Some proponents of virtopsy propose to partially or completely replace traditional autopsy with this approach, including its creator.[3]
Dirnhofer has asserted that virtopsy fully satisfies the requirement that medical forensic findings provide “a complete and true picture of the object examined”.[4] Furthermore, virtopsy is said to achieve the objective “that the pathologist’s report should ‘photograph’ with words so that the reader is able to follow his thoughts visually”.[5]
Forensic pathology is a field within which physicians are mainly preoccupied with examining what initially are victims of possible, suspected or obvious violence that ultimately die. Clinical forensic medicine essentially does the same but with living victims; traffic medicine and age determination are applications that are not, strictly speaking, restricted to clinical forensic medicine in that general practitioners, pediatricians, and other specialists also provide services for such requests.
As examinations typically are performed under the legal and task restraints of investigative authorities such as courts, prosecutors, district attorneysorpolice, there are constraints as to cost, time, objectivity and task specification depending on local law.
The most relevant step is adequately documenting findings. Virtopsy employs imaging methods that are also used in clinical medicine such as computed tomography (CT), magnetic resonance imaging (MRI).[6] Also, 3D surface scanning typically used in automotive industry is being employed to integrate body surface documentation with 3D scene or tool scans. The choice of methods is further supplemented with 3D imaging-guided biopsy systems[7] and post mortem angiography.[8]
CT is well suited to show foreign objects, bone and air or gas distribution throughout the body, whereas MRI sequences are strong in detailing organ and soft tissue findings. A comprehensive analysis of both surface and deep tissue findings may require fusion of CT, MRI and 3D surface data.[9]
Resulting data can be archived and reproduced without loss,[10] analysed elsewhere, or distributed to specialists for technically demanding analysis.
Autopsy still produces both different and ancillary findings compared to virtopsy results so that currently, virtopsy is not a generally accepted method to entirely replace autopsies.[11] In fact, the first scientific study detailing the results of comparing postmortem CT scanning with conventional autopsies was conducted by a team from Israel and was published 1994.[12] Their conclusion already had been that single methods were not as useful to maximize on yielding as many findings as possible as the combination of scanning and autopsy were.
The term “Virtobot” is a trademark also registered to Prof. R. Dirnhofer. It describes a multi-functional robotic system.[7]
The Virtangio machine is a device that is trademarked to Prof. R. Dirnhofer [13] and manufactured by Fumedica [1].[14]
Usage of Greek words in the context of examining deaths may not withstand the test of falsification that spearheaded the virtopsy idea to begin with, but, in fact, usage of existing and creation of new neologisms may have to be reconsidered.[15]
The Virtopsy project started as a research project that was initiated at the end of the twentieth century by Prof. Richard Dirnhofer, and now covers both applied methods and research. Virtopsy contains applied research into various methods of high-tech imaging with the goal to introduce them into the practice of forensic pathology.[6]
With Prof. Michael Thali as operative head of the group, the virtopsy research team operates out of the Institute of Forensic Medicine at the University of Zurich, Switzerland since early 2011.[16]
The idea to conduct virtual autopsy is not new. In 2003, the British Museum contacted the University of Bern's Institute of Forensic Medicine in Switzerland for their virtopsy to do autopsy on a 3000-year-old mummy named Nesperennub without compromising the body.[17] While manner of death,[6] cause of death,[6] time of death,[18][19] identification of deceased and a range of practical and reconstructive applications are obviously related to medicolegal investigation of death, virtopsy methods were ground breaking in that they have established a new high-tech toolbox into both research and practice morphological investigation aspects of modern forensic pathology.
Since virtopsy is non-invasive, it is less traumatic for surviving family members and may not violate religious taboos against violating bodily integrity.[20]
Non-invasive imaging is also conducted in living or surviving subjects, but as that has been the main clinical application of CT and MR imaging to begin with, their use in medicolegal investigation of the living is not as ground breaking as using them for investigation of death. Nevertheless, a number of applications that may be regarded as specific for medicolegal imaging applications in the living have found attraction for virtopsy-derived methods:
Matching weapon or injury-causing agent and injury. The application of 3D surface documentation of injuries for the benefit of medicolegal reconstruction must be accredited to Brueschweiler et al. (2003).[21]
Strangulation and estimation of risk of death. The first paper documenting systematic application of MRI to survivors of strangulation for the benefit of forensic medicine was published by Yen et al. in 2005.[22]
Body packing. According to a paper of the virtopsy group, CT scanning may be more suitable to body packer identification than conventional or plain abdominal X-rays.[23]
The technology currently used for conducting a “virtual autopsy” comprises
Robot-guided surface scanning for three-dimensional documentation of the surface of the body, to scale and in color.[7] This supplements the external postmortem examination of the body" that is done in a conventional autopsy;
Multislice spiral CT and MRI for visualising the body in 3D. This supplements the internal postmortem examination of the body in an autopsy;[6]
Post mortem angiography, which visualises the cardiovascular system of the deceased with the aid of a peristaltic pump and contrast medium;[8]
Image- and robot-guided, contamination-free sampling for a wide range of supplementary forensic analyses, such as histology, bacteriology, virology, toxicology and diatomology.[7] This procedure replaces the usual collection and storage of sample material from the body.
The virtopsy idea was generated to yield results along a comprehensive number of performance indicators:
The practical objective of both research and application of virtopsy methods are to improve the objectivity of findings made in forensic autopsies.
The academic objective of virtopsy research is to publish original and validation type research.
Last but not the least, financial gains are also a relevant aspect of new technology particularly in the private industry sector whereas saving cost is an aspect for public institutes or offices.
Virtopsy methods have helped to solve a range of cases that would have been difficult or impossible to solve otherwise.[24] While academically, case-reports tend to be looked down on by medical faculty, they can expand the existing experience by significant contributions.
One cannot determine the color of internal organs and color changes
One cannot determine all the pathological conditions (e.g. inflammation)
One cannot determine the infection status of tissue
It is difficult to differentiate antemortem from postmortem wounds and postmortem artifacts
Small tissue injuries may be overlooked
The limitations for surface scanning apply:
Recording concave features, out of view
Turning the body over for total body recording can alter the body shape due to gravity (e.g. stomach) which may disturb the merging of recorded surfaces
Recording reflective or transparent surfaces (e.g. the eye)
Merging data from multiple techniques will always result in some loss of precision
A reliance on imagery alone may lead to omissions (e.g. bruising under the scalp not visible with surface scanning)
Validity
No proper validation of the method has been made using closely prepared prospective studies
No error rate available
No juridical validity (yet)
As applicable to all simulated evidence presented in the court room, there are concerns of suggestiveness
Objectivity
It has not been investigated whether experts are consistent in their judgment
Context effects (e.g. post-hoc target shifting in cases in which injury patterns are compared to possible injury-causing objects)
The National Research Council in the USA, as part of its proposals for reforms in the forensic sciences, has proposed virtopsy as “Best Practice” for the gathering of forensic evidence [www.ncjrs.gov/pdffiles1/nij/grants/228091.pdf].
In addition, the International Society of Forensic Radiology and Imaging was founded in 2012 with the aim of enabling a continuous exchange of research results among its members and developing quality standards for the techniques employed [2].
A Technical Working Group Forensic Imaging Methods [3] was founded in 2005 by Michael Thali and Richard Dirnhofer. It aims to promote an increasingly internationally standardised approach.
Furthermore, a TTechnical Working Group Postmortem Angiography Methods was founded in 2012 to promote best practice. Under the direction of the University Hospital of Lausanne and comprising nine European institutes of forensic medicine, it is developing reliable, standardized methods and guidelines for conducting and assessing postmortem angiographic examinations [www.postmortem-angio.ch].
Brogdons's Forensic Radiology, 2nd Edition Michael J. Thali, Mark D. Viner, Byron Gil Brogdon, 2011 CRC Press
The Virtopsy Approach: 3D Optical and Radiological Scanning and Reconstruction in Forensic Medicine Michael J. Thali, Richard Dirnhofer, Peter Vock, 2009 CRC Press
In the CSI: Miami episode "Deep Freeze", Dr. Woods performs a virtopsy on a recently murdered athlete to prevent damaging him so that he could be cryogenically frozen.
In the CSI: NY episode "Veritas", Sid does a virtual autopsy on Derek, showing Stella that the bullet that killed him entered through his cheek.
^Richard Dirnhofer; Peter J. Schick; Gerhard Ranner (2010). Virtopsy - Obduktion neu in Bildern. Wien, Austria: Manzsche Verlags- und Universitaetsbuchhandlung. ISBN978-3-214-10191-6.
^ abcdeThali MJ, Yen K, Schweitzer W, Vock P, Boesch C, Ozdoba C, Schroth G, Ith M, Sonnenschein M, Doernhoefer T, Scheurer E, Plattner T, Dirnhofer R (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. doi:10.1520/JFS2002166. PMID12665000.
^ abcdEbert LC, Ptacek W, Naether S, Fürst M, Ross S, Buck U, Weber S, Thali M (2010). "Virtobot--a multi-functional robotic system for 3D surface scanning and automatic post mortem biopsy". Int J Med Robot. 6 (1): 18–27. doi:10.1002/rcs.285. PMID19806611. S2CID41263796.
^ abGrabherr S, Djonov V, Friess A, Thali MJ, Ranner G, Vock P, Dirnhofer R (2006). "Postmortem angiography after vascular perfusion with diesel oil and a lipophilic contrast agent". American Journal of Roentgenology. 187 (5): W515-23. doi:10.2214/AJR.05.1394. PMID17056884.
^Thali MJ, Braun M, Buck U, Aghayev E, Jackowski C, Vock P, Sonnenschein M, Dirnhofer R (2005). "Virtopsy--scientific documentation, reconstruction and animation in forensic: individual and real 3D data based geo-metric approach including optical body/object surface and radiological CT/MRI scanning". J Forensic Sci. 50 (2): 428–42. doi:10.1520/JFS2004290. PMID15813556.
^Aghayev E, Staub L, Dirnhofer R, Ambrose T, Jackowski C, Yen K, Bolliger S, Christe A, Roeder C, Aebi M, Thali MJ (2010). "Virtopsy - the concept of a centralized database in forensic medicine for analysis and comparison of radiological and autopsy data". J Forensic Leg Med. 15 (3): 135–40. doi:10.1016/j.jflm.2007.07.005. PMID18313007.
^Scheurer E, Ith M, Dietrich D, Kreis R, Hüsler J, Dirnhofer R, Boesch C (2005). "Statistical evaluation of time-dependent metabolite concentrations: estimation of post-mortem intervals based on in situ1H-MRS of the brain". Journal of Magnetic Resonance Imaging. 18 (3): 163–172. doi:10.1002/nbm.934. PMID15578674. S2CID36862603.
^W. Brueschweiler and M. Braun and R. Dirnhofer and M.J. Thali (2003). "Analysis of patterned injuries and injury-causing instruments with forensic 3D/CAD supported photogrammetry (FPHG): an instruction manual for the documentation process". Forensic Science International. 132 (2): 130–138. doi:10.1016/s0379-0738(03)00006-9. PMID12711193.
^Flach PM, Ross SG, Ampanozi G, Ebert L, Germerott T, Hatch GM, Thali MJ, Patak MA (2005). ""Drug mules" as a radiological challenge: sensitivity and specificity in identifying internal cocaine in body packers, body pushers and body stuffers by computed tomography, plain radiography and Lodox". Eur J Radiol. 81 (4): 501–510. doi:10.1016/j.ejrad.2011.11.025. PMID22178312.
^N. Ohashi (1989). "Diagnosis of the causes on CPAOA cases: usefulness and problems of postmortem CT". KANTO J. Jpn. Assoc. Acute Med. (in Japanese). 10: 24–25.
