Ionizing Radiation in Medical Imaging Practice - Essay Example

The Risks associated with Ionizing Radiation in Medical Imaging practice, and the Precautions required for Protection against them. Modern science has been transfigured by the medical imaging technology and trends. It has come forward as an undefinable opportunity to safe one’s life by identifying and detecting diseases at earlier stages. Likewise, medical imaging is integrated with radiation therapy; it has minimized the requirement of therapies and surgeries, consequently decreasing the recovery time for the patient. Moreover, medical imaging has also facilitated as a tool for various cancer treatments. However, cancer treatments are conducted by two radiation methods i.e. ionizing and non-ionizing radiations. The ionizing radiation includes X-rays and Gamma rays, as (Yale 2001) identified a disadvantage of passing ionization radiation process from the body. The ionization radiations are absorbed by thick tissues in the body that enables them to be chemically reactive resulting in a cell damage. The study concluded restrictions for using ionization radiation to a minimal as it can raise issues related to human health. Disclosure to ionization radiation is another factor that needs consideration, as there are evidences available that has linked disclosure of low-level ionization radiation by the doses, which are given for the development of cancer by medical imaging. An inclusive review of biological and epidemiological data associated with health risk of ionization radiation exposure was conducted by the ‘National Academy of Sciences’ National Research Council. Moreover, the review is recently published in the form of a report named as the Biological Effects of Ionization Radiation (BEIR) VII Phase 2. In the report, the epidemiologic data demonstrated the survivors of the atomic bomb along with the population living near the facilities that are equipped with nuclear technology throughout the releases of Chernobyl, which is a radioactive material. Moreover, report also includes the workers who are exposed by occupations and populations, who faced exposure with the aid of therapeutic and diagnostic medical studies. Commonly used CT examinations that includes radiation doses that are received by humans, amplify the risk of cancer. For instance, increased risk of cancers is identified within the survivors of Hiroshima, as Nagasaki atomic bombs affects on these people were exposed by the ranges of 10 to 100 milli-sieverts (mSv). This value is equivalent to a single CT scan radiation exposure and patients do conduct CT scans multiple times during the treatment. (Smith-Bindman et al 2009) Risks involved in the use of Ionizing radiation The first hard tumour that was found, resulted from the ionization radiation effects. Consequently, securing from the ionization radiation methods that facilitates medical procedures has grabbed significant concerns. Predominantly, the rise in various medical procedures incorporating ionization radiation(Davros et al 2007). In order to protect people from this kind of radiation, an establishment of an International Commission for Radiation Protection took place in 1928. "The International Commission on Radiological Protection (ICRP) estimates that the average person has an approximately 4-5% increased relative risk of fatal cancer after a whole-body dose of 1 Sv. However, other studies on multiple cohorts of radiation workers have largely failed to establish statistically significant cancer risks. When multiple occupational cohorts were combined and evaluated in a somewhat systematic way, a combined excess relative risk of cancer death of just less than 1% was estimated" (Cardis et al 2005). In between years 1950s and 1960s, many traces become visible conclusion that the ionization radiation is dangerous for humans. Likewise, experimentations were conducted on rats by passing X-rays has also concluded the contribution of ionization radiation at low levels causing imminent deaths. Similarly, there are many proofs to conclude that the frequent use of radiation can cause immense risk along with diseases such as many types of irritations, skin erythema etc. (Egbe et al 2009). Moreover, there are also side effects associated with it. For instance, nausea, dizziness and low pain headaches. Risk that are associated with exposure to radiation are relatively high in ‘hepato-biliary’ scans. A study that was conducted by McCollough et al (2009) concludes that it was involved in several cases as the body areas that are frequently exposed to X-rays were coupled by the onset of cancer. More studies by McCollough suggests "0.4% of cancer cases in the United States are related in some way to ionizing radiation and 1.5 – 2.0% of organ specific cancers are related to the ionizing radiation from medical procedures". Furthermore, as per Chau et al (2008), there are biological effects of ionization radiation that can risk the life of pregnant women. Precautionary measures and safety issues For eliminating the negative effect of ionization radiation on health of patients can be prevented by all means possible as this scenario relates to a theory of ALARA, a radiation safety regulation principle. The acronym for ALARA is As Low As Reasonably Achievable, pointing towards the reduction of radiation doses by all possibilities. As exposure is the most crucial term in radiology, as per the ALARA regulation, all the medical imagers and radiologists must ensure to take strict precautionary measures and steps to accomplish required image quality without exposing unnecessary parts of the body of the patient to the radiation (Durham 2007). Moreover, the exposure of body parts for the staff that is associated with the medical image practices (Tsiklakis et al 2005). The staffs associated with ionization radiation and working in radiology departments are exposed to the radiation on a daily basis or several times a day. The maximum limit for the dose is 20m Sv for the operational staff. Moreover, the use of dosimeter is essential (Bor et al 2009; delle Canne et al 2006) along with wearing a lead protective apron. As though, there is a requirement to monitor the dose level. In order to evaluate the exposure of body parts to the radiation, the operational staff must wear Thermo-luminescent dosimeters placed under the lead aprons. If some areas of the body are exposed, the dose limit will exceed from the required level. Similarly, the operational staffs conducting X-rays on daily basis also requires dose limit identification. The risks associated with X-rays are prevented by frequently and closely monitoring the organs that are exposed along with the overall health of the operational staff, ensuring that the operator has not passed the allocated annual dose limit (McCollough et al 2009). However, for fluoroscopy, extra precautionary measures are implemented. For instance, configuring an appropriate size of the field, kV and mAs for acceptable exposure level (Topaltzikis et al 2008). Moreover, timing is essential in terms of reducing the risk for over exposing the body. However, eyes should also be protected by not exceeding the dose limit. Furthermore, for protecting eyes, suspended shields can be used (Muhogora et al 2006). (Triantopuolou et al 2005) concluded that the use of an adequate filter could eliminate the hazardous effects of radiation, however, the thickness and type are considered, as the thickness and type can affects the quality of the image. For instance, copper filter can process adequate quality images and minimize the dose level for the patient simultaneously. Need for Image optimization and techniques for risk reduction In the process of minimizing risk factors for the patients, importance of the staff is also categorized as top most priority. There is a requirement to find ways for enhancing the image quality obtained from medical imaging. However, exposure level cannot be compromised at any level along with the quality of the image that is extracted from medical imaging, should be of a good quality. As per (Matthews and Brennan 2008), this process is called as optimization. Optimization is appropriate for all the various processes in which ionization radiation is implemented such as dental radiation (Gavala et al 2008). In order to evaluate the quality of the image and eliminating the exposure level simultaneously is known to be the use of automation exposure control (Imhof et al 2003). Many methods are used to reduce the radiation dose without influencing the image quality. Some of the techniques demonstrate an unsynchronized image with a rate of 60 frames per second. On the other hand, synchronized image demonstration can minimize the dose levels along with improvement in image quality. For example, in a cardio operation, the operational staff can configure the frame rate to 5 frames per second for reducing the radiation dose to a smallest possible. However, there is a drawback associated with it as the noise increases due to configuring the FPS to 5. Noise increment can be eliminated by configuring the mA that protects the quality of the image. If the operational staff has a significant tolerance to lagging images, dose levels can significantly be reduced to a minimum level. Unfortunately, this approach is not widely adopted as there are some misconceptions associated with image quality. In order to eliminate these problems, theoretical frameworks are constructed including Quality Function Deployment model (Moores 2006). By implementing the dose spreading methods, dose levels can significantly be minimized. As an example of optimization by (Triantopoulou et al 2005) includes the rotation of a C-arm machine along with the intervention site maintaining its position to the centre and can be viewed by the field of view. Consequently, this example illustrates the elimination of dangerous effects of radiation on the human body, including skin that is exposed to longer periods and higher dose are involved. Whereas, the use of small beam takes place and the operational staff must concentrate on the beam closely. Likewise, the small movements C-arm rotation will not bother the operator or his /her procedures. However, the involvement of large fields, larges ratios of movements take place. In this case, the large movements up to 180 degree can bother the operational staff from procedures. The recommendations are the Doses that are divided in this case with insignificant obstruction. Other options for minimizing the dose levels are Ultra low dose fluoroscopy imaging automation. Although it is still under development, it is the operator’s responsibility to configure the parameters of the machine. In order to operate the machine, it is essential that the operational staff must be experienced. Moreover, computers can control the Ultra low dose fluoroscopy imaging automation and apply them to the required area throughout an examination. The advantage of this process includes the elimination of radiation effects on the operational staff and patients. Digital fluoroscopy is another technique or methodology that is used for reducing the exposure of radiation in which an image is demonstrated on the display (Triantopoulou et al 2005). During the examination of the image by the staff, no radiation is used on the patient. Moreover, the image can also be utilized as a reference image of transferred to other machines. These factors can significantly reduce the dose levels. Furthermore, the still image can also be utilized for techniques associated with road mapping. In a complex angiographic digital fluoroscopy, a comparison takes place between two images i.e. reference image and pulse fluoroscopy image. The method can significantly improve the appearance of vessels. As the reference image is utilized as a mask that may result in an efficient vascular system via navigation along with concurrent activation of dosage elimination. As Interventional angiographic procedures encompass a high quality movable image, the staff will not require a full view of the field. Moreover, dose can be minimized by via adequate aperture positions along with high intensity beams with low reference image quality. When there is a requirement of a region of interest, a phantom image is implemented as a reference for enduring radiation exposure. The hub on the region of interest avoids the complete region from extensive radiation exposure. This method is under a phase of improvement, as it does not support good quality images as mentioned above. There are several methods that are discusses that are related to radiation exposure. Moreover, many methods, techniques and safety procedures are also demonstrated. In spite of coping up with all the measures, experience of an operator or operational staff is superior. Moreover, in the field of medical imaging, safety standards are essential and must be followed, as radiology is associated with constructing diseases such as cancer. Furthermore, in order to ensure minimal exposure to radiation, development in terms of technology is required to overcome ionization radiation exposure to the next safest level for both the patients and the operators. Reference List Bor, D., T. Olgar, T. Toklu, A. Caglan, E. Onal and R. Padovani. 2009. "Patient doses and dosimetric evaluations in interventional cardiology." Physica medica 25(1):31-42. Canne, S., A. Carosi, A. Bufacchi, T. Malatesta, R. Capparella, R. Fragomeni, N. Adorante, S. Bianchi and L. Begnozzi. 2006. "Use of GAFCHROMIC XR type R films for skin-dose measurements in interventional radiology: Validation of a dosimetric procedure on a sample of patients undergone interventional cardiology." Physica medica 22(3):105-10. Chau, A., and K. Fung. 2008. 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