X-Rays were first discovered in 1895 by a Physicist named Roentgen. X-Rays are the same wave-like electromagnetic energy form as visible light rays, however X-Rays have a shorter wavelength which is not visible to the naked eye.
What are X-rays?
X-rays can be used to view structures within the body because of their ability to pass through our tissues. The more dense tissues such as bone appear white on a X-Ray film because they block more of the rays. Soft tissues allow more rays to pass through and so appear darker. The lungs appear black as they are mostly air. When there is a break in a bone, more rays escape through the interruption in the bone, showing up as a darkened line. When x-raying for conditions such as a lung tumour this will appear as a lighter patch within the black lungs.
What happens when you go for an X-Ray?
Before having an x-ray the patient must remove all jewelry and other metal and females should be asked if they are pregnant as x-rays may harm the baby.
Most X-Ray machines consist of an X-ray tube suspended over the table on which the patient lies. The X-ray film onto which the image is recorded is located under the table. Many x-ray machines are now digital and the images are stored directly onto a computer, rather than printed onto a film.
In order to protect you from radiation, a lead apron may be placed over areas which are not being scanned. The Radiologist will also wear one.
You will be asked to stay very still and may be given pillows to position yourself more easily to get the required view. The Radiologist will either leave the room or stand behind a screen whilst taking the x-rays. You may have two or more taken, in varying positions, to allow for a comprehensive view of the injury.
What are the risks?
X-Rays are a very low risk procedure, although not as low risk as an MRI scan. Because of the radiation, there is always a very small chance of developing cancer from excessive exposure to x-rays. However, each single x-ray exposes the patient to 20 milliroentgens of radiation. Each year we are exposed to over 100 milliroentgens of radiation, mainly from the sun, so really the risk is minimal.