CT Angiography by reduced tube voltage more than a single step.

Recently, lay and scientific reports have raised concerns regarding the radiation doses associated with CCTA. These published data remain confusing for the nonphysicist, given the complexity of measuring radiation exposure and estimating risk. Radiation imparted by CT is most easily described by the dose-length product (DLP), a summary measure of the integral of radiation dose and scan length. Yet the DLP method, although useful for ascribing absolute radiation exposure, does not account for organ-specific susceptibilities to radiation risk. For this, the effective biological radiation dose—measured in millisieverts (mSv)—is preferred and permits comparison of CCTA with other radiation-based medical tests. Effective radiation doses can be determined by multiplication of the DLP by organ-specific conversion coefficients. The recommended conversion