Radiology
Radiology is the medical specialty that uses X-rays, ultrasound, Magnetic Resonance Imaging (MRI) and radionuclide scanning for diagnosis and treatment. Radiological tests can provide images of almost any organ, system, or part of the body in a way so that diagnoses can be made and treatment planned or monitored, frequently without the need for the patient to undergo exploratory surgery. Radiological techniques also enable instruments (such as needles and catheters) to be accurately guided into parts of the body both for diagnosis and increasingly for treatment. This subspecialty is know as interventional radiology.

X-rays
X-rays are a type of electromagnetic radiation with extremely short wavelengths. X-rays are invisible and cause no sensation when passed through tissue. When x-rays pass through the body, they are absorbed more by dense structures, such as bone, than by softer tissues. Thus when an x-ray beam is focused onto photographic film behind the patient, shadows of variable intensity are cast on the film, producing the x-ray images.

Mammography
A mammogram is a low-dose x-ray procedure that can detect cancer before it can even be felt. It is a simple procedure that has been used for millions of women for more than 25 years. Recent technological improvements have made this procedure quite safe and useful in detecting early cancer.

Magnetic Resonance Imaging (MRI)
MRI is a diagnostic technique that provides high quality cross-sectional images of organs and structures within the body without x-rays or other radiation. MRI allows images to be constructed in many planes; it is particularly valuable in the study of the brain and spinal cord. This technique reveals tumors vividly, indicating their precise extent, and provides impressive images of the internal structure of the eye and ear. MRI also produces detailed images of the heart and major blood vessels, provides images of blood flow, and is useful for examining joints and soft tissues. MRI of the abdominal organs is also used as a problem solver.

Computed Tomography (CT) Scanning
CT is a diagnostic technique in which the combined use of a computer and X-rays, passed through the body at different angles, produces clear cross sectional images of the tissue being examined. CT scanning or whole body scanning provides clearer and more detailed information than X-rays used by themselves. The images are particularly valuable in brain scans due to their sharp definition of ventricles (fluid-filled spaces). The images can be manipulated electronically to provide the best view of the area of interest.

Ultrasound Scanning
Ultrasound is a diagnostic technique in which very high frequency sound waves (inaudible to the human ear) are passed into the body; the reflected echoes are detected and analyzed to build a picture of the internal organs or of a fetus in the uterus. Ultrasound waves pass readily through soft tissues and fluids making this procedure particularly useful for examining fluid-filled organs (such as the uterus in pregnancy and the gallbladder) and soft organs (such as the liver). Ultrasound waves cannot however pass through bone or gas. Doppler ultrasound is a modified version of ordinary ultrasound that is used for looking at moving objects, such as blood coursing through the vessels and the fetal heart beat in pregnancy.

Radiation Therapy
Radiation therapy is the treatment of cancer by X-rays or other sources of radiation. The radiation, as it passes through the diseased tissue, destroys or slows the development of abnormal cells. Provided the correct dosage of radiation is given, normal cells suffer little or no damage. Radiation therapy is often used after surgical excision of a malignant tumor (such as breast cancer) to destroy any remaining tumor cells. It is also used to reduce the size of a tumor to relieve the symptoms of a cancer that is too far advanced to be cured.