These coils are normally used to select slices for creating three-dimensional images, but the magnetic fields they create can also be used to exert a force on a small magnetic object inside a scanner.
Google created some seriously nifty infrared camera technology that detects the three-dimensional shape and angle of book pages when the book is placed in the scanner.
A member of the team, Raffaella Righetti of Texas A&M Engineering University, has therefore developed a portable ultrasonic scanner that can give instant three-dimensional images of a bone.