Essay on Computerized Axial Tomography (CAT) is published for informational purposes only. The free papers are not written by our writers, they are contributed by users, so we are not responsible for the content of this free sample paper. If you want to buy a quality Essay on Essay on Computerized Axial Tomography (CAT) at affordable prices please use our essay writing services offered by EssayEmpire.

In 1967, Godfrey Newbold Hounsfield conceived the idea for a machine that could create detailed images of the internal structures of the body by taking X rays at various angles. He realized that if X rays were taken perpendicular to each other, a cross section of the examined object could be obtained. If the X-ray beam was collimated and moved around the axis of the body with the X-ray detector opposite, the maximum information about that slice of the body could be collected. Further, by moving the body through the beam as the slices were recorded, the maximum data about the interior of the body could be obtained. The cross-sectional X-ray images could then be assembled by a computer to present a three-dimensional view more detailed than an individual two-dimensional X ray.

Hounsfield invented a density scale, now called the Hounsfield scale, to change signals from the detector into numbers that could be manipulated by the computer. The Hounsfield scale uses Hounsfield units (HU) and ranges from -1000 HU (air) to 0 HU (water) to +1000 HU (bone). The computer takes the numbers from the X-ray detector and solves a series of equations to reassemble the slices and to obtain an image of the interior of the body. The first computers were very slow, and producing a scan of the head took hours. Now, with much faster computers, a high-resolution scan of the entire human body can be obtained within minutes.

Hounsfield's computed tomography (CT), or computerized axial tomography (CAT), scanner was first used on a living patient in the fall of 1971. CAT scanners have since changed the world of medical imaging and now make it possible to measure accurately the position, size, and density of an object within the human body. It is an indispensable tool for localizing a cancer prior to surgery or radiation therapy. Although the procedure is expensive and has a higher radiation dose than an individual X ray, it has helped save thousands of lives.

The invention of the CAT scanner by Hounsfield was the first major advance in medical imaging since Wilhelm Conrad Röntgen's discovery of X rays. An X ray is a two-dimensional picture that is most useful in observing dense objects such as bones. However, it is not sensitive enough to resolve tissues with different densities within the body and cannot distinguish between two organs that lay one above the other. Hounsfield's CAT scanner produced clearer images of soft tissues. After EMI built the first commercial CAT scanner and sold a few of the models to hospitals in England, the utility of the device became obvious.

The first CAT scanners could only scan small volumes and were designed to look for lesions or nodules in the brain that could not be seen by conventional X rays. The CAT scanners were bulky and expensive, but as transistors and integrated circuits became available, the scanners could be used for more than brain scans. Improvements were made to the X-ray detectors to improve the resolution. With more collimated X-ray sources and faster computers, scans can now be made in minutes.

By the year 2000, there were about seven thousand CAT scanners in use in the United States. The scanner is the instrument of choice for cancer diagnostics. Some researchers have claimed that there has been an overuse of CAT scans in the United States, unnecessarily exposing patients to radiation, which may increase their cancer risk. . .

Free essays are not written to satisfy your specific instructions. You can order a term paper, research paper or custom TOPIC at our site which offers professional essay writing services. Get your high quality custom paper at relatively cheap prices. EssayEmpire is the best solution for those who seek help in essay writing related to TOPIC and other relevant topics.