Miniature PET Brain Scanner Allows Patients to Stand and Move

Patients undergoing a positron emission tomography (PET) scan in today’s bulky, donut-shaped machines must lie completely still. Because of this, scientists cannot use the scanners to unearth links between movement and brain activity. What goes on up there when we nod in agreement or shake hands? How are the brains of people struggling to walk after a stroke different from those who can?