Quick answer
What is an x-ray?
An X-ray is a quick imaging test that uses a low dose of radiation to produce pictures of bones and some internal tissues, commonly used to detect fractures, chest infections and joint disease. The procedure is fast and may involve wearing a gown and removing metal objects, and you should tell staff beforehand if you are or might be pregnant.
What is plain radiography?
A plain X-ray uses a small amount of radiation to create an image of the inside of the body. Dense structures such as bone absorb more radiation and appear white on the image, which makes bones and other dense tissue easy to see. X-rays are quick to perform and widely available, which is why they are often the first imaging test used in both routine and urgent care.
What an X-ray can detect
X-rays are commonly used to look for fractures, chest infections, arthritis and dental problems. They can also give some indication of bowel obstruction, although this is not their main use and findings can be limited in this area. Because different conditions show up more or less clearly on an X-ray, a doctor will choose this test when it is likely to answer the clinical question at hand.
What happens during an X-ray
A radiographer positions you for the images needed and asks you to hold still briefly while each picture is taken. The whole procedure is usually quick, and in urgent settings such as A&E, results are often available the same day so that treatment decisions are not delayed.
Alternatives to X-ray imaging
Other scans are used when an X-ray is not the best tool for the job. An MRI scan gives more detail of soft tissue, a CT scan is often used for complex trauma, and an ultrasound scan is commonly used to look for gallstones. Which test is used depends on the clinical need in each case, and a doctor will choose the imaging method most likely to show the suspected problem.
Common questions about the x-ray
- How much radiation risk is there from an X-ray?
- An X-ray involves a very small dose of radiation, and the benefit of finding or ruling out a problem generally outweighs this small risk. Doctors only request an X-ray when it is clinically indicated for this reason.
- Can I have an X-ray if I am pregnant?
- You should tell staff if you are or might be pregnant before having an X-ray. They can then use shielding or consider an alternative form of imaging if one is more appropriate.
- Can an X-ray miss a fracture?
- Yes, some fractures are not visible on an X-ray straight after an injury and only show up later. If a fracture is still strongly suspected, a repeat X-ray or an MRI scan may be arranged.
- What can a chest X-ray show?
- A chest X-ray can show problems such as pneumonia, an enlarged heart or lung masses. It does not show every possible condition, so further tests are sometimes needed if symptoms continue.