Safety
PET scanning is non-invasive, but it does involve exposure to ionizing radiation. The total dose of radiation is significant, usually around 5–7 mSv. However, in modern practice, a combined PET/CT scan is almost always performed, and for PET/CT scanning, the radiation exposure may be substantial—around 23–26 mSv (for a 70 kg person—dose is likely to be higher for higher body weights). When compared to the classification level for radiation workers in the UK of 6 mSv, it can be seen that use of a PET scan needs proper justification. This can also be compared to 2.2 mSv average annual background radiation in the UK, 0.02 mSv for a chest x-ray and 6.5–8 mSv for a CT scan of the chest, according to the journal Chest and ICRP. A policy change suggested by the IFALPA member associations in year 1999 mentioned that an aircrew member is likely to receive a radiation dose of 4–9 mSv per year.
Read more about this topic: Positron Emission Tomography
Famous quotes containing the word safety:
“For hours, in fall days, I watched the ducks cunningly tack and veer and hold the middle of the pond, far from the sportsman;... but what beside safety they got by sailing in the middle of Walden I do not know, unless they love its water for the same reason that I do.”
—Henry David Thoreau (1817–1862)
“The Declaration [of Independence] was not a protest against government, but against the excess of government. It prescribed the proper role of government, to secure the rights of individuals and to effect their safety and happiness. In modern society, no individual can do this alone. So government is not a necessary evil but a necessary good.”
—Gerald R. Ford (b. 1913)
“Once women begin to question the inevitability of their subordination and to reject the conventions formerly associated with it, they can no longer retreat to the safety of those conventions. The woman who rejects the stereotype of feminine weakness and dependence can no longer find much comfort in the cliché that all men are beasts. She has no choice except to believe, on the contrary, that men are human beings, and she finds it hard to forgive them when they act like animals.”
—Christopher Lasch (b. 1932)