CT scans (formerly known as a "CAT scan" for "Computer Axial Tomography") are special x-ray tests that produce cross-sectional images of the body using x-rays and a computer. These images, called "tomograms", allow the radiologist (a medical doctor who specializes in images of the body) to look at the inside of the body just as you would look at the inside of a loaf of bread by slicing it.
An x-ray test uses a broad beam of radiation aimed from only one angle. A CT scan uses a pencil-thin beam to create a series of pictures taken from different angles. Each angle produces a slightly different view of the organs and soft tissues. The information from each angle is fed into a computer, which calculates how the images overlap. The computer then creates a single black and white picture that shows a slice of a specific area of the body.
CT scans demonstrate the density (thickness) of different types of body tissues. This scan is useful for showing several types of tissue very clearly. The types of tissue investigated are the lungs, bones, soft tissues and blood vessels. The CT scan is one of the best tools for studying your chest and abdomen. It can be used to find out whether you have excess fat in your liver (fatty liver). Sometimes CT scans are also used by doctors to help guide entrance sites for biopsies.
The picture can be made clearer by the use of special contrast materials which can be swallowed as a liquid, put into a vein or put into the intestines through the rectum as an enema. Because body tissues absorb these materials differently, the CT image will show greater contrast between types of tissues. This allows abnormalities like cirrhosis or tumors to be seen more clearly.
By placing CT image slices on top of each other, doctors can create a 3-dimensional (3-D) scan, which provides even more information about certain cancers. The 3-D image can be rotated on a computer screen to look at different views.
Abdominal and pelvic CT scans look at the abdominal and pelvic organs (such as the liver, spleen, kidneys, pancreas and adrenal glands) and the gastrointestinal tract. These studies are often ordered to check for a cause of pain and sometimes to follow up on an abnormality seen on another test such as an ultrasound.
_NOTE: the CT technician that administers the test is NOT qualified to
analyze the captured images! You MUST wait for your doctor to analyze
the results!