Under your skin

Imagine what it must have been like to have seen the first x-ray picture of the living human hand? Or of a set of ribs inside a chest?

In the late 19th century “fluoroscopes” were the precursors of our modern x-ray machines and must have had the same “wow” factor as the first television sets.

(Fluoroscopes provided moving images…so you could see your fingers wiggling back at you!)

The discovery of x-rays was a game changer for the medical professions.

The Early Days

In 1895 the German physicist Wilhelm Roentgen discovered a new type of radiation which he called “X radiation” (as it was “unknown”). He found that they could pass through solid objects… books, papers… and of course his wife’s hand!

Frau Roentgen’s hand became the first ever medical x-ray (she apparently said “I have seen my death”). The radiation became known as “X rays” (but are still called Roentgen rays in some other languages).

We all know that x-rays need to be used safely. But that wasn’t known by the early pioneers of this scientific discovery. The first users of x-ray machines inadvertently subjected themselves to high doses of x-rays. X-ray machines were brought along to dinner parties where the taking of a chest x-ray was viewed as a diverting parlour trick!

Radiation was “fashionable” in other ways…it was considered to be a healthy in small doses. Water from hot springs had been found to be radioactive due to the presence of the metal Radium and these springs became popular health tourism destinations. Radium products were incorporated into bath salts, toothpastes, hair creams… even food!

How do they work?

Nowadays the use of x-rays (and of radioactive substances in general) is rather more controlled! Healthcare professionals have rigorous training to ensure that the right x-rays are taken safely for our patients.

But how do this technique actually work? What is so special about x-rays?

X-rays are part of the electromagnetic spectrum (EMS). Visible light is also part of the EMS and has energy waves of differing “wavelengths” which you see in a rainbow. Red represents longer waves, violet shorter, with all the colours we know in between (Richard Of York… etc).

Ultraviolet radiation (which is invisible to the human eye but you can see its effects… it gives you your holiday tan) is shorter wavelength than visible light. X-rays have a shorter wavelength still.

If visible light hit an opaque (i.e. non-transparent) object such as a hand, some of the waves are absorbed, some are reflected (this contributes to what we see as the “colour” of the hand). But none of them pass through.

If x-rays hit a hand, some of them pass right through and some will be blocked. And what kind of substance blocks x-rays? Bone.

So if a photosensitive plate is placed behind the hand, it will pick up all the x-rays that have passed through but none of those that were blocked. This is what gives the white/ black look on a x-ray film… and how we can see the bones of your hand.

Under the skin

X-ray techniques allow doctors to “see” into your skull, your chest, your jaws, your limbs. This can help in making a more accurate diagnosis for all sorts of conditions. And a more accurate diagnosis means more effective treatment planning.

X-ray films allow us to see limb fractures, bone abnormalities and signs of infection. They can pick up anatomical features, fluid levels and even soft tissues shadows.

“Barium swallows” can help diagnose problems of the gastrointestinal tract.  CT scans can produce detailed images of structures in your body such as the internal organs, blood vessels and tumours.

And what about orthodontics?

Most patients who start orthodontic treatment have dental x-rays taken before braces are fitted. What kind of things are we looking for?

• Are your teeth healthy? Is there any tooth decay that needs treating before braces are fitted?
• Is the bone around your teeth healthy?
• How long are the roots of your teeth? If they are quite short, it may not be a good idea to have braces
• If some teeth have not come through, why haven’t they… and where are they!?

There are other reasons why dental x-rays may be taken by your orthodontist. We will always let you know why they are being taken… and we will be more than happy to show you what you look like on film!!

Want to know more?

How Stuff Works – Learn about everything!

X-ray photography by Hugh Turvey – See the world in a different light

X-ray movie of how a fly moves – From the New Scientist

Image courtesy of fotographic1980 / FreeDigitalPhotos.net