history of radiology


X-rays are a form of electromagnetic radiation. Light in colors visible to the human eye have longer wavelengths than x-rays, which are invisible to the human eye. At the longer end of the electromagnetic spectrum are microwaves and radio waves – also invisible to the human eye, but with longer wavelengths than visible light.

Because x-rays are so short, they can penetrate solid objects like many of the tissues that make up the human body. Medical x-ray images are created by sending an x-ray beam through a part of the patient. The beam is picked up by a detector on the other side of the patient. Because some, but not all of the x-ray beam is absorbed, the x-ray image appears as lightness and shadow.

X-rays revolutionized medicine, allowing doctors to see much of what goes on inside the body without cutting it open. They’re responsible for the entire specialty of radiology, and allow radiologists to see normal structures inside the body as well as fractures, abnormalities, and foreign objects.

A Brief History of X-Rays

Discovered in 1895 by a German physicist named Wilhelm Roentgen, x-rays were the result of experiments with streams of electrons in vacuum tubes known as cathode rays. After completely covering a glass cathode ray tube with black cardboard, Roentgen noticed that a glow was nonetheless projected on a fluorescent screen several feet away. The first medical image made with x-rays was of the bones in Roentgen’s wife’s hand.

Roentgen’s discovery of x-rays marks one of the most important medical discoveries in history. Roentgen, a PhD-level physicist at the University of Wurzburg, upon seeing the projection through the cardboard-covered cathode ray tube, quickly hypothesized that the tube was emitting a light ray that could penetrate solid objects while remaining invisible to the eye.

He wasn’t believed at first. Renowned physicist Lord Kelvin pronounced the new rays a hoax, though it didn’t take long for other scientists to replicate Roentgen’s work. Ultimately, Roentgen won the first Nobel Prize in Physics in 1901 for his discovery.

The Rapid Adoption of X-Rays in Medicine

It only took a few months after Roentgen’s announcement before scientists everywhere were experimenting with x-rays. The very next year, the Glasgow Royal Infirmary set up one of the first ever x-ray departments. There, a Dr. John Macintyre produced several x-ray “firsts” including the first x-ray of a kidney stone and one of a coin swallowed by a child.

Soon, x-rays were being used to make diagnoses. By the time of the Boer War in 1899, x-rays were being used to treat soldiers, and they were in even wider use by the start of World War I, helping field doctors find fractures and embedded bullets and shrapnel. Eventually the dangers of x-rays and ionizing radiation in general, were understood, but at the same time, the damaging properties of x-rays were discovered to be powerful in fighting some types of cancer.

Interesting Facts About X-Rays

X-rays are made up of especially energetic photons emitted by electrons orbiting the nuclei of atoms. Because they are so short, x-rays allow visualization of structures smaller than the wavelength of visible light, such as atomic-scale materials. Furthermore, there are both “hard” and “soft” x-rays. Soft x-rays are quickly absorbed by their surroundings, while hard x-rays are the ones used in medical diagnoses.

X-rays were eventually used in a technique called x-ray crystallography, which allowed scientists James Watson and Francis Crick to discover the double-helix structure of DNA. Other uses for x-rays include x-ray microscopy, which is different from the standard optical microscopy with which most people are familiar. With x-ray microscopy, scientists can use film or another x-ray detector to absorb the rays that pass through microscopic samples, and then recreate images based on what the detector shows.

Advanced X-Ray Technologies

Advanced x-ray technologies, like computed tomography (CT) would not be possible without x-rays. With CT, x-rays are directed through a patient’s body from multiple angles so that a much more detailed two-dimensional image of the interior structures of the body can be created. CT scans have achieved importance in medicine that would be hard to overestimate. A CT scan in an emergency department can confirm or rule out a diagnosis, and has spared countless people from exploratory surgery, allowing them to be treated appropriately and faster than would otherwise have been possible. Modern medicine without CT scanning is difficult to imagine for most doctors.

As mentioned above, the same harmful properties of x-rays have proven to be valuable in treating cancers such as those in the breast and lung, by damaging cancerous cells’ DNA. In fact, radiation oncology is now an important medical specialty and is used to kill leftover cancer cells after surgical removal of tumors. It can also be used in palliative care by allowing radiation oncologists to shrink inoperable tumors, helping relieve pain caused by some forms of cancer.

Recently it was discovered that sheets of graphene, which is a two-dimensional form of pure carbon, could generate surface waves known as plasmons when the graphene is struck by an intense radiation pulse from a laser. The plasmons in turn may be capable of generating their own radiation pulse that could be “tuned” to any wavelength, including x-ray wavelengths. The hope is that such a system will someday enable lower dose x-rays that are safer to patients and medical providers.

Could Roentgen Have Envisioned Radiology’s Fundamental Place in Medicine?

Roentgen knew he had discovered something with the potential to change medicine, but perhaps even he could not have envisioned the prominent position of radiology in modern medicine. The Board-certified owner-operators of SteleRAD not only have extensive expertise in traditional radiology, but also in advanced imaging techniques, some of which don’t use ionizing radiation. The discovery of x-rays revolutionized medicine and ultimately made it so radiologists like those at SteleRAD could contribute significantly to the healthcare of South Floridians by working with hospitals, imaging centers, and physician practices. If you’re interested in learning how SteleRAD can help your South Florida facility, we invite you to call 954-358-5250 or contact us at any time.