I'm substituting for Professor Hornegger today.

And when I'm not here, I work for Siemens in, you guessed it, extra imaging.

And so this is my topic.

I like it a lot.

And I hope I can show you that it's pretty useful.

And so I hope none of you will ever need extra imaging in your life.

But if you do need it, I think we're there to help you.

Okay, let's get started.

So this picture has a little quiz for you.

During the lecture, you can try to figure out what that is.

I mean the one on the right.

So that's an extra image of something my kids like very much.

So we have five topics here.

First, I'll give you a brief review of extra imaging fundamentals, very high level.

Then I'll show you some two-dimensional clinical applications.

Then I turn from two-dimensional extra imaging to 3D extra imaging.

We do that using a cone beam 3D tomography, CRM system.

Again, I'll show you clinical applications.

And then I wrap up with a project we did when I was still working at the Stanford University.

There we scanned child mommy, and she was called Sherry, and we won a few prizes for

her.

So you're going to see an award-winning movie.

All right.

So everything in x-ray starts with x-rays.

And you have to generate your x-rays.

So for that, you need an x-ray tube.

And an x-ray tube, in essence, is like your TV at home, just with a much higher voltage

and a different target.

There is no visual energy coming out or light coming out.

There's x-rays coming out.

And how do you do it?

Well, you heat up a filament, which you see here on the right.

And then you have a high voltage between your electrons, which are emitted here, and the

anode, the target.

So then you accelerate the electrons.

They fly.

They hit the target.

And at that point, three things happen.

So these electrons can excite other electrons and atoms, generate heat.

They can ionize the atoms, generate even more heat.

And they can produce something called Bram's Strahlung.

Only 1% of all the energy we put into a tube actually comes out.

And that technology is about 100 years old.

It was discovered in Wurzburg by a guy called Röntgen.

And he won a Nobel Prize for it.

So we're close to home, so to speak.

So what's Bram's Strahlung?

Well, you can look at the guy coming down the hill, taking some curves.

An electron does actually produce Bram's Strahlung, something similar.

So it flies into the atom.