Postmortem computed tomography (PMCT) and disaster victim identification.

Radiography has been used for identification since 1927, and established a role in mass fatality investigations in 1949. More recently, postmortem computed tomography (PMCT) has been used for disaster victim identification (DVI). PMCT offers several advantages compared with fluoroscopy, plain film and dental X-rays, including: speed, reducing the number of on-site personnel and imaging modalities required, making it potentially more efficient. However, there are limitations that inhibit the international adoption of PMCT into routine practice. One particular problem is that due to the fact that forensic radiology is a relatively new sub-speciality, there are no internationally established standards for image acquisition, image interpretation and archiving. This is reflected by the current INTERPOL DVI form, which does not contain a PMCT section. The DVI working group of the International Society of Forensic Radiology and Imaging supports the use of imaging in mass fatality response and has published positional statements in this area. This review will discuss forensic radiology, PMCT, and its role in disaster victim identification.

Post-mortem computed tomography ventilation; simulating breath holding.

Whilst the literature continues to report on advances in the use of post-mortem computed tomography (PMCT), particularly in relation to post-mortem angiography, there are few papers published that address the diagnostic problems related to post-mortem changes in the lungs and ventilation. We present a development of previous methods to achieve ventilated PMCT (VPMCT). We successfully introduced a supraglottic airway in 17/18 cases without causing overt damage, despite rigor mortis. Using a clinical portable ventilator, we delivered continuous positive airway pressure to mimic clinical breath-hold inspiratory scans. This caused significant lung expansion and a reduction in lung density and visible normal post-mortem changes. All thoracic pathology identified at autopsy, including pneumonia, was diagnosed on VPMCT in this small series. This technique provides a rapid form of VPMCT, which can be used in both permanent and temporary mortuaries, allowing for the post-mortem radiological comparison of pre-ventilation and post-ventilation images mimicking expiratory and inspiratory phases. We believe that it will enhance the diagnostic ability of PMCT in relation to lung pathology.

Accuracy of targeted post-mortem computed tomography coronary angiography compared to assessment of serial histological sections.

Post-mortem computed tomography with coronary angiography (PMCTA) could have a role in the investigation of sudden natural death. This study assesses the accuracy of targeted coronary PMCTA, using both air and iodinated contrast media, to provide sensitivity and specificity for critical stenosis (CS) on a segmental basis, based on a gold standard of 3-5 mm serial sections of the coronary arteries using macroscopic and histological techniques. Assessment of stenosis at 1 mm intervals on PMCTA was compared with the data from pathological analysis. Stenosis was defined as "critical" when the stenotic region reaches ≥75 %. Regions were defined every 20 mm or by a clear change in stenosis. Discrepancies were defined as significant if only one test showed CS. Five cases with 25 vessels with 124 regions were assessed. PMCTA was unable to identify plaque hemorrhage or dissection (but this was normally associated with CS). Eighteen segments had significant discrepancies, giving a sensitivity and specificity of 50 and 91.5 %. When an alternative gold standard was constructed by excluding regions beyond a CS (five cases), taking PMCTA as correct where a heavily calcified vessel opens under contrast injection (four cases), and correcting for misregistration of distance (one case), the sensitivity rose to 85.7 %. There was complete agreement when the right or left coronary arteries are assessed as a whole. This study shows that PMCTA is not a perfect replacement for histological examination of coronary vessels, but may have a role in routine post-mortem investigation.

The use of post-mortem computed tomography in the investigation of intentional neonatal upper airway obstruction: an illustrated case.

We present a single case report illustrating the diagnostic role of multi-slice computed tomography (MSCT) in the investigation of suspicious child death where mechanical asphyxia is suspected. The case illustrates how radiological findings that may not be observable on conventional plain X-ray were identified by post-mortem MSCT. We illustrate how MSCT can illustrate the position of a foreign body within the upper airway of a neonate without the need for in situ dissection and how the combination of post-mortem MSCT with skeletal survey can provide enhanced diagnostic information in the investigation of not only whether the child was liveborn but also the consideration as to whether or not death has been caused by upper airway obstruction.

Methadone toxicity in infants: a report of two fatalities.

Fatalities in infants resulting from methadone toxicity are rare within the United Kingdom. We report two cases of fatality attributed to methadone toxicity in infants aged 3(1/2) and 15 months of age, respectively. One of the two cases was also associated with diazepam ingestion. We discuss the difficulties with the interpretation of paediatric forensic toxicology and review the current literature related to methadone and diazepam toxicity in infants and older children.

Computed tomography of projectile injuries.

Computed tomography (CT) is a gold standard in clinical imaging but forensic professions have been slow to embrace radiological advances. Forensic applications of CT are now exponentially expanding, replacing other imaging methods. As post-mortem cross-sectional imaging increases, radiologists will fall under increasing pressure to interpret complex forensic cases involving both living and deceased patients. This review presents a wide variety of weapon and projectile types aiding interpretation of projectile injuries both in forensic and clinical practice.

Investigation into the usefulness of DNA profiling of earprints.

DNA profiling of biological trace evidence has been used for many years. The application of this technique specifically to the DNA profiling of earprints has not to date been thoroughly investigated. This report presents the results of 60 earprints collected from three healthy adult volunteers under controlled laboratory conditions. DNA profile analysis revealed that high levels of non-donor alleles are observed when earprints are collected for DNA profiling. The source of these non-donor alleles is investigated and the impact that their presence within the profile may have on the use of this technique is discussed.

Postmortem examination of the lungs: a preservation technique for opening the bronchi and pulmonary arteries individually without transection problems.

The classic methods of examining both the pulmonary arteries and bronchi postmortem partly destroy the anatomy of one of these systems. A technique is described whereby the bronchi and pulmonary arteries are dissected and preserved. The principal difference of this technique is that most of the upper lobe vasculature is opened from the hilum. The exception to this is the lingula, which because it is the embryological homologue of the right middle lobe should be treated in the same way--that is, with the vessels opened from the pleural side and the bronchi from the hilum. One general practical point is that there is a great variation in the number of pulmonary arterial branches in each lobe, particularly in the upper lobes, and especially in the left upper lobe. Furthermore, there is some variation in the local anatomic relations of the vessels and bronchi and on occasion the technique will not work as described and will require some modification. However, most of the time this technique should allow the pathologist to preserve the anatomy of the bronchial tree and pulmonary arteries for better demonstration and photographic purposes when the need arises.

The possible role of hypoxia in the formation of axonal bulbs.

AIMS: To assess the possible role of hypoxia in the formation of axonal bulbs. METHODS: Study material comprised sections from 28 brains showing evidence of cerebral hypoxia with no history of head injury, four with a history of head trauma but no evidence of hypoxic change, eight with a history of head trauma and hypoxic change, and four from control brains originally described as "diffuse axonal injury." These were subjected to microwave antigen retrieval and immunohistochemistry using monoclonal antibodies to beta amyloid precursor protein (beta APP), glial fibrillary acid protein (GFAP), and CD68-PGM1. RESULTS: Positive staining for beta APP was seen in all four controls, all four cases of head injury only, seven of eight cases of head injury and hypoxic changes, and 12 of 28 cases of hypoxia without history of head injury; 22 of 25 cases who had been ventilated showed positive staining. The majority of cases showed evidence of cerebral swelling. CONCLUSIONS: Axonal bulbs staining positively for beta APP may occur in the presence of hypoxia and in the absence of head injury. The role of hypoxia, raised intracranial pressure, oedema, shift effects, and ventilatory support in the formation of axonal bulbs is discussed. The presence of axonal bulbs cannot necessarily be attributed to shearing forces alone.

Malignant glioma in laboratory workers.

In 1989 an increased risk of cancer, with a higher than expected incidence of brain tumours, was reported in laboratory workers at the Pasteur Institute, Paris. Three cases of primary brain tumours occurring in three laboratory workers from one laboratory in a district general hospital also came to light. Although this may have been due to coincidence or geographic clustering, the need for stringent safety standards in all laboratories is reiterated, and it is proposed that a national register should be established to record the causes of death in laboratory workers.

Videos have a role in postgraduate necropsy education.

AIMS: This is the first study to investigate the usefulness of structured, scripted videos as an adjunct to the mortuary based training of histopathology trainees in necropsy techniques. METHODS: Four structured and scripted videos describing aspects of necropsy health and safety, evisceration, general dissection techniques, specialist dissection techniques, and reconstruction were shown to histopathology trainees attending the 2001 University of Sheffield short course on the autopsy. Delegates who agreed to participate in the study were asked to complete a short questionnaire seeking Likert-type and free text responses concerning the usefulness of the videos in postgraduate necropsy training. Free text responses were analysed using a themed content analysis. RESULTS: All 38 delegates who viewed the videos agreed to participate in the study. Of these, 35 found the videos enjoyable and 34 found them interesting. Thirty one felt the videos enhanced their learning experience. Advantages of the videos included the ability to learn about specialist techniques rarely encountered in the mortuary, the ability to teach large numbers of students at once, allowing students to learn at their own pace, and as a tool for revision. Repetition between the videos, a lack of interactivity, and a lack of sufficient detail on general necropsy techniques were felt by participants to be the principal disadvantages of this teaching tool. CONCLUSIONS: Videos are an acceptable teaching tool for students. They have a valuable role to play as an adjunct to dissection in teaching junior histopathology trainees about specialist necropsy dissection techniques.

Are coroners' necropsies necessary? A prospective study examining whether a "view and grant" system of death certification could be introduced into England and Wales.

AIMS: To determine whether the cause of death could be accurately predicted without the need for a necropsy, and thus to consider whether a "view and grant" system of issuing a cause of death could be introduced into England and Wales. METHOD: A one year prospective necropsy study was performed incorporating 568 deaths. Before necropsy, in each case the cause of death was predicted from the available history without examination of the body, and this cause was then compared with the cause of death found at necropsy. RESULTS: The ability of the pathologist involved in the study to predict a cause of death before necropsy, either while in the mortuary or as a paper exercise, was shown to vary between 61% and 74% of cases. After the necropsy, the number of correct predicted causes of death ranged from 39% to 46%. Ischaemic heart disease was found to be the most common and most accurately predicted cause of death. Some natural diseases were frequently misdiagnosed, whereas certain types of unnatural disease were always identified correctly. CONCLUSIONS: This study highlights the advantages and disadvantages of a view and grant system. Although it identifies a potential use of such a system, in some cases such as natural cardiac disease, because of the potentially high diagnostic error rate, the continuation of the present system of postmortem examination as part of the coroner's enquiry is recommended.

How should the chest wall be opened at necropsy?

AIMS: To compare several different instruments used to open the chest wall during necropsy and to assess whether any one type reduced the production of sharp rib ends and thus the potential for receiving an injury. METHODS: During the necropsy the pathologist opened the chest wall using two randomly assigned instruments from a selection of hand saw, electric saw, rib shears, and bread knife. The age, weight, sex, and height of the deceased were recorded, in addition to the textures of the resultant exposed rib ends. During the procedure, the speed, length, production of spray, and site of incision were also noted. The thoracic cavity was inspected and any details of tumours, adhesions, fluid, or organ damage were noted. RESULTS: Twenty four necropsies were carried out on an equal number of men and women. The total number of ribs that were incised was 422, with 206 through the bony aspect (49%). Sixty seven per cent of the bony rib ends were rough, and this was found to be instrument dependent. The rib shears produced the highest number of rough bony and cartilage rib ends. The electric saw produced the smoothest contoured rib ends. Spray occurred in 29% of cases, exclusively with the use of the electric saw. Organ damage was most frequently associated with the use of the bread knife. CONCLUSION: Rib shears, the instrument most frequently used to open the chest wall, appear to cause the highest frequency of rough, potentially dangerous rib ends. The electric saw produced the smoothest rib ends, both in cartilage and bone, and thus seems to offer the most efficacious method of reducing the potential hazard associated with ragged, spiky bone ends during the opening of the thoracic cavity. Although each of the procedures detailed in this study was shown to have its own advantages and disadvantages, personal preference and operator experience are perhaps the most important factors in ultimately determining the method used.

Bruising in non-accidental head injured children; a retrospective study of the prevalence, distribution and pathological associations in 24 cases.

Non-accidental head injury, be it shaking, impact(s) or a combination of the two, is characterised by subdural and/or subarachnoid haemorrhages with retinal haemorrhages, but minimal or absent external cranio-facial trauma. The classical assault scenario depicts the infant being gripped around the head, face, chest and abdomen and shaken or being gripped by a limb and swung. This gripping might be expected to leave physical evidence in the form of bruising. A study was undertaken to establish the prevalence, distribution and pathological association of external bruising in 24 cases of fatal non-accidental head injury in children. At autopsy, 17 cases had new external bruises, 15 old external bruises and 13, a combination of both. However, seven (29%) cases showed no fresh external bruising and five (21%) showed no external bruising at all. Thus, external bruising may be absent in children with fatal intracranial injury. The face was shown to be the commonest site of bruising followed by the forehead and buttocks. Limb, chest and abdominal bruising were found to be uncommon. Retinal haemorrhages were confirmed in 23 (96%) cases. It is hypothesised that bruising, when present, may be a result of abuse in the form of punches and slaps rather than due to gripping during the assault. We discuss why gripping does not necessarily result in external bruising.

Cavernous haemangioma of the nasal bones.

A case report of a cavernous haemangioma arising in the nasal bones is described, together with a discussion of the relevant literature. The condition, although rare, can be reliably diagnosed pre-operatively.

Forensic web watch 3.

Since the publication of the first 'Forensic Web Watch' article a new search engine has become available, free of charge at the time of writing, to surfers of the Internet (Net). Fast Search claims to seek out sites of interest for the user from 'all the Web, all the time trade mark ' as opposed to parts of the Net as is more common with other search machines. It is easy to use, extremely fast but as it searches so much more of the Net, the end result is considerably larger. This, in turn, may lead to a longer time to seek out useful information as opposed to the obscure. Having said this, it is recommended to add to your search engine bookmarks. A search for sites on issues related to 'Police Surgeons' will yield limited information, as each country will have a different person filling this role, all referred to by different terms. The one common feature, however, to all such groups as well as forensic pathologists and scientists, is that they will work with, or in some cases for, the police services of their respective country. Thus, in this article we will look at sites related to the police which may have useful information related to their work, specific cases of interest and research and development which may effect our practice.

Forensic web watch.

Now that one has logged onto the world wide web (WWW) and utilized one or more of the home pages listed previously (or used another equally good home page) to seek out basic information available to forensic practitioners, the question now arises of how to go about making the most of the information available. One feature consistent to most home pages is links to the home pages of Associations and Societies, one or more of which most practitioners will be members of. With access to the WWW not only have you access to your own association/society, but you can also keep up to date with all the others to which you have not paid subscriptions. Although an internet search using a WWW search engine or the 'top 6' home pages may assist in identifying a large number of association and society sites, one of the most useful places to start is the home page of the Indian Academy of Forensic Medicine (IAFM). This, to date, lists a total of 139 such sites. To access all the home pages listed may take in excess of 6 h so the following review looks at the range of sites available and recommends some places the author considers many people may wish to know and visit. Again, this is inevitably a personal choice and it is recognized that those sites not listed may, in fact, be the preferred choice for other users of the forensic WWW.

Forensic web watch.

Since the development of the Internet (Net) by the Americans in the 1970s as a potential means of communication following a future world war, it has evolved over the decades into the graphical format of the world-wide web (WWW, Web) that we know today. Anyone accessing the Net, be it from home or work, has access to information and resources on almost anything but with this comes the time-consuming and potentially expensive task of identifying those sites of use in one's professional work from those of purely interest or fun. These reviews will try and direct those working within forensic practice in all professions towards sites considered by the author to be practical resources. They are, by their very nature, a personal opinion and the author recognizes that the review of a site by one person may differ considerably from that of another user or the site designer. The articles will assume a basic knowledge of how to access and use the WWW using either Netscape or Microsoft Explorer. They will address groups of sites related to common areas of practice listing key web addresses to allow those interested to access sites reviewed. Because of the time between writing and publishing some sites may no longer be valid

Forensic web watch 4.

Finding dedicated sites on the World Wide Web (WWW) touching upon issues related to the autopsy which could be of use to forensic practitioners is, as with other areas of forensic medicine and science, a time-consuming task. Unfortunately, one has to wade through lists related to 'Alien autopsy' sites and even 'Furby autopsy' sites that are generated by the most commonly used web search engines, which have been featured in earlier web reviews. Numerous sites containing large archives of autopsy photographs are available on the web. However, many of these sites represent the darker side of the WWW as they are often presented purely for titillation. Unfortunately, one can equate these sites to the modern-day version of the Victorian 'freak show'--Typically, these sites ask for your Visa card number to view their contents, and several have links to pornography sites; one even links to a Satanist site. Luckily a few of these sites do now require age confirmation codes. As many of these sites show autopsy photographs from real cases one has to ask how these were obtained and who is placing them on the WWW. This review does not list any of these sites for obvious reasons, but it does draw the reader's attention to sites touching upon issues related to autopsies which forensic practitioners may wish to visit or use.

Under-reporting of suicide in South Yorkshire (West): a retrospective study of suicide and open verdicts returned by HM Coroner, 1992-1997.

A retrospective study was performed using information obtained from HM Coroner for South Yorkshire (West) over the period 1992-1997. All inquests which received a suicide or open verdict were reviewed to investigate the regional suicide statistics and the actual number of cases. Particular attention was paid to the age, sex, mental health and mode of death. There were 295 deaths believed to be suicidal in nature. Of these only 79% had suicide verdicts given and these comprise the official statistics. Of the open verdicts, many were suggestive of suicide but the circumstances were insufficient for the Coroner to be satisfied beyond reasonable doubt of the victims intention to kill themselves. Males and females had the same proportion of verdicts (80 and 76% respectively). Hanging was the commonest mode of suicide, (sex ratio 4.06 male: 1 female) and received a high percentage of suicide verdicts (81.5%). Self-poisoning was second but received suicide verdicts in only 66.3% of cases, whilst carbon-monoxide poisoning had a 98.1% rate of suicide verdict. Of the 295 cases, 202 decedents (88.5%) had a history of mental illness. Depression accounted for 153 cases (75.7%). Twelve decedents had psychotic illness (4%), one-half dying by jumping from a height. Official national data may under-report the annual suicide rate by over 20%. Deaths from poisoning by solid or liquid and jumping from a height appear particularly difficult to establish as suicide in coronial practice, with one-third of cases declared an open verdict.