CT Scan

Excerpt

A computed tomography (CT) scan, commonly referred to as a CT, is a radiological imaging study. The machine was developed by physicist Allan MacLeod Cormack and electrical engineer Godfrey Hounsfield. Their development awarded them the Nobel Prize in Physiology or Medicine in 1979. The first scanners were installed in 1974. Since then, technological advances and math have allowed single images to be computed into two-dimensional informative images.

The CT scan is essentially an X-ray study, where a series of rays are rotated around a specified body part, and computer-generated cross-sectional images are produced. The advantage of these tomographic images compared to conventional x-rays is that they contain detailed information about a specified area in cross-section, eliminating the superimposition of images, which provides a tremendous advantage over plain films. CT scans provide excellent clinicopathological correlation for a suspected illness.

CT scan augments the physician's ability to diagnose a patient's illness accurately. Low-dose CT scans are proving useful in preventative medicine and cancer screening. The study was initially called a CAT scan representing computer axial tomography, where the table moved after each axial image was obtained. In a spiral or helical scan, the table moves continuously as the x-ray source and detectors rotate. This reduces the duration of the study significantly to provide quick results in emergent situations. It rapidly substituted cerebral angiography for detecting head trauma injuries and brain masses in a fast and extremely reliable way. A radiologic technician acquires CT scans, which are interpreted and reported by a trained radiologist.