Computerized tomography (CT) is an x-Ray system used to produce images of various parts of the body, such as the head, heart and abdomen. Doctors use CT images to help diagnose and treat diseases. The technique is also called computer tomography or computerized axial tomography (CAT).
To produce a CT image, the patient lies on a table that passes through a circular scanning machine called a gantry. The table is positioned so that the organ to be scanned lies in the centre of the gantry. A tube on the gantry beams X Rays through the patient's body and into special detectors that analyse the image produced. The gantry rotates around the patient to obtain many images from different angles. A computer then processes the information from the detectors to produce a cross sectional image on a video screen. By moving the table in the gantry, doctors can obtain many scans of the same organ or even the entire body.
Sometimes an iodine solution, called a contrast agent, is injected into the body to make certain organs show up clearly in the CT scan. For scans of the abdomen and pelvis, the patient drinks a barium mixture (which is opaque to X Rays) to outline the inner surfaces of the stomach and bowel.
Doctors use CT scans to diagnose many conditions, such as tumours, infections, blood clots and broken bones. CT also assists in treating some diseases that might otherwise require surgery. For example, doctors can use a CT scan to guide catheters ( small tubes) to an abscess in the body and drain pus from infected area.
http://www.cancer.gov/cancertopics/diagnosis-staging/ct-scans-fact-sheet
http://www.nlm.nih.gov/medlineplus/ency/article/003330.htm
http://www.radiologyinfo.org/en/sitemap/modal-alias.cfm?modal=ct
http://www.medicinenet.com/script/main/art.asp?articlekey=10349
http://www.nytimes.com/health/guides/test/ct-scan/overview.html
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