According to a new study, compared to other countries’ patients, the typical US patient gets more frequently exposed to extreme radiation at the time of myocardial perfusion imaging. Also called a nuclear stress test, myocardial perfusion imaging is conducted on millions of the US people alone in a year to aid diagnose and treat coronary artery disease.

Researchers reported in JAMA Internal Medicine, online on December 28, that a typical the US patient got a 20% higher radiation dose as compared to someone receiving the test out of the US, partially because American labs were less probably adhere to recommended dosing guidelines.

Via email, senior study author Dr. Andrew Einstein of Columbia University Medical Center in New York, said, “When it is appropriately performed, benefits of a nuclear heart scan far outweigh this radiation exposure, however it is still incumbent upon doctors to minimize amount of radiation that patients receive from such testing while simultaneously ensuring a good quality heart study”.

With the motive to minimize the slight cancer vulnerability linked to radiation exposure, guidelines have recommended that exposure during myocardial perfusion tests should be restricted to 9 millisieverts (mSv). However, just 24% of patients in the US received doses of 9 mSv or less, in comparison to 43% of people treated beyond the US.

The dose was under 9.7 mSv half the time, outside the US. However, half the time, the dose was over 11.6 mSv inside the US.