One of the main methods for PM imaging is the use of X-ray images, a technique that has been used for a relatively long time now [10]. PM X-ray images allow clear visualisation of fractures and radio-opaque foreign bodies within the deceased, and in this way are useful in guiding TAs in certain circumstances, for example in traumatic deaths. This imaging can also limit the TA, perhaps by providing information that would be difficult to access during the invasive examination, such as fractures in areas like the base of the skull which would require extensive, time-consuming, and delicate dissection. Another benefit for taking X-ray images is the portability and speed. However, a pitfall for this imaging method is its two-dimensional quality; to gain any appreciation of structures in a three-dimensional state, multiple X-ray images must be obtained, often through laborious manoeuvring and balancing of the body into many different positions for each image [10]. This is a tedious process and in terms of coronial investigations, its usage is limited to specific circumstances and deaths.

As such, the evolution of more modern, three-dimensional clinical imaging techniques has taken place, and these imaging methods have emerged into PM investigations, instead of being used only with living patients. The current availability of imaging methods for VA are largely PMCT techniques. Full body PMCT scanning is growing in usage for coronial autopsies, for example where there are large Muslim or Jewish communities [12]. PMCT is also available privately in Wales and the South of England for families who wish to avoid a TA for their loved ones [12]. The cost of a private PMCT for the next of kin in these areas is quoted as £500–£1500 [13,14,15].

Whilst PMCT techniques are currently at the forefront of VA in England and Wales, PMMR methods are also available. The difference in the use of current VA methods may explain the disparity in the amount of studies reported on PMCT and PMMR; namely, there is a lot more literature on the former than the latter. Practically, there are many areas in which PMCT is superior to PMMR. PMCT is both cheaper and faster to perform than PMMR, with a PMCT taking around five to ten minutes to perform in comparison to the approximate hour taken for PMMR [4,16,17]. PMCT is also more widely available across England and Wales; together, these may be the main reasons for the currently more frequent use of PMCT over PMMR [12,16,18,19]. However, one advantage of PMMR over PMCT is that MRI scanning does not use radiation in order to acquire images [20], rendering it a safer VA technique for mortuary technicians, who tend to be the team members who manoeuvre the bodies in and out of the scanners. On the other hand, one issue posed by the use of PMMR is metal artefacts within the body; the presence of metal can not only distort the images on the scan, but may even disrupt the body if ripped out by the strong magnetic fields used to image [21].

Typically, the current method for VA is to perform a full-body scan; this would be undertaken alongside an external examination of the body by a pathologist. As with TA, this is in conjunction with scrutiny of the Coroner’s office report detailing the circumstances surrounding the death, as well as the medical records of the deceased [22]. The imaging would then be interpreted by a radiologist, who then offers either a cause of death to the pathologist, or a recommendation for TA; a TA would be recommended in the instance that the scan is inconclusive regarding cause of death, or when there is a degree of uncertainty regarding any significant lesions on VA. The radiologist’s report will be considered by the pathologist, who will either proceed with a TA anyway, or complete the cause of death form on the basis of the lesions seen at VA and the opinion of the radiologist.

There are many advantages of VA over TA. The images obtained through VA serve as a permanent record of the autopsy, unlike during TA, where the body goes on to be destroyed by cremation or decomposition in burial without any evidence of the lesions except in the pathologist’s report. Not only would the records of VA enable pathologists to more readily seek second opinions, but they would also allow more scrutiny of autopsies, which could help to improve the quality of autopsy reports being produced by pathologists [23,24,25].

Further, nearly 40% of all deaths being reported to the Coroner in England and Wales require an autopsy [26]; the increased speed of an accurate VA in comparison to TA has the potential to help with the management of this huge workload for the mortuary and pathologist. This could also improve turnaround times to release the body, a positive for the loved ones of the deceased, but also regarding mortuary storage capacity [8]. This time-saving and service expansion is also of importance considering the current shortage of pathologists across England and Wales who are willing to perform TAs [27]. Indeed, perhaps the emergence of non-invasive investigations would encourage more pathologists to continue performing PM investigations instead of choosing to opt out.

Lastly, another advantage of VA over TA is the lack of physical contact involved with the body, since the scans are performed with the deceased remaining zipped in a body-bag. As aforementioned, this proved to be essential during the COVID-19 pandemic, in order to reduce the risk of the SARS-CoV-2 virus infecting mortuary staff and pathologists; the transmission of bloodborne and airborne diseases would be reduced by a lower number of TAs. Further, this practice contains any entomological infestations of a decomposing corpse within the body-bag, reducing the risk of infestation spreading to other bodies as well as within the mortuary itself, particularly during the hot summer months. A non-invasive autopsy also means that fewer sharp instruments are used, reducing the risk of needlestick injuries for mortuary staff and pathologists, as well as further transmission of bloodborne diseases [28].

However, there is a caveat: these advantages of VA can only be achieved through accurate diagnoses. If a VA is performed and no cause of death can be found, the TA may have to be performed anyway. This combination of TA following VA would result in an invasive examination regardless, as well as prolonged turnaround times in comparison to TA alone, not to mention the cost of both autopsies instead of one. As such, the accuracy and effectiveness of VA techniques must be optimised in order to justify using VA as a first-line investigation into the cause of death, as well as the financial and spatial investments in setting up such services.

Finally, it is an unfortunate fact that not every mortuary, particularly public mortuaries which are not part of a hospital, has the space or funding to realistically consider on-site installation of VA scanning facilities. This would mean transferring bodies to other facilities in order to perform scanning, which is timely and costly. If mortuaries do have scanners on site, they may have to share the usage with scans for living patients; this juggling could mean longer waiting times for autopsies to take place, depending on how busy the hospital is.

PMCT and PMMR each have individual strengths and weaknesses, in practical, financial, and imaging terms. VA can provide detailed, non-invasive information about the whole body, although for truly thorough imaging, at present, one method would not be sufficient to adequately analyse all areas. There are still flaws in the ability of VA to detect very common causes of death when used in general coronial investigations. As such, VA is currently a useful adjunct or preliminary investigation method to TA, but not a replacement just yet; the usefulness of VA seems to depend on the circumstances and pathologies surrounding the death. However, together, VA and TA may be able to achieve a more complete and thorough autopsy than either method alone.