X-RAY

X-ray imaging is perhaps the most commonly known form of diagnostic testing. Similar to visible light, x-rays use electromagnetic radiation which contain wave-like forms of energy. The energy found in electromagnetism comes from tiny, powerful particles called photons.

In x-rays, the wavelengths are shorter and the photons hold more energy than those of visible light. It is these shorter wavelengths that allows for penetration and imaging of the human body. The technical name for x-ray energy is ionizing radiation. Many different diagnostic techniques, such as angiography, also employ x-ray technology in capturing internal images of the human body. There are two different types of x-ray imaging: fluoroscopy, which requires a moving x-ray camera and a monitor displaying the internal images, and radiography, which uses traditional film technology.

How an x-ray works
An x-ray mechanism or source shaped somewhat like a camera emits x-ray beams through the body. Once the source emits the x-ray beams, the area of focus absorbs the radiation. The beams then pass through the body and hit a cassette of film, much like film for a camera. The image that appears on the film depends on the various strengths of the beams. Beam strength depends on the density of the internal mass. For example, since bones are much more dense than the soft tissue of an organ, the beams passing through the bones will hit the film with less strength. This area of the film will appear white. Conversely, air present in an organ such as in the lungs or intestines allows the beams to pass through without losing much of their strength. This will be reflected in the film as dark or black areas. Therefore, the x-ray produced "photograph" is a reflection of varying beam strength

In some instances, as in angiography, a dye is given to the patient in order to create more density in the area of focus. This liquid will absorb the x-ray beams better, giving a more defined image on the film. The patient may be required to drink the dye or it may be injected or given through an enema depending upon the area of focus. This dye is considered to be harmless as severe reactions are rare. Any concerns should be discussed with the patient's physician.

Because this diagnostic test does involve exposure to ionizing radiation, modern machines are more precise in targeting an area with x-rays so as not to expose other areas of the body needlessly. In addition, a heavy, lead cover may be placed over the patient to prevent unnecessary exposure to radiation. Women who are pregnant or have reason to believe they might be pregnant should consult their physician before having an x-ray test.

What an x-ray test looks at
X-ray testing can look at any bone structure or organ of the body, including:

Did you know. . .?
Radiation sources occur naturally throughout the galaxy. The sun and stars, such as those that make up constellations, are some sources of ionizing radiation. As mentioned, natural light also emits this type of energy.