Large, brown, hard-shelled seed of the coconut palm. One side of the coconut has a deep incision.

Prior to 1980 most techniques for obtaining NMR images produced only two-dimensional projections which were far too inefficient and complex to scale up for use on the human body. C.M. Lai and Paul Lauterbur (1929-2007) addressed this problem in their 1981 paper, "True Three-Dimensional Image Reconstruction by Nuclear Magnetic Resonance Zeugmatography."

Although Lauterbur proposed such 3D imaging as far back as 1973, very few examples of techniques for obtaining these images were ever described. In their paper, Lauterbur and Lai described a procedure that created a complete 3D array of an object, which could be displayed as slice images with any orientation. As an example of the technique, they reconstructed a complete 3D image of this coconut from 30 separate two-dimensional pictures.

They used the coconut for their first tests because of the simplicity of its three components (the shell, the meat, and the milk). This allowed them to perfect their techniques before persuing more complicated projects. The images published in the above-mentioned paper are the first 3D images obtained using the first magnet that was ever constructed specifically for MRI.