From the Research
The typical radiation dose for a lumbosacral spine X-ray is approximately 1.1 mSv, as reported in a study published in Acta radiologica in 2014 1. This dose is relatively low compared to other medical imaging procedures like CT scans, which can deliver 5-10 mSv or more. The radiation exposure from a lumbosacral X-ray is approximately equivalent to 6-12 months of natural background radiation that we're exposed to in everyday life. While this level of radiation carries a very small increased risk of cancer, the diagnostic benefits typically outweigh this risk when the examination is medically necessary. Factors that can affect the dose include the patient's size (larger patients require more radiation for adequate image quality), the number of views taken, and the use of digital versus film technology, with digital systems generally requiring less radiation. Healthcare providers aim to use the ALARA principle (As Low As Reasonably Achievable) when ordering imaging studies to minimize unnecessary radiation exposure.
Some key points to consider when evaluating the radiation dose of a lumbosacral spine X-ray include:
- The use of low-dose CT as an alternative to radiography, which can provide superior image quality at a comparable radiation dose 2
- The selection of the less radiation-sensitive side of the body for X-ray exposure, which can reduce the effective dose by up to 64% 3
- The estimation of organ and effective doses using software such as PCXMC, which can help to minimize radiation exposure 4 However, the most recent and highest quality study, published in 2016 in Acta radiologica, reported that low-dose lumbar spine CT at about 1 mSv has superior image quality to lumbar spine radiography with more anatomical and diagnostic information 2.
In summary, the recommended radiation dose for a lumbosacral spine X-ray is approximately 1.1 mSv, and healthcare providers should aim to use the ALARA principle to minimize unnecessary radiation exposure, considering factors such as patient size, number of views, and technology used, as well as alternative imaging modalities like low-dose CT. It is also important to note that the radiation dose can be reduced by performing x-ray exposures through the less radiation-sensitive sides of the body, which are PA in the frontal position and right lateral in the lateral position, as reported in a study published in The Spine Journal in 2016 3.