If you’re considering a radiology degree, you may have questions about safety track records in this career. Radiation, even at low doses, can prove harmful if a person stands close to the source unprotected, or if the amount of time spent with this equipment is inordinate. But, the health benefits far outweigh its risks, especially when diagnosing patients. The 25 quick facts listed below share some of the history behind x-rays, protective measures, and alternative imaging methods used today.
X-Ray and Radiology Facts
- X-rays were discovered in 1895 by Wilhelm Conrad Röntgen who received the first Nobel Prize in Physics in 1901. Since then, 14 Nobel Prizes have been awarded to 23 individuals in physics, chemistry, and medicine for their important discoveries using x-rays.
- Radiology that involves use of x-ray is called roentgenology. Modern day radiological imaging is no longer limited to the use of x-rays, and now includes technology-intensive imaging with high frequency sound waves, magnetic fields, and radioactivity.
- Intraoral x-ray images, or radiographs, have long been standard diagnostic tools used during dental examinations. Dental radiographs provide critical information that helps diagnose a number of common diseases related to the teeth, face, and jaws.
- Medical imaging is still the best known use of x-rays, but scientists and engineers have devised a host of new uses for this uniquely penetrating form of light, including x-ray astronomy, visible-light lasers, x-ray microscopy for biological studies, and art.
- X-rays consist of a type of radiation known as ionizing radiation, which is a high-energy radiation. It can damage the cells of the body and cause mutations in the DNA (deoxyribonucleic acid), which can trigger cancer in later life.
- Kids may be more sensitive to radiation exposure received from medical imaging scans than adults. One factor to consider is that children have more rapidly dividing cells that can be exposed to the low-level radiation. Also, they have a longer expected lifetime for the effects of radiation exposure to manifest as cancer.
- The American Society of Radiologic Technologists (ASRT) is the world’s largest and oldest membership association for medical imaging technologists and radiation therapists. Founded in 1920, the ASRT now has more than 144,000 members. Its business office is located in Albuquerque, N.M.
Radiation Protective Measures
- Madam Curie’s discoveries of radium and polonium would gain her a revered place in science as a female pioneer in this field, but would also cause her death. Winner of the Nobel Prize in Chemistry in 1935, safety advancements were made in the fields of radiography and radiology, thanks to her work.
- By 1915, the British Roentgen Society had adopted a resolution to protect people from overexposure to X-rays. This was probably the first organized effort at radiation protection. American organizations adopted British protection rules by 1922.
- A common practice to reduce the exposure dose is to reduce the length of time exposed to ionizing radiation through practices such as work planning or job rotation. The cumulative duration of exposure is directly proportional to exposure dose. Reducing the exposure time by one-half will reduce the radiation dose received by one-half.
- Maintaining a safe distance represents one the simplest and most effective methods for reducing radiation exposure to workers. The external radiation exposure decreases in direct proportion to the square of the change in distance from the source. This inverse square law, used as an approximation, indicates that by doubling the distance from the source of radiation exposure, the exposure would decrease by one-fourth of the original amount.
- Radiation exposure can also be reduced by placing shielding material between a worker and the x-ray tube. Shielding is a principal method in controlling exposure to external radiation hazards. Shields often consist of metal lining surrounding the x-ray tube; personal protective attire such as lead aprons, thyroid collars, or leaded glasses; permanent barriers such as leaded glass, concrete, and lead walls.
- Technologists and technicians wear badges measuring radiation levels in the radiation area, and detailed records are kept on their cumulative lifetime dose.
- Patients can keep a “medical x-ray history” with the names of radiological exams or procedures, the dates and places where they were performed, and the physicians who made the referrals.
- Medical radioactive waste tends to contain beta particle and gamma ray emitters. In diagnostic nuclear medicine a number of short-lived gamma emitters such as technetium-99m are used. Many of these can be disposed of by leaving it to decay for a short time before disposal as normal waste.
Alternatives to X-Rays
- Magnetic resonance imaging (MRI) is a very good tool for imaging using magnets, and it will produce very clear images to help diagnose multiple sclerosis, brain tumors, torn ligaments, tendonitis, cancer, and strokes without using x-rays.
- Fluoroscopy is a type of medical imaging that shows a continuous x-ray image on a monitor, much like an x-ray movie. It is used to display the movement of a body part or of an instrument or dye coursing through the patient’s body.
- Contrast media are often used in conjunction with a fluoroscope. In fluoroscopy, the X-rays pass through the body onto a fluorescent screen, creating a moving X-ray image. Doctors may use fluoroscopy to trace the passage of contrast media through the body. Doctors can also record the moving X-ray images on film or video.
- Ultrasound uses high-frequency sound waves to look at organs and structures inside a body. It is most often used to diagnose gallstones, but it also is used to examine a fetus in a pregnant woman’s body. Ultrasound does not involve radiation exposure.
- Digital mammography is performed the same as a traditional mammogram, and may be more beneficial for women under 50 years old, women with dense breats, and women who have not yet gone through menopause. In this procedure, x-ray film is replaced by solid-state detectors that convert x-rays into electric signals similar to those found in digital cameras.
- Computerized tomography, or CT scans, often are used instead of x-rays to determine the cause of lower back pain. According to a 2008 study, patients receiving estimated doses of radiation from medical diagnostic imaging studies, such as CT, or “CAT” scans, may be detrimental to their long term health, putting them at an increased risk of developing cancer.
- Varicose veins are often diagnosed with Doppler ultrasound, as this test uses sound waves to see how blood flows through a blood vessel. It can show blocked or reduced blood flow through narrowing in the major arteries of the neck that could cause a stroke. It also can reveal blood clots in leg veins (deep vein thrombosis, or DVT) that could break loose and block blood flow to the lungs (pulmonary embolism).
- Another way to create images of flowing blood, arteries, and veins in virtually any part of the body is through magnetic resonance angiography (MRA), which uses a powerful magnetic field, radio waves and a computer.
- Nuclear medicine tests differ from most other imaging modalities in that diagnostic tests primarily show the physiological function of the system being investigated as opposed to traditional anatomical imaging such as CT or MRI. Nuclear medicine imaging studies are generally more organ or tissue specific.
- The next step beyond nuclear medicine is molecular medicine, which strives to understand normal body functioning and disease pathogenesis at the molecular level. This technology may allow researchers and physician-scientists to use that knowledge in the design of specific molecular tools for disease diagnosis, treatment, prognosis, and prevention.