The radiation dose from an X-ray examination depends on the imaging method used and the body part being examined. Since the sievert (Sv) is a large unit, doses from examinations are measured in millisieverts (mSv, one-thousandth of a sievert) or microsieverts (µSv, one-millionth of a sievert). The lowest doses are typically associated with imaging of the lungs, teeth, and limbs.
Radiation is present throughout our environment. The effective dose can also be used to estimate the time during which a person living in Finland would receive an equivalent dose from all natural sources of radiation. For example, a four-hour flight at an altitude of 10 km results in a dose of 0.02 mSv.
Watch the video: Radiation Safety ABC – What kind of doses result from radiological examinations? Produced by OYS, with subtitles in Finnish and Swedish.
Average radiation doses from examinations
The accordion table provides information on average radiation doses from examinations in adults. Doses for children are significantly lower than those listed in the table. The data applies to an average adult. The dose received by an individual may vary depending on factors such as body size and imaging technique. Radiation doses in examinations can vary widely. In nuclear medicine examinations, the dose depends on the specific radiopharmaceutical and its administered activity.
A standard knee X-ray results in a radiation dose of less than 0.01 mSv, which is slightly lower than that of a chest X-ray (PA view). The dose from a knee X-ray corresponds to the average dose a person in Finland receives from all radiation sources in less than one day.
The radiation exposures listed in the tables represent average effective doses from the examinations. Dose calculations are based on ICRP reports.
Clarification of terms used in the table
1 Effective dose: A quantity that describes the overall health impact caused by ionizing radiation, taking into account the sensitivity of different organs.
2 PA chest X-ray: A chest X-ray taken from the back.
3 Average radiation exposure for Finns is 5.9 mSv (STUK, 2018). Of this, over 5 mSv comes from natural radioactive sources and less than 1 mSv from medical use of radiation.