Computer Tomography: Radiation Dose Reduction Strategies

The high levels that have along with Computer Tomography technology are currently making a major threat to the health of patients and CT administrators. Discussed is an analysis of the findings attained from the analysis of the reduction dosage threat. As a result, knowledgeable people and institutions have come up with ways to help reduce the health risks involved in CT administration. Some of these improvements in CT administration have been put into action, therefore, reducing the health risk that results from this therapeutic practice.

Computer Tomography use has exponentially increased since its initiation into the medical field of practice in the 1970s. CT has remarkably changed the world of diagnostics in medicine and though it has become an important tool in the practice of medicine there are distinctive negative effects that any practitioner must consider when performing CT imaging. One of the cautions placed in CT administration has been abbreviated as ALARA which means that the radiation levels used should be As Low As Reasonably Achievable. This concept has been used to ensure that optimal diagnostic information is provided from CT scans while ensuring that the individual is exposed to the least possible dosage of radiation as they lead to stochastic and deterministic outcomes on the human body. (Seeram, 2009)

The stochastic effects of CT scanning include Leukemia, Hereditary defects, and cancer. The study on potential health defects and deficiencies due to the ionizing effects of radiation is based on the information collected from radiation workers; atomic bomb survivors and patients exposed to radiotherapy. The radiation from CT scans is referred to as X-radiation and though different from that atomic bomb survivors are exposed to; the outcomes have been as the same in medical terms through Linear Non- Threshold (LNT) models to explain the ionizing effects of these radiations on the body. The LNT model correlates data to show that there is no possible safe threshold to which one may be exposed to; after the ionization effects of radiations without facing the risk of detrimental effects. It was also established that cancer is monoclonal or single cell in origin, meaning that one radiological event may trigger the start of a carcinogenic effect. Medical x-rays have also been referred to as carcinogen sources by the Food and Drug Administration. (Alderson & Nikoloff 2001).

Medical data also show that CT exams are on the increase as seen that in 2002 approximately 60 million CT scans were performed accounting for 70% of all medical radiation exposure and are higher in recent years. The risk of cancer related to medical radiation exposure is 0.35% but related to the number of exposures that amount to 60,000,000 makes the exposure problem a major public health concern; especially to women who have higher radio sensitivity as compared to that of children. The dosage received by an individual is cumulative according to reports on biological effects of ionizing radiation which has a Lifetime Attributable Risk of 100 mSv exposure to be 1 in 100 to generating of solid cancers or Leukemia. According to FDA a single CT scan e.g. an abdominal scan has an effective dose of 10mSv that gives an LAR of 1 in 1000. In the case of abdomen scanning that is done two or three times raises the radiation dosage from 20mSv to 40 or 60 depending on the sex and age of the patient? The dosage on kids or neonates is higher by 50% when the scan parameters used are the same as that for adults that can alter or ionize DNA directly causing development and growth defects in off springs. The exposure of radiation to a fetus in a pregnant individual may also lead to spontaneous abortion. (Seeram, 2009)

The deterministic effects ionization that depends on threshold levels includes inflammation, erythema injury, skin irritation and epilation. Other effects of radiation include chest pain, fever, heart friction sound and blindness as a result of the opacification of the lens of the eye. Exposure to radiations above 100 mSv may lead to the development of cardiovascular disorders. Stochastic effects of ionizing radiation are rigorous, defined by linear non-threshold and take place on influence by an instance of radiological exposure. The induction of cancer is a major stochastic effect having a latency period of 10-30 years depending on threshold and dosage levels. (Alderson & Nikoloff 2001).

However medical breakthroughs already adopted changed the long scan times; obtained thinner slices; allowed for multi-slice and volume scanning that has improved the CT scanning conditions and reduced the time of exposure. These technological advances have also improved the levels of information that can be acquired from scans, but placed patients at higher risks of radiation dosage due to the detailed multiple scan procedures. (Slovis, 2002)

As discussed earlier the effects of radiation exposure are on the rise and therefore the following recommendations are proposed to help reduce the long-term effects of CT scanning and other sources that expose individuals to radiations.

The practitioners that carry out CT scans should be certified by the American Register of Radiologic Technology in CT field to ensure that they expose their patients to the least possible levels of threshold and duration. An A.C.T certification program should be adopted to play the role of evaluating the workforce; images and apparatus to ensure that the tests are performed in an up to standard mode but involving minimum risk levels. (Cody, 2005).

CT administration personnel should expose their patients to the minimum number of scans that are necessary for the diagnostic process, so as to reduce the unnecessary levels of exposure to radiation. Physicians should discuss the risks involved in CT scanning with their patients, so that they can be able to weigh their options in deciding to take or avoid the scans. (ASRT, 2009).

As a measure to reduce the levels of exposure; CT technologists should limit the scans to only the regions of the body where the problem under test is located as well as limiting the amount and intensity of repeat CT scans whenever possible. CT institutions should adopt the use of scanners than can be adjusted to suit the different levels of exposure needs for different patients depending on their sex and age. According to Dr Cody the levels of radiation exposure subjected to patients during scout scans that are only used for positioning purposes should be reduced to the least intensities possible. (Cody, 2005).

CT technicians should alter the placement and scan parameters to levels where the intensity of exposure is the least but capable of producing up to standard scan images. CT scanning machine manufacturers should help the situation through manufacturing scan machines that produce quality diagnostic images at low radiation dose levels. An example of these is the archetypal Toshiba 160-slice Aquilion quality scanner that ensures 50 percent radiation reduction but still preserving the image quality. CT technicians should adopt Iterative Reconstruction in Image Space expertise that would allow for the reconstruction of raw data leading to a 60% decrease in radiation levels. (ASRT, 2009).

There have been great improvements in the technology of Computer Topography that saw reduced durations and improvement retrieval from scanning processes. However these improvements came along with increased radiation dosage that puts the health of patients at risk. However different measures can be adapted to reduce the radiation dosage therapy including the adoption of new technology maintains image quality while reduce the radiation dosage.

Reference list

Alderson, P., & Nikoloff, E. (2001). Radiation Exposures to Patients from CT: Reality, Public Perception, and Policy. American Journal of Roentgenology, 177, 285-287. Web.

ASRT. (2009). ASRT Supports Efforts to Minimize CT Radiation Dose.

Cody, D. (2005). Several Small Steps Can Reduce Radiation Dose from Survey Scans.

Seeram, E. (2009). Computed Tomography: Physical Principles, Clinical Applications, and Quality Control (3 Ed.). Philadelphia: W.B. Saunders Company.

Slovis, T. (2002). Computed radiography: the pictures are great, but is the radiation dose greater than required? American Journal of Roentgenology. 179, 39-41.