The near future will hopefully see the rendering process incorporated into the scan, meaning that volume rendering displays will instantaneously emerge from a CT scanner. Once the volume rendering display has been compiled, the opacity can be suppressed in order to examine different tissues. On the other hand, if they want to examine everything, then they can see a 3D image of the abdominal wall. If they wanted to examine something in between these two extremes, such as to suppress the subcutaneous fat and look at solid viscera, they have that option. Figure 9 Volume rendering provides great flexibility in terms of varying opacity curves.
Clinicians can also change their views of where they obtain their images.
For example, figure 10 is a CT angiogram with a display that has the light shining externally. This view frees clinicians from the subcutaneous tissues in the skull. The light source can also be shined intravascularly, showing the neck of the aneurysms, thereby performing virtual angioscopy. The ability to move the light source around, obtaining different and unique views inside the vessel or external to the vessel, or inside the cranium or external to the cranium, makes perspective volume rendering a very powerful tool. Figure 12 Figure 12 shows the abdominal aorta.