Generation of depth-perception information in stereoscopic nuclear magnetic resonance imaging by non-linear magnetic field gradients.

Stereoscopic NMR images have been produced in the past. However, because of the gradients are linear, only isometric projections can be produced, i.e., they do not carry correct depth-perception information. The resulting stereoscopic image will not have correct relative sizes at different depths. This paper gives an analysis of what perception information is needed and shows that it can be produced by a non-linear magnetic field gradient. The concept is exemplified by simulations and its implementation is demonstrated successfully by experiments. The depth-encoding gradient can be generated by static steel pieces or by current loops. The procedure can be incorporated into any existing hardware and pulse sequences, and has potential application in surgery.