Radiation Risks and Safety in Cardiac CT

X-ray imaging is associated with exposure to ionizing radiation which has the potential to cause harm. Risk from radiation is commonly categorized as deterministic (or non-stochastic) vs. stochastic. Non-stochastic risk from CT imaging is exceedingly low, typically stemming from major human errors. Estimating stochastic risk from CT imaging, on the other hand, is controversial. The general assumption is that there is a linear non-threshold relationship between radiation dose and cancer risk. While such risk is very low for a given individual, the risk is considerable on a population level due to the many studies performed. Furthermore, it is conceivable that repeated exposure from medical imaging increases the probability of cancer development in a person. Radiation safety is critical to minimize radiation exposure and to reduce risk. This chapter covers fundamental principles of radiation dose concepts, estimation of dose, measures to reduce dose, and appropriate monitoring/reporting.