He obtained MBChB in 1990. Postgraduate medical education led to MRCP (Member of the Royal College of Physicians) in 1993.
He was appointed specialist Registrar in Radiology at The Northwick Park and St Marks Hospital Trust training scheme in 1994, gaining the FRCR (Fellow of the Royal College of Radiologists) in 1997. By this time he had begun subspecialty training in Neuroradiology at The Royal Free Hospital, The National Hospital Queen Square and Great Ormond Street Hospital. This continued during a year long research post at Atkinson Morley’s Hospital, a specialist Neuroscience centre. He was appointed as a Consultant Neuroradiologist there in 2001.
He now also provides expert opinion in Neuroradiology at Royal Surrey County Hospital in Guildford. Dr Johnson has written many scientific papers and presented work both nationally and internationally. His specialist interests are in all aspects of neurological imaging of the brain and spine and he is familiar with the latest techniques including vertebroplasty. He also performs cerebral and spinal interventional procedures particularly concerned with pain relief. Dr Johnson is able to provide routine and medico-legal second opinions on any aspect of imaging of the brain and spine.