Radionuclides are naturally occurring or artificially produced atoms with unstable nuclei. Therefore radionuclides undergo a radioactive decay, and emit gamma ray(s) and/or subatomic particles.
Radionuclides are used as agents in nuclear medicine and to destroy tumors in cancer therapy.

See Isotope and Radioactive Decay.

Thermography is a method for example used in breast imaging. Thermography measures the body heat at the skin surface to identify hot spots caused by inflammation or cancer.

Virtual colonoscopy provides a less invasive option to conventional polyp detection in the large intestine (colon and rectum). A virtual colonoscopy is a synthesis of a computed tomography (CT) scan, digital processing and virtual reality computer software.
A virtual colonoscopy is less invasive and more comfortable for patients than either conventional colonoscopy or a barium enema. No sedation is required and the examination takes less than 30 minutes.
A CT colonography offers a new option for a total colon evaluation and cancer detection and has the potential to be used for screening. A problem is the amount of information captured in a CT exam. Reviewing these images can be time-consuming and challenging.

See also Computed Tomography Enterography.