Computed Tomography (CT Scan)

A CT scan is an X-ray that produces precise cross-sectional images of the body. Instead of taking one picture, like a conventional X-ray, a CT scanner takes many pictures as it rotates around the part of the body being studied. A computer then combines these pictures into a cross-sectional view.

In some cases, the patient may be asked to drink a substance called oral contrast material. This helps outline the intestines. In other cases, the patient may receive an intravenous line through which the contrast dye is injected.  IV contrast material can be used to distinguish normal and abnormal tissues in the body. 

CT scans can also be used to guide a biopsy needle precisely into a tumor or an area where it is suspected that cancer may have spread. For this procedure, called a CT-guided needle biopsy, the patient remains on the CT scanning table while a radiologist advances a biopsy needle toward the location of the mass. CT scans are repeated until the providers are sure that the needle has penetrated the mass. A sample of tissue is removed and examined under a microscope.