Radiology is the medical specialty that utilizes and interprets imaging technologies to diagnose disease. Traditionally it was the branch of medical science dealing with the medical use of X-rays emitted by X-ray machines or other such radiation devices for the purpose of obtaining visual information as part of medical imaging. Radiologists now also use all other imaging technologies (such as ultrasound, computed tomography (CT) and magnetic resonance imaging) to diagnose or treat disease. Interventional radiology is the performance of (usually minimally invasive) medical procedures with the help of medical imaging.