CT scan stands for Computed Tomography Scan. In medical science it is the process of creating image. Tomography is the process of generating a two-dimensional image of a slice or section through a 3-dimensional object. CT scanner is a large machine and uses X-rays. Where X-ray forms a two dimensional image of a three dimensional organ inside the body, there the image formed by CT scan machine is three dimensional.
The CT scan machine uses digital geometry processing to generate a three dimensional of the inside of an object. The three dimensional image is made after many 2- dimensional X-ray images are taken around a single axis of rotation. This job is done using a computer. A CT scanner emits a series of narrow beams through the human body as it moves through an arc. While an X-ray machine sends just one X-ray beam through the body of the patient. As a result, the final picture formed by CT scan is far more distinct and detailed than an X-ray one. The X-ray detector used in a CT scanner can detect hundreds of different levels of density in patient’s body. This data collected by the detector is transmitted to a computer. Computer builds up a three dimensional picture of the part of the body and displays it on the screen.
Three dimensional images of soft tissue, blood carrying veins or arteries, lungs, brain, etc. is obtained by CT scan. CT scan is used for detection of cancer in lever, lungs and pancreas. The image obtained by CT scan helps a physician to detect tumor, to determine the size and position of the tumor and how much the tumor infected the adjacent tumor. By the CT scan of head, any type of bleeding inside the brain, swelling of artery and existence of tumor can be detected. Whether there is a problem in the blood circulation is also known by the CT scan. Generally CT scan test is not done in case of pregnant women. If dye is used in CT scan test there is a possibility of allergic reaction.