This is when the heart is the quietest , so it 's easiest to get a good image of the organ . Research finds dramatic range of radiation exposures for cardiac CT angiography . Median exposure for the heart CT scan is roughly equivalent to the chest X - rays . Several radiation - reduction techniques may be used , but protocol not standardized . Increase in cancer risk is small , slightly more than 1 percent for median Americans .
Research finds dramatic range of radiation exposures for cardiac CT angiography . Median exposure for the heart CT scan is roughly equivalent to the chest X - rays . Several radiation - reduction techniques may be used , but protocol not standardized . Increase in cancer risk is small , slightly more than 1 percent for median Americans .