or 3D volume rendering, more than 50 contain direct comparisons of these techniques. Artifacts and limitations remain for each of the techniques. In addition, interoperator variability of user-determined rendering parameters calls for more careful review and suggestions for 3D protocols. Studies have demonstrated that significant levels of accuracy are achievable with volume rendering and that 3D volume rendering has some potential advantages over other rendering techniques.
A 3D Volume Rendered image of a normal dog's thorax.
There are many applications for 3D volume rendering in medicine. Perhaps the most important long-term application is for routine reading of volume data. Although such an application may not get the attention that other, more novel emerging research areas generate, it is likely to be the development that affects the radiologist most profoundly in daily practice. What this means to our daily practice is not yet clear. However, the attention this focuses on the analytic abilities the radiologist brings to other areas such as diagnosis and treatment planning underlines his or her vital role in the medical community. Indeed, surgeons will someday have their own interactive volume displays, which suggests how the role of radiology will rest more firmly on shared resources and expanded communication. The role of 3D volume rendering in radiology continues to grow rapidly. Areas that have received a great deal of attention to date include evaluation of musculoskeletal trauma, vascular imaging, and numerous applications in oncology.
A 3D Surface Shaded Surface display image of a normal dog's thorax.