Professor Barker has worked in Magnetic Resonance Imaging research as applied to neurological and psychological disorders for over 20 years.  Much of his work to date has been on technique development, both for image acquisition and processing, and on the optimisation of protocols that make these techniques applicable to patient populations.  He has a particular interest in the implementation and development of quantitative Magnetic Resonance Imaging (MRI) techniques, including T1 and T2-mapping, Diffusion Tensor Imaging (DTI), and quantitative Magnetisation Transfer (MT) measurements.  He is also involved in the development, optimisation and application of functional MRI (fMRI) techniques.

Current research projects - using this battery of neuroimaging techniques - span neurodegeneration, epilepsy, stroke, psychosis, affective disorders, developmental disorders, and normal brain function.

1986 - 1988: University of Florida, USA

On completing his Ph.D. at the University of Nottingham in October 1986, Dr Barker moved to the Department of Radiology at the University of Florida, Gainesville, USA, where his research involved use of ’coherence transfer pathway’ methods to predict artifacts in multiple echo Magnetic Resonance Spectroscopy (MRS) and Magnetic Resoance Imaging (MRI).

1988 - 2002: Institute of Neurology, University College London, UK

In 1988 Dr Barker moved to the Institute of Neurology, University College London, where for a General Electric Signa 1.5 Tesla whole body MR imager was dedicated to the study of Multiple Sclerosis (MS) and related diseases.  In 1995 the MS imager was joined by an identical scanner dedicated to research and treatment of epilepsy.  Early work concentrated on Magnetisation Transfer, and the NMR Research Unit was one of the first in the world to be able to reliably measure the Magnetisation Transfer Ratio ((MTR) a marker of myelin integrity) and later to estimate parameters including the ‘bound water fraction’, potentially allowing demyelination (and re-myelination) to be quantitatively assessed. Dr Barker’s work also involved other quantitative techniques such as relaxation time measurements and diffusion imaging, and “firsts” from this time include the first in vivo diffusion images of the human cervical spinal cord and the first in vivo mean apparent diffusion coefficient maps for the human optic nerve.

2002- Present: Institute of Psychiatry, King's College London, UK

In 2002 Dr Barker became Professor of Magnetic Resonance Physics at the Institute of Psychiatry, Kings College London, where for many years the Neuroimaging Research Group (NRG) has used MR scanning in the study of psychiatric and neurological disorders. The NRG is now part of the Centre for Neuroimaging Sciences (CNS), a joint venture of the Institute of Psychiatry and the South London and Maudsley NHS Foundation Trust, partly funded by the award of a Wellcome Joint Infrastructure Funding bid. Completed in early 2004, the centre provides, under one roof, an interdisciplinary research environment that combines on-going technical developments in high resolution structural, functional and metabolic mapping techniques, with expertise in the definition, diagnosis and treatment of neurological and psychiatric disorders.

Quantitative Magnetic Resonance Imaging (MRI) techniques, including T1 and T2-mapping, Diffusion Tensor Imaging (DTI), and quantitative Magnetisation Transfer (MT) measurements.