He has continued his interests in imaging in several ways, including as Chair of the Imaging Working Group for UK Biobank, which is pioneering an ambitious programme for very large population imaging as part of the UK Biobank (Prof Sir Rory Collins, CEO). MRI scanning of the brain, heart and body, along with DEXA and 3D carotid ultrasound, was initiated in a dedicated imaging centre at UK Biobank's Cheadle (Manchester) site in May, 2014. This has developed into a broader commitment to large data analytics through collaborative work with colleagues in the Imperial College Data Science Institute and the EPSRC Centre for Mathematics in Precision Healthcare, in which he is a co-investigator.
Amongst many external commitments, Professor Matthews is Chair of the MRC Neurosciences and Mental Health Board and a member of the Executive Committee for the UK Dementias Platform, the Steering Committee for UK Biobank, the Netherlands Organisation for Scientific Research Spinoza Prize Committee, the Japanese RIKEN Brain Dynamics Research Centre Advisory Council and the Canadian Multiple Sclerosis Society Medical Advisory Committee. He is a Fellow by Special Election of St Edmund Hall, Oxford, and a Visiting Professor in the University of Oxford, McGill University and Nanyang University's LKC School of Medicine.