Incidental brain findings common with MRI
Incidental brain findings on MRI, including subclinical vascular pathologic changes, are common in the general population, according to recent study findings published online in the Nov.1 issue of the New England Journal of Medicine.

Researchers at Erasmus MC University Medical Center, Rotterdam, Netherlands conducted the study due to the increased usage of MRI and other imaging scans to determine how often asymptomatic disorders appear.

To assess the rate of incidental brain findings, researchers gathered data from 2,000 volunteers from a population-based Rotterdam study. Participants were between the ages of 46 and 97 (an average age of 63), who underwent high-resolution, structural brain MRI (1.5 T).

Two technologists recorded all brain abnormalities, including asymptomatic brain infarcts. The volume of white-matter lesions was quantified in milliliters with the use of automated postprocessing techniques. Two neuroradiologists reviewed all incidental findings. All diagnoses were based on MRI findings, and additional histologic confirmation was not obtained.

Investigators determined that asymptomatic brain infarcts were present in 145 persons, approximately 7.2 percent of the study population. Other than the brain infarcts, cerebral aneurysms (1.8 percent) and benign primary tumors, mainly meningiomas (1.6 percent), were the most frequent. The prevalence of asymptomatic brain infarcts and meningiomas increased with age, as did the volume of white-matter lesions, whereas aneurysms showed no age-related increase in prevalence.

There is evidence that “improvements in scanner hardware and MRI sequences are likely to detect unexpected, asymptomatic brain abnormalities, such as brain tumors, aneurysms and subclinical vascular pathologic changes,” researchers said.

Results showed that “incidental brain findings on MRI, including subclinical vascular pathologic changes, are common in the general population. The most frequent are brain infarcts, followed by cerebral aneurysms and benign primary tumors. Information on the natural course of these lesions is needed to inform clinical management.”