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Question:
How much radiation does one receive during a SPECT-CT scan?
How much radiation did I receive from a nuclear stress test with a SPECT-CT scan done at rest and again after exercise for a 6FT 210lb. man?
submitted by John on 9/8/2014
Answer:
by Texas Heart Institute cardiologist, Benjamin Y. Cheong, MD
To set the stage, the normal "background radiation", i.e. the amount of average radiation per year that each person receives (just living in planet earth with any medical test) is about 3 mSv. For a simple chest x-ray, it is reported to be approximately 0.1 mSv.
I believe the "SPECT-CT" that has been referred to mean "Single-photon emission computed tomography". The dose will vary between patient size as well as the compound used for imaging. Assuming one is using a Technetium-99m base agent, the 1-day rest/stress test would be approximately 9 – 10 mSv. The dose will be higher if a combination of agents are used.
One also has to consider that while these stress tests will involve radiation, the result that the test provides could give the ordering doctor a lot of information regarding the management pathways, and therefore the benefit could outweigh the potential/theoretical risk.
Finally, the side effect of the radiation to a grown-up will also be minimal, assuming the tests are infrequently performed.
If there is any concern, one should always discuss with the referring physician the risk / benefit / alternatives of the stress test, as well as the need of the stress test.
A good reference article is http://www.asnc.org/media/PDFs/PatientCenteredImagingFINAL.pdf.
Best wishes.
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Updated September 2014
