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Glossary of terms

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computed tomography (CT)
Sometimes referred to as CAT scan (computerized axial tomography).

Imaging anatomical information from a cross-sectional plane of the body, each image generated by a computer synthesis of x-ray transmission data obtained in many different directions in a given plane.

Developed in 1967 by British electronics engineer Godfrey Hounsfield, CT has revolutionized diagnostic medicine. Hounsfield linked x-ray sensors to a computer and worked out a mathematical technique called algebraic reconstruction for assembling images from transmission data. In 1973, the Mayo Clinic began operating the first machine in the U.S. Early machines yielded digital images with at least 100 times the clarity of normal x-rays. Subsequently, the speed and accuracy of machines has improved many times over. CT scans reveal both bone and soft tissues, including organs, muscles, and tumors. Image tones can be adjusted to highlight tissues of similar density, and, through graphics software, the data from multiple cross-sections can be assembled into 3-D images. CT aids diagnosis and surgery or other treatment, including radiation therapy, in which effective dosage is highly dependent on the precise density, size, and location of a tumor.

computed tomography (CT) angiography
A method of examining blood vessels utilizing x-rays and injection of iodine-rich contrast material (dye).

For details see the CT Angiography page.

CT colonography (CTC)
Also called virtual colonoscopy.
A procedure in which computed tomography (CT) scanning is used to produce detailed pictures of the inside of the colon and rectum.

CT enteroclysis
CT enteroclysis is a special type of computed tomography (CT) imaging that produces detailed images of the small bowel by infusing contrast material through a tube positioned in the upper small bowel.

CT enterography
CT enterography is a special type of computed tomography (CT) imaging performed with contrast material to produce images of the small intestine. See the CT Enterography page for more information.