Ultrasound

Transcript

Let’s talk about ultrasound, in fact when we could do ultrasound, for a minute. Let me explain first of all how it works. So these sound waves come out of this ultrasound machine, out of that little wand if you’ve seen it. And those sound waves go down through the tissue and most of them go right on through and hit the floor. But every now and again one will go down, hit the tissue and bounce back and then that transducer spends most of its time listening. And then it will take that echo of sound and put it through the computer and turn that echo into a pixel, a white dot so that we can put it on a screen. So if you look at this baby for example, can you see that profile? Look up here on the forehead. You can tell that’s a forehead because there are a lot of white dots there. It’s because it’s a bone and bone is dense and so it has a lot of sound wave reflection. That’s why it’s shades of gray. So you can see over here where the fluid is, there’s not many sounds because the sound waves don’t bounce up, and so forth.

So that’s basically how it works. That magic transducer sends those sound waves down in there and they bounce back as echoes. Now obviously somebody’s got to look at that computer screen and then interpret what those shades of gray mean and that’s our job, as either ultrasound technicians or physicians who do lots of ultrasound.

Now is ultrasound a “yes or no” test? Does it tell you the baby’s going to be normal or the baby’s not going to be normal? I wish, right? Again it can tell us about higher or lower risks. It can detect anomalies and abnormalities and sometimes, fortunately very rarely, we find abnormalities on ultrasound that I can tell you, “Oh, the baby has this and this is what’s going to happen.” Now that really is only in a few cases where things are really bad, you know, and so it’s uncommon that we find things that are “yes or no.” But it is common to find what we call minor ultrasound abnormalities or another term is abnormalities of undetermined significance. These are a collection of little things that seem to happen in about two percent of pregnancies. Each one of these things are themselves associated with chromosome problems and there’s enough of these things, there’s four or five of them so that if we send everybody to do an ultrasound. There’s going to be 10 to 15 percent of the moms who are going to have a result where we find one of these minor abnormalities. Then what? Then you get a phone call, right? I’ll tell you about that in a second.