Diagnostic Imaging of Bone Disease Causes - Research Proposal Example

Diagnostic Imaging of Bone Disease Causes as Opposed to Non-Accidental Injuries Key Words: CT Scan; MRI; X-rays; Nuclear medicine scan; ultrasound; NAI; child abuse; osteopenia; osteoporosis; osteomalacia; bone injury. Student ID Number Total Number of Words: 3,000 Abstract Background: Diagnostic imaging devices like X-rays, computed tomography (CT) scans, positron emission tomography (PET), and magnetic resonance imaging (MRI) scans are used not only for diagnostic and treatment but also for autopsy purposes. Considering the risk for errors in the actual measurements and imaging process, this study will conduct a literature review to learn more about the actual practices needed to increase reliability of these images when used in detecting bone-related problems caused by metabolic bone diseases and Non-Accidental Injuries. Method: Databases of MEDLINE and NCBI/Pubmed were used in search for highly relevant journals. Using the inclusion and exclusion criteria, useful journals and academic books that were published between 2008 to 2013 were used throughout the completion of this study. Conclusion: Several imaging devices such as DXA, pDXA, X-rays, PET, CT scan, and MRI can be use in assessing not only the bone mass but also diagnose bone fracture which can be done by carefully observing the bone’s macrostructure. However, each type of radiological equipment has some limitations when it comes to the clarity of the image it can provide. For this reason, it is crucial for radiologists to take note of certain factors that could result to inaccurate or misleading images. Acknowledgements I would like to give special thanks to my family who has given me more than extra support to complete this study. Table of Contents Abstract ……………………………………………………………………………………. 2 Acknowledgement ……………………………………………………………………….. 3 Table of Contents ………………………………………………………………………… 4 1. Introduction ……………………………………………………………………….. 5 1.1 Rationale for Conducting the Review ………………………………. 5 1.2 Relevance for Specific Profession …………………………………. 6 2. Research Method …………………………………………………………………. 6 3. Result / Findings …………………………………………………………………... 8 3.1 Differences between Metabolic Bone Diseases and Non-Accidental Injuries (NAI) ………………………………………. 8 3.2 Actual Practices behind the Use of Imaging Technologies ........... 9 3.2.1 Dual Energy X-ray Absorptiometry (DXA) ................... 10 3.2.2 CT Scan ....................................................................... 11 3.2.3 MRI .............................................................................. 12 3.2.4 PET .............................................................................. 12 3.3 Ethical Issues behind the Use of Imaging Technologies ............... 12 4. Discussion and Implications …………………………………………………….. 14 5. Conclusion and Recommendations ............................................................... 16 References ……………………………………………………………………………… 17 - 19 Appendix I – Diagram Showing the Physiological Effects of Insufficient Intake of Calcium, Phosphorus, and Vitamin D .................................. 20 1.0 Introduction Diagnostic imaging such as x-rays, computed tomography (CT) scans, positron emission tomography (PET), and magnetic resonance imaging (MRI) scans are used for diagnostic and treatment purposes (WHO, 2013; Kirpalani and Chew, 2011). Today, a wide-range of diagnostic imaging modalities are use to identify bone-disease caused disorders as opposed to non-accidental injuries (NAI) (Kirpalani and Chew, 2011). In relation to the use of digital diagnostic imaging, this study will evaluate and synthesize literature with regards to the actual practices, theoretical and conceptual issues, ethics, and methodological concerns when using these imaging technologies. 1.1 Rationale for Conducting the Review Radiological examinations are used in the studying of bone trauma caused by NAI and metabolic bone disorders (Gall and Payne-James, 2011, p. 63; El Magharaoui and Roux, 2008). The application of these imaging devices is also necessary when there is a need to conduct an autopsy (Eisenstein et al., 2012). However, diagnostic imaging devices can sometimes result to measurement errors (El Magharaoui and Roux, 2008). Wrong diagnoses can lead to either a harmful and ineffective treatment (Gall and Payne-James, 2011, p. 63) or a misleading autopsy result (Eisenstein et al., 2012). Therefore, conducting this review is necessary to compare the differences in the use of diagnostic imaging devices on NAI and those that are caused by certain pathological issues, or both. Eventually, the research findings will be useful in determining the best clinical practices and ethical considerations that each radiographer should consider when using these devices. 1.2 Relevance for Specific Profession Radiographers are the ones who control the usage and look after the diagnostic imaging devices whereas radiologists or physicians are the ones who interpret the diagnostic imaging results of x-rays, CT scans, PET scans or MRI scans, and write some prescriptions for the patients (Pandya et al., 2011; El Magharaoui and Roux, 2008; Mody, 2008). To ensure that radiologists would provide the physicians with a highly reliable radiogram, all radiologists are expected to avoid coming up with images that could lead to ineffective diagnosis. Even though some people may think that radiologists are the ones who should read and interpret these images, it is a common practice in the field of medicine that physicians are the ones who perform the actual diagnosis (Mody, 2008). 2.0 Research Method In search for relevant literature, access to the databases of MEDLINE and NCBI/Pubmed were essential. To narrow down the search for related literature, the following “keywords” and “phrases” were used in this study: (1) CT scan rickets osteopenia osteoporosis osteomalacia; (2) MRI rickets osteopenia osteoporosis osteomalacia; and (3) X-rays rickets osteopenia osteoporosis osteomalacia among others. Eventually, inclusion and exclusion criteria were used to define exactly the journals that will be included in the review of literature (Nesbitt, 2004, p. 24). In this study, the following inclusion and exclusion criteria were carefully observed in the search for related literature: Inclusion Criteria Exclusion Criteria Books and journals related to the use of diagnostic imaging to identify metabolic bone diseases and non-accidental injuries (NAI); Books and journals published on 2008 onwards. Books and journals related to the use of diagnostic imaging but not applied in the case of metabolic bone diseases and non-accidental injuries (NAI); Books and journals published prior to 2008; Research studies with unreliable research method and biased findings; Books and journals that are written in different languages other than English. Using the “keywords” and “phrases” presented earlier, the number of “hits” gathered for this study is as follows: Cochrane NCBI / Pubmed CT scan rickets osteopenia osteoporosis osteomalacia 0 2 MRI rickets osteopenia osteoporosis osteomalacia 0 4 X-rays rickets osteopenia osteoporosis osteomalacia 0 53 Nuclear medicine scan rickets osteopenia osteoporosis osteomalacia 0 14 Ultrasound rickets osteopenia osteoporosis osteomalacia 0 0 CT scan MRI x-rays nuclear medicine scan child abuse 0 8 CT scan non-accidental injury 0 51 MRI non-accidental injury 0 36 x-rays non-accidental injury 1 114 nuclear medicine scan non-accidental injury 0 3 CT scan bone injury 1 13087 MRI bone injury 29 10255 x-rays bone injury 4 49373 nuclear medicine scan bone injury 1 2352 Radiology ethics 1 848 3.0 Result / Findings 3.1 Differences between Fracture Caused by Metabolic Bone Diseases and Non-Accidental Injuries (NAI) The weakening of the bones can be triggered by the imbalances of calcium, phosphorus, and vitamin D3 (Sahay and Sahay, 2012; Brickley and Ives, 2008, p. 76). There are also some cases wherein the presence of genetic defects can lead to a poor absorption of calcium and phosphorus (Unnanuntana et al., 2011). (See Appendix I – Diagram Showing the Physiological Effects of Insufficient Intake of Calcium, Phosphorus, and Vitamin D on page 20) Inadequate supply of calcium and phosphorus can lead to the development of rickets in children and diffuse osteopenia, osteoporosis, and osteomalacia in adults (Sahay and Sahay, 2012). People who are diagnosed with either rickets or complications of hyperparathyroidism such as diffuse orsteopenia, osteoporosis, and osteomalacia are prone to suffer from bone-related fracture (Gulielmi et al., 2011; Unnanuntana et al., 2011). The Institute of Medical Illustrators (IMI) defined non-accidental injury (NAI) as “any physical or emotional abuse purposefully inflicted on a person” (IMI, 2013). As compared to the adults, the bones of children are basically softer due to its fragile growth plates. Therefore, it is common for the victims of child abuse to be at risk of suffering bone trauma caused by the presence of mechanical forces like “fingertip pressure” (Gall and Payne-James, 2011, pp. 63 – 64). Other than skin trauma, fractures of the rib, skill, humeral, and femur are among the next common sign of child abuse whereas features like “multiple fractures after minor trauma, blue sclera, osteopenia, wormian bones, dentinogenesis imperfect, and a family history of fractures or bone disease” are common among patients with metabolic bone disorder (Pandya et al., 2011, p. 806). Based on the systematic review of Pandya et al. (2011, p. 810), fractures caused by NAI and metabolic bone disorders can show confusing signs and that physicians make the final diagnosis as to whether or not the patient has either a bone-related disorder or NAI based on the patient’s “family history, physical examinations, and radiographic findings”. 3.2 Actual Practices behind the Use of Imaging Technologies Regardless of the type of diagnostic imaging used in detecting bone-related problems, it is a common knowledge that the use of “babygram” examination is not the best method when it comes to detecting signs of bone fracture. Basically, when the beam from these devices is highly angulated from the body parts being captured in the film, radiologists would most likely lose the detail that is present in the “periphery of the field of view” (Dwek, 2011, p. 778). Radiologists should also keep in mind that the density of the body parts can affect the kind of radiographic technique they should use to be able to obtain an optimal image (Dwek, 2011; Muncie and Leblanc, 2010; El Magharaoui and Roux, 2008). This explains why body positioning is very important when using these devices. Before using any of these radiological imaging devices, radiologists should know whether or not a woman is pregnant because of the risks wherein the presence of a strong magnetic field would adversely affect the developing baby (Greenberg, 2010, pp. 130 – 131; Wright, 2010). It is equally important for radiologists to know whether there are metal objects in the patients’ body (i.e. pacemaker, screws, artificial joints, etc.) (Wright, 2010). 3.2.1 Dual Energy X-ray Absorptiometry (DXA) The actual measurements take from this particular diagnostic imaging device can sometimes lead to an acceptable errors (El Magharaoui and Roux, 2008). Considering the fact that the DXA scanners have 2 x-ray energies which captures the bone mineral, adipose and lean tissues, there is a higher risks risk wherein the “inhomogenous distribution of adipose tissue” can trigger error in DXA results (El Magharaoui and Roux, 2008). To avoid measurement errors, radiologists should focus on identifying and detecting factors such as wrong patient information, hip and spine scanning problems (i.e. spine too close to the left or right side of the image, misidentified vertebral levels, adducted or abducted femur, etc.), wrong positioning or sudden movement of the body, the application of flouroscopy when positioning the body, the loading of multiple cassette films, intermachine variance, and the presence of diseases and implanted medical devices that can significantly influence the result of DXA scans (Muncie and Leblanc, 2010; El Magharaoui and Roux, 2008). To reduce the risk of measurement errors, El Magharaoui and Roux (2008) strongly suggest the need to perform another DXA scan under the same environmental condition and densitometer to enure that there is no discrepancy between the first and second DXA result. It means that radiologists should use the same DXA machine to avoid the risk of measurement discrepancy caused by intermachine variance (Muncie and Leblanc, 2010). Different healthcare organizations in UK and US have different recommendations with regards to the frequency of using DXA scanners (Muncie and Leblanc, 2010). For instance, in UK, the National Osteoporosis Guidelines Group provided no specific recommendation with regards to the use of DXA scanner (Muncie and Leblanc, 2010). The American Association of Clinical Endocrinologists and the North American Menopause Society suggest that there is a need to repeat DXA imaging every two (2) years until stable whereas the Institute for Clinical Systems Improvement and the National Osteoporosis Foundation recommends the need to repeat DXA imaging at least one (1) to two (2) year after the therapeutic intervention (Muncie and Leblanc, 2010). Only the National Osteoporosis Foundation and the International Society for Clinical Densitometry recommends the need to repeat DXA imaging based on the medical necessity of each patient (Muncie and Leblanc, 2010). 4.2.2 CT Scan Radiologists are required to “calibrate the CT scanners to the x-ray attenuation to the water” (DElia et al., 2009, p. 240). Eventually, radiologists should place a bone mineral phantom on the scan field in order to convert the Hounsfield Units (HU) to bone mineral equivalents in mg/cm3 (DElia et al., 2009). When using CT scanners, radiologists should keep in mind that the dose of radiation should depend not only on the volume of subject being scanned but also the type of scan sequences, preferred resolution, quality of the image, and the patients’ physical characteristics (DElia et al., 2009). In case there is a need to scan a fractured vertebrae, radiologists should position the scanner “in the middle of each vertebral body (L1-L3), parallel to the end plates” whereas the “bone equivalent phantom should be placed on the scanning table just below the lumbar spine” (DElia et al., 2009, p. 241). Before using the CT scanner, radiologists should ensure that the patient has not eaten for four hours and has refrained from any strenuous exercises prior to his schedule (Wright, 2010). 4.2.3 MRI To get high resolution images, radiologists should know that the use of dye or tracer like gadolinium chelates – a type of salt can further improve the imaging contrast (Aronson, 2011, p. 968; Wright, 2010). However, there are some patients who may have allergic reaction with tracers. Therefore, radiologists should perform allergy prep or skin-testing first before using dye or tracers (Greenberg, 2010, p. 130). 4.2.4 PET When using PET scanners, radiologists may require the need to inject a small amount of “radio-active material” like fluorodeoxyglucose – a form of sugar tracer in the patients’ bloodstream and then place a ring detector outside the body parts which needs to be scanned (Wright, 2010). Basically, what the fluorodeoxyglucose does is to trigger the production of gamma-rays whereas the ring detector will detect the gamma-rays that will be emitted by the sugar tracer (Wright, 2010; Kim et al., 2013, p. 15). 3.3 Ethical Issues behind the Use of Imaging Technologies It is the duty of radiologists to provide the patients with the best care that is totally free from harm (Abujudeh and Bruno, 2012, p. 334). It means that radiologists should always keep in mind that they are the ones who are personally responsible for being able to limit the patients’ and their own risks of being exposed to excessively harmful radiation. As a standard practice, radiologists are obliged to seek consent from the child’s parents before allowing a child to undergo radiological examination (Gall and Payne-James, 2011, p. 64). As part of professional ethics, the inability of radiologists/radiographers to obtain informed consent from the patients is already considered as a ‘medical malpractice’ and is subject for future legal actions (Semelka et al., 2012; Pinto and Brunese, 2010). To avoid the risk of facing legal actions or losing certification or license to use diagnostic imaging devices, radiologists and radiographers should not only carefully observe the law of confidentiality but also be careful with the technical issues behind the actual interpretation of these images and the use of these imaging devices respectively (Chhem, Hilbbert and Van Deven, 2009, p. 115). It is equally important to inform the patients about the purpose and process of radiological exam and encourage the patients’ parents (in case of minors) or the adult patient himself to sign the informed consent form (Chhem, Hilbbert and Van Deven, 2009, p. 115). This explains why radiologists and radiographers are responsible in continuously upgrading their knowledge and skills with regards to the use and advantages or disadvantages of various diagnostic imaging facilities. With regards to the methodological concerns when using these imaging devices, it is a common rule for each radiologist to deliver an optimal image at all costs. It means that it is but ethical for each radiologist to do something about the patients’ casts, IV catheters, or bandages to avoid distrupting the clarity of the image (Dwek, 2011). 4.0 Discussion and Implications Most of the people with metabolic bone diseases (i.e. rickets, orsteopenia, osteoporosis, and osteomalacia) suffer from bone weakening due to a significant reduction in bone mass causing them to suffer from bone fracture. To detect early signs of bone mass reduction, the patients’ bone density in the lumbar spine, forearm, and femoral neck is often measured with the use of DXA whereas peripheral DXA (pDXA) can be used in assessing the patients’ peripheral skeleton and other skeletal sites such as the heel, hands, and forearm (Muncie and Leblanc, 2010; DElia et al., 2009; El Magharaoui and Roux, 2008). Although X-rays can be used in detecting bone fracture on distal radius, the use of X-rays may not be effective in terms of detecting bone problems in the hips and spine (DElia et al., 2009). Because of the imaging limitations of conventional x-rays, DElia et al. (2009) explained that radiologists should refrain from using x-rays when diagnosing osteoporosis since the use of this particular equipment does not detect signs of rarefaction not until 20% to 40% of the bone mass is already lost. To give a more sensitive and reliable images, most radiologists today are using DXA or pDXA when assessing the patients’ bone density particularly in the hip and lumbar spine (Muncie and Leblanc, 2010; DElia et al., 2009; El Magharaoui and Roux, 2008). Radiologists can get 3-dimensional images with a higher spatial resolution and higher contrast resolution when using CT scanners and MRI equipments respectively (DElia et al., 2009). In fact, CT and MRI are also considered effective when detecting fractures caused by bone lesions (DElia et al., 2009). Unlike MRI, CT scan is commonly used in evaluating intracranial injuries, a “hole in the rib”, and solid organ injuries such as significant changes in the soft tissue caused by “pulmonary contisions, pleural effusions, and extrapleural soft tissue swelling and hemorrhage” (Dwek, 2011, p. 779). PET scans are also effective in detecting bone fractures. After evaluating the sensitivity of fluorine 18-labeled sodium fluoride in PET scan when used in assessing skeletal trauma, Drubach et al. (2010) found out that PET has a higher sensitivity (85%) to detect all types of bone fractures (i.e. 92% thoracic fractures like clavicle, ribs, sternum, and scapula, 93% posterior rib fractures, and 67% classic metaphyseal lesions). Despite the advantages of each imaging device, there will always be some limitations in each type of equipment. For instance, although MRI provides a higher contrast resolution as compared to CT scan, the MRI will never be a good choice when it comes to giving a good image of the trabecular bone (DElia et al., 2009). MRI also has a limitation when it comes to detecting “complex cardiac malformations, anomalous connections between structures (trachea-esophageal fistulas), and bowel perforations” (Eisenstein et al., 2012, p. 697). As compared to other 2D imaging devices, CT is capable of eliminating superimposition coming from body parts that are not being diagnosed. Because of its high-contrast resolution, images coming from CT scans will provide a clear distinction between bones and tissues that are present in the body parts being tested. It will also provide radiologists with a better “selective assessment of both trabecular and cortical bone” (DElia et al., 2009, p. 240). However, CT scan is not effective in terms of detecting signs of “contusions or superficial lesions of solid organs, small soft tissue contusions, brain contusions, and hematomas smaller than 3 mm, and vascular transections or lacerations” (Eisenstein et al., 2012, p. 697). 6.0 Conclusion and Recommendations Several imaging devices such as DXA, pDXA, X-rays, PET, CT scan, and MRI can be use in assessing not only the bone mass but also diagnose bone fracture which can be done by carefully observing the bone’s macrostructure. However, each type of radiological equipment has some limitations when it comes to the clarity of the image it can provide. Although there are quite a lot of studies available with regards to the use of different diagnostic imaging devices on detecting disease-related bone problems and those that are caused by non-accidental injuries (NAI), very few studies have bothered to discuss deeply the radiation limit when using each type of radiographic examination equipment. Therefore, future research study should focus on compare and contrast the practical uses and technical limitations of each type of radiological equipment. References Abujudeh, H. and Bruno, M. (2012). Quality and Safety in Radiology. NY: Oxford University Press. Aronson, J. (2011). Side Effects of Drugs Annual 33. Oxford: Elsevier. Brickley, M. and Ives, R. (2008). The Bioarchaeology of Metabolic Bone Disease. 1st Edition. Oxford: Elsevier. Chhem, R., Hilbbert, K. and Van Deven, T. (2009). 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(2011). Diseases Affecting Bone Quality: Beyond Osteoporosis. Clinical Orthopaedics and Related Research, 469(8), pp. 2194-2206. WHO. (2013). Diagnostic imaging. Imaging modalities . WHO. [Online] Available at: http://www.who.int/diagnostic_imaging/en/ [Accessed 24 March 2013]. Wright, A. (2010). Brain scanning techniques (CT, MRI, fMRI, PET, SPECT, DTI, DOT). Cerebra. [Online] Available at: http://www.cerebra.org.uk/SiteCollectionDocuments/Research%20PDF%27s/Brain%20scanning%20techniques.pdf [Accessed 31 March 2013]. Appendix I – Diagram Showing the Physiological Effects of Insufficient Intake of Calcium, Phosphorus, and Vitamin D Source: Brickley and Ives, 2008, p. 76 Read More