A computerized tomography (CT) scan combines a series of X-rays taken from different angles to make detailed picture of a part of your body, for example, organs, blood vessels, bones and the spinal cord. To have the scan, you lie down on a table attached to the scanner, which sends X-rays through the body part being studied. Each scanner rotation takes an image of a thin slice of the body part, and then all of these images are combined and can be printed. The scan is used both for diagnosis and to plan medical, surgical or radiation treatment.
Magnetic resonance imaging (MRI) uses powerful magnets, radio waves, and a computer to take detailed images of a body part such as organs, tissues and skeletal system. Unlike a CT scan, or x-rays, an MRI does not use radiation. The scan can be used both for diagnosis of an illness or injury, and to monitor how well you are responding to treatment.
Ultrasound uses sound waves to create images of a body part. To form an image, an instrument called a transducer sends out high-frequency sound, and then records the echoes as the sound waves bounce back. This helps to determine the size, shape, and consistency of soft tissues and organs. The information is relayed to a computer screen in real time. The image created is used to diagnose conditions and to guide doctors through medical procedures.