Computed tomography (CT) applies X-ray imaging to produce a 3-D anatomical tomographic image. The use of contrast media enables soft tissue segmentation and some functional imaging.
Specifically, tomographic imaging is a method that derives 3-D data from a series of projection images. Tomography specifically refers to viewing 3-D data as 2-D slices. Hard tissue such as bone shows up clearly in CT images. However, soft tissues, like organs, have very similar intensity and cannot be distinguished from each other easily in standard CT images. In these cases, chemical compounds called contrast media that absorb X-rays are used to increase the contrast in soft tissues. When a contrast medium is injected, it accumulates in the organ it was designed to target. Thus, the CT scan will show that organ illuminated against the surrounding organs.
Advances in computer technology now allow CT images to be rendered in 3-D instead of a series of 2-D tomographic images. This has made spatial relationships between objects in the image much easier to understand and makes images easier to analyze.
CT can be used to study the skeleton, lungs, heart, liver, kidneys and GI tract.
Specific applications include:
Resolution: ~20 µm