okay well nottingham university is
famous for
having developed the technique of
magnetic resonance imaging so we thought
that for easter we'd have a go at taking
an image using magnetic resonance of a
creme egg well so we're going into an
area where the magnetic field's very
strong so we have to take out anything
that could be magnetic because there's a
danger it will get pulled into the
magnet
in order to get a signal in mri we have
to use radio waves the creme egg
inconveniently for mri is
surrounded by a metallic foil radio
waves won't pass through this foil so in
in an mr scanner an mri machine what
we're doing is measuring a signal that
comes from
hydrogen nuclei those hydrogen nuclei
they behave a bit like tiny magnets they
line up with the magnetic field and
we're able to excite them in some way
using radio waves which have a very
particular frequency when we excite them
they give us also back a radio wave
signal that's what we pick up and the
signal that we then use to make an image
and the key thing with mri is that we
make the signal a little bit different
depending on where in the object it came
from then we can tell where the signal
came from then in an image we can say
this much signal came from this place
this much came from this place and we
can build up a two-dimensional even a
three-dimensional picture of an object
normally we're obviously imaging human
subjects vast majority of hydrogen
nuclei in the body are found in water
molecules so normally we're looking at
water but there's also actually quite a
lot of hydrogen nuclei in in fat in fact
probably what we're most likely to see
if we see anything in the cream egg is
actually the fat
that's present in the chocolate and also
in the in the cream filling okay so this
is karen who's going to put the things
into the scanner because i'm wearing a
mic which one i can't take into the
magnet your camera also uh
doesn't like very strong magnetic fields
so if you took it too close there's
probably enough ferromagnetic material
in there that it would eventually get
pulled in
we actually first to explain we put in
two cream eggs just to get a bit of a
stronger signal the bright region here
around the outside is the is the
chocolate so probably i guess what we're
seeing there is the fat inside the
chocolate so we've seen the hydrogen
nuclei
in the fatty part of the chocolate then
inside the slightly darker mottled
region is the
is the creamy filling where probably
we're seeing the water in that which uh
is also giving us a signal but there's
also fat in there as well giving rise to
a signal mri is a bit more complicated
than that and the signal depends on a
few other factors like how solid the
material is so that makes a bit more
complicated to explain but it's also
what makes mri a very powerful medical
imaging technique because you can
differentiate between tissues which have
quite similar amounts of water but
slightly different properties in terms
of say their stiffness or how much
proteins there and that's what allows us
to
differentiate disease tissue from normal
tissue in some conditions so as we step
through you can see we're kind of going
from the thick bit of the cream egg down
to the
the thinner bit at the end of the egg
and there it's just chocolate so you can
see that you just have a bright bit and
not much
darkness around it the thing that a lot
of people do is when they first set up a
system a new scanner they don't want to
put a person in first so the thing that
a lot of people scan is fruit
so we've scanned probably
most fruits that are available or
vegetables have been scanned so
pineapple
okra is very good one of the first
images that was ever made in mri was
actually of a red pepper so done by sir
peter mansfield when he was developing
the technique
and he used that to really demonstrate
that imaging was possible and have you
ever imaged a cream egg before today i
have to say i haven't so it's a new
experience for me so we thought probably
it would be a good idea to also look at
some real eggs as well as cream eggs and
see what we can see there we can
probably differentiate the yolk from the
surrounding egg whites let's have a go
at doing that
[Music]
okay so we put actually this time three
eggs three real eggs in here so we're
looking at again the cross sections and
we're seeing the egg whites
which is appearing as this sort of
slightly lower intensity there we're
looking at mainly the water
in the egg white and then the brighter
bit is the the yolk where we're looking
at the
mainly probably the fat we don't see
anything from the shell itself because
the shell has no water or fat in it so
it doesn't give us any signal it's
interesting there's a little bit of air
inside the
the egg which i think if we go up yeah
there there's a little bit of air
which is at the this is basically the
top this is vertically up so the air is
up at the top here
and i think that's that's in there
because the egg kind of after it's laid
it cools down and the fluid shrinks a
bit and it leaves a little air pocket in
there so these are the air pockets in
these other two eggs so again they're at
the top you know the air is at the top
of the of the egg
apparently that's what when you boil an
egg it's the air bit that gives you that
flattened end on the
the round a bit of the of the boiled egg
because what the images we acquired
they're three dimensional they lots of
slices scanning through
and that allows you to then sort of see
the three-dimensional structure
that's i guess obviously much more
useful if you're looking say a set of
brain images and you want to
understand the relationship of you know
different regions of the brain to one
another or to
if you're a surgeon planning an
operation you wanted to find the the
best path to get to a particular
area in the brain this kind of 3d view
can be very useful so it's a 3d
rendering now of the cream eggs so i'm
going to hopefully rotate them around so
you can see
they're actually a little bit different
than one another and there's a little
bright splodge in one of them but not in
the other one which seems to be
on the edge of the chocolate do you like
henry cream mix oh yeah i really like
cabbage
[Music]
will these ones be safe to wait
oh yeah absolutely yeah yeah they'll be
they'll be probably very good
[Laughter]