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What is the difference between CT scans and X-rays?

Dr. John C. Lipman, MD
Vascular & Interventional Radiologist

X-rays and CT scans work by the same process in that they both use radiation to create an image. An x-ray is a static image in a single projection, which in the past was developed on film, but nowadays is created with a digital image. CT scans are a dynamic study with an x-ray tube rotating 360 degrees in a gantry about the patient which can be produce single "slices" of a particular area of the body imaged or create a 3D image of that same area. The resolution of CT is much greater than plain x-rays but also has a higher x-ray exposure to the patient.

Traditional x-ray machines can only take one picture at a time. Computerized tomography (CT) scans, also called computed tomography or CAT scans, rotate around the body and take hundreds of pictures from lots of different angles. These individual pictures are sent to a computer that puts them together to make 2D and 3D images of the inside of the body.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.