CT scanners became widely available in the mid-1970s. It allows doctors to look at specific areas of interest, such as the brain, spine, or abdomen. It revolutionized medicine in that doctors no longer had to perform invasive surgeries to diagnose certain conditions or diseases. It is frequently used with cancer patients to determine progression or remission of the cancer.
In preparation for a CT scan, the patient is sometimes injected with a contrast, or dye, so that normal tissues can be separated from abnormal tissues. Scans can take anywhere from a few minutes to an hour, depending on the type of scan being done.