What is a Contrast Agent and How is it Used in CT Scans?

The CT scan procedure usually requires the use of what is known as a contrast agent. The contrast agent can either be administered orally or through an IV tube, though it generally depends on which area is being examined by the CT scan. The purpose of the contrast agent is to help highlight parts of the images the CT scan produces, allowing for a more defined outline of each structure. While these agents have been in question about their safety, they allow doctors to diagnose early cancers and conditions more easily.

Uses of a CT Scan

The primary use of a CT scan is to scan and image the area from the chest to the abdomen. Its unique ability to image organs, bone, and blood vessels makes it instrumental for finding cancers early. It has been known to have the ability to discover lung cancer in an early, treatable form, and has been used many times for liver and pancreatic cancer. These two cancers are among the most difficult to detect early. A CT scan can provide detailed information about:

The head, including the brain, eyes, ear, and sinuses

The chest, including the heart, aorta, and lungs

The neck, shoulders, and spine

Reproductive systems, stomach, and bladder

Bone structure

The pelvis is fairly limited in CT scans imaging. For looking for abnormalities in the pelvic region, ultrasounds, or MRI scans are generally used.

How Does a CT Scan Work?

CT scanners are rotating device that take complicated x-rays int he form of cross-sectional images of the body. The machine is round or square shaped with an opening in the middle where the patient lies on a table. The table can move up and down the ring as the machine takes images with the large rotating device moving around the patient.

The process of the CT Scan

New technology has made the process of undergoing a CT scan much quicker and easier. Instead of performing one revolution at a time at a slow pace, a CT scan now continuously rotates up and down a patient and can be performed and completed in seconds. This is called a spiral CT scan. Multi-slice CT scanners now take up to four different images or "slices" in one total revolution. This allows for eight times the amount of data to be collected in less time.

Advantages and Disadvantages of a CT Scan

The CT scan has changed the way doctors diagnose cancer and other conditions. While there are some risk of danger as mentioned below, many doctors and researchers agree that the benefits of a CT scan greatly outweigh these disadvantages.

Advantages:

More focused approach than a traditional x-ray

Early detection of cancer (especially lung cancer)

CT scans leave room for much technological improvement

Disadvantages:

Radiation exposure is a concern, especially for women and children

The contrast agent has questionable safety

Noted Dangers of CT Scans:

A great deal of research has been done to determine the link between CT scan radiation and cancer. This research suggests that children that are given CT scans have a greater chance of developing cancer later in life. About 500 children out of 600,000 have been proven to be affected by the radiation involved in CT scans. Some people may also develop cancer in as little as two years after being exposed to the radiation in a CT scan.

Although this research has raised growing concerns, doctors, and researchers agree that the benefits from a CT scan greatly outweigh the slight risks involved. CT scans have helped thousands of people diagnose their cancer in its earliest and treatable stages. Also, new technology has limited the amount of radiation that is exposed on a patient.