Transcript YNIC Presentation

Archbishop Holgate’s School Visit
to YNiC
Wednesday 16th January
A brief introduction
• Running for about 3 years
• Collaboration with
many departments
What do we do?
How we do it
E = mc2
???
Angelo Mosso
Italian physiologist
(1846-1910)
Our Facilities
• 248 Channel MEG machine
• 3 Tesla MRI
• High performance computing cluster.
GRID enabled 100 node G5
It’s All About Magnets
0.0007 Tesla (T)
MRI
3T
0.005 T
MEG
0.000 000 000 001 T
How Strong is the Magnet?
3 Tesla…
Very Strong!
Start with the easy one
Build your own MEG
• MEG measures magnetic field
• You will need some wire and a current
meter…
• Coil your wire into a loop
• Attach to your current meter
• Voila…
Well understood physics
• If you move electricity, you get
magnetism (that’s how a motor works)
• If you move a magnet, you get electricity
(that’s how a generator works)
– As the magnetic field changes we pick up
very small changes in the electricity in our
coil of wire.
But where does the magnetism
come from?
We think with
electricity!
All the brain cells talk
to each other with tiny
electric currents
Magnetic fields are produced
which pass straight through
skull and other tissues
• Magnetic field will generate a current in a
coil
• Fields are small - 1 thousand million
times smaller than a fridge magnet
• Need to use supersensitive coils
(SQUIDS)
• Can sample magnetic field around head
thousands of times per second
• Sensitive to synchronous activity in
about 50 000 brain cells, but that’s ok
because we have about:
100 000 000 000
(so less than 0.000 05 %)
Some applications
MRI
• Principles of MRI are more complicated
• Reliant on weird and wonderful effects
of quantum physics
• Now well established clinical and
research technique
Quantum Mechanics
This is very hard.
No really, very, very difficult indeed.
Don’t worry if this doesn’t make a lot of sense,
or you don’t quite believe me.
(But it’s all true, I promise)
A Slight Diversion
x 100 000 000 000 000 000 000 000 000
Protons
In MRI we actually look at protons
in the simplest atom, Hydrogen,
mostly in water molecules
So how does that help?
• Normally, the direction that these tiny
magnets point in is random
• If we apply an external field, the
magnets want to align with it, in exactly
the same way as a compass
• But they can’t, because they spin
Just like a gyroscope
The protons precess
around the field, like
a gyroscope in the
gravitational field of
Earth
So how do we get pictures?
• In our scanner the protons in Hydrogen
precess about 128 million times a second
• But just like the gyroscope the speed depends
on what else is going on
• As they spin they send out radio waves (like
using a motor near a radio at home)
• And we can tweak the magnetic field to see
where things are happening
• So…at last…we can measure how much water
there is and where it is. (Phew.)
Great, but what about the
pictures?
DTI or tractography:
Gives us the “wiring diagram” of the
brain
Time of Flight or Angiography
Gives us the “plumbing” of the brain
3D reconstructions
High Resolution at 3T
More showing off
fMRI
• As well as structural images we can
investigate activation of brain areas in
certain conditions
• As the brain is used the neurons fire
more rapidly, and use more energy
• Body responds to this by providing more
oxygen to the area
• Excess oxygen is measured via BOLD
Applications
• You name it, we image it
• Different size and shape coils allow the
imaging of any body part
• Many applications from sports injuries to
tumor monitoring
Pretty cool eh?
• We can see inside your head
• We can see what you’re thinking
• Hmm, wait a minute.
Yes Sam, that
was a really
interesting talk
Sheesh, that was boring,
show us the scanners
already!
More immediate problems:
Even bigger (or smaller)
problems: