Virtual Autopsy or Virtopsy - Coursework Example

?VIRTUAL AUTOPSY Introduction The role of radiology in autopsy has been extended to include multidetector computed tomography (CT) and magnetic resonance (MR) imaging. According to Thali et al (2003), the term Virtual Autopsy or Virtopsy refers to the technique of postmortem imaging with multidetector CT and/ or MR imaging. Conventionally, in forensic investigation and autopsy, the use of full-body radiography is well established and routinely applied to document “fractures, injury patterns, occult injuries, and foreign body and metallic fragmentation localization” (Levy, Abbott, Mallack et al, 2006, p.522). Full body radiography also helps in identification of human remains when conventional methods such as fingerprinting or DNA analysis cannot be used, or are not available. Thesis Statement: The purpose of this paper is to investigate the new development of virtual autopsy in forensic science, and identify its advantages and disadvantages over conventional autopsy procedures that have been employed until recently. Virtual Autopsy with the Help of Multidetector Computed Tomography The application of imaging methods for non-invasive documentation and analysis of relevant forensic findings in living and dead persons has not kept abreast of enormous technical development of imaging methods. Forensic radiology is now a rapidly growing interdisciplinary subspeciality of both forensic medicine and radiology. The new modalities that are now increasingly being promoted for use in forensic investigations include Computer Tomography (CT) including spiral multislice, and Magnetic Reso-nance Imaging or MRI (Thali et al, 2007). The VIRTOPSY project aims to utilize radiological scanning to upgrade low-tech documentation and autopsy procedures in the contemporary high-tech field of medicine. The purpose of this is to improve scientific value, and to increase significance and quality in the forensic field. The term VIRTOPSY is the combination of the terms virtual and autopsy. The term means to see with one’s own eyes (virtus: useful, efficient and good; autos: self; and opsomei: I will see), as translated from Latin. Thus autopsy means to see with one’s own eyes. Thali et al (2007) aimed to eliminate the subjectivity of “autos”, hence they combined the two terms virtual an autopsy, deleting “autos”, and creating VIRTOPSY. Today the project VIRTOPSY groups the research topics under one scientific category, is characterized by a trans-disciplinary research approach that integrates “Forensic Medicine, Pathology, Radiology, Image-Processing, Physics, and Biomechanics” (Thali et al, 2007, p.100), to an international scientific network. Levy et al (2006) conducted a study to retrospectively assess virtual autopsy performed with multidetector computed tomography (CT) for the forensic evaluation of gunshot wound victims. They found that multidetector CT can aid the prediction of lethal wounds and the location of metallic fragments. Similarly, Ljung, Winskog, Persson et al (2006) devised a procedure for virtual autopsies based on interactive 3D visualizations of large scale, high resolution data from CT-scans of human cadavers. Using examples from forensic medicine, the researchers stated that “based on the technical demands of the procedure, state-of-the-art volume rendering techniques are applied and refined to enable real-time, full body virtual autopsies involving gigabyte sized data on standard graphics processing units (GPUs)” (Ljung et al, 2006, p.1). The techniques applied include transfer function based data reduction using level of detail selection and multiresolution selection techniques. The paper also describes a data management component for large, out-of-core data sets and an extension of the GPU-based raycaster for efficient dual text field (TF) rendering. The authors demonstrated the added value and future potential of virtual autopsies in the medical and forensic fields. Data sets from forensic cases provide detailed benchmarks of the pipeline (Ljung et al, 2006). The Use of Magnetic Resonance Imaging (MRI) in Virtual Autopsy Magnetic resonance imaging is now a commonly used technique in medical diagnostics since its introduction in 1980. Using radio waves beamed through a powerful magnetic field, MRI creates images of extremely accurate detail. But the process is not an automated one, requiring operators to learn elaborate protocols to extract images from different types of body tissue. Cooler temperatures of refrigerated research subjects would wreak havoc on results, because the MRI machine “operates by translating the signature vibrations emanating from the nuclei of different kinds of atoms” (Sachs, 2004, p.53). These nuclear vibrations slow down at cooler temperatures. Therefore, MRI technologists have to create special protocols to compensate for the lower body temperatures of refrigerated specimens. The advantage is that the resulting images have high clarity. Moreover, there is no beating heart, no circulating blood, no digestive motions to blur our images. Virtual autopsy or Virtopsy is considered to be the ultimate no-mess autopsy, being precise, objective and non-destructive. Additionally, death’s every data point is captured permanently on compact discs stored in security vaults. The twin medical imaging technologies of computed tomography (CT) and magnetic resonance imaging (MRI) are adapted to create three-dimensional, high resolution images of a crime victim’s internal organs. When the digitized blood and guts are poured into a hollow-man replica of the victim, the result is a head-to-toe cyber corpse, that a pathologist can view along with his wounds, from any depth and angle, including inside-out (Sachs, 2004). One of the main disadvantages of using virtual autopsy is that the equipment required includes an MRI machine costing upward of $1 million, a CT scanner priced at about $500,000, and a 3-D surface scanning equipment worth more than $100,000. Numerous medical examiners are therefore content to use an X-ray machine. In the present time for a short term this type of extremely expensive technology will be considered a big luxury (Sachs, 2004). Besides the high cost, another major disadvantage of virtopsy is that it is very inadequate for diagnosing poisoning, as well as common natural causes of death such as infection or heart failure. It is extremely important to rule out such natural causes in cases of suspected murder. The Advantages of Using Imaging Techniques in Forensic Medicine In the present time, imaging techniques are acknowledged as excellent tools for forensic medicine. Similar to inspection and photography, but different to other techniques, they freeze the findings at the moment of investigation without causing any damage to the evidence. Freezing refers to permanent: either analogue or digital preservation as a document of proof, whether the victim is dead and undergoing postmortem decay or surviving and losing evidence due to healing. The essential requirement of causing no damage is fulfilled completely, in living persons. Even in dead persons, nondestructive documentation is essential for two reasons: First, the information is given without precluding any other conservative or destructive investigation. Second, it can be used in cultures and situations where autopsy is not tolerated by religion or rejected by family members (Thali et al, 2007). It is increasingly certain that radiological minimally invasive “virtual autopsy” in defined situations will replace the classical or conventional dissection technique. Two innovative forensic documentation methods that are emerging are: the combination of sectional imaging with surface documentation methods, such as photogrammetry and 3D optical scanning; and the combination of noninvasive imaging with minimally invasive image-guided tissue sampling from any body location required (Thali, Braun, Buck et al, 2005). Tissue samples can be used for cytology, histology, chemical and microbiological analysis. Additionally, radiologic virtual autopsy offers other advantages such as: an easy examination of bodies contaminated by infection, toxic substances, radionuclides or other biohazards; 2D and 3D postprocessing incredibly helps to visualize the findings to people not present during the examination, for example in court. Further, complete and easily retrievable digital archives and teleconsultation will support the process of quality improvement. To support this process, the authors founded the Technical Working Group Forensic Imaging Methods (Thali et al, 2005). Virtopsy is a bloodless approach as compared to the messy job of the conventional autopsy method. The added benefit of permanency is also accorded to the digitally preserved bodies of the Virtopsy project. Murder victims’ bodies decompose, hence police and pathologists have since the earliest times of forensic investigations, documented such disappearing evidence with photographs and detailed medical reports. Photos are limited by their two-dimensionality, and the inherent distortion of camera angles. Further, medical reports frequently remain unacceptably subjective. In the courtroom, prosecutors and defense lawyers often present two pathologists in conflict with each, each reinterpreting autopsy reports to favor one side or the other. The jury’s difficulty in following such arguments is often complicated by the presentation of gore-drenched autopsy photographs. Thus, virtopsy promises a future in which “any pathologist taking the witness stand can bloodlessly redissect the victim in full view of the jury by calling forth the original data stored on the discs” (Sachs, 2004, p.51). This helps to provide graphic but not gory details of the victim’s internal parts. Some scientists, after performing virtual autopsy, follow it up with a conventional autopsy to confirm the findings, although the virtual autopsy has proved to be highly accurate. The technique is particularly beneficial for detecting internal bleeding, bullet paths and hidden fractures that can be difficult to isolate among the mass of blood and gore that results when a pathologist is forced to essentially eviscerate the body. One of the best uses of virtopsy is the way computerized tomography (CT) and magnetic resonance imaging (MRI) scans highlight emboliair bubbles that obstruct blood vessels, that have entered the body through a wound. “Such effervescent evidence can vanish as soon as a pathologist slices open a vein or organ to look for it” (Sachs, 2004, p.52). This problem is so difficult that some scientists have proposed performing underwater autopsies in swimming pools to detect escaping air bubbles. Further, the scans render it much easier to detect aspirated or inhaled water and blood in the lungs. Identifying when a victim entered the water or sustained an injury can be crucial for determining whether an apparent drowning or car crash was staged to cover up a murder. Pockets of air, blood or water show up clearly on CT or MRI scans as spots black, white or grey against the background of body tissues (Sachs, 2004). Conclusion This paper has highlighted virtual autopsy or virtopsy, and investigated the use of this new development in forensic science. The advantages and disadvantages of virtual autopsy over conventional autopsy procedures have been identified. The evidence from research indicates that the expansion of radiology into the more recent techniques of multidetector computed tomography and magnetic resonance imaging has ushered in an era of greater accuracy of criminal investigations in forensic science, besides numerous other crucial advantages such as capability for digital preservation of evidence, easy examination of bodies contaminated by radioactive or infective substances. Among the comparative disadvantages are the high cost of virtopsy and its inadequacy in detecting poisoning or natural causes of death such as heart failure. It is predicted that virtual autopsy will improve the procedure of autopsy by guiding the pathologist’s scalpel and preserving a record of what the internal organs looked like before dissection (Sachs, 2004). That is, it will support, facilitate and increase the accuracy of postmortem diagnosis and forensic tests, but will not replace completely the conservative method of autopsy. This is because seeing with one’s own eyes will always remain the gold standard in autopsy. References Levy, A.D., Abbott, R.M., Mallak, C.T., Getz, J.M., Harcke, H.T., Champion, H.R. & Pearse, L.A. (2006). Virtual autopsy: Preliminary experience in high-velocity gunshot wound victims. Radiology, 240(2): pp.522-529. Ljung, P., Winskog, C., Persson, A. & Lundstrom, C. (2006). Full body virtual autopsies using a state-of-the-art volume rendering pipeline. Paper presented in IEEE VGTC sponsored conference proceedings. Retrieved on 30th April, 2011 from: http://www.cmiv.liu.se/Members/clalu/pubs/ljung06autopsy-pp.pdf Sachs, J.S. (2004). Why give a dead man a body scan? Forensic scientists in Switzerland are pioneering a whole new way to do autopsies. No scalpel required. Popular Science, 265(4): pp.50-55. Thali, M.J., Jackowski, C., Oesterhelweg, L., Ross, S.G. & Dirnhofer, R. (2007). VIRTOPSY- The Swiss virtual autopsy approach. Legal Medicine, 9: pp.100-104. Thali, M.J., Braun, M., Buck, U., Aghayev, E., Jackowski, C., Vock, P. et al. (2005). VIRTOPSY- Scientific documentation, reconstruction and animation in forensic: Individual and real 3D data based geometric approach including optical body/ object surface and radiological CT/ MRI scanning. Journal of Forensic Science, 50(2): pp. 428-442. Thali, M.J., Yen, K. & Vock, P. (2003). Image-guided virtual autopsy findings of gunshot victims performed with multi-slice computed tomography and magnetic resonance imaging and subsequent correlation between radiology and autopsy findings. Forensic Science International, 138: pp.8-16. Read More