What are CT scans, nuclear medicine studies, and fluoroscopy?
In a normal X-ray, a person gets a blast of radiation that creates an image on a two-dimensional square of film. During a computed tomography or CT scan (sometimes called a CAT scan), a rotating device shoots X-rays through the body to produce several cross-sectional images. A computer assembles these images into a 3-D image of the inside of the body. Scans that take more images — and expose the patient to more radiation — yield sharper images. During nuclear medicine studies, such as positron emission tomography or PET scans, the patient is given a small amount of a radioactive substance. A detector then views an image of this “radiotracer” as it moves through the body. During fluoroscopy, a device passes continuous X-rays through the body to yield a real-time moving image.
