An X-ray examination is used to create images of internal organs or bones of the body to help diagnose conditions or diseases. An X-ray machine produces a small amount of ionising radiation. This radiation passes through the body and travels onto a film or similar device to produce the image.
Plain X-rays use a small amount of radiation, it is a painless and non-invasive procedure. You will not be radioactive after the test. The dose of radiation is different for every examination but on average is roughly the same as you would receive from the general environment in about one week. Patients must tell their doctor if they are pregnant or think they may be, another type of test may be recommended.
How X-rays work
X-rays are a type of radiation. They're similar sources of energy to light. However, light has a much lower frequency than x-rays and is absorbed by your skin. X-rays have a higher frequency and pass through the human body.
As X-rays pass through the body, energy particles (called photons) are absorbed at different rates. This creates a pattern which shows up on the X-ray images.
The parts of your body made up of dense material, such as bone, show up as clear white areas on an X-ray image. The softer parts, such as your heart and lungs, show up as darker areas.
When X-ray examinations are used?
This test is very common. It is used for:
Diagnosis of fractures or dislocations - detection of broken bones is one of the most common uses of this test or when the bones of a joint are abnormally positioned.
Diagnosis of bone or joint conditions - for example arthritis or some types of cancer.
Diagnosis of chest conditions - such as pneumonia, emphysema or heart problems.
For therapeutic interventions such as steroid injections into arthritic joints, to help guide equipment to the area being treated.
X-rays can also be used to show up internal organs such as the bowel or blood vessels using contrast medium. This is liquid that contains dye. It is sometimes swallowed or injected before an X-ray is taken and shows up clearly, helping to distinguish between different structures in the body.
The majority of X-ray examinations do not require any special preparation. The radiology department will give you instructions on how to prepare for the test and what to expect if this is required.
X-ray examination procedure
Depending on the part of the body being examined you may be asked to undress, remove jewellery and wear a hospital gown.
The basic procedure involves:
You will be asked your Date of Birth and address to confirm your identity
You will be positioned according to which part of your body is being investigated.
The radiographer will place you between the X-ray machine and the device that captures the x-rays being transmitted through that part of your body.
The radiographer may need to touch you in order to position your body correctly for each picture.
The radiographer operates the controls while each image is taken. To do this, they will stand behind a screen and call instructions to you if necessary.
You may be asked to hold your breath for a couple of seconds as each picture is taken, so that the breathing movement doesn't blur the images.
An X-ray examination of the hand for example, usually takes a few minutes in total. Other types of X-ray examination may take longer.
Once the procedure is completed you can get dressed and leave the department. A radiologist or specially trained radiographer will interpret the x-ray images.