Ionising radiation occurs as either electromagnetic rays (ie xrays and gamma rays) or particles ( such as alpha and beta particles).
It occurs naturally (ie from the radioactive decay of natural radioactive substances such as radon gas and its decay products) but can also be produced artificially.
Everyone receives some exposure to natural background radiation.
When patients undergo radiological investigations, consideration must always be given to the benefits one might expect to obtain to manage the patient appropriately versus the risks to radiation exposure.
Appropriate imaging parameters must always be utilised to reduce the amount of radiation exposure. The ALARA ( as low as reasonable achievable) principle must always be adhered to.
Children are more at risk to the deleterious effects of radiation than adults. Gonadal shielding thus is used whenever possible and where it does not compromise image quality.
Breast shielding is used routinely during CT scanning where higher doses of radiation are experienced.
To compare the effective dose when undergoing various investigations with a comparison to background radiation click on the following link