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

Because the use of radiology in modern forensic medicine has been, until today, mostly restricted to conventional X-rays, which reduces a 3D body to a 2D projection, a detailed 3D documentation of a gunshot's wound ballistic effects was not possible. The aim of our study was to evaluate whether the progress in imaging techniques over the last years has made it possible to establish an observer-independent and reproducible forensic assessment using multi-slice computed tomography (MSCT) and magnetic resonance imaging (MRI) technologies for the documentation and analysis of gunshot wounds. The bodies of eight gunshot victims were scanned by MSCT and by MRI; the data of these imaging techniques were post-processed on a workstation, interpreted and subsequently correlated with the findings of classical autopsy. With the spiral CT and MRI examinations and the subsequent 2D multi-planar reformation (MPR) and 3D shaded surface display (SSD) reconstruction, the entire gunshot-created complex skull fractures and brain injuries (such as wound channels and deeply-driven bone splinters) could be documented in complete and graphic detail. CT and MRI also documented vital reaction to the gunshot by demonstrating air emboli in the heart and blood vessels and the classic pattern of blood aspiration to the lung. Gunshot residues deposited within and under the skin were visible. In conclusion, we think that the radiological methods of MSCT and MRI have the potential to become a routine "virtual autopsy" tool in the future. Bullets and relevant histological samples from specific sites then might be won in image-guided minimally invasive fashion via percutaneous biopsy. The rapid application of developing radiological methods may lead to new horizons in forensic documentation and intravital as well as postmortem examination.     

Pneumomediastinum and soft tissue emphysema of the neck in postmortem CT and MRI; a new vital sign in hanging?

Spontaneous pneumomediastinum commonly occurs in healthy young men or parturient women in whom an increased intra-alveolar pressure (Valsalva maneuver, asthma, cough, emesis) leads to the rupture of the marginal pulmonary alveoli. The air ascends along the bronchi to the mediastinum and the subcutaneous space of the neck, causing cervico-fascial subcutaneous emphysema in 70-90% of cases. Ninety-five forensic cases, including five cases of hanging, were examined using postmortem multi-slice computed tomography (MSCT) and magnetic resonance imaging (MRI) prior to autopsy until December 2003. This paper describes the findings of pneumomediastinum and cervical emphysema in three of five cases of hanging. The mechanism of its formation is discussed based on these results and a review of the literature. In conclusion, when putrefaction gas can be excluded the findings of pneumomediastinum and cervical soft tissue emphysema serve as evidence of vitality of a hanged person. Postmortem cross-sectional imaging is considered a useful visualization tool for emphysema, with a great potential for examination and documentation.     

Into the decomposed body-forensic digital autopsy using multislice-computed tomography

It is impossible to obtain a representative anatomical documentation of an entire body using classical X-ray methods, they subsume three-dimensional bodies into a two-dimensional level. We used the novel multislice-computed tomography (MSCT) technique in order to evaluate a case of homicide with putrefaction of the corpse before performing a classical forensic autopsy. This non-invasive method showed gaseous distension of the decomposing organs and tissues in detail as well as a complex fracture of the calvarium. MSCT also proved useful in screening for foreign matter in decomposing bodies, and full-body scanning took only a few minutes. In conclusion, we believe postmortem MSCT imaging is an excellent vizualisation tool with great potential for forensic documentation and evaluation of decomposed bodies.     

Postmortem diagnostics using MSCT and MRI of a lethal streptococcus group A infection at infancy: a case report

Postmortem cross-sectional imaging using multislice computed tomography (MSCT) and magnetic resonance imaging (MRI) was considered as a base for a minimal invasive postmortem investigation in forensic medicine such as within the Virtopsy approach. We present the case of a 3-year-old girl with a lethal streptococcus group A infection and the findings of postmortem imaging in this kind of natural death. Postmortem MSCT and MRI revealed an edematous occlusion of the larynx at the level of the vocal cords, severe pneumonia with atelectatic parts of both upper lobes and complete atelectasis of both lower lobes, purulent fluid-filled right main bronchus, enlargement of cervical lymph nodes and pharyngeal tonsils, and additionally, a remaining glossopharyngeal cyst as well as an ureter fissus of the right kidney. All relevant autopsy findings could be obtained and visualized by postmortem imaging and confirmed by histological and microbiological investigations supporting the idea of a minimal invasive autopsy technique.     

Post-mortem forensic neuroimaging: correlation of MSCT and MRI findings with autopsy results

Multislice-computed tomography (MSCT) and magnetic resonance imaging (MRI) are increasingly used for forensic purposes. Based on broad experience in clinical neuroimaging, post-mortem MSCT and MRI were performed in 57 forensic cases with the goal to evaluate the radiological methods concerning their usability for forensic head and brain examination. An experienced clinical radiologist evaluated the imaging data. The results were compared to the autopsy findings that served as the gold standard with regard to common forensic neurotrauma findings such as skull fractures, soft tissue lesions of the scalp, various forms of intracranial hemorrhage or signs of increased brain pressure. The sensitivity of the imaging methods ranged from 100% (e.g., heat-induced alterations, intracranial gas) to zero (e.g., mediobasal impression marks as a sign of increased brain pressure, plaques jaunes). The agreement between MRI and CT was 69%. The radiological methods prevalently failed in the detection of lesions smaller than 3mm of size, whereas they were generally satisfactory concerning the evaluation of intracranial hemorrhage. Due to its advanced 2D and 3D post-processing possibilities, CT in particular possessed certain advantages in comparison with autopsy with regard to forensic reconstruction. MRI showed forensically relevant findings not seen during autopsy in several cases. The partly limited sensitivity of imaging that was observed in this retrospective study was based on several factors: besides general technical limitations it became apparent that clinical radiologists require a sound basic forensic background in order to detect specific signs. Focused teaching sessions will be essential to improve the outcome in future examinations. On the other hand, the autopsy protocols should be further standardized to allow an exact comparison of imaging and autopsy data. In consideration of these facts, MRI and CT have the power to play an important role in future forensic neuropathological examination.     

Charred body: virtual autopsy with multi-slice computed tomography and magnetic resonance imaging

The correct examination of a charred body is a forensic challenge. Examination, interpretation, and conclusion in respect to identification, vital reactions, toxicological analysis, and determining cause and manner of death are all more difficult than without burns. To evaluate what can be seen in the case of a charred body, we made an examination with the new radiological modalities of cross-section techniques, via multi-slice Computed Tomography (MSCT) and Magnetic Resonance Imaging (MRI), prior to performing the classical forensic autopsy. In a charred body case of a single motor vehicle/fixed object collision with a post crash fire, the radiological methods of MSCT and MRI made it possible to document the injuries caused by burn as well as the forensic relevant vital reactions (air embolism and blood aspiration). In conclusion, we think postmortem imaging is a good forensic visualization tool with a great potential for the forensic documentation and examination of charred bodies.     

论虚拟解剖

“开放式”解剖是法医学死亡调查中的传统手段。随着科技进步和技术发展,现在的断层扫描影像学技术已经可以部分甚至全部取代传统的解剖技术。计算机断层扫描成像技术可以提供个体的损伤或死后变化的二维或三维影像信息．可以充分而客观地反映如骨折、气体检塞、皮下气肿、气压损伤、腐败改变及器官损伤等。这些反映个体损伤或者死后变化的计算机断层扫描成像技术可以为司法实践提供直观、有力的法医学证据。而另一种影像学技术．核磁共振成像技术在探查软组织损伤、器官损伤及非外伤性损伤等方面具有独特优势。但是,如何辨别生前和死后骨折形态的差异,如何调整生前死后变化的信号检查强度等方面。一直没有系统地研究报道。本文将综述有关计算机断层扫描和磁共振成像技术在法医解剖方面的应用,引入“虚拟解剖”的概念．系统地介绍这种独立、客观和微创的新型解剖方式．并对其在法医学死亡调查中产生的影响做出前瞻性预测。可以预见,在今后大量、广泛的法医死亡调查中．“虚拟解剖”将成为一种普遍应用的损伤和死亡的分析鉴定方式。     

Virtopsy,a new imaging horizon in forensic pathology: virtual autopsy by postmortem multislice computed tomography (MSCT) and magnetic resonance imaging (MRI)--a feasibility study

Using postmortem multislice computed tomography (MSCT) and magnetic resonance imaging (MRI), 40 forensic cases were examined and findings were verified by subsequent autopsy. Results were classified as follows: (I) cause of death, (II) relevant traumatological and pathological findings, (III) vital reactions, (IV) reconstruction of injuries, (V) visualization. In these 40 forensic cases, 47 partly combined causes of death were diagnosed at autopsy, 26 (55%) causes of death were found independently using only radiological image data. Radiology was superior to autopsy in revealing certain cases of cranial, skeletal, or tissue trauma. Some forensic vital reactions were diagnosed equally well or better using MSCT/MRI. Radiological imaging techniques are particularly beneficial for reconstruction and visualization of forensic cases, including the opportunity to use the data for expert witness reports, teaching, quality control, and telemedical consultation. These preliminary results, based on the concept of "virtopsy," are promising enough to introduce and evaluate these radiological techniques in forensic medicine.     

Microscopic myocardial changes and their significance for forensic medical diagnosis

Morphological myocardial changes essential for diagnosis in forensic medical medicine are listed as well as alterations in the vessels of the myocardium, cardiac muscular fibers and cardiomyocytes important for diagnosis of death of ischemic heart disease, acute alcohol poisoning, alcohol cardiomyopathy, closed cardiac lesions. Changes induced by reflex impacts on the heart and postmortem alterations are also shown.     

Experimental study of postmortem change under field conditions: effects of freezing, thawing, and mechanical injury

Understanding the processes of postmortem change in biologic systems is important to the forensic sciences. Previous experimental studies of postmortem change in animals under field conditions made use of animal carcasses that had been incidentally exposed to the effects of freezing and thawing or mechanical damage, or both, and were limited to gross observations. The current study was designed to document intrinsic processes of postmortem change, and the effects of freezing-thawing and mechanical injury, under controlled conditions in the field, using histologic and microbiologic techniques, as well as gross observation. Insect and microbiologic succession sequences, and patterns of decomposition and disarticulation, were observable over time. Previously frozen-thawed animals showed predominantly decay (aerobic decomposition) in the field, while freshly killed animals showed predominantly putrefaction (anaerobic decomposition). Previously frozen animals showed the same sequence, but accelerated rates, of disarticulation. Mechanically injured tissues showed accelerated rates of decomposition. These findings have implications for the interpretation of results of previous studies, as well as the interpretation of human and animal remains subjected to freezing and thawing.     

Application of 3D documentation and geometric reconstruction methods in traffic accident analysis: with high resolution surface scanning, radiological MSCT/MRI scanning and real data based animation

The examination of traffic accidents is daily routine in forensic medicine. An important question in the analysis of the victims of traffic accidents, for example in collisions between motor vehicles and pedestrians or cyclists, is the situation of the impact. Apart from forensic medical examinations (external examination and autopsy), three-dimensional technologies and methods are gaining importance in forensic investigations. Besides the post-mortem multi-slice computed tomography (MSCT) and magnetic resonance imaging (MRI) for the documentation and analysis of internal findings, highly precise 3D surface scanning is employed for the documentation of the external body findings and of injury-inflicting instruments. The correlation of injuries of the body to the injury-inflicting object and the accident mechanism are of great importance. The applied methods include documentation of the external and internal body and the involved vehicles and inflicting tools as well as the analysis of the acquired data. The body surface and the accident vehicles with their damages were digitized by 3D surface scanning. For the internal findings of the body, post-mortem MSCT and MRI were used. The analysis included the processing of the obtained data to 3D models, determination of the driving direction of the vehicle, correlation of injuries to the vehicle damages, geometric determination of the impact situation and evaluation of further findings of the accident. In the following article, the benefits of the 3D documentation and computer-assisted, drawn-to-scale 3D comparisons of the relevant injuries with the damages to the vehicle in the analysis of the course of accidents, especially with regard to the impact situation, are shown on two examined cases.     

Use of multislice computed tomography in disaster victim identification--advantages and limitations

After a mass fatality incident (MFI), all victims have to be rapidly and accurately identified for juridical reasons as well as for the relatives' sake. Since MFIs are often international in scope, Interpol has proposed standard disaster victim identification (DVI) procedures, which have been widely adopted by authorities and forensic experts. This study investigates how postmortem multislice computed tomography (MSCT) can contribute to the DVI process as proposed by Interpol. The Interpol postmortem (PM) form has been analyzed, and a number of items in sections D and E thereof have been postulated to be suitable for documentation by CT data. CT scans have then been performed on forensic cases. Interpretation of the reconstructed images showed that indeed much of the postmortem information required for identification can be gathered from CT data. Further advantages of the proposed approach concern the observer independent documentation, the possibility to reconstruct a variety of images a long time after the event, the possibility to distribute the work by transmitting CT data digitally, and the reduction of time and specialists needed at the disaster site. We conclude that MSCT may be used as a valuable screening tool in DVI in the future.     

Virtopsy hemorrhage of the posterior cricoarytenoid muscle by blunt force to the neck in postmortem multislice computed tomography and magnetic resonance imaging

In forensic autopsies, one of the most important and common signs of violence to the neck is hemorrhages of the soft tissues. The Institute of Forensic Medicine in Bern evaluates the usefulness of postmortem multislice computed tomography (MSCT) and magnetic resonance imaging (MRI) of forensic cases prior to autopsy. The aim of this study was to prove the sensitivity of postmortem MSCT and MRI in the detection of hemorrhages of the neck muscles. A full body scan prior to and a detailed scan of the explanted larynx after autopsy were performed. MSCT detected multiple fractures of the larynx. Detailed MRI was able to demonstrate the hemorrhage of the left posterior cricoarytenoid muscle. The minor hemorrhage of the right posterior cricoarytenoid muscle could not be detected with certainty. Although more experience is required, we conclude that combined MRI and MSCT examination is a useful tool for documentation and examination of neck muscle hemorrhages in forensic cases.     

体视学技术在医学影像学中的应用及其法医学价值

基于Cavalieri原理的体视学技术经常运用在组织学和病理学的研究中,但是现在,这种技术已经被运用于医学影像学(如CT、MRI、ECT、超声等)的测量。体视学的方法提供了一个非侵入性的、精确的、无偏的、简单的和快速的测量方法。所以该方法在医学影像学的形态计量学的测量中有临床使用价值。而影像资料的定量测量结果则有助于法医学实践。     

A Holistic Multi-Scale Approach to Using 3D Scanning Technology in Accident Reconstruction

Three-dimensional scanning and documentation methods are becoming increasingly employed by law enforcement personnel for crime scene and accident scene recording. Three-dimensional documentation of the victim's body in such cases is also increasingly used as the field of forensic radiology and imaging is expanding rapidly. These scanning technologies enable a more complete and detailed documentation than standard autopsy. This was used to examine a fatal pedestrian-vehicle collision where the pedestrian was killed by a van while crossing the road. Two competing scenarios were considered for the vehicle speed calculation: the pedestrian being projected forward by the impact or the pedestrian being carried on the vehicle's bonnet. In order to assist with this, the impact area of the accident vehicle was scanned using laser surface scanning, the victim was scanned using postmortem CT and micro-CT and the data sets were combined to virtually match features of the vehicle to injuries on the victim. Micro-CT revealed additional injuries not previously detected, lending support to the pedestrian-carry theory.     

Application of ultrasonography to postmortem examination. Diagnosis of pericardial tamponade

In postmortem examination, it is difficult to diagnose pericardial tamponade in a dead body from the findings of conventional external examination alone. However, ultrasonography is a common diagnostic tool for pericardial tamponade in clinical practice. We studied the postmortem diagnosis of pericardial tamponade at external examination level by applying an ultrasonographic device. The ultrasonographic findings were compared with the conventional autopsy findings. Among 455 cases of forensic autopsy in Hamburg and Tokyo conducted within 5 days after death, we successfully diagnosed 11 cases of pericardial tamponade by ultrasound imaging prior to autopsy, and failed to diagnose pericardial tamponade in only two cases. In addition, 79 cases of external examination conducted at the Tokyo Medicinal Examiner's Office were also examined with ultrasonography, and we diagnosed three cases of pericardial tamponade and five cases of pericardial effusion. The differences in ultrasonographic findings between tamponade and effusion were relatively clear. Although autopsy provides definitive evidence for the cause of death, sometimes autopsy cannot be performed due to some social factors. In such cases, conventional external examination alone cannot establish a cause of death by pericardial tamponade, and application of diagnostic imaging technique will be helpful. While CT and/or MRI may provide more detailed information than ultrasound imaging, these techniques require special equipment, room and specialist, and most of all involves high cost, which is perhaps the most important consideration in the present atmosphere of medical cost containment. On the other hand, the ultrasonographic devices we use are compact, and can be used directly at the scene of death. Postmortem application of ultrasonography may be a valuable adjunct in the work of medical examiners and forensic pathologists.     

Pneumomediastinum and Soft Tissue Emphysema in Pediatric Hanging

Postmortem computed tomography (CT) is increasingly being used as a tool in forensic pathology. The exact value of postmortem imaging in detecting specific conditions has not yet been established, but in specific cases, it can be used as a diagnostic tool demonstrating findings that remain undetected during autopsy, as in this case. Pneumomediastinum and soft tissue emphysema were detected with postmortem CT in a 3‐year‐old girl after hanging. It was not found during autopsy. This radiological finding matches 3 adult cases previously described. It is assumed that in this case, the first reported in a child, hanging was the most likely cause as well. In the adult cases, it was interpreted as a vital sign; the person must have been alive to create a pressure gradient causing rupture of the alveoli. This case demonstrates one of the added values of postmortem imaging, the possibility of demonstrating findings that remain undetected during autopsy.     

3D surface and body documentation in forensic medicine: 3-D/CAD Photogrammetry merged with 3D radiological scanning

A main goal of forensic medicine is to document and to translate medical findings to a language and/or visualization that is readable and understandable for judicial persons and for medical laymen. Therefore, in addition to classical methods, scientific cutting-edge technologies can and should be used. Through the use of the Forensic, 3-D/CAD-supported Photogrammetric method the documentation of so-called "morphologic fingerprints" has been realized. Forensic, 3-D/CAD-supported Photogrammetry creates morphologic data models of the injury and of the suspected injury-causing instrument allowing the evaluation of a match between the injury and the instrument. In addition to the photogrammetric body surface registration, the radiological documentation provided by a volume scan (i.e., spiral, multi-detector CT, or MRI) registers the sub-surface injury, which is not visible to Photogrammetry. The new, combined method of merging Photogrammetry and Radiology data sets creates the potential to perform many kinds of reconstructions and postprocessing of (patterned) injuries in the realm of forensic medical case work. Using this merging method of colored photogrammetric surface and gray-scale radiological internal documentation, a great step towards a new kind of reality-based, high-tech wound documentation and visualization in forensic medicine is made. The combination of the methods of 3D/CAD Photogrammetry and Radiology has the advantage of being observer-independent, non-subjective, non-invasive, digitally storable over years or decades and even transferable over the web for second opinion.     

心包液检测在法医学鉴定中的应用

心包液是存在于心包腔内的一种浆液.相对于血液易受自溶和腐败等死后变化的影响、玻璃体液含量少、脑脊液易受血液污染等缺陷,心包液存在于封闭的浆膜腔内,不易受尸体死后变化的污染和影响,且容易获取,不仅是临床上重要的检测样品,在法医鉴定中也有广泛的应用前景.本文阐述了心包液的理化性质及临床应用,重点综述了心肌病变、溺死或窒息时心包液中不同生物化学检测指标的变化及其在法医病理学鉴定中的意义,并介绍了心包液在法医物证学、法医毒物分析等相关领域的应用情况.随着研究的深入,心包液在法医学领域中将发挥越来越广泛的作用.