Without evidence of benefit, an intervention should not be presumed to be beneficial or safe.

- Rogue Medic

Patient Perceptions of Computed Tomographic Imaging and Their Understanding of Radiation Risk and Exposure – Part III

Also posted over at Paramedicine 101 (now at EMS Blogs) and at Research Blogging. Go check out the excellent material at these sites.

Continuing from Part I and Part II.

After assessing what it is that the abdominal pain patients want/expect from a visit to the ED (Emergency Department), and how many X-rays it takes to deliver the same radiation as an abdominal CT (Computed Tomographic imaging), they move on to part 3.


Use imagery to switch the perspective from the rational to the emotional.

That would be more likely to get an emotional response from an architect.

A person with radiation injuries. That is more likely to produce an emotional response.

Bringing up the imagery of Hiroshima radiation exposure in a study is one way to get us to by-pass the purpose of an objective study, while retaining the appearance of objectivity. Was this the intent of the authors? Probably not, since they got this question from an earlier study. However, they may have appreciated the emotional appeal.

I don’t spend a lot of time examining patients after a CT, but they tend not to have that burned appearance. Visible burns are not the only damage from radiation, so the absence of that burned appearance does not mean that there is no damage.

Berrington de González et al4 projected 29,000 excess cancers as a result of the CT scans conducted in 2007.4 These cancers are expected to appear in the next 20 to 30 years, with an associated 50% mortality rate. Strategies for decreasing the risks associated with CT imaging include increasing efforts to educate physicians, improving radiation protocols to enable technicians to select the lowest-dose scanning techniques without compromising resolution, and increasing patient awareness of their own radiation exposure by using aids such as FDA medical imaging history cards.2,8,11,15-18 [1]

How much of the risk of radiation is understood well enough to have clear Yes/No answers?

The most important omission is the context.

In what way can the radiation exposure of 2 to 3 CT scans be similar to the radiation exposure of survivors of Hiroshima?

What kind of understanding do these patients have of the varieties of radiation exposure experienced by the survivors of Hiroshima?

We could be asking the patients, How often does a CT make the diagnosis clear in the assessment of undifferentiated abdominal pain?

Or – How often does the CT change the diagnosis for undifferentiated abdominal pain?

This is one question that should be an obvious Yes.

Is it reasonable to disagree with the statement 2 to 3 abdominal CTs over a person’s lifetime can increase the chances of cancer?

This is not quantifying risk, but only stating that it can increase cancer risk.

Let’s turn the statement around and restate what the most popular answer means. 2 to 3 abdominal CTs over a person’s lifetime cannot increase the chances of cancer.

Is anyone really suggesting that?

What would be the basis for such a claim?

Again, would physicians do much better in answering the same questions?

To be continued tomorrow in Part IV.


[1] Patient perceptions of computed tomographic imaging and their understanding of radiation risk and exposure.
Baumann BM, Chen EH, Mills AM, Glaspey L, Thompson NM, Jones MK, Farner MC.
Ann Emerg Med. 2011 Jul;58(1):1-7.e2. Epub 2010 Dec 13.
PMID: 21146900 [PubMed – indexed for MEDLINE]

Free Full Text from Annals of Emergency Medicine with links to Free Full Text PDF Download

Baumann BM, Chen EH, Mills AM, Glaspey L, Thompson NM, Jones MK, & Farner MC (2011). Patient perceptions of computed tomographic imaging and their understanding of radiation risk and exposure. Annals of emergency medicine, 58 (1), 1-700 PMID: 21146900



  1. Good summaryof how most patients aren’t capable of understanding the true risk/lack of risk in the use of radiation in medical tests/treatments.

  2. Outstanding post however , I was wanting to know if you could write a litte more on this subject? I’d be very grateful if you could elaborate a little bit more. Appreciate it!

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