Medical Tech

Many patients unaware of risks that go with some medical scans

April 27, 2011: A X-ray of a patient with a lung tumour caused by smoking is seen at Ruijin Hospital in Shanghai.

April 27, 2011: A X-ray of a patient with a lung tumour caused by smoking is seen at Ruijin Hospital in Shanghai.  (Reuters)

Over half of people receiving medical scans such as X-rays do not know if they are exposed to radiation and many have unanswered questions even as they are waiting to undergo the test, a small U.S. survey found.

Previous studies have shown that when patients have more information and can share in the decision-making process, they have less anxiety and more satisfaction with their treatment, the study authors write in the Journal of the American College of Radiology.

Dr. Andrew Rosenkrantz, lead author, told Reuters Health that while the United States performs a high volume of medical scans, many patients are not informed about what the tests entail.

“We did this study seeking to gain insights into just how well patients understood their own tests that they were about to undergo,” Rosenkrantz, an associate professor of Radiology at NYU Langone Medical Center in New York City, said in an email.

The study team recruited 176 patients who were waiting to have medical imaging scans, including CT and nuclear medicine scans, which involve radiation, and MRI and ultrasounds, which do not.

The participants completed surveys asking about their knowledge regarding their procedures, and what the tests were for. They also reported on whether their doctor had explained the exam, how well it was explained and whether they still had unanswered questions.

The researchers found that only about 46 percent of people correctly identified whether the test they were about to undergo employed radiation. Among people who would be drinking a radioactive contrast agent for their test, just over half knew it, while among those who would be getting the contrast agent by injection, just over 70 percent knew it.

Patients had the greatest understanding of CT scans, a powerful type of X-ray that shows cross-sections of the body. Patients reported the least understanding of nuclear medicine, in which the radioactive liquid contrast agents are used to enhance the image.

About 78 percent of participants said their doctor explained the exam in advance and 72 percent were satisfied with the explanation. However, nearly one in five still had unanswered questions while awaiting the test.

For each kind of exam, those who had not had the test before had less understanding of it.

One in five patients had used the Internet to learn about the exam, while the same proportion consulted friends and family.

In addition, over half of patients said they would be interested in discussing the exam with a radiologist in advance.

Although the benefits of medical testing generally outweigh the risks, being exposed to radiation can increase a person’s risk of getting cancer later in life, according the Centers for Disease Control and Prevention.

Dr. Michael Zwank, a physician at Regions Hospital in Saint Paul, Minnesota, who studies physician-patient communication, said patients should be more aware of the risks of these exams.

“It is concerning that there is a big group of patients that seem to not have the awareness of radiation exposure that they are or are not experiencing with this imaging,” Zwank, who was not involved in the study, said in an email.

Rosenkrantz noted that the results may be skewed, since people who knew the answers to the survey questions may have been more likely to complete the survey. For this reason, the study results may show a higher level of awareness than is actually true for most people, he pointed out.

“Patients should also feel comfortable asking about logistics of the exam, ranging from what exam is being performed, which body part is being evaluated, the reason for the exam,” Rosenkrantz said.

Zwank added that he encourages all patients to ask their doctors: “1. Is the test necessary? 2. What are the risks? 3. Are there alternatives?”