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Abstract Summary The application of imaging techniques for non-invasive documentation and analysis of relevant forensic findings in living and dead persons has lagged behind the enormous technical development of imaging methods. The trans-disciplinary research project Virtopsy is dedicated to implementing modern imaging techniques into forensic medicine and pathology in order to augment current examination techniques or even to offer alternative methods. This study aims to define virtopsy and describe its technique and illustrate various applications of virtopsy in forensic medicine. It focuses on comparison of autopsy findings and virtopsy findings in different forensic applications and highlights the advantages and disadvantages of virtopsy as a new imaging technique in forensic radiology. Autopsy: Autopsy is the scientific examination of bodies after death, where whole surface of the body as well as all the body cavities are explored to record the findings. There are two types of autopsy: 1-hospital autopsy which is performed to learn the extent of a disease or for research purposes and needs consent of relatives of the deceased to be carried out. 2- Forensic autopsy which is conducted in a government facility and consent is not sought from the next of kin. Forensic autopsy procedure includes: 1) Death scene investigations which is done by the police and the medical examiner. 2) Identification of the body: Direct identification of the body by the family members is not always reliable. The highest order of identification is scientific including DNA and Summary 159 fingerprints analysis and dental identification. 3) Physical examination of the body (internal and external body examination). 4) Ancillary procedures: This step is followed by reconstitution of the body such that it can be viewed by relatives of the deceased. 5) Autopsy report should contain the name of the deceased and an accession number, birth date, and gender. Autopsy reports have objective sections dealing with the external examination the internal examination and ancillary procedures. The subjective section of autopsy report consists of the diagnoses, the cause-of-death according to the pathologist opinion. The autopsy rates have declined since the latter half of the 20th century and refused by relatives of the deceased and some religions. Radiology in forensic medicine In 1895, Wilhelm Röntgen discovered “x-rays”. Few years later x –ray found entry into the courtrooms as evidence of projectiles in living and dead persons. Today, X-ray images are admissible in courts of law and are accepted as scientific evidence. In modern forensic practice a range of radiological techniques are available. These include plain X ray, fluoroscopy, ultrasound, angiography, and axial radiography (Computed Tomography (CT) and magnetic resonance imaging (MRI)). The stage at which radiology is implemented during autopsy will vary according to every case circumstances. Generally, radiographs are taken after the external examination and before the dissection, except in cases of bombings and charred bodies, where it should be performed before external examination. Summary 160 The applications of forensic radiology include: identification, trauma cases and detection of packing and smuggling. Identification: The direct comparison of antemortem and postmortem X-rays is widely applied for personal identification. Radiographs of skull, chest, abdomen and pelvis areas are the most frequently used for identification purpose. Dental identification is the most useful and powerful tool in identification especially in mass disaster victims. Forensic radiology has a major role in determination of biological file of the individuals and identification of individual remains. Trauma cases: Forensic imaging has another major application which is documentation of injury. Bone injuries, as fractures and hematomas can easily be detected by radiology. The presence of a pneumothorax is demonstrated on chest Xray in similar manner of its clinical evaluation In gunshot wounds, radiography is invaluable in the forensic investigation. It is used to locate the bullet, identify the type of ammunition and weapon used, document the path of the bullet, and to assist in the retrieval of the bullet. In battered child syndrome, radiology especially CT is advocated for detection of skull fractures while MRI is effective to document and localize intracranial injury. Other specific skeletal fractures as spiral-oblique fractures of long bones, corner and bucket-handle fracture and multiple posterior rib fractures are easily detected radioligically. Detection of packing and smuggling: plain abdominal xray is a relatively good screening tool in evaluating suspected body packers. Summary 161 Virtopsy The Virtopsy, or ”virtual autopsy” was developed by Richard Dirnhofer and his colleagues at the University of Berne’s Institute of Forensic Medicine, Switzerland. Virtopsy basically consists of (a) internal body documentation using CT, MR imaging, and micro-radiology; and (b) 3D body surface documentation using photogrammetry and 3D optical scanning. Additional applications that have also been implemented into the Virtopsy project are post-mortem biopsy, post-mortem angiography, Micro-MR, Micro-CT and MRspectroscopy. Finally, the resulting data sets can be postprocessed and fused by volume-rendering tools at a workstation to perform a 3D reconstruction. All virtopsy studies aim to validate this new approach by systematically comparing the radiologic and surface scanning findings with those obtained at traditional autopsy Virtopsy is a valuable technique in many forensic applications, as in identification especially in mass disaster situations, poly-trauma cases, blunt and sharp trauma assessments, firearms injuries and drowning cases. Also, it is helpful in revealing some causes of death and some potmortem changes. MSCT offers excellent spatial resolution for the visualisation of the fracture system, foreign bodies such as bullets, and gas (e.g.; air embolism, subcutaneous emphysema, and decomposition effects).While, MRI shows soft-tissue pathology excellently. Emerging technologies such as micro-CT and MR microscopy provide images with high resolution. They will have a comparable impact on histopathology leading to virtual histology. Summary 162 By using body surface scanning and post-processing 3D visualization, virtopsy allows 3D reconstruction of traffic accident and crime scene and allows comparison between patterned injuries and assumed injury causing tool. Virtopsy is superior to autopsy, as it is non-destructive, allowing second examination of the corpse and can be done in reasonable time compared to autopsy. It also provides large information sets which can be stored for years, re-examined by experts for second opinion, and transferred worldwide (teleconsultation). Forensic imaging, even if minimally invasive, is more acceptable by deceased relatives and some religions. Virtual autopsy has a number of disadvantages. Postmortem MSCT and MRI imaging provide no colour documentation of the body, no information about histology and chemistry, nor visualization of the circulation and possible bleeding. These limitations can be solved to certain extent by using MSCT-guided biopsies or MR spectroscopy and postmortem angiography. A major virtopsy limitation is its limited ability to detect all causes of death especially natural causes as hyper-acute myocardial infarction (commonest cause of sudden death). Postmortem changes may cause confusion with antemortem findings especially if the radiologist has minimal forensic knowledge. Also, the area of estimation postmortem interval is still lagging in virtopsy application and needs more studies. Current studies provide inconsistent evidence on virtopsy reliability to be an alternative for autopsy. To examine both the complementary (add-on) and replacement function of virtopsy in postmortem examination of deceased, welldesigned and larger prospective studies are needed. |