Radiology is the branch or specialty of medicine that deals with the study and application of imaging technology like x-ray and radiation to diagnosing and treating disease.

Radiologists direct an array of imaging technologies (such as ultrasound, computed tomography (CT), nuclear medicine, positron emission tomography (PET) and magnetic resonance imaging (MRI)) to diagnose or treat disease. Interventional radiology is the performance of (usually minimally invasive) medical procedures with the guidance of imaging technologies. The acquisition of medical imaging is usually carried out by the radiographer or radiologic technologist.

Procedures other than computed tomography usually require no special preparation. For some procedures, it may be better to abstain from using talc or underarm deodorant prior to your test, or to abstain from eating or drinking. Your physician or a member of the radiology department staff will tell you about any necessary preparations before the day of your test.

Your physician will receive a formal report from the radiologist who performs your procedure. In most cases, the radiologist reviews the scan as soon as the procedure is completed. If you have an appointment with your physician later in the day, your doctor will usually have spoken with the radiologist about your results by the time he or she meets with you. Patients having mammograms will receive a written report on their procedure at the time of their visit. If you do not have an appointment with your physician shortly after your test, ask your physician how the results of your test will be given to you.

A computed tomography (CT) scan is a non-invasive diagnostic technique that enables a physician to scan a patient's chest, abdomen, and pelvis for abnormalities such as masses. CT is often accompanied by dyes or other image enhancers called "contrast media." You may take the contrast media orally (drinking it), be given via injection, or both. The contrast media is absorbed differently by different tissues in your body, and helps each type of tissue show up more clearly when scanned. After a few hours, the contrast media dissolves and is passed out of your body when you urinate. The CT scanner includes an x-ray machine that picks up signals from the contrast media absorbed by your body, and a computer that turns signals from the scanner into a three-dimensional image. This image gives the radiologist a finely-detailed picture of the area scanned.

A bone scan is a diagnostic test that uses a small amount of radioactive material (tracer) to visualize the bones in your body. The tracer will be injected into a vein, usually in the forearm. After administration of the radioactive material, you must wait approximately three hours while the tracer localizes in the bones and clears from the soft tissues.

A gallium scan is a diagnostic test that uses a small amount of radioactive material (tracer) to visualize sites of disease throughout your body. The tracer will be injected into a vein, usually in the forearm, from one to four days before the scan is performed.

A hepatobiliary scan (DISIDA or HIDA) scan is a diagnostic test that uses a small amount of radioactive material (tracer) to visualize the liver and the biliary system including the gallbladder. The radioactive material will be injected into a vein, usually in the forearm.

A radionuclide ventriculogram (RVG, also known as a gated blood pool scan or MUGA scan) is a diagnostic test that uses a small amount of radioactive material (tracer) to assess the efficiency of the pumping action of the heart.