Popularly called a “CAT scan,” the CT scan is a primary tool for diagnostic medicine. It employs a unique design of x-ray technology coupled with constantly advancing computer technology. With computerized tomography (CT), views are taken in a single plane, and the data is computer processed and then displayed as a cross-section image.
Because it provides detailed, cross-sectional views of all types of tissue, CT is one of the best tools for studying the chest and abdomen. It is often the preferred method for diagnosing many different cancers, including lung, liver, and pancreatic cancer, since the image allows a physician to confirm the presence of a tumor and measure its size, precise location, and the extent of the tumor’s involvement with other nearby tissue. CT examinations are often used to plan and properly administer radiation treatments for tumors, to guide biopsies and other minimally invasive procedures, and to plan surgery and determine surgical resectability.
A positron emission tomography (PET) scan is a diagnostic tool used to detect cancer and find out the cancer’s stage (a way of describing where the cancer is located, if or where it has spread, and whether it is affecting the functions of other organs in the body). Knowing the cancer’s stage helps you and your doctor decide what kind of treatment is best and helps predict prognosis. The scan can also be used to evaluate the effectiveness of cancer treatments, such as chemotherapy or radiation therapy. A PET scan is often used to complement information gathered from a CT scan, magnetic resonance imaging (MRI), or a physical examination.
In many cases, the doctor will recommend an integrated PET-CT scan. This combines the images from a PET scan and a CT scan that have been performed at the same time using the same machine. Together, these two scans create a more accurate picture of what is going on in the body than either test can offer alone.
A triphasic, or triple-phase, CT scan is an enhanced CT technique mostly used to evaluate liver pancreatic and kidney lesions. This technique acquires images at three different time points, or phases, following the administration of a contrast. In general, tumors in the vacuolated organs tend to show up better in the additional two phases of a triphasic CT scan.