An apparatus and a method for increasing the magnitude of the magnetic gradient for MRI without causing nerve stimulation. As an example, the short ramp time of magnetic gradients, for example less than 150 microseconds is contemplated. These short ramp-time magnetic gradients are used for the imaging of structures with short relaxations times, such as teeth, without causing nerve stimulation. The apparatus comprises a generator of magnetic gradients of at least 1 milliTeslas in magnitude with at least one gradient ramp time shorter than 150 microseconds and which induces no peripheral nerve stimulation.