How a CT Scan Works by Vanderbilt Biomedical Engineers

The workings of the Computed Tomography Scan described through the music of some of Disney's classic songs.


"A Whole New Scan"
(to the tune of "A Whole New World")

I can show you your brain
kidney, liver or pancreas
Tell me, princess, now when did
you last see your heart in 3D

Now we can use CT
Computed Tomography can go
Over, sideways and under
In a helical CT scan

A whole new scan
created by Hounsfield in '72
Using lots of X-rays
and detector arrays
that measure x-ray intensity

A whole new scan
the electrons start off in a tube
they come from a heated source
and then fly towards
the anode that sends photons out to you
the anode that sends photons out to you

the xrays fly through your body
attenuated by tissues
bone or skin, fat or muscle
affect xrays differently

A whole new scan
Don't you dare move around
as the scanner moves around your head
Hold your breath now, I'm serious
beams that went through you now
will be less intense
because of what Beer's law has done to them

A whole new scan
detectors gauge intensity
and now that, that is done
here comes the fun
of using math to visualize your brain

A whole new scan
A whole new scan
The CT scan
The CT scan
Tomography
that's what we'll use
to see your brain



"Back Projection"
(to the tune of "Hakuna Matata")

Back projection, it takes 1D arrays
back projection, it uses many angles
and then it smears them, into 2D matrices
and then it rotates them; each one differently
by their respective angles

So what do you do now?
We add them on top of each other
What's that do?
It gives us the image. A map of attenuation coefficients.
Wait, but wouldn't that be blurry?
Let me explain, take Frankel here!
Why, when he was a young little boy
When I was a young little boy!
Very nice. Thanks.

He fell and hurt his head when he was riding his bike
but he felt really bad cause it was only a trike

I got my head imaged, but it made no sense
cause the image that came out was too blurry to read
and I couldn't understand! no he couldn't see
what's that in my head? Is that a tumor?!?
So we need a filter? Yes, that should work!
so let's apply a filt-
CAREFUL! FRANKEL! watch your domain...
Oh. Sorry.

The Fourier transform! It takes the spatial domain
The Fourier transform! converts to frequency...

Now we can fix it, using a frequency filter
Multiply the filter now, with the frequencies
of the blurry image!

Now take, the inverse, fourier, transform!
Now take, the inverse, fourier --

And now we have an image, better than we had before!
And its all because...we used some math
The Fourier Transform!
The Fourier Transform!
Frankel's okay!



"Using CT"
(to the tune of "Under the Sea")

The images we acquire
Are slices through the body, yeah
The doctors, they can scroll through them
to find what they looking for
They looks at them all together
from your head down and through your toes
it all makes a 3D image
what more could you ask me for?

Using CT
Using CT
to look at the heart now
as it is beating
not so easy!
Using a 64-slice CT
we can image so very quickly
we acquire data
in between beats, yeah
Using CT

One thing that the doctor looks for
Is coronary calcium
Plaque builds up inside the vessels
Bad plaque contains calcium
The scan gives us the amount of
calcium in the plaque
A score is then given that can
give likelihood of disease (Oh no!)

Using CT
Using CT
Say someone's tummy
makes them feel crummy
What could it be?
Go to the doctors, what they say?
Get a CT and right away!
What made you quiver?
it was your liver!
Using CT (Using CT)
Using CT (Using CT)
Since you don't feel keen
it could be your spleen
Let's look and see! (let's look and see see see see)

No matter the organ in the gut
surgeons won't have to make a cut
liver and colon
see if they're swollen
Using CT

Using CT (using CT)
Using CT (using CT)
pancreatitis
appendicitis
Any of these?
abscesses in the abdomen
maybe its diverticulitis
is it lymphoma
save you from coma
Using CT
vessels clogged up here
you don't have to fear
Using CT
kidneys all messed up
symptoms don't add up
colon inflamed now?
don't be ashamed now
If you have cancer
we'll find the answer
Using CT

Category:

Education

Tags:

• Vanderbilt
• BME
• CT
• Scan
• Disney
• Aladdin
• Lion
• King
• Little
• Mermaid
• Engineer
• Biomedical
• Computed
• Tomography
• Imaging

[Lpenrose]

What was the original reason for the production? Was this a class project or Problem Based Learning product?

[jotatanv]

You guys rule!!!

Grettings from Chile! :D

[darthporkius]

ct-scanners are so magical lol

greatings from the Rotterdam University faculty of medical engineering.

[nikkibloms]

That. Was. Awesome. :)

[somalitramps]

WTF

[calvinthedestroyer]

Let me guess, This is what interns do all day?

[53525252252]

You can get cancer.

[CarolinaChristie]

LUV it!!!!!!!!!!!!!!

[Misslcd5]

that was brilliant. Made me smile

[dontchaseme22]

lyricsss plsssssss