A computed tomography scan (“CT scan” or “CAT scan”), which is a procedure that takes no more than a few minutes, is a medical imaging method that is used to create three-dimensional x-ray images. CT scanning has a number of benefits over traditional medical radiography. For example, CT scanning eliminates superimposed structures outside the area of interest and tissues that differ in physical density can be more easily identified. The most crucial part of the scan is usually completed in under a minute, but prolonged scanning could result in a number of severe health risks due to high radiation exposure.
A typical dose of radiation for a CT scan that includes the head and chest would result in exposure to 7.3 mSv (millisievert) of radiation. For comparison, the average survivor of the Hiroshima and Nagasaki bombings were exposed to 40 mSv of radiation, and the average radiation exposure from natural sources to an individual within the United States is about 3 mSv. Additionally, the effects of low doses of radiation—less than 100 mSv—are observed on a cellular level and may not be detected for up to twenty years after exposure.
According to the United States Nuclear Regulatory Commission, the exposure to radiation can have three effects: 1) cells are injured or damaged and then later repair themselves, resulting in no enduring damage; 2) cells could be killed, which happens on a large scale every day; or 3) cells incorrectly repair themselves, which results in a biophysical change.
Genetic effects and the development of cancer are the primary adverse effects attributed to radiation exposure. Cancer is five times more likely to occur after radiation exposure than a genetic effect.
With CT scanning technology on the rise, the likelihood for public exposure to harmful levels of radiation increases. Traditionally, it was a physician’s decision whether or not to scan a patient; but today, an individual may undergo a scan of their entire body without consulting a primary care physician.
There exists a lack of awareness of the risks of radiation exposure. Patients who undergo CT scanning, as opposed to other imaging techniques, are exposed to higher levels of radiation. For example, MRI is safer, but more expensive and has limited availability. As CT technology increases, the necessary dose of radiation also increases. Therefore, there is an increase in radiation exposure to the public, as well as its adverse health effects.
Due to the increased public exposure to radiation, there is an increase in controversy regarding a more conservative use of CT scanning. For example, asking the question “Is there a reasonable need for a CT scan in this situation?” might help decrease the detrimental effects of radiation on the public.