Last modified on Fri 12 Mar 2021 13.00 EST
From the earliest X-rays to the latest body scanners, the ability to visualise the inside of the living body has revolutionised medical diagnosis. With a profound understanding of physics, great technical ingenuity and a mission to put these skills to use in the service of medicine, John Mallard, who has died aged 94, was one of the first to establish routine scanning services that revealed tumours in organs such as the brain and the liver. His team at the University of Aberdeen built the first whole-body MRI (magnetic resonance imaging) scanner and produced the first clinically significant MRI images of a hospital patient.