Understanding Cancer Tests and Screenings
Screening tests like mammography, magnetic resonance imaging (MRI), and computed tomography (CT) scans help health care professionals screen for cancer.
- Screen for cancer: Screening tests are completed for people without any symptoms as a way to detect cancer early. Examples of this include annual Pap smears to screen for cervical cancer, mammograms to screen for breast cancer and CT lung screenings for former smokers.
Imaging tests are used to locate cancer within the body and are helpful in determining the stage of the cancer and the necessary targeted treatment area. Common imaging tests include:
- Computed tomography (CT): A combination of x-rays and computer technology that produces horizontal, or axial, images of the body.
- Positron emission tomography (PET): A radioactively-linked substance is injected into the body. Then, images are taken to see areas of substance uptake.
- Magnetic resonance imaging (MRI): Radio waves in a strong magnetic field are used to create a detailed image of inside the body.
- Radionuclide imaging: Radioactively-linked substances are either ingested or injected into the body. Then, images are taken to see areas of substance update. These scans are particularly useful in bone, liver and thyroid scans.
- Ultrasound: Sound waves above the skin’s surface are used to create an image of what is inside the body.
- X-ray: A radiograph is used to create a two-dimensional image of the body.