Professor Hallux: Looking inside the Human Body!

Find out what's Inside the Human Body with Professor Hallux

More From Professor Hallux: Looking inside the Human Body!

Looking inside the Human Body: How Ultrasound Works

How does an ultrasound scanner work?

hallux - radiology

Body has swallowed Professor Hallux’s keys to the fridge, after hearing Nurse Nanobot tell him he needed more iron in his diet! Whoops!

Now Body isn’t very well and he’s in lots of pain! The only thing is, they need to know exactly where the keys are in Body’s body, and they need some cool gadgets to help.

Professor Hallux, Nurse Nanobot and Body have made their way to the Imaging Department in their local hospital.

There are different types of radiology technology to see inside your body when you’re feeling poorly. And one type uses sound waves to see inside your body. It’s called Ultrasound!


Radiographers doing ultrasound scans are known as sonographers.

Ultrasound don’t use radiation to take images. They use sound waves which are so high in frequency (hence ‘ultra’) that we can’t hear them. But like all sound waves, they bounce! If you’ve shouted into a cave or down a well you can see this in action, it’s an echo! echo! echo!

  • It’s a very safe and painless way to get a look inside, which is why it’s used to see babies inside their mummy’s tummies.


As well as looking at babies, ultrasounds are often used to look at the heart and other squishy organs inside your body. Sometimes they’re used when you’re having trouble with muscles and movement too.

Even though ultrasound tests are simple, you still might have to prepare a bit.

  • If the scan is on your lower tummy, you might be asked to drink plenty and hold in your wee for an hour or two.
  • Or you might be asked not to eat for a little while beforehand so that there isn’t too much food in the way.
  • You may well be asked to wear a hospital gown to avoid getting any squidgy gel that the sonographer uses over your clothes.

You are normally asked to lie down on a bed and the area to be examined is exposed. Don’t worry, the rest of your body remains covered. A squidgy gel is then applied to your skin in the exposed area to help the sound waves pass in and out of your body.


The sonographer will then place a ’probe’ – that’s a smooth hand held device – onto your skin and move is over your skin using gentle pressure. It’s moved with a sliding action to allow an image to be created on a television screen.

Mostly it just feels a bit cold thanks to the gel! Although longer than an X-Ray, it doesn’t take much time for each ultrasound scan to be made, maybe 15 minutes each.

  • During the examination you might be asked to roll over a bit or breathe in and out.
  • These movements can help the sonographer get a better look and helps them see what the problem is.

One of the great things about ultrasound is that it doesn’t matter if you wriggle a bit.

  • Whilst other scans need you to be as still as you can, it’s not as important with an ultrasound – like the difference between holding still for a photograph but being able to move for a video.
  • Although being as still as you can be certainly helps the sonographer! It sounds like the perfect scan for Body who finds it really hard to sit still!

Click here for a virtual tour of a real Imaging Department!



Click on a topic below to explore more radiology!

[related tag=”radiology”]

> Visit the Inside The Human Body homepage
> Download the free Inside The Human Body podcast from iTunes

Professor Hallux: Looking inside the Human Body!

Find out what's Inside the Human Body with Professor Hallux

More From Professor Hallux: Looking inside the Human Body!