Radiography, or an x-ray, as it is most commonly known, is the oldest and most frequently used form of medical imaging. Discovered more than a century ago, x-rays can produce diagnostic images of the human body on film or digitally on a computer screen.
X-ray imaging is the fastest and easiest way for a physician to view and assess broken bones, such as skull fractures and spine injuries. At least two images (from different angles) are taken and often three images are needed if the problem is around a joint (knee, elbow or wrist). X-rays also play a key role in guiding orthopedic surgery and in the treatment of sports-related injuries. X-ray may uncover more advanced forms of cancer in bones, although early screening for cancer findings requires other methods.
To this end, radiologists have developed alternative imaging methods that do not rely on radiation, such as ultrasound and magnetic resonance imaging (MRI). However, because x-ray was the first imaging modality, many people (and medical imaging professionals) continue to use the term "radiology" to include all types of imaging. Strictly speaking, though, radiology refers to the use of x-rays.