My primary research consists of development
of magnetic resonance methods for greater scientific understanding
of the human brain.
In the initial stages (1986-88), this
involved precise design of MRI gradient coils, based on the
Maxwell Equations, to allow ultra-fast echo-planar imaging
(EPI), capable of recording the rapid changes in blood flow
associated with brain function. The design principles I established
are now universally employed by MRI scanner manufacturers.
Using a home-built coil, I demonstrated
(1992) that EPI could be used in humans to study brain function
(fMRI) at the high field strength of 4 Tesla, and introduced
the technique at the USA's National Institutes of Health.
Subsequently, as a founder Principal
at the Functional Imaging Laboratory in London, I set up functional
MRI methodology, forming the Physics Group for this purpose,
now headed by Dr Ralf Deichmann. This Group also has responsibility
for the cognitive interface between experimenter and subject
that allows well-designed and properly controlled functional
brain mapping experiments to be performed.
Water mobility in the brain can be
measured with MRI (diffusion-weighted imaging, DWI), but to
avoid artifacts due to head motion it is necessary to use
EPI. I was the first researcher (1990) to demonstrate this
technique, which is now used widely to map brain abnormalities
and to track the axonal bundles of nerve fibres connecting
brain regions. I continue to investigate potential improvements
in MRI methods for fibre tracking.
MRI has the
capability to detect subtle differences in brain tissue. My
primary goal now is to useMRI to provide excellent anatomical
depiction of the human brain. With the FIL Physics Group I
improved existing techniques for this purpose.
Moving in 2003 to the adjacent High
Field Laboratory headed by Professor Roger Ordidge, I continue
to refine MRI anatomical techniques to a point where intracortical
details can be visualized. Combining grey matter anatomy,
axonal fibre connectivity, and functional brain imaging, it
is becoming possible to map the functional organization of
individual's brains in fine detail, and to correlate this
with underlying anatomy. Currently I am pursuing this research
using the 4 T MRI scanner at the Research Center in Jülich,
Germany, with Professor Jon Shah and Professor Karl Zilles.
Secondary research areas are: the
anatomy and logistics of cortical surface vasculature; investigation
by fMRI of brain systems involved in production and perception
of music; and integration of the insights of social anthropology
with models of brain function.