On the 2003 Nobel Prize in medicine or physiology awarded to Paul C. Lauterbur and Sir Peter Mansfield

The awarding of this year’s Nobel Prize in medicine or physiology to Professors Paul C. Lauterbur and Peter Mansfield, fills me, as editor of this journal, with great joy and pride—an excitement that I trust the overwhelming majority of Magnetic Resonance in Medicine’s readership shares with me. Both of these Nobel laureates (Fig. 1) have been honorary members of this journal for many years, and this year’s ultimate science prize was perceived by many of us as long overdue recognition for the ingenuity and dedication of two scientists whose work led to one of the greatest innovations in diagnostic medicine. Here I take the liberty of briefly recounting what I believe are the key historical events in the evolution of a field of science and technology that has revolutionized medical diagnostics, and without which neither this journal nor the society it serves would exist. Of course, this note is not meant to be an account of the early history of MRI per se (which is covered, for example, in Ref. 1), and thus it falls far short of doing justice to the many early contributors whose work led to the creation of whole-body clinical MRI. As Becker et al. (2) so eloquently stated in the Encyclopedia of NMR: “The history of NMR, like any history, has no real beginning. Every development, every discovery, can be traced back to antecedents that provided basic theory or applicable technology ready to be exploited. ” In 1973, two papers on NMR were published. Neither of these works received a great deal of attention at that time, and perhaps the majority of those who read them considered them to be esoteric at best. One, authored by Dr. Paul Lauterbur, then Professor of Chemistry at the State University of New York at Stony Brook, appeared in Nature and was entitled “Image Formation by Induced Local Interactions: Examples Employing Nuclear Magnetic Resonance” (3). It introduced an NMR method that generated a series of spectra by exposing an object (in that particular case, two water-filled vials) to a magnetic field gradient during signal collection. The experiment was performed on a 60 MHz Varian A 60 spectrometer (the first mass-produced NMR spectrometer for structure analysis). Like the majority of NMR systems, the electromagnet-based spectrometer used continuous-wave excitation, achieved by sweeping the magnetic field across the spectral resonances. The magnetic field gradient was generated by the system’s linear z-shim. Lauterbur recognized that the spectra obtained in this manner represented projections of the object’s spin density distribution onto the gradient axis, and that by rotating the object in equal angular increments, one could obtain a series of angular projections. He was also aware of the mathematics of back projection used in computed tomography. Because the interaction can be regarded as a coupling of two fields (polarizing and gradient), Lauterbur dubbed the technique “zeugmatography” (derived from the Greek word —“that which is used for joining”). Lauterbur also understood the signal modulations induced by differences in relaxation times. In this particular case, this was achieved by doping one of the samples with Mn ions and cranking up the power of the B1 field to achieve partial saturation of the sample with the longer relaxation time. Almost at the same time, Dr. Peter Mansfield, along with postdoctoral research fellow P.K. Grannell in the Department of Physics at the University of Nottingham, published a paper with the provocative title, “NMR ‘Diffraction’ in Solids? ” (4). In this study they explored the potential of NMR for mapping the 3D structure of crystalline solids, in a manner analogous to X-ray crystallography. Their objective was to evaluate the feasibility of observing diffraction in the free induction decay (FID) resulting from interference of the signals emanating from different lattice sites in the presence of a linear field gradient. In analogy to diffraction of monochromatic light at a grating, the point sources at the lattice sites would accumulate differential phases by virtue of the different frequencies at which the spins resonated in the gradient field. The authors concluded that in the case of solids, such an experiment