Digital subtraction angeography - Imaging in medicine (12/13)

Uploaded by OUlearn on 25.07.2008

We're going to look at your arteries.
This patient needs an examination
to look at the blood flow in his femoral arteries.
This is going to be carried out
using a technique called digital subtraction angiography.
A fluoroscopy system is used.
This consists of an x-ray source, in this case under the bed,
and an image intensifier above.
The image intensifier produces continuous digital images
which are displayed on a monitor and can also be recorded for later use.
The doctor will pop a needle into your artery
and put a tube up and inject some x-ray dye.
You'll get a warm feeling as the dye goes down your legs
and we'll take pictures of what's happening.
All you have to do is lie there nice and still
and we'll tell you what's going on as we go along.
The dye mentioned is a contrast medium containing iodine.
As iodine has a high atomic number,
it attenuates the x-rays far more than blood or soft tissue.
So if it's injected into the bloodstream,
the blood vessels will show up clearly on an x-ray image.
You'll feel a little sting in the groin.
I'm going to put the needle into the artery
and I'm going to put the guide wire up through the artery.
You shouldn't feel much now.
Once the catheter has been inserted a remote control pump can be used
to introduce the contrast medium to the patient's artery.
So you'll get that very warm feeling now
and then the camera's going to move down your legs.
So just keep absolutely still.
Continuous digital images are taken
before and after the injection of the contrast medium.
When one is subtracted from the other
an image clearly showing the blood vessels is obtained.
We're going to keep you there while Dr Jackson looks at the pictures.
All right, that's fine. I've seen all the pictures now quickly
but I need to have a proper look at them later.
But I haven't seen any major problem at all.