Peter Mansfield discovered that use of gradients in the magnetic field gave signals that rapidly and effectively could be analysed and transformed to an image. This was an essential step in order to obtain MR images. Mansfield also showed how extremely rapid imaging could be achieved by very fast gradient variations (socalled echo-planar scanning). This approach became possible in clinical practice a decade later.

object (camphor and cardboard)	spectrum
three layers without gradient (blue) and with gradient (red)	result without gradient – only one peak
signal	image
mathematical transformation of the signal	result with gradient – three peaks