The action of a video game could help train children to lie completely still before an MRI and avoid the need for general anesthetic.

In an MRI, even the smallest movement can distort the images. Children who can’t lie still for long enough need sedation or general anesthesic. The anesthesia carries a slight risk of minor adverse events, costs hundreds more and has a longer wait time than MRIs that can be done without the medication.

Sometimes children get general anesthetic when it’s not needed and other times, a child has an MRI without the drug and ends up having to come back, said Dr. Jill Chorney, a clinical psychologist at the IWK Health Centre.

At the Halifax regional children’s hospital clinicians such as Chorney are testing whether a video game successfully teaches children aged five to 11 to be still.

When children play "Don’t Stumble, Tumble," they lie on their backs and look up at an iPad screen as Tumble the monkey runs through a jungle.

The monkey balances a bucket of water on his head. Children control the monkey’s moves with their fingers. But if the child fidgets then the bucket might spill and the game is over.

Even the smallest movements are tracked by the game.

Movements and successes are fed into a dashboard read by MRI technicians and physicians who can see the child’s progress, said Nathan Kroll, president of Current Studios, the Dartmouth-based developer of the game.

Currently, the need for general anesthesic is based on judgment alone.

The hope is for the video game to be built right into the MRI machine itself someday so kids can play while they're having the test and stay still until it's over.