How much radiation exposure is there for a patient undergoing coronary CTA?
Radiation exposure is a perennial issue for all CT studies. Opponents of coronary CTA have touted high radiation dose from the study as a reason to choose the more established catheter angiography or nuclear stress test. Prospective gating results in an average dose of 4 mSv; however newer techniques with lower tube voltage can reduce the dose to 1 to 2 mSv in some cases. In comparison, diagnostic catheterization results in an average dose of 5 to 7 mSv, with considerable operator-dependent variation. A nuclear medicine study using sestamibi with stress and rest phases provides a radiation dose of about 15 mSv. Regardless, all efforts should be made to reduce dose and to consider which organs are exposed. It is prudent to be especially conscious of radiation dose in young women because of the relatively high breast dose from coronary CTA.