Blocked blood vessels most common discovery, researchers report
WEDNESDAY, Oct. 31 (HealthDay News) -- Screening MRIs can uncover potential trouble in the brain, a new study suggests.
As a matter of fact, that might happen more than 10 percent of the time, according to Dutch researchers who found that 7.2 percent of those who received MRIs had blocked blood vessels in their brains, 1.8 percent had cerebral aneurysms, and 1.6 had benign brain tumors.
"Our study shows that incidental findings are much more frequent than was thought previously," said study co-author Dr. Aad van der Lugt, an associate professor of radiology at Erasmus MC University Medical Center in Rotterdam, the Netherlands.
The findings are published in the Nov. 1 issue of the New England Journal of Medicine.
The researchers began this study, because MRI and other imaging scans are being used more frequently in research studies and as diagnostic aids in clinical practice. Because of this increasing use, van der Lugt and his colleagues felt it was important to know how often asymptomatic disorders might show up.
To assess the rate of incidental findings, the researchers culled data from the Rotterdam Study and included information from 2,000 study volunteers between the ages of 46 and 97, with an average age of 63 years. All had undergone a screening MRI and, prior to the MRI, had no known brain abnormalities.
One hundred and forty-five of the study participants -- 7.2 percent -- were found to have a brain infarct, which means the blood supply to a specific part of the brain is blocked. Thirty-five people -- 1.8 percent -- were found to have an aneurysm in the brain. An aneurysm is a defect in the blood vessel wall that can rupture and cause a potentially fatal hemorrhage.
Thirty-one people -- 1.6 percent -- were found to have benign brain tumors, mostly meningiomas. Only one person was found to have a malignant brain tumor.
Some people had more than one condition.
The researchers had expected to find some people with undiagnosed infarcts, because blood vessel changes are common in older adults, according to van der Lugt, but "we were very surprised to find such a high frequency of other findings such as aneurysm and meningiomas, as previous studies reported much lower frequencies."
He said it's especially important for researchers conducting brain MRIs to be aware that they may have a significant number of incidental findings, so these findings aren't attributed to a study treatment, for example.
Van der Lugt said that general screening for these conditions wouldn't be recommended, because it's not yet clear if these asymptomatic conditions should be treated.
Dr. Arno Fried, chairman of the department of neurosurgery at Hackensack University Medical Center in New Jersey, agreed.
"Screening would probably create too many problems unless someone was experiencing specific symptoms. If someone has recurrent headaches, it may be worthwhile to screen with MRI just to make sure it's not a tumor creating the headaches."
He said neurosurgeons are often presented with incidental findings, because scanning technology is so good.
"The problem is what to do about incidental findings," he noted. "What's most important is to correlate clinical status with what we see on the scan. Most of the time, we won't do anything about those incidental findings. Some people will be asymptomatic forever."
Fried suggested that people, "Don't panic when an incidental finding is seen. Many people don't need surgery." He said that while a brain tumor may sound scary, many that are small and aren't causing symptoms don't need to be removed. Aneurysms may require treatment, but if they do, it's generally better that it was discovered early.
The bottom line, said Fried, is that "technology and imaging don't take the place of good clinical judgment. If the technology is taken out of context, it may lead to surgeries that don't need to be done."
To learn more about MRI, visit the U.S. National Library of Medicine.
SOURCES: Aad van der Lugt, M.D., Ph.D., associate professor, radiology, Erasmus MC University Medical Center, Rotterdam, the Netherlands; Arno Fried, M.D., chairman, department of neurosurgery, Hackensack University Medical Center, N.J.; Nov. 1, 2007, New England Journal of Medicine
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