1. Functional Neuroimaging: a window on the working human brain
23/05/2019
Functional Neuroimaging: a window on the working human brain
Dr. Matt Brookes
Sir Peter Mansfield Magnetic Resonance Centre

2. MRI in Nottingham
1978
2011
MRI now a standard diagnostic tool in hospitals worldwide
~60 million scans performed every year

3. MRI in Nottingham
Professor Sir Peter Mansfield and Professor Paul Lauterbur shared the Nobel prize for physiology or medicine in 2003

4. MRI in Nottingham
0.1 T: 1977
7 T: 2011

5. Structural imaging at ultra high magnetic field Imaging brain function
Overview:
Structural imaging at ultra high magnetic field
Imaging brain function
Functional MRI at 7T
Imaging electrical current in the brain
Measurements of neurochemistry
Conclusions

6. Structural Imaging Images of the Cerebellum at 1.5 T and 7 T
In plane resolution increased from 1mm to 0.4mm

7. Structural Imaging 3T system 7T system
Different relaxation times at 7T means new contrast mechanisms

8. Functional Imaging Time
Functional MRI provides the ability to image human brain function in vivo
Time
Whole head images are acquired in a fraction of a second. This enables rapid, real time imaging of the entire brain.
We detect small changes in blood flow, volume and oxygenation. Therefore we can image brain function.

9. Functional Imaging DIGIT NUMBER
Higher contrast in fMRI at 7T enables functional mapping with high spatial resolution ~1mm
Here we show functional changes due to finger movement

10. Functional Imaging
BLOOD VESSELS
NEURON

11. Functional Imaging BLOOD VESSELS NEURON
Blood flow in the brain can be measured using functional MRI
BLOOD VESSELS
NEURON
We want to measure electrical activity in neurons

12. Magnetoencephalography
A set of 275 magnetic field detectors placed around the head. Sensors can measure field changes to an accuracy of ~10fT
Measure the magnetic fields induced outside the head by flow of current through electrical cells in the brain

13. Magnetoencephalography
Technical Challenge:
Measure magnetic field outside the head, and turn it into an image of current density in the brain
MEG Beamformer
Projects sensor space data into source space and allows imaging of electrical brain activity

14. Magnetoencephalography
Change in brain current induced by a moving visual stimulus (rotating wedge)

15. Magnetoencephalography
BOLD fMRI
MEG -ERS
The MEG signal is rich in information with a range of detectable
The time scale of the electrical effects is at the ms level whereas BOLD ~ 5-8s
Nevertheless BOLD and neuro-electrical effects are closely related
MEG mirrors invasive recordings made in animal brains
MEG -ERD
MEG -ERS

16. Functional Imaging BLOOD VESSELS NEUROCHEMISTRY NEURON
Blood flow in the brain can be measured using functional MRI
BLOOD VESSELS
Can we gain insight into neurochemistry?
NEUROCHEMISTRY
NEURON
Measure electrical activity using MEG

17. MR Spectroscopy
In MRI we measure the distribution of free water in the body
However, MR is sensitive to the molecular surroundings of water molecules and so measurements can be chemically specific
MR spectroscopy therefore enables measurement of the concentration of different neuro-chemicals is specific brain regions
Example of MRS showing metabolite concentrations in the visual cortex

18. Our work has begun to use MRS to investigate the neurochemical origin of electrical brain activity
We have shown significant correlations between the concentration of neurotransmitters and the frequency of electrical signals
These exciting new results have the potential to explain both normal brain processes, and how they are perturbed by disease.

19. Conclusions
Structural imaging has been revolutionised at 7T with increased spatial resolution and novel contrast mechanisms enabling new clinical insight.
Functional neuroimaging offers exciting insights in to the internal workings of the human brain.
We can measure blood flow, electrical activity and neurochemistry non-invasively using fMRI, MEG and MRS.

20. Conclusions cont…
Neuroimaging is multi-disciplinary and success requires collaboration between Physicists, Statisticians, Engineers, Neuroscientists, Medics, Psychiatrists, Psychologists…
Nottingham’s continued success in this area is based on academic excellence across multiple subject areas
Continued development and clinical application of neuroimaging technology will ensure that the next 30 years is even more exciting that the last 30 years!!

21. THANKYOU!
Prof. Sir Peter Mansfield, Prof. Peter Morris, Prof. Richard Bowtell, Prof. Penny Gowland, Dr. Sue Francis and all colleagues at the Sir Peter Mansfield Magnetic Resonance Centre.
Thanks also to the BBC for allowing us to show the tomorrows world clip, which was first broadcast in 1978