X-rays are waves of electromagnetic energy. They behave much in the same way as light rays, but at much shorter wavelengths. When directed at a target, X-rays can often pass through the substance uninterrupted, especially when it is of low density.
Higher density targets (like the human body) will reflect or absorb the X-rays. They do this because there is less space between the atoms for the short waves to pass through. X-rays are one of the most common radiology procedures. X-rays produce a still picture of bones and organs.
Since Roentgen’s discovery that X-rays can identify bone structures, X-rays have been developed for their use in medical imaging. Radiology is a specialized field of medicine that employs radiography and other techniques for diagnostic imaging. X-rays are especially useful in the detection of pathology of the skeletal system, but are also useful for detecting some disease processes in soft tissue.
Diagnostic imaging techniques help narrow the causes of an injury or illness and ensure that the diagnosis is accurate. These techniques include X-rays, computed tomography (CT) and magnetic resonance imaging (MRI) scan.
These imaging tools let your doctor see inside your body to get a picture of your bones, organs, muscles, tendons, nerves, and cartilage. Your doctor uses these tools to determine if there are any abnormalities.
X-ray (radiograph) is the most common and widely available diagnostic imaging technique. Even if you also need more sophisticated tests, you will probably get an X-ray first.
The X-ray or radiograph is produced by the transmission of energy. A beam of high-energy photons is passed through the body, some of which are attenuated or blocked when they strike subatomic particles.
The higher the atomic weight of the substance through which the photons are passing, the “denser” it appears to photons, and the more likely they are to be blocked or attenuated. In decreasing order of density, the principal densities visible in a radiograph are metal, bone, water (including soft tissues such as muscle), fat, and air.
Risks of X-Ray
There is very little risk with having one X-ray test. However, with repeated tests there is a risk that the X-rays may damage some cells in the body, possibly leading to cancer in the future. The dose of X-ray radiation is always kept to the minimum needed to get a good picture of the particular body part being examined.
Also, radiographers who take the X-ray pictures always wear lead aprons or go behind a protective screen when the X-rays are fired to avoid repeated exposure to X-rays.
Pregnant women, if possible, should not have an X-ray test as there is a small risk that X-rays may cause an abnormality to the unborn child. This is why women are asked before having an X-ray if they are, or might be, pregnant.