X-rays are a form of electromagnetic radiation, used in medical settings for diagnostic radiography and crystallography. Also known as the Röntgen radiation, after its founder Wilhelm Röntgen, x-rays are similar to radio waves, microwaves, visible light and gamma rays.

Like any other form of electromagnetic radiation, x-rays are produced in parcels of energy called photons. The x-ray photons are highly energetic and have enough energy to break up molecules and hence damage living cells. When x-rays hit a material, some are absorbed and others pass through. This is what gives x-rays the power to ‘see inside’ things.

Structures that are dense, such as bones will normally block most of the photons and will appear white on the developed film. On the other hand, structures containing air will be black on film and muscle, fat and fluid will appear as shades of gray.

The Procedure

The machine is fitted with an x-ray tube. An electron gun inside the tube shoots high-energy electrons at a target made of heavy atoms, such as tungsten. X-rays are emitted because of the atomic processes induced by the energetic electrons shot at the target.

Two different atomic processes can produce x-ray photons. These are:







K-shell emission



When you get an x-ray taken at a hospital, an x-ray sensitive film is put on one side of the body and the x-rays are shot through. For instance, at a dentist, the film is put inside your mouth, on one side of the teeth and x-rays are shot through the jaw.

Uses and Benefits

Due to the series of varied properties of X-rays, these can be used in various applications in science and industry, the most common being the field of medicine. X-rays are especially useful in the detection of pathology of the skeletal system and disease processes in soft tissue.

Some of the most common medicinal uses of x-rays are in the chest x-rays that can be used to identify lung diseases such as pneumonia, lung cancer or pulmonary edema. In addition, abdominal x-rays are also common and are used to detect ileus (blockage of intestines), free air from visceral perforations and free fluid in ascites.

Some of the more specific uses of x-rays include:




X-ray crystallography



X-ray astronomy



X-ray microscopic analysis



The basic science of x-ray generation and detection is the key behind general radiographs of the body, mammography, fluoroscopy and computed tomography (CT).

Risk Factors

Minimal amounts of risks are involved with x-rays and the way they are conducted. X-rays need to be administered with caution in pregnant women, since there is some risk that the radiation can harm the fetus.

Care should also be taken while using the procedure with small children due to the possible harmful effect of the radiation.