A Computed tomography scan, or CT Scan, also sometimes known as a CAT scan, is a noninvasive medical test that helps doctors to both diagnose and discern treatment for medical conditions. CT scans use X-rays to make cross-sectional images of the body that are then pieced together to make a 3 dimensional image of the area of the body being examined.
CT scans have been around since the early 1970’s. The inventors, while working together, managed to create a device that would go on to save thousands of people. For their efforts, they were awarded the Nobel Prize.
Hailed as an innovative medical breakthrough, they were perfected over the many years that they have been used, and today are a major part of the scientific and medical world.
How it works
A CT scan uses special X-ray equipment and very sophisticated computers to make multiple 3 dimensional pictures of the inside of the body. These pictures are made up of cross-sectional images of the area being examined. When combined into a singular image, the result is a 3-D model that doctors can then study and use for the basis of their diagnosis.
While being scanned, the patient lies on a table, which slowly passes through the middle of a large X-ray machine. This part of the machine resembles a box with a short tunnel, and when the area of the body that is being examined passes into the tunnel, the machine slowly spins the X-ray machine around the patient. The X-ray tube and X-ray detectors, located on opposite ends of the tunnel, (which is called a gantry), then begin to take and receive many images of the body. 
This entire process is controlled by a technologist who operates the scanner and monitors the examination from another room, although they are always nearby so they may assist the patient in the event that something goes wrong. 
CT scans can be used to help diagnose many diseases, give doctors a more in-depth view of injuries to various parts of the body, and also help doctors make better decisions as to what the best method of treatment would be. 
Some of the most common ailments that CT scans are used to look for are:
CT scans have become one of the most efficient tools for studying the chest, abdomen, and pelvis because they provide very clear and detailed views of all types of tissue. Since a CT scan provides a 3 dimensional view of the body, it has become invaluable in finding cancer, because it allows doctors to see the exact size, shape, and location of cancerous tumors. In addition to these major diseases, it can also be incomparable in the treatment of spinal injuries and problems in the hands, feet, and other skeletal structures. This is due to the fact that it can clearly show even the smallest bones and their surrounding tissue, such as blood vessels and muscle. 
Computed tomography (CT) was first discovered by Dr. Alan Cormack and a British engineer Sir Godfrey Hounsfield. Today, it is often used to help in the diagnosing of major medical diseases and assisting in the healing of minor injuries. In 1979, Hounsfield and Cormack were awarded the Nobel Prize for their innovative work. 
The first CT scanning was performed on October 1st, 1971, by Sir Godfrey. The patient who was scanned was registered in Atkinson Morley Hospital in Wimbledon, London. The first CT scan prototype was certainly not very awe-inspiring. The first official clinical test took a full 9 days to complete the scan, the reconstruction took 2.5 hours, printing the image took another 2 hours, and the resolution of the pictures were only 80 x 80. 
After several tests, CT scans began to be installed in 1974. Currently, there are over 6,000 CT scanners in the U.S.A. alone. Because technology has come so far in the past forty years, CT scans are much faster, which allows for greater comfort in patients who need scanning. Also, the advancements allow for higher resolution images, and this allows for more precise diagnosis of diseases. 
CT scanning is very low-risk. The process involves exposure to radiation, but because the dosage is so minimal, it is a very safe procedure. The only real risk comes when a need for a contrast (or dye) injection is needed. 
This injection helps doctors to distinguish between normal and abnormal tissues, and also helps to distinguish blood vessels from lymph nodes and other structures. This injection can cause some people to have a bad reaction. However, the chance in having a fatal reaction to the injection is about 1 in 100,000. 
People with increased risk sometimes require special treatment, and they should be tested in a hospital setting. People with prior reactions to contrast injections, severe allergic reactions to other medications, asthma, emphysema, or severe heart disease are at increased risk, and should be sent to a hospital for an x-ray to complete the exam. Even in people who are at minimal risk, there is always a risk of leaking when an injection is done into a vein. In the case of the contrast injection, if too much of the injection leaks under the skin, the skin itself can begin to break down.