What Anatomical Structures Are Well Seen With CT

CT can display differences between soft tissues that differ in physical density by as little as 1%. Most anatomic structures are visualized on CT scans, including bone, air, fluid, fat, and soft tissues.

All of these structures are better demonstrated on CT than on radiography. This results from a combination of factors, including the very sensitive CT detectors that differentiate smaller differences in densities, the excellent spatial resolution CT affords, and the fact that the images are single "slices" of the body (while radiographs represent a superimposition of a number of structures).

ABDOMEN

Compare these images of the abdomen. The image on the top is a radiograph and the bottom is a CT image of the mid-abdomen. The radiograph shows the bones well, and air within the bowel, however airless bowel, the individual organs, blood vessels, lymph nodes and other soft tissue structures cannot be seen. In contrast, the CT shows the individual organs, the bowel that contains air as well as the bowel which is airless (fluid filled), blood vessels and all of the fat intervening between and around these structures.