Radiography & X-Rays

X-rays are a form of electromagnetic radiation. Their extremely short wavelength—only about 1/10,000 that of light or even less—gives them the ability to penetrate materials that absorb or reflect ordinary light. Like a light bulb, an x-ray tube generates specific electromagnetic radiation. Each tube is composed of a negatively charged cathode and a positively charged anode. The cathode contains a filament.

Voltage, or current, is applied to the filament. This generates a stream of electrons that hurtle the short distance into the metal anode at nearly the speed of light. The collision produces xrays.

Traditional radiography involves the use of film to capture x-ray images. The exposed film is chemically processed to create a visible image that physicians use to diagnose a patient's condition. Making diagnoses based on the images from x-ray film has been the standard for medical imaging because of the x-ray’s functional utility and high image quality. Increasingly, digital systems are replacing the conventional film cassette with an electronic receptor that directly converts the x-rays to digital images.

The x-ray has evolved into one of the most important devices ever invented to help physicians detect disease or other illnesses. The x-ray, accompanied by various substances taken orally or by injection, makes it possible to detect changes in tissue or bone at their earliest stages. For example, a dentist uses an x-ray to find cavities in teeth or abscesses at the roots of teeth. The brain specialist uses it to find tumors or abscesses in the brain or spinal cord. A nose and throat specialist uses x-rays to locate trouble in the sinuses.