FORENSIC ODONTOLOGY SECTION: REVIEW ARTICLE
Year : 2017 | Volume
: 29 | Issue : 4 | Page : 368--370
Image Guided Virtual Autopsy: An Adjunct with Radiographic and Computed Tomography Modalities - An Important Tool in Forensic Identification
Shalu Rai, Deepankar Misra, Kuber Tyagi, Mukul Prabhat, Purwa Gangwal
Department of Oral Medicine and Radiology, Institute of Dental Studies and Technologies, Kadrabad, Modinagar, Uttar Pradesh, India
Department of Oral Medicine and Radiology, Institute of Dental Studies and Technologies, Kadrabad, Modinagar, Uttar Pradesh
The forensic examination of dead bodies is very helpful in order to identify the person, cause of death, gender, and solving the mysterious cases. It includes a number of techniques, out of which autopsy is the primary investigation that is performed in every medicolegal case. Because of mutilation technologies, traditional autopsy technique is most disturbing in terms of emotions and rituals of relatives. The use of radiology in forensic science comprises performance, interpretation, and reporting of radiographs that is helpful in detecting those changes that are not clinically visible. Forensic radiology plays an important role for identification of humans in mass disasters, criminal investigations, and evaluation of cause of death. The introduction of radiological modalities in autopsy techniques is a complementary tool for forensic identification and is known as virtual autopsy. The advance imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI) is used in virtual autopsy in order to visualize and reconstruct the internal organs to know the site, type, and depth of injury. This review elaborates the role of maxillofacial imaging in image-guided virtual autopsy.
|How to cite this article:|
Rai S, Misra D, Tyagi K, Prabhat M, Gangwal P. Image Guided Virtual Autopsy: An Adjunct with Radiographic and Computed Tomography Modalities - An Important Tool in Forensic Identification.J Indian Acad Oral Med Radiol 2017;29:368-370
|How to cite this URL:|
Rai S, Misra D, Tyagi K, Prabhat M, Gangwal P. Image Guided Virtual Autopsy: An Adjunct with Radiographic and Computed Tomography Modalities - An Important Tool in Forensic Identification. J Indian Acad Oral Med Radiol [serial online] 2017 [cited 2020 Jul 14 ];29:368-370
Available from: http://www.jiaomr.in/text.asp?2017/29/4/368/225470
The word “autopsy” is a Greek word that means “to see with one's own eye” or “self study of a dead body,” which is carried out for clinical or pathological and medico-legal purposes. The purpose of clinical or pathological autopsy is to evaluate the cause of death and the purpose of medicolegal autopsy is to solve the mysterious unnatural death. The conventional autopsy procedures comprises mutilating techniques that is sometimes sensitive in terms of emotional aspects of the victim's relatives, therefore majority of them object to performing autopsies. So autopsy is usually a conflicting situation for forensic examiners. Moreover, in some religions like in Judaism, it is completely prohibited to permit autopsy on the dead. Considering these objections, and in an attempt to ameliorate the autopsy results, alternative aids in diagnosing the cause of death were developed. Use of imaging in medicolegal purposes was seen in forensic practice since 1896. Numerous cases were reported in which liver, heart, brain, and bone injuries were investigated radiographically revealing the possible cause of death.,
Image-guided autopsy or virtopsy is a new technique which consists of internal examination of dead bodies using computed tomography (CT) and magnetic resonance imaging (MRI), without opening the body or body parts. It also allows the reconstruction of a three dimensional view of the analyzed cadaver, thereby helping in answering main forensic questions without autopsy., The teeth has been a primary means for individual identification in single cases as well as mass disasters that includes comparing postmortem dental radiographs to antemortem records. The use of CT is a new modality for this purpose. CT scans are performed using mobile CT-scanning equipment. Maximum intensity projection (MIP) is a very fast imaging technique which takes just several minutes to create a radiographic model of the dead bodies to be investigated. This review aims to update the knowledge of dental professionals about the use of maxillofacial imaging in image-guided virtual autopsy and its applications that are helpful in forensic identification.
Wullenweber et al. (1977) initially applied CT in forensics in order to identify radiographic patterns of gunshot injuries to head. The foundation stone for use of digital autopsy was laid down after the generation of the “Virtual Mummy” at the British Museum in year 2004. The application of virtopsy in dentistry was also described by Oesterhelweg et al. in a victim suffering from respiratory obstruction from a foreign body. CT and MRI were used to differentiate the obstructive structure. The information provided by virtopsy was more accurate and clear. Birngruber et al. reported a positive identification of an individual after comparing ante-mortem radiographs with postmortem CT images. Jackowski et al. performed pioneering researches on virtual autopsy. They expressed different density of restoration materials, such as composites, temporary fillings, and ceramics in Hounsfield units (HU) by ultra-high-resolution CT imaging. Ampanozi et al. described the advantage of virtopsy to obtain information about the depth of trauma from sharp instruments.,
Methods of Virtopsy
CT is the most frequent imaging tool in forensic sciences. With modern scanners, 2D and 3D reconstructions based on slice thicknesses of 0.5 mm are not only possible, but are becoming routine standard. It is used for detection of foreign bodies, fractures, gas, and fluid accumulations such as blood. It also demonstrates calcifications such as coronary sclerosis and larger vessels easily and can be used in conjugation with postmortem angiography.
Magnetic resonance imaging
Contrast based MRI is a nonionizing imaging modality which can illustrate soft-tissue injuries and pathologies clearly and is also useful when examining living victims of assault, such as manual strangulation.,
This method uses a biopsy gun, to obtain samples of organs of interest, e.g., the heart, or specific pathologies seen in CT or MRI. It also aids in collection of tissue and fluid samples that can be collected for toxicological and microbiological examinations. Besides the manual sampling, image-guided sampling with a dedicated robot has been introduced recently.
3D photogrammetry-based optical surface scanning
It uses a surface-scanning unit, which projects a fringe pattern over a surface and is in turn recorded by two cameras; a 3D image can be calculated using special software. True color 3D surface reconstructions are then obtained by adding digital photography of the surface from different angles which are added to the data. It is an accurate documentation that can document structures less than 1 mm in size.
Virtopsy provides a fast and noninvasive bloodless visualization of region of interest with excellent accuracy regarding the size, volume, and orientation of damaged organ or foreign bodyIt provides contamination free sampling (poisons, infections, tissue, etc.) as there is no mutilation of dead bodiesIt also produces detailed 3D records that demonstrates the cause or manner of death with intact tissue and avoids human interventionIt is an easy method for identification in mass disaster cases where bodies are severely damagedThree dimensional forensic facial reconstruction can be carried by virtopsy techniques and can be used for medicolegal purposesThe digitally stored data is very precise and can be helpful in further investigation of cases.
Virtopsy cannot provide information about the status of infection, texture of tissue, and color changes It is still less informative than the conventional invasive autopsy as it depends upon radiographic interpretation and sometimes minor tissue injuries may get missedThis technique is cost effective, technique sensitive, and require highly skilled radiologistsIt has limited feasibility and judiciary acceptance among professionals.
Identification of deceased: Virtopsy in the form of postmortem CT is a rapid examination technique that enables identification of dead by providing accurate anatomical details including degenerative changes or surgical implants if anyForeign body: Virtopsy accurately identifies foreign body in 3D manner. It describes the entry point of foreign object (bullet tract) and exit pattern of wounds, pattern of bony fracture, and soft tissue damage. Postmortem CT enables the measurement of the radiopacity of foreign bodies precisely in HU. Postmortem MRI can be used to diagnose soft tissue injury, contusions, hematoma, and neurological as well as non-neurological traumaMRI spectroscopy is a new technique that is helpful in detecting changes in metabolic activities in order to determine the death timing and is also helpful in detecting death due to electric shockAdjuvant to autopsy: It has many advantages over autopsy as it does not impose a physical contact or severing of tissues in order to observe findings. It is useful in assessment of multiple comminute fractures as it does not tamper with preexisting structures. In cases of gas poisoning and decomposed bodies, there is collection of pathological gases which can be easily recognized by means of virtopsyComparison of postmortem data to the antemortem records is an important tool in virtopsyForensic facial reconstruction using virtopsy provides more valuable information.
Emerging Applications of Virtopsy
Robotic virtual autopsy is a multifunctional system that can perform automatic postmortem and three dimensional surface scanning which qualitatively increase the improvement in the outcome of forensic investigations. The robotic virtual autopsy also helps in detecting the change in color of tissue ,Volume-analysis software used in virtopsy helps in accurate estimation of mass of internal organs Postmortem angiography is a virtopsy technique that is helpful in visualization of the cardiovascular system that includes infusion of contrast medium with the aid of peristaltic pump and contrast medium.
Virtopsy using maxillofacial imaging establishes a new technical tool in both research and forensic identification and reconstruction. This review concludes that the virtopsy using maxillofacial imaging favors the development of future forensic investigations and is helpful in medicolegal cases.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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