Magnetic resonance imaging (MRI) is familiar to us all, and with some 36,000 scanners and 100m scans undertaken annually, it is hard to imagine a world without it. Yet it is only 40 years since the development of the MRI scanner, which revealed internal human anatomy in exquisite detail and revolutionised diagnostic medicine. Sir Peter Mansfield, who has died aged 83, was its inventor and principal architect.

MRI uses the magnetic properties of hydrogen nuclei and in particular, those found in the water molecules that constitute more than half of our bodyweight. In a magnetic field they have two possible states, parallel and opposed to the magnetic field. A radiofrequency field precisely tuned to the energy difference between them will induce a transition (resonance). Mansfield realised that, in a magnetic field gradient, the resonance frequency would correspond to position, enabling an image to be generated.

He wanted to use this to study crystal structure, but he could not generate strong enough gradients. Biological samples proved more amenable – a lupin stem from his garden, an okra seed pod from the greengrocer, and, in 1976, in the first demonstration of live human anatomy, the finger of his PhD student. But could the magnets be scaled up to accommodate the whole human body? Peter convinced the Medical Research Council they could and within two years was himself the subject for the first whole body scan in his prototype machine, now in the Science Museum in London.

The scan took place the evening before he and I were due to fly to the US for a conference. Ian Pykett and I were at the controls, Peter’s wife, Jean, and my future wife were present in case of difficulties – an analysis sent to us by a respected imaging scientist suggested that switching the field gradients at the rate we intended could induce a cardiac arrest. It did not and 50 minutes later Peter emerged, unscathed. But he was not satisfied; he wanted much faster scans so he could “freeze” the beating heart.

His brainchild, echo-planar imaging (EPI), a technique that required even faster switching of the magnetic field gradients proved the answer. EPI is technically challenging and was not made available on commercial scanners for more than another decade. The problem was the eddy currents it generated in the magnet bore. Again it was Peter who found the solution, in active screening. The belief that something was possible and the dogged determination to succeed characterised Peter. He was an inventor par excellence, and the development of MRI can be followed in his patents.

MRI reveals injury and disease on the basis of structural abnormalities. It is the diagnostic method of choice for many applications, particularly in the brain. EPI underpins a newer technique, functional MRI (fMRI), which exploits the changes in blood flow and oxygenation to identify regions of brain activity. With its ability to unlock the secrets of the human mind and to identify the brain networks affected in psychiatric disorders, fMRI promises a second revolution in diagnostic medicine.

At a recent meeting to celebrate 25 years of the Sir Peter Mansfield Imaging Centre at Nottingham University, Peter expressed his pleasure that a few people were still interested in developing what he had started. The lecture theatre was of course full to capacity.

Peter was born in Lambeth, south London, to Sidney George Mansfield, a gas fitter, and Rose Lillian (nee Turner). The youngest of three brothers, Peter grew up in Camberwell. His early education was disrupted by war evacuations and he left school aged 15, having failed his 11 plus and with no formal qualifications. When asked about science, his careers officer said he “should consider a career in something less ambitious”, and so he took a job in a printing works as an apprentice compositor.

For Peter, growing up through the blitz had not proved to be the terrifying experience one might imagine; he had been fascinated by the V1 and V2 rockets that fell on London in 1944 and wrote to the editor of the Daily Mirror asking how he could find a job in rocket science.

He was told to contact the Ministry of Supply, and so he began work in its Rocket Propulsion Department in Westcott, Buckinghamshire. His studies at evening classes led to A-levels and a place at Queen Mary College, London, to read physics. He continued there studying for a PhD in nuclear magnetic resonance and was the first to observe the phenomenon of solid (“magic”) echoes – the reappearance of a signal long decayed, as if time had been reversed.

In September 1962, the same year he completed his PhD, he married Jean Kibble. After a postdoctoral fellowship with Charles Slichter at the University of Illinois, in 1964 he was appointed lecturer in physics at Nottingham University, where, despite many offers to move, he remained for the rest of his scientific career, as professor of physics from 1979 until his retirement in 1994.

Though Peter generally eschewed foreign travel, he was an excellent linguist, particularly proficient in German and Russian. He remained interested in flight and, for many years, he offered as an undergraduate project the development of a man-powered helicopter. Peter himself flew light aircraft and helicopters, but his flying ambitions were eventually curtailed by ill health.

Peter was elected fellow of the Royal Society in 1987 and was awarded its Wellcome and Mullard medals in 1984 and 1993, respectively. He was knighted in 1993 and shared the 2003 Nobel Prize for Physiology or Medicine with Paul Lauterbur, a recognition long overdue. The city in which he had worked and lived for more than 50 years also recognised his achievements, conferring on him the freedom of the City of Nottingham in 2013 and naming one of its new trams in his honour.

He is survived by Jean, their two daughters, Gillian and Sarah, and four grandchildren.

• Peter Mansfield, physicist, born 9 October 1933; died 8 February 2017