Incidental Findings Appear on Brain MRI Scans of More Than 20 Percent of Children

More than 20 percent of children have incidental findings (IF) that show up on brain MRI scans. Knowing how commonly some abnormalities occur could help providers decide whether routine screenings are appropriate for investigations.

In a study published March 22 in JAMA Neurology, a team of investigators from both the University of California at San Francisco (UCSF) and the University of California at San Diego (UCSD) examined baseline neuroimaging findings from nearly 12,000 children who were enrolled in the Adolescent Brain Cognitive Development study.

Knowing how frequently specific IFs occur can potentially help providers contextualize the importance of similar findings when they pop up in clinical settings, said the team led by Leo Sugrue, M.D., Ph.D., assistant professor and neuroradiologist at the University of California.

“Our results provide information about the rates of IFs in a large, demographically diverse pediatric population,” said Sugrue’s team. “Overall, our findings support earlier smaller studies that suggested a relatively higher rate of IFs in the general pediatric population, but suggest that only 4 percent of the children had findings of potential clinical significance.”

In general, the team said, they determined that 1 in 25 children had findings on structural brain MRI that warrant clinical referral, and 1 in 500 needed an urgent clinical referral.

To make this determination, the team evaluated 3T T1 and T2 sequence brain MRI studies conducted at 21 sites nationwide on 11,810 9- and 10-year-olds between Sept. 1, 2016 and Nov. 15, 2018. Based on their analysis, they divided the identified IFs into four categories: no abnormalities (category 1), no referral recommended (category 2), consider referral (category 3), and consider immediate referral (category 4). As examples, smaller masses that were not associated with a significant effect were placed into category 3, and larger masses that compressed nearby brain structures were put into category 4.

Of the 11,810 children imaged, 11,679 (98.8 percent) had interpretable baseline structural MRI results, the team said – 21.1 percent of which were considered IFs. However, only 431 (3.7 percent) and 20 (0.2 percent) were placed into category 3 and category 4, respectively.

Among the category 4 cases, mass-like regions of signal abnormality concerning for glial neoplasm and hydrocephalus were the most common findings. For category 3, it was periventricular nodular heterotopia, white matter abnormalities, and arachnoid or intraventricular cysts large enough to cause mass effect or potentially cause hydrocephalus.

Ultimately, the team said, having a better understanding of how commonly these IFs occur – and which ones appear most often – can help with decisions around whether brain MRI should be a regular component of research efforts that will support future clinical decision-making.

“Knowing the value of routine neuroradiologic screening of research brain MRIs can inform ongoing discussions about the appropriateness of making such screening standard practice,” the team concluded.

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