Bone Mineral Density Scan (Bone Densitometry or DXA Scan)
What are the generally accepted indications for a BMD scan? The following indicate an increased risk for bone loss (osteoporosis)…Read more
All X-ray examinations involve exposure to ionising radiation and therefore have a theoretical risk of harm to the patient. In view of this, there must be a clear potential benefit to the patient to have the X-ray.
The amount of radiation involved in a chest or limb X-ray is very small (see radiation risk of medical imaging for adults and children) compared with the small amount of radiation that we all receive each day. This is called “background radiation” and is part of our normal environment. X-rays of the chest, abdomen, head, or limbs involve much less ionising radiation than CT scans of the same areas. However, some children with chronic conditions such as spinal problems (e.g. scoliosis) or chronic lung problems (e.g. cystic fibrosis) can require many, many X-rays over a period of years.
Radiologists require a clearly written request with sufficient clinical information to ensure that the most appropriate examination is performed. Not only does this enable the correct study to be performed, it also enables provision of a meaningful report.
If there is no medical benefit to be derived from having the X-ray then the study should not be performed.
If it is possible that the patient may be pregnant, and there is an alternative examination that does not involve ionising radiation that may allow the clinical question to be answered, this alternative should be considered. As always, the small risk of the ionising radiation should be balanced against the risk of not performing the X-ray, which may mean a missed or delayed diagnosis that will have its own adverse consequences for the patient.
X-ray examinations of females that include the abdomen or pelvis should only be performed if the patient is not pregnant or the procedure is medically urgent. Referring practitioners share responsibility to ensure that pregnant females are not X-rayed unnecessarily. If it is possible that the patient may be pregnant, and there is an alternative examination that does not involve ionising radiation that may allow the clinical question to be answered, this alternative should be considered.
As always, the small risk of the ionising radiation should be balanced against the risk of not performing the X-ray, which may mean a missed or delayed diagnosis that will have its own adverse consequences for the patient.
There are no immediate side effects from ionising radiation at the doses used in usual diagnostic X-ray studies (see radiation risk in medical imaging for adults and children).
Other imaging modalities such as ultrasound, CT or nuclear medicine imaging may be appropriate. However, the simplicity of a plain X-ray examination makes it a useful investigation that can significantly complement information obtained by other imaging modalities. It is reasonable to have an X-ray performed as a first line investigation (particularly for limb or joint pain), even if it is likely that a CT or MRI is also being performed.
Page last modified on 26/7/2017.
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