COMMENT OBITUARY Peter Mansfield (1933–2017) Physicist who developed MRI, revolutionizing medicine.

illions of people have benefited Mansfield was the brave guinea pig, and from an insight that Peter Mansfield became the first person to have their abdo- had in 1972, which led to the men imaged using the relatively speedy Mdevelopment of magnetic resonance imag- technique of line-scan MRI. ing (MRI). A classically trained physicist, Imaging speeds concerned Mansfield, Mansfield realized he could exploit the and in 1977 he developed echo-planar phenomenon of nuclear magnetic resonance imaging (EPI) to address the problem. EPI RANN CHANDRIC/EYEVINE (NMR) to create cross-sectional images of requires rapidly switched magnetic field living tissue. The safe and non-invasive tech- gradients to collect the data needed to form nique he developed images soft tissue and an entire image in a fraction of a second, organs in a ‘slice’ of an organism in spectacu- about 100 times faster than earlier methods. lar detail, revolutionizing medical diagnosis Mansfield developed this mainly for and changing how the human brain is stud- cardiac imaging, producing the first real- ied. The work won him a share of the 2003 time MRI observations of coronary vessels. Nobel Prize in Physiology or Medicine. The first MRI scanner for clinical use was Mansfield, who died on 8 February, was built in 1980 at the University of Aberdeen and born in London in 1933, in the most ordi- was on the market by 1984. The technique’s nary of circumstances. His father was a gas non-invasiveness and excellent soft-tissue fitter, his mother a waitress. His school edu- contrast led to dramatic developments in cation, disrupted by war, ended at age 15. diagnostic radiology, driving a new industry. Working in a printing firm, he continued In the late 1980s, having been recruited his schooling at evening classes, and later from Mansfield’s Nottingham lab to the US worked in the rocket-propulsion depart- National Institutes of Health, I showed that ment of Britain’s wartime Ministry of Supply EPI could instantaneously map changes in in Westcott. After a stint in the army, Mans- distribution of spins. In a key experiment, he cerebral blood oxygenation, which led to field studied science in part-time courses applied a magnetic field gradient (an uneven functional MRI (fMRI) techniques, now used that took him into a physics degree at Queen field) to a sample of millimetre-thick layers to probe human brain activity in real time. Mary College, London, at the age of 24. of camphor, a waxy material, between plastic Mansfield was elected a fellow of the Royal Here, he established an enduring link with sheets, and measured the NMR spectrum. Society in 1987 and knighted in 1993. He NMR physicist Jack Powles. NMR exploits The field gradient spread out the NMR signal held many patents and felt it important that the fact that nuclei of certain atoms, including into an unmistakable diffraction pattern of inventors were properly rewarded. Signifi- hydrogen, act like tiny bar magnets and line the layers. This information could then be cant patent royalties and increased research up in a magnetic field. Subjected to pulses of reconstructed as an image using the well- funding led to the opening of the Sir Peter a radio-frequency magnetic field, their align- known mathematical Fourier transform. Mansfield Imaging Centre, dedicated to MRI ment is disturbed, and a signal can be detected Mansfield learned that Paul Lauterbur research, at Nottingham in 1991. as their magnetization returns to equilibrium. (who later shared the Nobel prize) had Peter (always known to his team as ‘PM’) From this, the structure of the molecules in almost simultaneously shown that rotating a retired in 1994 but continued to collaborate which the atoms sit can be inferred. magnetic gradient could produce crude with colleagues. His leadership, enthusiasm, In 1959, as a PhD student, Mansfield dis- NMR images of liquids. So he, too, moved to meticulousness and scholarship set a high covered an unexpected ‘solid echo’, observ- imaging liquids, given the potential for imag- standard. Always devoted to the experiment, able in some solids following a pair of NMR ing living tissue with its high water content. he was happiest in the lab. He also loved radio excitation pulses. The finding required Mansfield invented a way to select a slice of languages, and once arranged for a postdoc sophisticated quantum mechanics to explain, a material to be imaged, and a key concept, to teach his research team Arabic. Warm and caught the attention of NMR pioneer ‘line-scan imaging’, to create the image. This and generous, he nurtured a steady flow of Charles Slichter, who invited Mansfield for a work was part of a succession of ground- talented PhD students to supply the postdoc at the University of Illinois, Urbana. breaking papers and the first book on MRI, burgeoning field of MRI science. Many Soon after he was recruited by Raymond NMR Imaging in Biomedicine (Elsevier, 1982). remember fondly his profound unpreten- Andrew, his PhD examiner, to the physics In 1977, Mansfield’s team created the tiousness — his often-repaired spectacles department at the University of Nottingham, first MRI image of a live human body part, and worn-out shoes — and his wry smile. ■ UK, where he remained for the rest of his a cross-section of a student’s finger. This career (and where we met). enabled the group to obtain funding for Robert Turner is emeritus director of In 1972, Mansfield was struck by the a magnet large enough to scan the entire neurophysics at the Max Planck Institute possibility that NMR could be an alterna- human body. In 1978, Mansfield and his for Human Cognitive and Brain Sciences tive to X-rays for studying crystal structures. team were confident enough in the scan- in Leipzig, Germany. He collaborated He realized that he could formulate spin ner they had built to image a human — with Peter Mansfield at the University of physics in ‘k-space’, a mathematical concept although they had concerns that the large Nottingham from 1984 until 1988. used in crystallography, to image the spatial magnetic field could induce a heart attack. e-mail: [email protected]

180 | NATURE | VOL 543 | 9 MARCH© 22017017 Mac millan Publishers Li mited, part of Spri nger Nature. All ri ghts reserved.