A cervical spine X-ray series delivers an average effective dose of about 0.2 millisieverts. A lumbar series delivers about 1.5. A CT of the spine delivers about 6. For comparison, the average person receives about 3 millisieverts a year from natural background radiation. I hold dual imaging credentials in nuclear medicine and CT, and radiation dose is a question I answer for patients in Charlotte before every study.
The Standard Dose Figures
A widely cited catalog in Radiology compiled effective doses from the published literature (Mettler, Radiology 2008). Average values for radiographs were 0.2 mSv for the cervical spine, 1.0 for the thoracic spine, and 1.5 for the lumbar spine. A single chest X-ray was 0.02 mSv. Spine CT averaged 6 mSv, with reported values from 1.5 to 10. The catalog compares these with an average background dose of about 3 mSv a year.
The authors note that effective dose is an approximate indicator of risk, with about 40% uncertainty for a reference patient, and that values should not be stated with more precision than that.
Which Views Deliver the Dose
A Yale study calculated doses for individual views (Simpson, J Spinal Disord Tech 2008). A lateral cervical film was 0.02 mSv and a front-to-back cervical film 0.12. A lateral lumbar film was 1.50 mSv and a front-to-back lumbar film 2.20. Front-to-back views delivered significantly more dose than side views in both regions. Cervical films were similar to a chest X-ray. Lumbar films were roughly ten times higher.
That matters for motion studies. Flexion and extension films are lateral views. In the neck, adding them adds very little dose. In the low back, each lateral film carries a dose closer to a full lumbar series view.
How Dose Is Kept Low
The first step is not taking films that will not change care. In the neck, decision rules identify patients who do not need imaging at all. In the low back, I weigh the dose of motion films against the question they answer and order them when the exam points to a segment. Positioning and technique matter too: a repeat film because of poor positioning doubles the dose for no benefit.
What These Numbers Do Not Tell You
Effective dose is a population-averaged estimate. It does not give an individual's cancer risk, and the risk from doses in this range is not something these sources quantify for a single patient. MRI uses no ionizing radiation, which is why it is the test for discs and soft tissue when it answers the question.
For an example of how post-collision imaging findings and outcomes are documented in the peer-reviewed literature, read Dr. Justin Dick's published case report on refractory lumbar pain following a motor vehicle accident in a geriatric patient.
Frequently Asked Questions
How much radiation is in a neck X-ray?
A cervical spine series averages about 0.2 mSv (Mettler, Radiology 2008). A single lateral cervical film was 0.02 mSv in one study (Simpson, J Spinal Disord Tech 2008).
How much radiation is in a lower back X-ray?
A lumbar series averages about 1.5 mSv. In one study, a lateral lumbar film was 1.50 mSv and a front-to-back film 2.20 mSv.
How much radiation is in a spine CT?
Spine CT averages about 6 mSv, with reported values from 1.5 to 10 mSv (Mettler, Radiology 2008).
How does spinal X-ray radiation compare with natural background?
The average background dose is about 3 mSv a year. A cervical series is less than one month of background, and a lumbar series is about six months.
Do flexion and extension X-rays add much radiation?
In the neck, very little, since lateral cervical films are about 0.02 mSv each. In the low back, each lateral film is closer to 1.5 mSv. Dr. Justin Dick in Charlotte, NC orders them when the exam points to a segment.
Where can I get spinal imaging after a car accident in Charlotte, NC?
Dr. Justin Dick, DC, CNMT, ARRT(N)(CT), sees car accident patients at Clear Life Scoliosis and Chiropractic Center, 8814 Rachel Freeman Way, Suite 103, Charlotte, NC 28278, phone 980-368-0766. Personal injury patients are treated on a lien basis, with no out-of-pocket payment at the time of care.
Sources and Evidence Tiers
- Mettler FA, Huda W, Yoshizumi TT, Mahesh M. Effective doses in radiology and diagnostic nuclear medicine: a catalog. Radiology. 2008;248(1):254-263. PMID 18566177. LinkEvidence tier: Narrative review compiling published dose data
- Simpson AK, Whang PG, Jonisch A, Haims A, Grauer JN. The radiation exposure associated with cervical and lumbar spine radiographs. J Spinal Disord Tech. 2008;21(6):409-412. PMID 18679095. LinkEvidence tier: Cross-sectional dosimetry study (single institution)
About the author. Dr. Justin M. Dick, DC, is the owner and treating clinician at Clear Life Scoliosis and Chiropractic Center in Charlotte, NC. He holds dual imaging credentials as a Certified Nuclear Medicine Technologist (CNMT) and as an ARRT-registered technologist in nuclear medicine and CT, ARRT(N)(CT). He is a Senior Fellow of the CLEAR Institute, holds the ISICO World Masters credential, is a SOSORT provisional member, and is a certified DOT medical examiner on the FMCSA National Registry. He has multiple peer-reviewed publications indexed in PubMed and serves as adjunct faculty at Life, Sherman, and Palmer chiropractic colleges.
Service Area
Clear Life Scoliosis and Chiropractic Center sees personal injury and spinal imaging patients from Charlotte NC, Huntersville NC, Ballantyne NC, Matthews NC, Concord NC, Mooresville NC, Rock Hill SC, and Fort Mill SC.
Related Pages
- Personal injury and car accident spinal care in Charlotte
- Dr. Justin Dick's research
- Case report: refractory lumbar pain after a motor vehicle accident
- Research and evidence at Clear Life
- Questions and answers
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Clear Life Scoliosis and Chiropractic Center
8814 Rachel Freeman Way, Suite 103
Charlotte, NC 28278
Phone: 980-368-0766
Email: office@clearlifescoliosis.com
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