Imaging tests create pictures of areas inside your body that help the doctor see whether a tumor is present. These pictures can be made in several ways:
CT Scan
A CT scan uses an x-ray machine linked to a computer to take a series of pictures of your organs from different angles. These pictures are used to create detailed 3-D images of the inside of your body.
Sometimes, you may receive a dye or other contrast material before you have the scan. You might swallow the dye, or it may be given by a needle into a vein. Contrast material helps make the pictures easier to read by highlighting certain areas in the body.
During the CT scan, you will lie still on a table that slides into a donut-shaped scanner. The CT machine moves around you, taking pictures. Learn more about CT scans and how they are used to diagnose cancer.
MRI
An MRI uses a powerful magnet and radio waves to take pictures of your body in slices. These slices are used to create detailed images of the inside of your body, which can show the difference between healthy and unhealthy tissue.
When you have an MRI, you lie still on a table that is pushed into a long, round chamber. The MRI machine makes loud thumping noises and rhythmic beats.
Sometimes, you might have a special dye injected into your vein before or during your MRI exam. This dye, called a contrast agent, can make tumors show up brighter in the pictures.
Nuclear scan
A nuclear scan uses radioactive material to take pictures of the inside of the body. This type of scan may also be called radionuclide scan.
Before this scan, you receive an injection of a small amount of radioactive material, which is sometimes called a tracer. It flows through your bloodstream and collects in certain bones or organs.
During the scan, you lie still on a table while a machine called a scanner detects and measures the radioactivity in your body, creating pictures of bones or organs on a computer screen or on film.
After the scan, the radioactive material in your body will lose its radioactivity over time. It may also leave your body through your urine or stool.
Bone Scan
Bone scans are a type of nuclear scan that check for abnormal areas or damage in the bones. They may be used to diagnose bone cancer or cancer that has spread to the bones (also called metastatic bone tumors).
Before this test, a very small amount of radioactive material is injected into your vein. As it travels through the blood, the material collects in abnormal areas in the bone. Areas where the material collects show up on pictures taken by a special scanner. These areas are called “hot spots.”
PET scan
A PET scan is a type of nuclear scan that makes detailed 3-D pictures of areas inside your body where glucose is taken up. Because cancer cells often take up more glucose than healthy cells, the pictures can be used to find cancer in the body.
Before the scan, you receive an injection of a tracer called radioactive glucose. During the scan, you will lie still on a table that moves back and forth through a scanner.
Ultrasound
An ultrasound exam uses high-energy sound waves that people cannot hear. The sound waves echo off tissues inside your body. A computer uses these echoes to create pictures of areas inside your body. This picture is called a sonogram.
During an ultrasound exam, you will lie on a table while a tech slowly moves a device called a transducer on the skin over the part of the body that is being examined. The transducer is covered with a warm gel that makes it easier to glide over the skin.
X-rays
X-rays use low doses of radiation to create pictures inside your body. An x-ray tech will put you in position and direct the x-ray beam to the correct part of your body. While the images are taken, you will need to stay very still and may need to hold your breath for a second or two.