Welcome to our Future of Forensics blog post series. We have to preface this first blog post by saying the virtual autopsy, which we’re about to dive into, isn’t something “of the future.” It’s happening right now. Well maybe not right now, right now, but the technology is available and it’s being used to conduct minimally invasive autopsies all around the world.
Behind the Technology
Virtual autopsies are obtained by computed tomography (CT) and magnetic resonance imaging (MRI) as an adjunct or alternative to the invasive autopsy. Forensic pathologists are able to do volume rendering and real-time viewing of the digital body from the 3000–5000 DICOM slices obtained from multisliced CT after whole-body scanning. This enables pathologists to conduct a full, noninvasive digital postmortem examination using a large, touch-screen tablet computer. The scanning process takes only a few minutes, and following the virtual autopsy process, the results are available almost immediately.
Benefits of the Virtual Autopsy
A clear benefit is time savings. A conventional autopsy on average takes between 2.5 and 4 hours. The results of a virtual autopsy are available within minutes. There are an estimated 500 full-time forensic pathologists in the United States, and projections suggest that 1000 are needed to provide adequate coverage in the United States.1 With the time savings, more decedents may be processed without adding to the already burdensome workload of forensic pathologists.
Also, because virtual autopsy images are saved in DICOM format and are interoperable with PACS, the acquired data can be digitally reused and the findings from a virtual autopsy, in contrary to the classical approach, can be reanalyzed as many times as necessary for a complete evaluation. For difficult cases, the obtained and stored data can be assessed by an appropriate expert of a specific subspecialty anywhere at any time. Think tele-forensic pathology!
The noninvasive nature of the virtual autopsy provides an alternative to traditional autopsy for people from certain cultures and religions which prohibits the autopsy as it mutilates and damages the body.
Barriers to Adoption
Although clinical CT and MR scanners are perfectly suitable for forensic purposes, there may be difficulties arising out of the sharing of such units for forensic and clinical purposes. For example, not many clinics (or patients) will be fond of the notion of scanning patients after a decomposed, maggot-ridden corpse has been in the machine before.2 Furthermore, most clinical radiology departments have more than enough workload themselves without having to deal with forensic cases. For this reason, specially dedicated forensic imaging units may be needed.
This brings us to cost. The mean cost of a minimally invasive autopsy was $1567. The mean cost of a full conventional autopsy was $1198.3 However, virtual autopsies are not meant to replace the conventional autopsy. In the case of one study, in 65% of cases the cause of death diagnosed after virtual autopsy matched the diagnosis reported after traditional autopsy. In 35% of cases, traditional autopsy was necessary to establish the cause of death.4 There will be instances when a virtual autopsy does not allow the forensic pathologist to render a diagnosis, and a traditional autopsy will be needed anyways. That’s doubling the cost of an autopsy. In many countries, not every larger hospital possesses its own CT, let alone an MR unit. It goes without saying that, should finances be made available, these will primarily be allocated to help the living, and not for examining corpses. Therefore, even though many forensic pathologists today would very much embrace post-mortem imaging, the lack of money will prevent such undertakings.
In conclusion, taking into consideration the challenges of the radiological approach, virtual autopsy could be used as an alternative postmortem diagnostic method or as a screening test only in selected cases where it can really provide additional relevant information with respect to the traditional postmortem investigation. In upcoming parts of Future of Forensics, we’ll dig in to the use cases for virtual autopsies and talk to active forensic pathologists/medical examiners about their thoughts on this technology.
2 Bolliger SA, Thali MJ. Imaging and virtual autopsy: looking back and forward. Philos Trans R Soc Lond B Biol Sci. 2015;370(1674):20140253. doi:10.1098/rstb.2014.0253
3 Wagensveld IM, Hunink MGM, Wielopolski PA, et al. Hospital implementation of minimally invasive autopsy: A prospective cohort study of clinical performance and costs. PLoS One. 2019;14(7):e0219291. Published 2019 Jul 16. doi:10.1371/journal.pone.0219291
4 Cirielli V, Cima L, Bortolotti F, et al. Virtual Autopsy as a Screening Test Before Traditional Autopsy: The Verona Experience on 25 Cases. J Pathol Inform. 2018;9:28. Published 2018 Jul 19. doi:10.4103/jpi.jpi_23_18