Do You Have Magnets in Do You Have Magnets in your Body?your Body?

Presentation to Matthews Hall Presentation to Matthews Hall

Grade 3A and 3BGrade 3A and 3B

Tuesday February 6, 2001Tuesday February 6, 2001Grace Parraga MSc, PhDGrace Parraga MSc, PhD

Associate Scientist, Robarts Research InstituteAssociate Scientist, Robarts Research Institute

Assistant Professor, Diagnostic Radiology and Nuclear Medicine, Assistant Professor, Diagnostic Radiology and Nuclear Medicine,

University of Western Ontario and University of Western Ontario and

Pierre’s MomPierre’s Mom

Magnets in your body?Magnets in your body?

After our time together you will After our time together you will know the answers to these know the answers to these questions!!!!questions!!!!

– Are there magnets in your head?Are there magnets in your head?– Are there magnets in your knee?Are there magnets in your knee?

– Are there MAGNETS IN YOUR BODY?Are there MAGNETS IN YOUR BODY?

Magnets in your Body?Magnets in your Body?

First lets take a vote!!!!First lets take a vote!!!!

– How many of you think, YES there are?How many of you think, YES there are?– How many of you think, NO there How many of you think, NO there

aren’t?aren’t?

– YES vote YES vote – NO voteNO vote

(I don’t get to vote or it will spoil the surprise)(I don’t get to vote or it will spoil the surprise)

Magnets in your Body?Magnets in your Body?

OK Let’s Do the Experiment!!!!!!OK Let’s Do the Experiment!!!!!!– Take two bar magnets, line them up Take two bar magnets, line them up

with opposite poles and see what with opposite poles and see what happens ………..RESULT?happens ………..RESULT?

– Take a magnet and place it close to Take a magnet and place it close to your head and see what happens your head and see what happens ……….RESULT?……….RESULT?

Magnets in your Body?Magnets in your Body?

So what do we think after this So what do we think after this experiment? experiment?

Hmmmmmmmm……………..Hmmmmmmmm……………..

ANYONE WANT TO CHANGE THEIR ANYONE WANT TO CHANGE THEIR VOTES??????VOTES??????

Magnets in your Body?Magnets in your Body?

Ok, let’s think about what we know Ok, let’s think about what we know about magnets……about magnets……

What really happens to magnetic What really happens to magnetic particles in bar magnets when they particles in bar magnets when they are placed together??????are placed together??????

Let’s go to the board and think it Let’s go to the board and think it through…..through…..

Magnets in your Body?Magnets in your Body?

The magnetic particles line up similar to The magnetic particles line up similar to each other when they are placed next to each other when they are placed next to another magnetic field, because that’s the another magnetic field, because that’s the easiest thing for them to do - it takes less easiest thing for them to do - it takes less energy than lining up against the stronger energy than lining up against the stronger magnetic field……magnetic field……

Its like your messy room, it’s easier to leave it messy Its like your messy room, it’s easier to leave it messy than clean it up!!!!! NO FORCE IS APPLIED IN THIS CASEthan clean it up!!!!! NO FORCE IS APPLIED IN THIS CASE

BUT IF YOUR MOM COMES BY, sees the mess and gets BUT IF YOUR MOM COMES BY, sees the mess and gets upset, it’s easier to clean it, right? THAT’S THE FORCE upset, it’s easier to clean it, right? THAT’S THE FORCE OF MOM!!!!OF MOM!!!! (stronger than most magnets!!!!)(stronger than most magnets!!!!)

Magnets in your Body?Magnets in your Body?

In the lab, we know that there are In the lab, we know that there are teeny, tiny, very weak magnets in teeny, tiny, very weak magnets in all living tissues, and we know this all living tissues, and we know this because of predictions from because of predictions from physics and math. physics and math.

The trick is how can we see them The trick is how can we see them or measure their strength?or measure their strength?

WHAT experiment would you do?WHAT experiment would you do?

Magnets in your Body?Magnets in your Body?

One way is to stick these very weakly One way is to stick these very weakly

magnetic tissues in a gigantic, strong magnetic tissues in a gigantic, strong

MAGNET and see what happens!!!!!! MAGNET and see what happens!!!!!!

This is the principle of Magnetic This is the principle of Magnetic

Resonance Imaging, (MRI) used in Resonance Imaging, (MRI) used in

hospitals and research today!!!!!!!!!hospitals and research today!!!!!!!!!

Magnets in your Body?Magnets in your Body? Let’s look at what we do in the labLet’s look at what we do in the lab

We use a very, very strong magnet - called We use a very, very strong magnet - called a 4 Tesla strength body magnet - about 5 a 4 Tesla strength body magnet - about 5 million times stronger than a fridge million times stronger than a fridge magnet !!! and spread over an area of a magnet !!! and spread over an area of a metermeter2 2 !!!!!!!!!!!!

We place patients in the magnet - the tiny We place patients in the magnet - the tiny magnets in their head, knee or hand line up magnets in their head, knee or hand line up with the big body magnet (like your room with the big body magnet (like your room getting cleaned up) and with this “signal” getting cleaned up) and with this “signal” we can produce pictures!!!!!!!!we can produce pictures!!!!!!!!

Magnets in your Body?Magnets in your Body?

Lets look at these neat pictures of Lets look at these neat pictures of your body magnets in action!!!!your body magnets in action!!!!

Magnets in your Body?Magnets in your Body?

The big body The big body magnetmagnet

Magnets in your Body?Magnets in your Body?

Pictures of your brain Pictures of your brain opened for a photoopened for a photo Imaged with MRI - no Imaged with MRI - no

surgery, no cuts, no surgery, no cuts, no pain!pain!

Magnets in your Body?Magnets in your Body?

Pictures of the inside of your knee Pictures of the inside of your knee and brain.and brain.

Are they ok? Which is which?Are they ok? Which is which?

Magnets in your Body?Magnets in your Body?

So, let’s vote again……So, let’s vote again……

– Are there magnets in your head?Y/NAre there magnets in your head?Y/N– Are there magnets in your knee? Y/NAre there magnets in your knee? Y/N

– Are there MAGNETS IN YOUR BODY? Are there MAGNETS IN YOUR BODY?

Y/NY/N

Magnets in your Body?Magnets in your Body? How do you make such How do you make such

a big/strong magnet?a big/strong magnet? What kinds of things What kinds of things

can you tell about can you tell about people by looking at people by looking at their body magnets?their body magnets?

THAT’S FOR NEXT THAT’S FOR NEXT time!!!! And thanks time!!!! And thanks for letting me visit!for letting me visit!

Magnets in your Body?Magnets in your Body?

GOOD BYE AND GOOD LUCK GOOD BYE AND GOOD LUCK WITH YOUR BODY MAGNETSWITH YOUR BODY MAGNETS