Patients in the emergency room worry more about getting an accurate diagnosis than any radiation risk from CT scans, yet most still prefer that ordering physicians discuss the risk and benefits of the procedure before ordering the test, according to a study published in the November issue of the American Journal of Roentgenology.

In the survey of 383 emergency department patients carried out at the Thomas Jefferson University in Philadelphia, researchers found 74 percent thought accurate diagnosis was more important than radiation risks. Still, 68 percent of patients wanted doctors to explain the risks of the exam beforehand.

"Because patients drive their care to some degree, it is important for physicians to understand patients' knowledge and attitudes about radiation exposure, particularly as they relate to CT," Dr. Kevin M. Takakuwa, lead author of the study and a doctor with Jefferson, said in a statement.

Whites and privately insured patients were more likely to prefer accuracy at the expense of radiation, Takakuwa said, and blacks and those with lower pain scores preferred a careful explanation of risks and benefits even if it took more time.

Most patients grasped that cancer risks from radiation were extremely small, according to the study. However, only one-third knew that CT scans emit more radiation than chest X-rays.