"There is a lot of talk about unnecessary imaging, but even if a test is negative it doesn't mean it was unnecessary, " says lead investigator Susanna Lee, a Massachusetts General radiologist.
While lying in a functional magnetic resonance imaging (fMRI) scanner, 19 volunteers were presented with a series of negative life events, such as being robbed or developing cancer, and asked to estimate the probability that this event would happen to them in the future.