how radiation affects the body, the different types of radiology procedures, and safety recommendations.


X-rays ionize human tissue and deposit energy that can cause harmful changes within the body (break the DNA chain). There is a cancer risk from X-rays. The dose of radiation is cumulative. X-rays are considered for carcinogen list. The government is attempting to avoid the use of unnecessary CT scans and x-rays to avoid unnecessary exposure to radiation. This highlights the cancer risk. Doctors need to pay close attention to the risks involved with the use of x-rays. The cancer risk associated with radiation exposure is documented in cases of atomic bomb survivors. The risk for medical uses is controversial and usually played down by physicians. Radiation at a high level is carcinogenic.
The level of radiation from x-ray exposure is low. The effects of low-level radiation is not known.
What is the safe radiation level? The safe level is not known. It is known that CT scans, fluoroscopy, mammography and x-rays expose the public to high levels of radiation especially in young females. The risk of exposure should balance the medical benefit.
Optimize radiation doses by exposing the patient only to enough radiation to get a clear image. There is a growing concern about the risk associated with giving patient large doses of radiation. The use of CT scans has increased recently in adults and children possibly exposing the patient to an unnecessarily high dose of radiation. CT scan is the method often used to diagnose cancer, diseases fractures and it exposes the patient to a much larger does of radiation than x-rays.
Radiation from CT scan of the pelvis equals the same amount as 100 chest x-rays. Children are ten times more sensitive to radiation than adults. 3-4 million children receive CT scans and about 1,500 of them will develop cancer two decades later. Children should not be given an adult dose of radiation.
Radiation dose limits:
CT scan of the pelvis has the highest level of exposure to the skin, marrow and gonads. Use mini fluoroscopy C-arm whenever possible. Fluoroscopy emits a lot of radiation. The closer the extremity is to the radiation source, the higher the dose of radiation the patient receives. When the distance from the beam increases, the dose of radiation is less. Attempt to decrease exposure time. Radiation intensity follows the inverse square law. It is all about distance. If the intensity of radiation at 1 meter from the source is 100 mR/hr then the intensity of radiation at 2 meters from the source is ¼ or 25 mR/hr in same unit area. At 3 meters from the source, the intensity of radiation is 1/9 the original or 11.1 mR/hr.
Units of radiation (radiation nomenclature)
•Roentgen: unit of radiation exposure in air.
•Rad: energy absorbed per gram of tissue.
•Rem: biological effect of a rad.
There is less exposure to the physician when imaging a smaller body part. Larger body parts create an increased exposure to the physician when imaging a patient with C-arm. Do not be in the direct path of the radiation beam.
Protection:
•Monitoring: a dosimeter badge only records how much radiation you have received. It does not protect you from exposure to radiation.
•Shielding: lead gowns and aprons work to stop exposure to fluoroscopy radiation. Lead aprons attenuate scattered radiation by about 95%.
•Position
Rapidly dividing cells are most sensitive to radiation exposure: sperms, lymphocytes, small intestine, and stomach. Radiation damage seldom appears at the time of radiation. The first effects of radiation damage is usually seen as a drop in the white blood cell count.
The first external sign of damage is seen as a skin burn. Studies suggest that people who use fluoroscopy extensively have a higher rate of cataracts.
Early effects or radiation exposure:
•Death
• Hematological depression
•Chromosome aberration
• Skin erythema
• Epilation.
Team exposure to radiation
•Direct beam 4,000 mrem/min
•Surgeon (1 ft.): 20 mrem/min whole body
•First assist (2 ft.): 6 mrem/min whole body
•No exposure (5 ft.) at scrub or anesthesiologist.
•6 feet is safe.

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