Assessment of the Compliance of Radiation Dosage Guidelines for Computed Tomography - Research Proposal Example

Research Proposal on Computed Tomography (CT) A critical assessment of the compliance of radiation dosage guidelines for CT by radiographers Introduction Computed tomography (CT) as an imaging technology to aid in the diagnosis of diseases and conditions became available in 1972, when the first commercial CT scanner became a reality (Brenner & Hall, 2007). Since then there has been an explosive growth in the use of CT as a diagnostic imaging technology. Three factors may be associated with this dramatic growth of CT as an imaging modality. These three factors are availability, speed and diagnostic benefits (Hara et al, 2009). The increasing number of clinical applications for CT and the continuing developments in CT technology are expected to only increase the use of CT as a diagnostic imaging modality. It is estimated that in the developed world the at the current use of CT every year twenty percent of the population go through at least one CT diagnostic evaluation for some purpose or the other. This suggests that every member of the population of the developed world will undergo at least one CT diagnostic evaluation once in five years (Coursey & Frush, 2008). CT essentially uses x-rays for the creation of the diagnostic images. However, the radiation and its distribution with CT are markedly different from conventional X-ray imaging and this weighs heavily on the quantum of radiation that an individual is exposed to during CT imaging (Bushberg et al, 2002). Radiation dosage is a significant factor in the possibility of radiation induced malignancies or radiogenic cancers. The accepted thumb rule according to Hofer, 2007, p.174 is “the lower the individual dose and the longer the interval between several radiation exposures, the lower the risk of a subsequently induced neoplasm”. Evaluation of the type of radiology examinations performed on an overall basis suggests that CT comprise between 11-13 percent of all radiology examinations. However, CT has been found to be responsible for in excess of two thirds of the total radiation dose associated with its use in medical imaging. It is estimated that the risk for cancer in the developed world has ridden from 0.4% to 2.0% with the dramatic surge CT being employed for medical imaging. Radiation dosage associated with use of CT in medical imaging has thus become a matter of concern both within the field of health care and outside it (Hara et al, 2009). When CT became available as an imaging technology it was accepted that the use of CT involved a relative high radiation dose technique. There was however clinical justification is the use of CT. It was used for quality imaging of the brain, which was unsurpassed by any other available imaging technique and on patients with malignant disease, where concern for radiation dose was not concerned relevant. The current use of CT is far different. It is extensively used even in young patients, where protection from radiation exposure should be the maximal, because of the high potential risk for radiation cancers. There is heightened awareness that CT contributes to the highest collective radiation dose from any diagnostic imaging, which carries a high risk for fatal cancer. During an abdominal CT examination an adult may be exposed to an effective radiation dose of 10mSv that carries with it an estimated lifetime risk of fatal cancer by 1 in 2000. Yet, the use of CT is rising and along with the potential risk for fatal cancer (Golding & Shrimpton, 2002). In CT Compton scattering is the main interacting mechanism. As a result there is considerable risk for radiation exposure, due to scattered radiation. This exposure can be greater than from the radiation dose of the primary beam. In conventional x-ray imaging scattered radiation is confined to the collimated beam profile, which is not the case with CT. Therefore the acquisition of CT images may result in considerable radiation dose to the adjacent tissues lying outside the primary beam. In most CT protocols there is the need for acquisition of a set of near-contiguous CT slices with regard to the tissue volume under consideration. In the acquisition of this series of near-contiguous CT slices means that tissues under review are exposed to not just the primary radiation, but also to the scattered radiation from other CT slices. This is the main reason for the risk of exposure to high radiation dose in CT (Bushberg et al, 2002). In radiation dosimetry the most basic quantity is radiation exposure. Radiation exposure is linked to the amount of ionization produced by an x-ray beam per mass of air. The quantum of radiation dose that gets absorbed in the body of the patient is expressed in rad or gray, where 1 rad = 10 mGy. Absorbed radiation dose however, does not take into account differences in the sensitivity of the various organs to damage from radiation. Effective dose calculation does this. Effective dose calculation is calculated by the absorbed doses in the organs weighted by the radiation sensitivity of the organ and is expressed in millisievert or rem. The benefit of the effective dose calculation is that it allows comparison of the potential radiation risk of specific CT examinations (Bae & Whiting, 2006). Table -1 below gives the radiation dose that a patient could receive for a complete CT examination. Table -1 Radiation Dose Associated with a Complete CT Examination Complete Exams Effective Dose mSv (mrem) CT Head 2.0 (200) CT Chest 8.0 (800) CT Abdomen 10.0 (1000) CT Pelvis 10.0 (1000) (Health Physics Society, 2009) The radiation dose exposure to a patient is directly proportional to the chosen mAs value and the scan length. Through an increase of mAs or scan length by fifty percent the radiation dose exposure also increases by fifty percent. Such radiation dose exposures may not be a matter of concern in a patient already with cancer, but it is a very relevant issue in other adults and the more susceptible children and infants. For example, just a single exposure to CT thorax imaging for females under the age of twenty increases the risk for breast cancer during the life time of the patient. Yet, for reasons of quality images radiation doses may get enhanced. This is due to the possibility of generating thinner images over a wider region. Noise gets enhanced in thinner collimation. To overcome this noise factor mA is enhanced to give the same image quality as received in thicker collimation. This runs against the grain of the guidelines and techniques for reducing radiation dosage (Ravenel, 2008). Certain strategies assist in lowering radiation exposure of patients. Reduction in gantry rotation reduces the radiation dosage. A substantial reduction in radiation dosage can be effected through the reduction in the kVp. Table speed or pitch is another factor that can be used to reduce radiation dosage. The higher the table speed or pitch the lower is the radiation dosage experienced by the patient (Garcia-Penna & Owens, 2008). The European Commission guidelines on the use of radiation based imaging are founded on two pillars. The first is the justification in the use of such imaging technology is the need for such imaging. The second pillar is the optimizing the protection to patients, particularly with respect to exposure to high radiations doses. The guidelines on optimizing radiation exposure refers to two factors and that is the quality of the image and as a low as possible the radiation dose per radiograph. Thus the European Commission guidelines recommend maintaining a balance between the image quality in CT imaging and the exposure to as minimal a radiation dose as possible (European Commission, 1996). These sentiments are echoed by the American College of Radiology when it calls for “the highest quality diagnostic image at the lowest reasonable radiation dose consistent with the clinical use of the equipment and the information requirement of the examination and to establish and maintain performance standards (American College of Radiology, 2006). The uses of CT as a diagnostic aid for clinical applications are expanding. The technology involved in CT imaging exposes the patient to radiation and the risk of cancer from radiation exposures. To minimize this risk guidelines and recommendations in the use of CT and the radiation dosages employed for imaging are in place. Unless these recommendations and guidelines are followed the risk radiogenic cancers is high in the use of CT. It is for this reason that this specific research has been chosen. AIM/Hypothesis The objective of this research exercise is a critical assessment of the compliance of radiation dosage guidelines for CT by radiographers. The hypothesis under investigation is that there is no strict compliance of radiation dosage guidelines for CT by radiographers. Method 1. Site of the Research The chosen site of the research is Abu Dhabi, United Arab Emirates. The study is planned to include the medical institutions of Al Noor Hospital, Al Rahba Hospital, Mafraq Hospital, Zayed Military Hospital, Al Ain Hospital, Tawam Hospital, Al Sila Hospital, Sheikh Khalifa Medical City, Gulf Diagnostics Centre, New Medical Centre (NMC) and Ahalia Hospital, functioning under the aegis of the Abu Dhabi Health Authority (SEHA). The author acknowledges that the narrow geographical area chosen for the site of the study is a limiting factor in extending the findings of the study to other geographical areas. However, the factors of time availability and financial resources availability are the reasons for the choice of a narrow geographical area for the study. Time and cost of a study do impose restrictions on a researcher’s ability to investigate a research problem from as a wide a perspective as would be preferred. Quite often in research to reduce time involved and the cost implications, researchers are forced to reduce many factors of the research (Holton & Burnett, 2005). 2. Research Design This study will use an inductive and deductive framework to find answers to the questions that the study explores. The reason for the combination of inductive and deductive frameworks lies in making use of the advantages of both. Many of the problems that research explores are done more effectively through the combination of inductive and deductive methods. The inductive method is better suited for the use and interpretation of qualitative data, while the deductive method has more emphasis on measurement and therefore is better suited for use in gathering quantitative data and the interpretation of quantitative data (Lancaster, 2005). According to Lancaster (2005), p.26, “we may begin a research project using inductive methods and approaches, by say, first observing and measuring a phenomenon or problem that we wish to explore. This in turn can lead us to develop theories that we can then test using deductive methods and approach”. This study follows this advice in making use of the literature review to explore the current body of knowledge on radiation dosage issues with CT, guidelines on radiation dosage exposure with CT and what is known on radiographers’ compliance with these guidelines. The study will use a literature review as part of the inductive. Nunes and Al-Mamari (2008), p.67, argue in favour of such an approach in the use of the inductive method to formulate early theories and problems in research. According to Nunes and Al-Mamari (2008), p.67, “the literature review process should therefore produce a priori theory that reflects the cumulative knowledge in the field on the phenomenon being studied, i.e., generic a priori categories that are strongly expected to be relevant in the discussion, explanation and understanding of that phenomenon”. Such an approach however does not imply that the subsequent findings need to be in keeping with these initial theories that arise from the literature review, for they only constitute the initial framework, which the subsequent part of the study may uphold or deny, based on the results obtained from the deductive process (Nunes & Al-Mamari, 2008). From Lancaster (2005), we get to understand the benefit of an inductive method in the exploring of a topic or issue through the use of qualitative data. The literature review thus will provide qualitative data that in effect provides the cumulative knowledge on radiation dosage issues with CT, guidelines on radiation dosage exposure with CT and radiographers’ compliance with these guidelines. Analysis of this data or the cumulative knowledge will provide the means to identify the common themes. This is the justification of the use of the understanding generated from the literature review, as the basis for the subsequent deductive approach for the study purposes. However, Nunes and Al-Mamari (2008), warn that the results of the subsequent deductive process may not uphold all that is derived from the literature review in the inductive process. The deductive or quantitative methods employed in the study thus are capable of verifying the common themes identified in the literature review and it is for this purpose that the deductive process is used as a second part in the methodology. The quantitative research approach has been used by the study, as it provides the means to provide verified answers to the questions related to the study. In addition, it allows drawing conclusions on a group of individuals being studied and then even extending the results of the studies beyond this group. The main attraction lies in the advantage that a quantitative approach provides in limiting the size of the sample in providing answers to the research question. This results in the benefits of reducing the time and cost on the study (Holton & Burnett, 2005). 3. Data Collection The importance of data and data collection lies in the need for data to provide answers to research problems. To provide the correct answers to these problems utmost attention needs to be paid to the data that is being collected, as also the sources from where the data is obtained. Inadequate attention to these factors could lead to inaccurate and insufficient data that no amount or depth used in the subsequent analysis can make up for. “Statistics is a subject which stands on two legs: one is data collection and analysis, and the other is probability” (Gibson, 1997, p.163). The study will use a literature review for collecting qualitative data on the current body of knowledge. Articles from academically accepted journals, books and Web Sites of health authorities will be the materials used in the literature review. Since the focus is on currently valid information, the inclusion criteria will be that the articles from journals, books and guidelines of health authorities should have been published on or after the year 2000. Relevant articles, books and guidelines published before the year of 2000 will be excluded. There are four main methods by which quantitative data is collected. These methods are interviews, tests/measures, observation, and questionnaires (Easterby-Smith, Thorpe & Lowe, 2004). This study will use an open questionnaire and observation notes as the methods for collecting quantitative data. The open questionnaire will be formatted on the basis of the Likert Scale providing five options to the interviewee to choose from. The open questionnaire using the Likert scale is a suitable method for collecting qualitative data to evaluate awareness. Collection of data through observation is well suited to understanding behaviour of individuals in different situations, through the observer being embedded into the environment in such a manner that the observer is unobtrusive to the subject (Easterby-Smith, Thorpe & Lowe, 2004). Observation notes will make up the second set of data collection methods. There will be the limitation in observation used in the study in that the observation will not be carried out in an unobtrusive manner. This is likely to reduce the reliability of the data received through observation. 4. Data Analysis The Statistical Package for the Social Sciences (SPSS) computer program that is used for statistical analysis will be employed for data analysis in this study. Analysis of variance (Anova) and correlation will be employed to arrive at the awareness of radiographers on radiation dosage guidelines for CT by radiographers and compliance of radiographers with radiation dosage guidelines for CT (Grafen & Hails, 2003). 5. Ethical Considerations Ethical Considerations Ethical Considerations Since the research involves the use of people (radiographers) and institutions, the following steps will be taken to meet ethical requirements for the research. 1. Administrative sanction from the institutions and permission from the radiographers will be received before starting the study and applying the questionnaire respectively. Only institutions and radiographers willing to participate in the research will be used in the study. 2. The institutions and radiographers will be clearly informed about the nature and purpose of the study, while taking the permission. 3. Professional ethics as a researcher will be maintained at all times during the study. 4. Data collected will be for academic purposes only. 5. Data will be collected in such a manner as to ensure confidentiality of the business organizations (Data sheets will be coded). 6. At the end of the study the data sheets will be handed over to the administrative authorities for safe keeping or destruction. 8. Timeline The study is proposed to be completed over a period of ten months extending from March 2010 to January 2011. The various activities related to the study have been identified and time frames allotted to each of the identified activities. A detailed breakdown of the activities and allotted time frames are given below. Issue researched Literature review Familiarization of research setting March 2010 Study design Preparation of Questionnaire and Observation note collection sheets. Arranging Statistical Analysis Requirements April 2010 Trial Data collection and Participant Contracts Completed May 2010 Application of Questionnaires and Observation June/July/August/ 2010 Data Analysis September 2010 Draft Report October 2010 Feedback to Participants November 2010 Revise Analysis and Report December 2010 Final Report January 2011 Literary References American College of Radiology. 2006, ‘ACR Technical Standard for Diagnostic Medical Physics Performance Monitoring of Radiographic and Flouroscopic Equipment [Online] Available at: http://www.acr.org/secondarymainmenucategories/quality_safety/guidelines/med_phys/radio_fluoro_equipment.aspx (Accessed February 14, 2010). Bae, K. T. & Whiting, B. R. 2006, ‘Basic Principles of Computed Tomography Physics and Technical Considerations’, in Computed Body Tomography with MRI Correlation, Fourth Edition, eds., Joseph K. T. Lee, Stuart S. Sagel, Robert J. Stanley & Jay P. Heiken, Lippincott Williams & Wilkins, Philadelphia, PA, pp.1-28. Brenner, D. J. & Hall, E. J. 2007, ‘Is Computed Tomography an Increasing Source of Radiation Exposure?’ New England Journal of Medicine, vol.357, pp.227-2284. Bushberg, J. T., Siebert, J. A., Leidholdt, Jr., E. M. & Boone, J. M. 2002, The Essential Physics of Medical Imaging, Second Edition, Lippincott Williams & Wilkins, Philadelphia. Coursey, C. A. & Frush, D. P. 2008, ‘CT and Radiation: What Radiologists Should Know’, Applied Radiology, vol.37, no.3, pp.22-29. Easterby-Smith, M., Thorpe, R. & Lowe, A. 2004, Management Research: An Introduction, Sage, California. European Commission. 1996, ‘European Guidelines on Quality for Diagnostic Radiographic Images’ [Online] Available at: http://www.sprmn.pt/legislacao/ficheiros/EuropeanGuidelineseur16260.pdf (Accessed February 14, 2010). Garcia-Penna, P. & Owens, C. M. 2008, ‘Helical Multidetector Chest CT’, in Pediatric Chest Imaging, Second Revised Edition, eds., J. Lucaya & J. L. Strife, Springer-Verlag, Heidelberg, Germany, pp.47-77. Gibson, W. 1997, Commercial and Industrial Statistics, Hodder Headline Plc, London. Golding, S. J. & Shrimpton, P. C. 2002, ‘Radiation dose in CT: are we meeting the challenge?’ British Journal of Radiology, vol.74, pp.1-4. Grafen, A. & Hails, R. 2003, Modern Statistics for Life Sciences, Oxford University Press, Oxford. Hara, A. K., Paden, R. G., Silva, C. A., Kujak, J. L., Lawder, J. H. & William, P. 2009. ‘Iterative Reconstruction Technique for Reducing Body Radiation Dose at CT: Feasibility Study’, American Journal of Roentgenology, vol.193, no.9, pp.764-771. Health Physics Society. 2009, ‘Radiation Exposure from Medical Diagnostic Imaging Procedures’ [Online] Available at: http://www.hps.org/documents/meddiagimaging.pdf (Accessed February 14, 2010) Hofer, M. 2007, CT Teaching Manual: A Systematic Approach to CT Reading, Third Edition, Theme New York, New York. Holton, E. F. & Burnett, M. F. 2005, ‘The Basics of Quantitative Research’, in Research in Organizations: Foundations and Methods of Enquiry, eds. Richard A. Swanson & Elwood F Holton, Berrett-Koehler Publishers, California Lancaster, G. 2005), Research Methods in Management: A Concise Introduction to Research in Management and Business Consultancy, Elsevier Butterworth-Heinemann: Oxford: Nunes, M. B. & Al-Mamari, S. H. 2008, ‘Inductive Approaches Using a Priori Coding in Information Systems Research: A Discussion’, in Seventh European Conference on Research Methodology for Business and Management Studies, Regent’s College, London, UK, 19-20 June 2008, ed. Ann Brown, Academic Publishing Limited, Reading. Ravenel, J. G. 2008, ‘Multidetector Computed Tomography’, in Cancer Imaging, ed. M. A. Hayat, Elsevier Academic Press, Burlington, MA, pp.17-25. Read More