Computer Tomography (CT) Scanning

Computers have found their way into almost every aspect of our everyday lives, so much so that the second half of the 20th century has been called the computer age. The computer’s application to medical imaging has been exemplified by the development of Computerized Tomography (CT). CT scanning is so important that it’s developers were awarded the Nobel prize for medicine in 1979.

CT images show organs of interest at selected levels of the body. They are the visual equivalent of bloodless slices of anatomy, with each scan being a single slice. CT examinations produce detailed organ studies by stacking individual image slices.

The scans are produced by having the source of the x-ray beam encircle or rotate around the patient. X-rays passing through the body are detected by an array of sensors. Information from the sensors is computer processed and then displayed as an image on a video screen. Film copies may be made for later study.

Computerized tomography can image the internal portion of organs and separate overlapping structures precisely. For example, the liver has bile ducts and blood vessels not seen on regular x-rays, but which are revealed by the CT scanner. Contrast agents may be used, but these are usually injected quickly and directly into an arm vein.

Computerized tomography has become the diagnostic tool of choice in a wide variety of situations. It has replaced a number of more painful radiological examinations.

Exploratory surgery, with greater risk or discomfort to the patient and higher cost, may also be avoided. The cost effectiveness of CT has proven a major advantage in today’s cost-conscious medical environment.