Diagnostic Imaging

What is diagnostic imaging?

Diagnostic imaging allows your health care team to look inside your body for clues about a medical condition. A variety of machines and techniques can create pictures of the structures and activities inside your body.

The type of imaging your clinician uses depends on your symptoms and the part of your body being examined.

Common types of diagnostic imaging include:


An X-ray is an image — most often your bones — created by placing a part of the patient in front of an X-ray detector and then lighting the body part with a short pulse of radiation. An X-ray detector creates a black and white image.

Computed Tomography

Computed Tomography (CT) scans use special x-ray equipment to make cross-sectional pictures of your body. During a CT scan, you lie still on a table. The table slowly passes through the center of a large X-ray machine. The test is painless. During some tests you receive a contrast dye, which makes parts of your body show up better in the image.

Nuclear Imaging

Nuclear imaging uses radioactive substances to show structures and functions inside your body. They use a special camera that detects radioactivity. Before a nuclear scan, you’ll receive an injection containing a small amount of radioactive material, although you may swallow or inhale it. Typically, a patient lies still for 20 to 45 minutes for a nuclear scan.

Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) uses a large magnet and radio waves to show organs and structures inside your body. Health care professionals use MRI scans to diagnose a variety of conditions. They’re very useful for examining the brain and spinal cord. During the scan, you lie on a table that slides inside a tunnel-shaped machine. The scan may take some time, and you must stay as still as possible. However, the scan is painless. Be prepared for the loud noise of the MRI machine; the technician can give you earplugs if needed.


Ultrasound uses high-frequency sound waves to show organs and structures inside your body. Health care professionals use it to view the heart, blood vessels, kidneys liver, and other organs. Unlike X-rays, ultrasound scans do not expose you to radiation. During an ultrasound, you lie on a table. A technician or doctor moves a device called a transducer over part of your body. The transducer sends out sound waves, which bounce off the tissues inside your body, and the ultrasound machine creates images from the sound waves.

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