HOW IT WORKS

CT scanning works like an x-ray examinations. The x-ray absorption varies in different types of body parts which is crucial to differentiate from one another on an x-ray film or CT electronic image.

In a conventional x-ray examination, small amount of radiation is bombarded and pass through the targeted area. The image is then recorded on a special electronic image recording tools. Bones will appear white on the film while the soft tissue such as the organs will produce gray image, and air appears black.

As the body moves through the arc, a CT scanner will emit a series of narrow beams. The final image produce by CT scan is far more detailed than X-ray image.  There is an x-ray detector inside the CT scanner which can see various levels of density. It can see tissue inside a solid organ. The data is transferred to a computer which will process it into a 3D cross-sectional picture of the targeted body parts and displays it on the screen. When the image slices are rearranged by computer software, the result is detailed multidimensional view of the targeted body part.

Sometimes, a contrast material is used to provide a clearer image of the targeted area. If a targeted area is abdomen, the patient needs to drink a barium meal. Barium will appear white on the scan as it travels through the digestive system. If the targeted is at lower body such as the rectum, then the patient may be given a barium enema. If the targeted are is blood vessels the patient will be injected with barium.

The accuracy and speed of CT scans can be improved with the application of spiral CT. The x-ray beam takes a spiral path during the scanning. The CT scanner then will gather continuous data with no gaps between the images.