by Manny Roman
One evening in November 1895, Wilhelm Conrad Roentgen made the foolish mistake of failing to compliment his wife, Bertha, on the dinner she served him. This event triggered the taking of one of the first and most famous radiographs in history.
In an effort to appease his wife, Roentgen, the researcher credited with the discovery of X-rays, took her to his downstairs laboratory to explain his preoccupation. He had recently been experimenting with an evacuated glass tube (vacuum tube) and had noticed that photographic plates near the tube glowed when the tube was energized by the application of an electric current. He concluded that the cause was a new type of rays emanating from the tube.
Further experiments demonstrated that these “unknown rays” had the ability to penetrate some objects. To demonstrate the wonders of the new rays, he exposed her hand on a photographic plate. The resulting radiograph of her hand, with one ring, was taken on Nov. 8, 1895. This radiograph has become famous as a symbol marking the discovery of X-rays. On Jan. 29, 1896, at a meeting of the Wurzburg Physico-Medical Society, Roentgen demonstrated the new invisible light by taking a radiograph of the two-ringed hand of anatomist Albert von Kolliker. It was Kolliker who suggested the name Roentgen’s Rays. This radiograph serves as the second symbol of the discovery.
A Glimpse Inside
Imagine the delight of the medical research community. The newly discovered unknown rays — X-rays — provided the ability to look inside the human body. Previously, exploratory surgery was the only means for viewing internal organs.
Obviously, at the time of the discovery there were no radiologists and none of the strict regulations on the use of X-rays that are in place today. The early radiographs were produced by the X-rays generated by readily available vacuum tubes. It seems that anybody who could energize these early tubes, by applying electricity to them, began building “Roentgen Ray Outfits,” as the early X-ray producing machines were called, and using them in experiments.
The first clinical Roentgen plate in America was produced in February 1896, in the physics lab of Dartmouth College by the astronomer Edwin Frost. The radiograph was of a Colles fracture of Eddie’s left wrist. He injured himself while ice-skating. The first total body radiograph was produced on multiple plates by Dayton Miller, the dean of physics at the Case School of Applied Sciences in Cleveland in early 1896. He had himself strapped in a frame to be immobilized and his wife operated the equipment during the one and one-half hour procedure.
An early manufacturer, and proponent of fluoroscopy, was the famous inventor Thomas Edison. His Vitascope was the inspiration for his coinage of the word fluoroscope. He began manufacturing X-ray machines in 1896 — his General Electric plant in New Jersey is the oldest firm in the X-ray business. Some other early manufacturers of X-ray apparatus who have survived over the years include Germany’s Siemens, the Dutch company Philips, and Japan’s Shimadzu.
Advances in the generation and control of X-ray technologies have greatly enhanced the use and usefulness of the invisible light. William Coolidge produced a hot cathode tube in 1913. This tube allowed for greater electrical current to flow through the tube thus a greater quantity of X-rays could be generated. Gustav Bucky made the grid in 1913 and Hollis made it reciprocate in 1915. Grids absorb stray radiation generated by X-rays in the subject thus making the resultant radiograph much clearer. In 1918, after Eastman Kodak produced double-coated films, Carl Patterson developed the double screen technique. Screens produce light relative to the X-rays striking them thus they help to expose the film in a shorter time. Tube manufacturer Henry Waite Jr. enclosed the X-ray tube and immersed it in oil in 1920, thus improving the electrical stability of the tube. Machlett Laboratories produced the rotating anode tube in 1939, which allowed for greater dissipation of the heat generated at the anode of the tube when X-rays are being produced. These advancements have been referred to as the “Golden Age of Radiology.”
Some of the other advancements in X-ray technology, include:
the phototimer in 1942;
the automatic hanger X-ray film in 1943;
the image intensifier in 1948 (with added closed circuit television in 1949)
cine-fluorography in 1954;
CT was introduced in the 1970s; and
digital image capture and Picture Archiving and Communications Systems (PACS).
Additional modalities such as MRI, ultrasound, and nuclear medicine have increased and enhanced the ability to see inside the human body. These modalities have employed other penetrating sections of the electromagnetic spectrum. MRI has been called the last window into the body because it used the last available section of the spectrum of energies that could penetrate the human body.
Museum Piece
In 1948, the Cleveland-based Waite Manufacturing Division of Picker X-Ray Corp. manufactured a style T10 Fluoroscope. This machine was featured as The Vault item in the March issue of TechNation. DITEC obtained this antique X-ray machine from a chiropractor’s office in New York City where it was still in use in 1998. It now resides in the RSTI museum. The X-ray tube is visible through the plastic window of the machine. The patient would stand just behind the fluorescent screen, while the radiologist moved it to the desired location in front of the patient. It brings to mind the X-ray machines depicted in cartoons where the bones of the character become visible on the fluorescent screen.
This relic serves to remind us of the progress in image quality, patient and operator safety as well as the complexity of design. The service manual for the Picker X-ray machine is a simple one-page schematic, which drew much amusement from DITEC students. The schematic is a far cry from the numerous books of information now necessary to service and maintain today’s imaging equipment. I believe Roentgen would be impressed by the T10’s advanced design, and amazed at today’s diagnostic imaging systems.
We are also reminded that times and technology change. Picker X-Ray became Picker International, then Marconi Medical Systems. Now, it is no more since its sale to Philips. The name of other pioneers in X-ray technology will also only exist in books and on old relics, such as the T10. The out-with-the-old, in-with-the-new concept is in full force in the diagnostic imaging industry.
The Future
In July, the MD Imaging Expo in Indianapolis will provide cutting-edge discussions and presentations in technological advances as well as maintenance requirements for today’s equipment. If you are involved in diagnostic imaging, I highly recommend that you participate in this inaugural industry event to keep up with the in-with-the-new. For more information, visit TheImagingExpo.com.