- X-rays were discovered by accident when German scientist Wilhelm Conrad Roentgen (27 March 1845–10 February 1923) was experimenting with vacuum tubes in 1895.e
- Wilhelm Roentgen, the scientist who discovered X-rays, was awarded the very first Nobel Prize in Physics in 1901. He refused to take patents out related to his discovery because he wanted humankind as a whole to benefit.h
- X-radiation or X-ray is a form of high-energy electromagnetic radiation. Other types of EM radiation that make up the electromagnetic spectrum are microwaves, infrared light, visible light, ultraviolet light, and gamma rays. They all travel in waves, but have different wavelengths.h
Roentgen's wife was less than impressed with his invention
- The first X-ray (or roentgenogram) was of Roentgen’s wife’s hand, complete with wedding ring, in 1895. His wife was less than impressed and declared: “I have seen my death!”g
- From identifying broken bones to disease, the X-ray is one of the most useful medical advancements in history. It is also the oldest and most common form of imaging.e
- X-rays can be divided into hard X-rays and soft X-rays. Because hard X-rays have higher energy and, therefore, higher penetrative ability, they are used in medical radiography and airport security.g
- The variant spellings of X-ray in the English language include x-ray, xray, and X ray.g
- The effect of X-rays is cumulative, which means that minor doses over several years can equal a large dose at one time.i
- The term “X-ray” is used to refer to both the image itself and to the method.h
- X-rays have enough energy to ionize atoms and disrupt molecular bonds, which makes them harmful to living tissue.f
- CAT scanners can take thousands of X-rays to make up one image. While X-rays can take pictures of our bones, CT scans can take photographs of the body’s internal organs, such as the heart, liver, and kidneys.b
- Wilhelm Conrad Roentgen was mystified by the radiation he had discovered when he discovered X-rays, so he temporarily called them “X-rays,” with the “x” being a mathematical symbol for something unknown. Although he objected, the name stuck, though X-rays are occasionally called Roentgen rays in German-speaking countries.h
- Rontgen had used a zinc box and a lead plate for his X-ray beams, which protected the photographic plates in his lab from being accidentally exposed. This coincidentally protected him. Other early scientists were not so lucky, and many suffered burns, radiation sickness, premature aging, hair loss, and cancer.e
- The first known human to be killed by X-rays was Clarence Dally who had spent a number of years working on Thomas Edison’s X-ray light bulb. After years of work, his hair fell out and his skin erupted in lesions that wouldn’t heal. While Edison cancelled the bulb, Dally continued working with X-rays. Burns on his hands became cancerous, and he had both of his arms amputated. He died in 1898 at the age of 39.g
Thomas Edison was afraid of X-rays
- After one of his assistants working on his X-ray project showed signs of illness, Thomas Edison said, “Don’t talk to me about X-rays. I am afraid of them.”e
- Emil Grubbe (1875-1960), a student at Hahnemann Medical College in Chicago, noticed that the skin from his hand would fall off after putting his hand in an X-ray machine. He suggested trying the rays on a breast-cancer patient, Rose Lee, who was diagnosed as hopeless. Her cancer shrank and seemed to remit. Radiotherapy was born.h
- The Earth’s atmosphere is thick enough that almost no X-rays from outer space can make it all the way to the Earth’s surface.g
- Many objects in space emit X-rays, including black holes, neutron stars, the sun, some comets, supernova remnants, and binary star systems.e
- An X-ray delivers about 10 million times more energy than a radio wave, which gives a sense of why radio waves don’t hurt us but X-rays can.e
- The scale from least dangerous (longest wavelengths) to the most dangerous (shortest) has radio waves at one end and then microwaves, infrared radiation, visible light, UV radiation, X-rays, and then gamma rays at the other end.i
- When X-rays are passed through the body, some waves pass through the tissue and turn the film black. Other waves are blocked (e.g. by bones), which leaves white shadows on the film. Each kind of tissue lets X-rays through differently.c
- After Roentgen discovered X-rays, Dr. Harvey Cushing of Harvard furthered the development of clinical X-rays that led to pioneering work in brain surgery. He would use X-rays to help him locate and remove tumors.e
- X-rays were initially thought to be safe—until scientists and others who worked with them began mysteriously dying. It was Marie Curie’s work that would lead to safety advancements in the field of radiology and radiography.e
The Chandra X-ray is the most sophisticated observatory ever built
- In 1999, NASA launched its Chandra X-ray, which was designed to capture X-ray emissions from hot regions of the universe to capture such spectacular images as exploding stars, black holes, and clusters of galaxies.g
- In 2011, a camera that uses X-ray technology was revealed. By way of comparison, HD cameras capture 24 frames per second. The X-ray camera can capture an unprecedented 4.5 million frames per second. It is hoped that the new invention will shed new light on matter.g
- Special types of X-rays include mammograms, dental X-rays, contrast X-rays, fluoroscopy, and CT scans. Other imaging techniques such as MRI and ultrasound do not use X-ray.b
- Pregnant women should not have X-rays except for an emergency. Exposure of the fetus to X-rays can increase the risk of the child developing leukemia.i
- X-rays remain the cornerstone of imaging techniques and account for at least 60%–80% of all diagnostic images.f
- Radiation from medical imaging exposure in 2006 constituted about 50% of total ionizing exposure in the U.S.f
- The common chest X-ray can be used to diagnose pneumonia, lung cancer, or pulmonary edema. An abdominal X-ray can detect bowel or intestinal obstruction, free air, and free fluid. X-rays can also detect gallstones or kidney stones.j
- There is no threshold which radiation is considered totally safe. Even small doses of gamma and X-rays increase cancer risks, although by a small amount.i
- Female patients who had been imaged several times with fluoroscopy as a teenager or young woman as treatment for tuberculosis have been found to have an increased risk of breast cancer years later.i
- The International Agency for Research on Cancer (IARC), which is a part of the World Health Organization, classifies X-ray and gamma radiation as a “known human carcinogen.”k
Young scoliosis X-ray patients have an increased cancer risk
- Young women and teenagers who had many X-rays to monitor scoliosis have been found to be at increased risk for developing breast cancer later on.e
- A recent study found that children who received a radiation dose of a least 30 mGy (milligray) from a CT scan to the bone marrow had three times the risk of leukemia compared to those who received a dose of 5 mGy or less.g
- Approximately 0.4% of current cancers in the U.S. are due to CT scans. b
- In 2006, Americans were exposed to more than seven times as much ionizing radiation from medical procedures than they were in early 1980s. The increase was due in part to higher use of compute tomography (CT) and nuclear medicine.f
- A plain chest X-ray exposes a person to the same naturally occurring background radiation that a person is exposed to every day for 10 days.i
- Exposure from a dental X-ray is roughly the same as being exposed to 1 day of environmental background radiation.i
- A CT scan on the chest is equivalent to being exposed to two years of naturally occurring radiation.i
- An X-ray on the spine is equivalent to 6 months of exposure to naturally occurring background radiation. A CT on the spine is equivalent to 2 years’ worth.i
- During the 1920s, both men and woman sought X-ray as a way to remove unwanted hair. However, when safer, weaker X-rays only temporarily removed hair, stronger X-rays were applied. Unfortunately, patients soon experienced serious injuries, including bone loss, skin tissue scarring, disfigurements, vascular lesions, hyperpigmentation, and hypopigmentation. While the FDA banned X-ray hair removal in the 1940s, many months and years later, many previous patients developed cancers.a
A shoe-fitting X-ray machine delivered a potent dose of radiation
- An X-ray shoe-fitting fluoroscope was common in shoe stores during the 1930s, 1940s, and 1950s. When a person put their foot in the fluoroscope, they were effectively standing on an X-ray tube. A shoe model for the shoe-fitting machines received such serious radiation burns that she had to have her leg amputated.j
- The first use of an X-ray for clinical purposes was by John Hall-Edwards in Birmingham, England, on 11 January 1896, when he X-rayed a needle stuck in the hand of his associate. He was also the first to use X-rays in a surgical operation.g
- X-rays are actually visible to the dark-adapted naked eye. Additionally, it is possible to see with the naked eye the ionization of the air molecules if the intensity of the X-ray beam is high enough.e
- In 2013, two New York state men were arrested for plotting to develop a mobile X-ray machine that would be used from a distance to kill people they thought were undesirables, namely “enemies of Israel.” d
- The discovery of the first cosmic X-ray source (besides the sun) occurred in 1962. Called Scorpius X-1, this extrasolar X-ray source is the strongest known source of X-ray in the sky. It is located about 9,000 light years away, in the Scorpius constellation. Today, many thousands of X-ray sources are known, though they are not as strong.g
-- Posted June 19, 2014
a Bickmore, Helen. 2003. Milady’s Hair Removal Techniques: A Comprehensive Manual. Clifton Park, NY: Milady.
b “Computed Tomography (CT Scan).” Medical Imaging World. 2012. Accessed: April 16, 2014.
c Davidson, Tish. “X Rays.” Gale Encyclopedia of Children’s Health: Infancy through Adolescence. 2006. Encyclopeida.com. Accessed: April 27, 2014.
d Ferrigno, Lorenzo. “Feds Nab KKK Member, Accomplice for Lethal X-ray Plot.” CNN.com June 21, 2013. Accessed: April 16, 2014.
e Gale, Robert Peter, M.D., and Eric Lax. 2013. Radiation: What It Is, What You Need to Know. New York, NY: Alfred A. Knopf.
f “Medical Radiation Exposure of the U.S. Population Greatly Increased since the Early 1980s.” National Council on Radiation Protection and Measurements. March 5, 2009. Science Daily. Accessed: April 16, 2014.
g Nelson, Craig. 2014. The Age of Radiance: The Epic Rise and Dramatic Fall of the Atomic Era. New York, NY: Scribner.
h Parker, Janice. 2000. Engines, Elevators and X-Rays. Austin, TX: Raintree Steck-Vaughn.
i “Patient Safety: Radiation Dose in X-Ray and CT Exams.” RadiologyInfo.org. October 10, 2013. Accessed: April 16, 2014.
j “Shoe-Fitting Fluoroscope (ca. 1930–1940).” ORAU. Updated April 20, 2010. Accessed: April 16, 2014.
k “X-rays, Gamma Rays, and Cancer Risk.” American Cancer Society. Revised April 18, 2014. Accessed: April 20, 2014.