When you think of X-ray vision, you’re probably tempted to think of the X-rays you’ve seen at your doctor’s or dentist’s office that look like a piece of black film with white shadows showing your bones or teeth.
Those radiographs, as the film images are called, are very much like photographs, but they are not examples of true x-ray vision.
With true x-ray vision, you can see what’s happening inside a person’s body while it is actually happening much more like television than photography. The machine that does this is a fluoroscope, and the process is called fluoroscopy.
Using a fluoroscope, it is possible to actually see someone’s heart beating, and the lungs expanding with each breath. You can watch someone swallow and the food pass into the stomach, and also see the intestines churning.
Fluoroscopic images have a similar appearance to x-ray radiographs, except they’re moving pictures, often recorded just as you would record your favorite TV show.
The underlying principle of fluoroscopy is similar to the principle of radiography, except that the x-rays are absorbed on a fluorescent screen instead of a piece of film. As with your camera, film can only be exposed one time, but the fluorescent screen in a fluoroscope is more like a television screen.
In a fluoroscope, x-rays pass through a patient’s body and cause the fluorescent screen to light up when they strike. Some parts of the body absorb more x-rays than others, so the amount of x-rays hitting the screen at any one spot depends on what they had to pass through. This creates shadows that represent thicker organs and bones that have absorbed more of the x-rays. As the organs and bones move during fluoroscopy, so the shadows on the screen move also, resulting in a motion image.
Because exposure to a lot of x-rays can cause radiation burns and radiation sickness, doctors don’t use fluoroscopy unless it’s absolutely necessary for diagnosing or treating the patient.
INTERESTING FACTS
William Roentgen, a German scientist, discovered x-rays in 1895. He also created the first fluoroscope using a cardboard box. Though it worked, it didn’t work that well.
Thomas Edison discovered a new type of fluorescent screen that made the fluoroscope’s images brighter, which led to commercialization.
Despite Edison’s improvements, the fluoroscopes images were still very faint and had to be viewed in a dark room, requiring the doctor let his eyes adjust to the darkness before starting the procedure. Scientists discovered that by wearing red glasses in lighted areas, the doctor’s eyes adjusted to the dark room much more rapidly. This is probably where the tales of x-ray vision glasses started.
In the 1930s through the 1950s, the Shoe-Fitting Fluoroscope was popular in shoe stores. It was largely an advertising gimmick. When the dangers of radiation became better known, merchants discontinued using the devices.
The age of electronics led to improvements in amplification, creating brighter images, and television technology that allowed the doctor to view the images outside of the fluoroscopy room, possibly saving the lives of many doctors from radiation sickness.
