|Year : 2020 | Volume
| Issue : 4 | Page : 148-151
Comparative analysis of CT virtual autopsy and traditional autopsy: A report of 3 cases
Longda Ma1, Rong Liang2, Yuluo Liu1, Qing Shi1, Xiangyang Xu3, Lian Yang4, Yiwu Zhou1
1 Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
2 Department of Radiology, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
3 Department of Radiology, Liyuan Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
4 Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
|Date of Submission||03-Oct-2020|
|Date of Acceptance||06-Dec-2020|
|Date of Web Publication||05-Jan-2021|
Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030
Source of Support: None, Conflict of Interest: None
The objective of the study is to compare the results of virtual autopsy and traditional autopsy and then to analyze the advantages and disadvantages of them. three cases with postmortem computed tomography (CT) examination and autopsy were selected. The CT images were sent to radiologists for interpretation and were compared with autopsy results. In the cases of death in traffic accidents, the two examination conclusions are relatively consistent; in the cases of sudden cardiac death, the information provided by virtual autopsy is limited; virtual autopsy has more strength on showing some lesions such as pneumatosis and fracture. Virtual autopsy has high application value in traffic accident cases, while its application in some sudden death cases remains to be improved.
Keywords: Computed tomography, forensic pathology, sudden cardiac death, traffic accident, virtual autopsy
|How to cite this article:|
Ma L, Liang R, Liu Y, Shi Q, Xu X, Yang L, Zhou Y. Comparative analysis of CT virtual autopsy and traditional autopsy: A report of 3 cases. J Forensic Sci Med 2020;6:148-51
|How to cite this URL:|
Ma L, Liang R, Liu Y, Shi Q, Xu X, Yang L, Zhou Y. Comparative analysis of CT virtual autopsy and traditional autopsy: A report of 3 cases. J Forensic Sci Med [serial online] 2020 [cited 2021 Jan 22];6:148-51. Available from: https://www.jfsmonline.com/text.asp?2020/6/4/148/306182
| Introduction|| |
Virtual autopsy (VA) uses imaging techniques to obtain information from corpses. Compared to traditional autopsy, VA is noninvasive, in situ, preservative, and objective, among other advantages. Here, we report three cases of computed tomography (CT) scans taken in hospital after death and analyze the application effects of VA in forensic identification based on the results of VA and autopsy.
| Materials and Methods|| |
Three cases subjected to postmortem CT and forensic autopsy were selected for analysis. Case 1 was a 61-year-old male patient. He was admitted to the hospital with esophageal cancer and died 10 h after radical resection of cancer in the upper and middle esophagus. Case 2 was a male patient with unknown identity who died after a car accident. Case 3 was a 60-year-old male patient. While riding an electric bicycle, he was hit by the rear end of a car, fell off the bicycle, and crushed to death by an off-road vehicle. The above three cases were subjected to CT and forensic examination after death.
All three corpses were subjected to plain CT in the supine position with head-first entry. The scanned regions included the head, face, neck, trunk, and limbs. CT image data were interpreted by two or more radiologists.
| Results|| |
The causes of death were confirmed by autopsy and histopathological examination in all three cases. Case 1 died from an acute attack of coronary heart disease after radical resection of cancer in the upper and middle esophagus. Case 2 experienced multiple injuries throughout the body and hemorrhagic shock due to the traffic accident.
Case 3 died from multiple injuries throughout the body due to the traffic accident and was in a state of acute alcoholism before his death (ethanol concentration: 256.4 mg/dL). The results of CT and forensic autopsy of the three cases are summarized in [Table 1].
|Table 1: Comparison of computed tomography and autopsy results of the three corpses|
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| Discussion|| |
VA applies imaging techniques to obtain information on both the inside and outside of the corpse to identify the cause of death, without affecting the integrity of the corpse. Commonly used techniques for VA include X-ray imaging, CT, and magnetic resonance imaging (MRI). To identify vascular lesions, postmortem angiography and other techniques have been developed. VA has demonstrated extremely high application value in forensic pathology, including the overall display of wound direction and depth in gunshot injury identification; the discovery of evidence of antemortem drowning, such as effusion in the respiratory tract, digestive tract, and paranasal sinus in drowning identification; and the identification of epidural hematoma and extradural heat hematoma in corpses at fire scenes. In this study, three cases, including one of death from an acute attack of coronary heart disease after surgery for esophageal cancer and two deaths from traffic incident injuries, were subjected to VA based on plain CT scans followed by judicial identification based on conventional autopsy and histopathological examination to analyze and compare the respective characteristics of VA and conventional autopsy.
Case 1 showed coronary artery calcification on plain CT scan [Figure 1]a, suggesting atherosclerosis; however, the information provided on the degree of coronary artery stenosis was limited. The autopsy to identify the grade of coronary atherosclerotic lesion and to determine the intraplaque hemorrhage clearly showed that the death occurred due to an acute attack of coronary heart disease. It is difficult to effectively detect the degree of coronary artery stenosis and myocardial ischemia with plain CT. If combined with postmortem coronary angiography, or even whole-body angiography, more information on vascular lesions can be obtained, the degree of vascular stenosis can be determined, and the difficult problem of identification of sudden cardiac death can be resolved with minimal invasion. In addition, MRI is valuable in the detection of myocardial ischemic lesions, but the identification of suspected sudden cardiac death by plain CT still faces certain difficulties.
|Figure 1: (a) Case 1 - Calcification of the left anterior descending coronary artery. (b) Case 3 - Three-dimensional reconstruction showing multiple rib fractures. (c) Case 2 - Spinal transverse process fracture. (d) Case 3 - Thoracic cavity pneumatosis and effusion|
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Cases 2 and 3 were found to have fractures, subarachnoid hemorrhages, pleural effusion, and lung contusions on plain CT, which were sufficient to support the conclusion that traffic accidents were the cause of death. Plain CT combined with three-dimensional reconstructive technology can directly display fracture dislocations and quickly diagnose the difficult and easily overlooked aspects in autopsy, such as the face, pelvis, and spine [Figure 1]b and [Figure 1]c. Pleural effusion, lung contusion, as well as rib and spine fractures, showed that the deceased cases suffered huge external force before death, resulting in a large amount of blood loss. It is not difficult to determine that the death of these individuals was caused by traffic accidents. The use of plain CT combined with corpse surface examination in the identification of traffic accident deaths has been reported. Using CT combined with finite element technology can even reproduce or partially reproduce the impact process, which provides a method for scene reconstruction of traffic accident injuries. For traffic accident corpses, the cause of death can be identified by plain CT.
In all the three cases, CT detected pneumatosis in soft tissues or body cavities [Figure 1]d, which were missed diagnoses in the autopsy. CT is more sensitive to gas examination than autopsy. Regarding pneumothorax, pulmonary vein air embolism, and other fatal diseases related to gases, subcutaneous pneumatosis of the neck soft tissues is a strong indicator of hanging before death. Generally, during autopsy, the presence of chest pneumatosis is assessed by observation of the parietal pleura or using the chest wall water injection method, and subcutaneous pneumatosis is assessed based on the presence of the crepitus sensation of the skin on the subcutaneous pneumatosis upon compression. However, if the possibility of pneumatosis is not anticipated before autopsy, the diagnosis may be missed due to negligence. In addition, it may lead to false-negative results due to a small amount of pneumatosis. It is difficult to determine the presence of chest pneumatosis once the chest is exposed to the outside world. In contrast, CT can detect trace amounts of gas and the image data can be stored for repeated examination; therefore, CT is recommended for gas-related lesions. After pneumatosis is found, it is necessary to identify whether this was caused by decomposition. The components of decomposition gas are hydrogen sulfide and ammonia. The gas can be extracted and analyzed by gas chromatography to detect the gas components to determine whether it is decomposition gas. CT can show the location of gas so as to guide gas collection and assist gas detection.
It should be noted that the slice thickness of CT scanning is 1 mm. Neither contusions and lacerations of the brain, liver, kidney, and other organs in Case 3, nor arteriolosclerosis in Cases 1 and 2, were detected due to small lesion sizes. It is even more difficult to distinguish spinal cord contusions under the interference of spinal artifacts. A corpse is different from a living body, and due to changes after death and other factors, lesion morphologies in many organs may change. The diagnostic criteria are, therefore, different from those for living bodies. In Case 3, peripheral blood required extraction for alcohol concentration detection. If toxicity caused by other toxicants is suspected, autopsy is still required to extract the corresponding samples.
In addition, as CT systems are expensive, public security organizations and forensic identification institutions mostly may not be able to afford one. To solve the problem of the expense of CT equipment, some forensic experts choose to cooperate with hospitals and gain their approval. It can be seen that it is feasible to use hospital equipment for CT scanning, and CT scanning for the three cases collected in this study was completed using local hospital equipment.
In conclusion, CT VA examination is more sensitive to the diagnosis of subcutaneous and body cavity pneumatosis. It has a high diagnostic value for fractures, lung contusions, pleural effusion, and other lesions. It is also less destructive to the corpse and does not affect the morphology of original injuries and adjacent structures. Furthermore, imaging data can be preserved for a long time. At present, VA can be used as auxiliary means for the forensic examination of sudden death-related diseases, quickly determining the anatomical key points before autopsy, and can even replace the need for autopsy in the identification of causes of death in traffic accidents with clear case details. However, it should be noted that biological samples for routine toxicology analysis are still required to be obtained by autopsy. We believe that with the progression of science, VA will partially or fully replace conventional forensic autopsies in the near future.
This study has been approved by the institutional ethic review board and the patient consent has been exempted.
This article was originally released in the Chinese language in the Chinese Journal of Forensic Medicine. This publication has been approved by the editorial office of Chinese Journal of Forensic Medicine.
Financial support and sponsorship
The project was funded by National Key R&D Program of China (2018YFC0807203) and National Key R&D Program of China (2018YFC0800701).
Conflicts of interest
There are no conflicts of interest.
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