CURATIO – Brief Report

Corresponding Author

*sanjayarh@yahoo.co.uk, sanjaya@sjp.ac.lk

Once a dead-body is referred for forensic-pathological/medico-legal examination, the forensic-pathologist is expected to examine and record the scientific findings and report the same in a method easily understandable by the legal professionals, other stakeholders of the criminal justice system as well as the general public.1 In addition to conventional methods, cutting-edge technologies could be used appropriately to record and illustrate the scientific data, making them more understandable and reproducible. The concept ‘VIRTOPSY’ is an attempt to implement new imaging techniques in radiology to fulfil the above objectives.2 The VIRTOPSY® project had been launched in the year 2000 by Professor Richard Dirnhofer of the University of Bern, Switzerland.3  The term was coined to eliminate the subjectivity attached with the traditional term ‘autopsy’. As such, VIRTOPSY (or the ‘virtual-autopsy’) is meant to be a tool for objective documentation and analysis of physical findings. The term ‘virtual’ originating from Latin means ‘useful’. ‘Autos’ in Greek means ‘by oneself’ and ‘opsomei’ means to ‘see with eyes’. Thus, the word ‘autopsy’ has a meaning of ‘observing with one’s own eyes’.

Radiological techniques including CT and MRI are the principal sources of extraction of information in VIRTOPSY. Though forensic radiology is as old as radiology itself, use of new imaging techniques in forensic pathology has become popular only within the past fifty years. The first-recorded CT imaging in forensics took place in 1977 in a fire-arm injury to the head.4 Today, Multi-Slice Computerized Tomography (MS-CT) and Magnetic Resonance Imaging (MRI) are being used in centres of excellence including Victorian Institute of Forensic Medicine (VIFM), Australia and Forensic Pathology Unit in Ontario, Canada. 2D and 3D reconstructions, magnifications and improvements in contrast and resolution are available with these techniques making them far superior in reproducibility.[2] CT-guided post-mortem angiography is an extremely useful minimally-invasive procedure enabling the diagnosis of vascular lesions without interfering with the original anatomy specially in sites which are difficult to be demonstrated by dissection.5 In contrast to clinical CT imaging, post-mortem CT can achieve better image-quality since exposure to radiation is not a limiting-factor.

Incorporation of newer techniques such as photogrammetry, three-dimensional surface scanning and robotics have certainly expanded the boundaries of virtual autopsy. A three-dimensional model with natural colours could be reconstructed using 2D photographs obtained in different angles by photogrammetry. The accuracy of the dimensions of this 3D model is enhanced by incorporation of optical surface-scanning technique. In cases where the diagnosis is mainly histologic, minimally invasive image-guided biopsy may be used to obtain histopathological evidence. The most recent advancement of virtual autopsy is the integration of robotics in autopsy techniques which is termed ‘VIRTOBOT’-a multi-tasked robot designed to perform optical surface-scans, photogrammetry and even image-guided post-mortem biopsies.6

Thus, via virtual-autopsy, one may arrive at cause of death and other medico-legal opinions in a ‘touch-free’ fashion evading an invasive autopsy dissection. In its cutting-edge, entire procedure would be fully automated to be regulated by a trained autopsy-technician. The autopsy-pathologist and the autopsy-radiologist (‘necro-radiologist’) will be chiefly responsible for interpretation of such digitally-collected data. Digital imaging techniques are superior in detecting certain pathological entities including air embolism, fractures, foreign bodies and vascular pathologies compared to traditional autopsy dissection. Early ischaemic changes, soft tissue trauma (cerebral trauma in non-accidental injuries in children) and cerebral parenchymal pathologies are more accurately visualized with MRI compared to conventional histopathologic methods.2 Virtual autopsy invariably acts as a method of digital storage. The reproducibility of data greatly eliminates subjective-bias and enhances the ease of obtaining a second-opinion from across the globe. It also allows a great research potential across time and geographical areas of this small world. Easy access to otherwise non-accessible sites, minimal disfiguration of the body, cultural acceptance and bio-safety (as in cases of COVID and CJD) are other advantages.1, 2, 3 Establishing a facility with virtual-autopsy is extremely costly. In addition to expensive instruments and infra-structure, it also needs specialized man-power including autopsy-pathologists and radiologists well-aware of post-mortem imaging artefacts and trained technicians and soft-ware operators. Maintenance of such unit and maintaining the confidentiality and integrity of digital-information are other challenges.7 Yet, once established, the relative cost per virtual-autopsy would be substantially less than for conventional autopsy. In complicated cases, the accuracy and precision of findings of virtual-autopsy would be much higher. Presently, these techniques are used in several high-end centres of excellence in the world, though this approach is being readily incorporated in to their systems in many other developed and middle-income countries today.

In Sri Lanka, access to post-mortem X-ray alone is a luxury. Extremely limited cases had been subject to post-mortem CT scans. Currently there is no single dedicated CT scanner maintained by a medico-legal unit in Sri Lanka. With the increasing number of natural and traumatic cases and emergence of new challenges including COVID-19 pandemic, the need of integration of forensic radiology with routine autopsy-work is imperative.

References

1. Thali MJ, B. M. (2003). 3D surface and body documentation in forensic medicine: 3-D/CAD Photogrammetry merged with 3D radiological scanning. J Forensic Sci, 48(6):1356-65.
2. Thali MJ, Y. K. (2003). Virtopsy, a new imaging horizon in forensic pathology: virtual autopsy by postmortem multislice computed tomography (MSCT) and magnetic resonance imaging (MRI)–a feasibility study. J Forensic Sci, 48(2):386-403.
3. VIRTOPSY. ( 2013, 08 28). wirtschaft.ch – trademarks – Universität Bern Institut für Rechtsmedizin (IRM) Prof. Dr. R. Dirnhofer, Direktor Bern – Trademark no. P-491277. Retrieved from wirtschaft.ch :
4. Wüllenweber R, S. V. (1977). A computer-tomographical examination of cranial bullet wound. Z Rechtsmed., 18;80(3):227-46
5. Bolliger, S. &. (2010). Postmortem Imaging-Guided Biopsy as an Adjuvant to Minimally Invasive Autopsy With CT and Postmortem Angiography: A Feasibility Study. American journal of roentgenology, 1051-1056.
6. Ebert LC, P. W. (2010). Virtobot–a multi-functional robotic system for 3D surface scanning and automatic post mortem biopsy. Int J Med Robot, 6(1):18-27
7. http://www.wirtschaft.ch/trademarks/VIRTOPSY/Universitaet+Bern/Prof+Dr+R+Dirnhofer+Direktor/04728/2001/ (accessed on 18/12/2021)