Answer to Question #10527 Submitted to "Ask the Experts"

Category: Medical and Dental Patient Issues — Diagnostic X Ray and CT

The following question was answered by an expert in the appropriate field:

Q
I received the following x rays in an emergency room. I have listed the doses estimated by your site.

1. Chest two-view PA/LAT0 — 0.6 mSv
2. Lumbar spine complete, five views — 1.8 mSv

I am unsure of the radiation dose from the following two procedures. I believe the dose for the cervical spine series on your website is for three views; however, as indicated below, I had six views taken. And I did not find information on the right rib series.

3. Cervical spine series, six views
4. Right rib series, five views

Could you please tell me if my calculations for numbers 1 and 2 are correct and in addition let me know what the approximate dose for numbers 3 and 4 would be?
A

The exposure from the chest PA (posterior-anterior) and LAT (lateral) views is 0.06 mSv, not 0.6 mSv. The lumbar spine series dose is correct at 1.8 mSv. 

I could not find any reference to a six-view cervical spine series. The typical three-view series includes an AP, LAT and open-mouth views. Since the area being exposed would be about the same for an additional three views, it is reasonable to estimate the exposure as twice the normal cervical series. This would be about 0.5 mSv. 

The right rib series is also complicated because doses from this procedure are not reported in the scientific literature. An estimate of 0.6 mSv was calculated by taking the doses from standard chest PA and lateral radiographs and adjusting the dose to account for differences in the x-ray machine settings. Chest radiographs were used as a starting point because the same internal organs are exposed. 

Your total dose from these procedures is estimated to be about 3 mSv.

Kent Lambert, CHP

Answer posted on 23 January 2013. The information posted on this web page is intended as general reference information only. Specific facts and circumstances may affect the applicability of concepts, materials, and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice. To the best of our knowledge, answers are correct at the time they are posted. Be advised that over time, requirements could change, new data could be made available, and Internet links could change, affecting the correctness of the answers. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society.