MR imaging is not useful for evaluating children with persistent symptoms after a sports-related concussion, according to a new study published in Journal of Neurotrauma.

The American Academy of Pediatrics has reported that emergency room visits for concussions in children aged eight to 13 have doubled, and concussions have risen 200 percent among teens aged 14 to 19 in the past decade.

A team of researchers from the University of Washington and Seattle Children's Hospital spent five years reviewing records of pediatric patients treated for sports concussion.

Their goal was to determine if MR revealed structural changes in the brain that could be related to persistent symptoms.

Concussion symptoms in adults usually disappear within several days. However, post-concussive effects such as headaches, irritability and cognitive difficulties can persist for a month or more in about 25 to 30 percent of children.

Although almost 13 percent of the children in the study underwent MR, the team found that the exam rarely identified brain injury.

John T. Povlishock, editor-in-chief of the journal, believes that these findings provide important guidance for clinicians caring for children with persistent symptoms of concussion.

"While not endorsing a prescriptive approach, this report does provide important insight for those clinicians considering conventional MRI in children with persistent concussive symptoms," he said in a statement.