Multimodal Structural Analysis of the Human Aorta: From Valve to Bifurcation.

OBJECTIVE: The aims of the present study were to assess the relative proportion of collagen and elastin in the arterial wall and to evaluate the collagen microstructure from the aortic root to the external iliac artery. METHODS: Arterial wall tissue samples sampled during post-mortem examination from 16 sites in 14 individuals without aneurysm disease were fixed and stained for collagen and elastin. Stained sections were imaged and analysed to calculate collagen and elastin content as a percentage of overall tissue area. Scanning electron microscopy was used to quantify the collagen microstructure at six specific arterial regions. RESULTS: From the aortic root to the level of the suprarenal aorta, the percentages (area fractions) of collagen (ascending, descending, and suprarenal aorta respectively with 95% confidence interval [CI] 37.5%, 31.7 - 43.2; 38.9%, 33.1 - 44.7; 44.8%, 37.4 - 52.1) and elastin (43.0%, 37.3 - 48.8; 40.3%, 34.8 - 46.1; 32.4%, 25.2 - 39.6) in the aortic wall were similar. From the suprarenal aorta to the internal iliac arteries, the percentage of collagen increased (abdominal aorta, common and internal iliac arteries and external iliac artery respectively with 95% CI 50.6%, 42.7 - 58.7; 51.2%, 45.5 - 56.9; 49.2%, 42.0 - 56.4) reaching a double percentage for elastin (23.6%, 15.7 - 31.6; 20.8%, 15.1 - 26.5; 22.2%, 14.9 - 29.5). Mean collagen fibre diameter (MFD) and average segment length (ASL) were significantly larger in the external iliac artery (MFD 6.03, 95% CI 5.95 - 6.11; ASL 22.21, 95% CI 20.80 - 23.61) than in the ascending aorta (MFD 5.81, 5.72 - 5.89; ASL 19.47, 18.07 - 20.88) and the abdominal aorta (MFD 5.92, 5.84 - 6.00; ASL 21.10, 19.69 - 22.50). CONCLUSION: In subjects lacking aneurysmal disease, the aorta and iliac arteries are not structurally uniform along their length. There is an increase in collagen percentage and decrease in elastin percentage progressing distally along the aorta. Mean collagen fibre diameter and average segment length are larger in the external iliac artery, compared with the ascending and the abdominal aorta.

Axonal injury is detected by ßAPP immunohistochemistry in rapid death from head injury following road traffic collision.

The accumulation of ßAPP caused by axonal injury is an active energy-dependent process thought to require blood circulation; therefore, it is closely related to the post-injury survival time. Currently, the earliest reported time at which axonal injury can be detected in post-mortem traumatic brain injury (TBI) tissue by ßAPP (Beta Amyloid Precursor Protein) immunohistochemistry is 35 min. The aim of this study is to investigate whether ßAPP staining for axonal injury can be detected in patients who died rapidly after TBI in road traffic collision (RTC), in a period of less than 30 min.We retrospectively studied thirty-seven patients (group 1) died very rapidly at the scene; evidenced by forensic assessment of injuries short survival, four patients died after a survival period of between 31 min and 12 h (group 2) and eight patients between 2 and 31 days (group 3). The brains were comprehensively examined and sampled at the time of the autopsy, and ßAPP immunohistochemistry carried out on sections from a number of brain areas.ßAPP immunoreactivity was demonstrated in 35/37 brains in group 1, albeit with a low frequency and in a variable pattern, and with more intensity and frequency in all brains of group 2 and 7/8 brains from group 3, compared with no similar ßAPP immunoreactivity in the control group. The results suggest axonal injury can be detected in those who died rapidly after RTC in a period of less than 30 min, which can help in the diagnosis of severe TBI with short survival time.

Comparison of findings identified at traditional invasive autopsy and postmortem computed tomography in suicidal hangings.

Cases of suicidal hanging are a common death referred for medico-legal autopsy throughout the world. Although some advocate using postmortem computed tomography (PMCT) without traditional invasive autopsy (TIA) to investigate such deaths, others reject this approach. There is currently limited evidence to guide practice. In this context, the TIA reports and PMCT images of 50 cases of suspected suicidal hanging during an 11-month period were reviewed. The reviewers were blinded to the findings of the other modality. A Cohen's Kappa coefficient (K) was calculated to assess agreement between TIA and PMCT across a range of pertinent findings. This analysis demonstrated perfect agreement for identification of a ligature (K = 1.00) and a strong level of agreement for identification of a ligature suspension point (K = 0.832) but only a minimal level of agreement for overall ligature mark (K = 0.223). PMCT demonstrated a weak level of agreement for fractures of hyoid bone (K = 0.555) and thyroid cartilage (K = 0.538). Three probable fractures not identified at TIA were identified on PMCT. TIA was shown to be superior in the identification of intramuscular and laryngeal fracture-related haemorrhage/bruising whereas PMCT was superior to TIA in identifying body gas deposition. There was overall good correlation between the natural disease and trauma identified elsewhere in the body during the TIA and PMCT. The study demonstrates that PMCT can assist the investigation of suspected suicidal hangings. However, the accuracy of many findings is limited, and if it is used as an alternative to the TIA, potentially pertinent findings, such as fractures of the laryngeal cartilages, could be missed.

Compression asphyxia and other clinicopathological findings from the Hillsborough Stadium disaster.

Ninety-six people died following a crowd crush at the Hillsborough Football Stadium, Sheffield, UK in 1989. The cause of death in nearly all cases was compression asphyxia. The clinical and pathological features of deaths encountered in crowds are discussed with a particular focus on the Hillsborough disaster.

Autopsy assessment of pediatric head injury: a proposal for aerosol mitigation during the COVID-19 pandemic.

During the Corona Virus Disease-19 (COVID-19) pandemic, there is still a requirement for post-mortems to continue, including those examinations performed in the context of medico-legal investigations. Currently, very little is known about how long this coronavirus can survive in deceased human bodies or whether un-embalmed human cadavers can be contagious to people who handle them. Therefore, it would appear to be prudent to consider implementation of additional safety measures for all necessary post-mortem procedures. During the post-mortem examination of babies and young children, it is important to open the calvarium to enable visualization of the brain and its coverings, particularly in cases where a head injury is likely to have occurred. Since October 2013, the use of neurosurgical equipment to open the calvarium during infant and young child autopsies has become routine practice in our unit. Both the neurosurgical craniotome and a standard oscillating mortuary saw produce particulate matter consisting of bone and body fluids (including blood) which can become aerosolized. Within this paper, we discuss the use of a transparent plastic tent whilst opening the calvarium during pediatric post-mortems, to reduce the spread of aerosols into the mortuary environment.

Remote post-mortem radiology reporting in disaster victim identification: experience gained in the 2017 Grenfell Tower disaster.

On 14 June 2017 at 00:54 h, the worst residential fire since the conclusion of the Second World War broke out in Flat 16, 4th floor of the 24-storey residential Grenfell Tower Block of flats, North Kensington, West London, UK. Seventy-one adults and children died, including one stillbirth. All victims of the Grenfell Tower disaster who died at the scene underwent post-mortem computed tomography (PMCT) imaging using a mortuary-sited mobile computed tomography scanner. For the first time, to the authors' knowledge, the disaster victim identification (DVI) radiology reporting was undertaken remote to the mortuary scanning. Over an 11-week period, 119 scans were undertaken on 16 days, with up to 18 scans a day. These were delivered to a remote reporting centre at Leicester on 13 days with between 2 and 20 scans arriving each day. Using a disaster-specific process pathway, a team of 4 reporters, with 3 support staff members, trialled a prototype INTERPOL DVI radiology reporting form and produced full radiology reports and supporting image datasets such that they were able to provide 96% of prototype DVI forms, 99% of image datasets and 86% of preliminary reports to the DVI teams in London within one working day of image receipt. This paper describes the first use of remote radiology reporting for DVI and exemplifies how remote PMCT reporting can be used to support a DVI process of this scale.

Myocardial Infarction Due to Coronary Artery Injury following High Force Blunt Trauma to the Upper Chest: A Case Illustrating the Prehospital, Hospital and Autopsy Findings.

Myocardial infarction (MI) is a rare complication of blunt chest trauma (BCT). We describe an extensive antero-lateral MI due to thrombosis of the left main stem coronary artery following a blow to the lower face and upper anterior chest during an industrial accident in a 52-year-old male. The patient presented with acute left ventricular failure. Our case highlights MI as an important differential in a BCT patient presenting with hypoxia where lung pathology has been excluded. We aim to highlight the importance of cardiac assessment in trauma scenarios particularly where patients are unable to report symptoms. Our patient sadly did not survive his injuries. This case describes MI following BCT from the initial prehospital presentation through to postmortem findings and adds to the limited literature on the pathological mechanisms underpinning this rare complication.

Using freely-available 3D software to reconstruct traumatic bone injuries detected with post mortem computed tomography.

Use of post-mortem computed tomography (PMCT) scanning to investigate natural and unnatural death has increased dramatically in recent years. Powerful software exists to allow detailed analysis of the scanned anatomy and pathology, and users of PMCT and other medical imaging will already be familiar with both two-dimensional and three-dimensional (3D) representations of this data. However, standard medical image viewing programs do not allow direct manipulation of the visible anatomy. By extracting anatomical features from medical images, this data can be exported into 3D manipulation software to enhance pathological examination and anatomical demonstration. Here we illustrate, using an example of lower limb fractures from a pedestrian road traffic fatality, that open source software (Blender) can be used not only to manipulate the anatomical data, but to produce high-quality images and animations that are superior to what is achievable using the available output of standard medical image viewers. The described software provides practitioners from many different disciplines an ability to manipulate medical imaging data that may previously have seemed too expensive or otherwise inaccessible. The potential applications for this technique are not limited to trauma analysis, and the purpose of this document is to encourage others to explore this powerful software and its abilities. The article contains many specific terms, and targeted online searches using this vocabulary will reveal an abundance of guidance and video tutorials that will help even the complete novice begin to undertake apparently sophisticated 3D software tasks with relative ease and at no additional cost.

Diagnostic accuracy of post-mortem CT with targeted coronary angiography versus autopsy for coroner-requested post-mortem investigations: a prospective, masked, comparison study.

BACKGROUND: England and Wales have one of the highest frequencies of autopsy in the world. Implementation of post-mortem CT (PMCT), enhanced with targeted coronary angiography (PMCTA), in adults to avoid invasive autopsy would have cultural, religious, and potential economic benefits. We aimed to assess the diagnostic accuracy of PMCTA as a first-line technique in post-mortem investigations. METHODS: In this single-centre (Leicester, UK), prospective, controlled study, we selected cases of natural and non-suspicious unnatural death referred to Her Majesty's (HM) Coroners. We excluded cases younger than 18 years, known to have had a transmittable disease, or who weighed more than 125 kg. Each case was assessed by PMCTA, followed by autopsy. Pathologists were masked to the PMCTA findings, unless a potential risk was shown. The primary endpoint was the accuracy of the cause of death diagnosis from PMCTA against a gold standard of autopsy findings, modified by PMCTA findings only if additional substantially incontrovertible findings were identified. FINDINGS: Between Jan 20, 2010, and Sept 13, 2012, we selected 241 cases, for which PMCTA was successful in 204 (85%). Seven cases were excluded from the analysis because of procedural unmasking or no autopsy data, as were 24 cases with a clear diagnosis of traumatic death before investigation; 210 cases were included. In 40 (19%) cases, predictable toxicology or histology testing accessible by PMCT informed the result. PMCTA provided a cause of death in 193 (92%) cases. A major discrepancy with the gold standard was noted in 12 (6%) cases identified by PMCTA, and in nine (5%) cases identified by autopsy (because of specific findings on PMCTA). The frequency of autopsy and PMCTA discrepancies were not significantly different (p=0·65 for major discrepancies and p=0·21 for minor discrepancies). Cause of death given by PMCTA did not overlook clinically significant trauma, occupational lung disease, or reportable disease, and did not significantly affect the overall population data for cause of death (p≥0·31). PMCTA was better at identifying trauma and haemorrhage (p=0·008), whereas autopsy was better at identifying pulmonary thromboembolism (p=0·004). INTERPRETATION: For most sudden natural adult deaths investigated by HM Coroners, PMCTA could be used to avoid invasive autopsy. The gold standard of post-mortem investigations should include both PMCT and invasive autopsy. FUNDING: National Institute for Health Research.

Postmortem CT Angiography Compared with Autopsy: A Forensic Multicenter Study.

Purpose To determine if postmortem computed tomography (CT) and postmortem CT angiography help to detect more lesions than autopsy in postmortem examinations, to evaluate the strengths and weaknesses of each method, and to define their indications. Materials and Methods Postmortem CT angiography was performed on 500 human corpses and followed by conventional autopsy. Nine centers were involved. All CT images were read by an experienced team including one forensic pathologist and one radiologist, blinded to the autopsy results. All findings were recorded for each method and categorized by anatomic structure (bone, organ parenchyma, soft tissue, and vascular) and relative importance in the forensic case (essential, useful, and unimportant). Results Among 18 654 findings, autopsies helped to identify 61.3% (11 433 of 18 654), postmortem CT helped to identify 76.0% (14 179 of 18 654), and postmortem CT angiography helped to identify 89.9% (16 780 of 18 654; P < .001). Postmortem CT angiography was superior to autopsy, especially at helping to identify essential skeletal lesions (96.1% [625 of 650] vs 65.4% [425 of 650], respectively; P < .001) and vascular lesions (93.5% [938 of 1003] vs 65.3% [655 of 1003], respectively; P < .001). Among the forensically essential findings, 23.4% (1029 of 4393) were not detected at autopsy, while only 9.7% (428 of 4393) were missed at postmortem CT angiography (P < .001). The best results were obtained when postmortem CT angiography was combined with autopsy. Conclusion Postmortem CT and postmortem CT angiography and autopsy each detect important lesions not detected by the other method. More lesions were identified by combining postmortem CT angiography and autopsy, which may increase the quality of postmortem diagnosis. Online supplemental material is available for this article.

How taphonomic alteration affects the detection and imaging of striations in stab wounds.

Stabbing with a kitchen knife is a common method of homicide in Europe. Serrated knives may leave tool markings (striations) in tissues. Documentation of striations is necessary for their use as forensic evidence. Traditional methods (physical casting and photography) have significant limitations, and micro-computed tomography (micro-CT) has been trialled in cartilage to "virtually cast" wounds. Previous research has shown the proportion of striations in cartilage falls following decomposition. This project has investigated the effects of taphonomic alteration and documentation methods of striations in porcine skin. Fresh, decomposed, mummified, burnt and waterlogged stab wounds in a porcine analogue were excised and imaged using photography, stereo-optical microscopy and micro-CT. The proportion of striations in each taphonomic group was determined from the images by independent analysts. Striations were observed more frequently in serrated blade wounds, although they were also identified in non-serrated blade wounds. The proportion of wounds showing striations declined following decomposition. An inversely proportional linear correlation between advancing decomposition and proportion of striations existed. Dehydration (mummification and burning) rendered serrated and non-serrated blade wounds indistinguishable. Water composition affected the preservation of striations. Identification of striations gradually declined after decomposition in tap water, but persisted to a point when left in brackish water. All three techniques imaged striations; however, the optimum technique was stereo-optical microscopy due to practical advantages and specific limitations affecting photography and micro-CT. This study demonstrates the effects of taphonomic alteration on striations and suggests stereo-optical microscopy is the optimum method for their documentation.

Forces generated in stabbing attacks: an evaluation of the utility of the mild, moderate and severe scale.

The commonest way of killing in the UK is by a sharp instrument. Knight reported in 1975 that it is impossible to discern with any degree of certainty the degree of force used to create a stab wound. Despite this, expert witnesses continue to approximate the degree of force used for their reports and evidence in court. It is usually subjectively categorized as mild, moderate or severe, based solely on the examination of the wound. We undertook a study considering forces generated in a range of blunt trauma actions, using a novel force plate dynamometer to measure the peak forces obtained by adult male and female volunteers. We then studied forces generated by stabbing skin simulants and porcine samples with knives and screwdrivers. Men generated more force than women during stabbings which was found to be equivalent to somewhere between the blunt trauma actions of pushing a button to a single-handed push. When asked to stab using what they thought was mild, moderate and severe force, although volunteers were able to actively decide the force used, the actual force was found to be influenced by the weapon, sex of the individual, hand used and biological/anatomical site penetrated. This study shows that the forces generated by volunteers in mild, moderate and severe stabbing tests in almost all cases were significantly greater than the forces required for skin penetration. We suggest that the use of subjective force scales is inappropriate. Rather than use of a subjective scale, we suggest that the force required in any stabbing requires investigation in four areas: the tip radius of the weapon, minimal force required for penetration, the sex of the assailant and whether the force required for penetration is greater than that that can be generated by a person stabbing. This allows for the use of an evidence-based two-tier scale to suggest the force required.

A systematic autopsy survey of human infant bridging veins.

In the first years of life, subdural haemorrhage (SDH) within the cranial cavity can occur through accidental and non-accidental mechanisms as well as from birth-related injury. This type of bleeding is the most common finding in victims of abusive head trauma (AHT). Historically, the most frequent cause of SDHs in infancy is suggested to be traumatic damage to bridging veins traversing from the brain to the dural membrane. However, several alternative hypotheses have been suggested for the cause and origin of subdural bleeding. It has also been suggested by some that bridging veins are too large to rupture through the forces associated with AHT. To date, there have been no systematic anatomical studies on infant bridging veins. During 43 neonatal, infant and young child post-mortem examinations, we have mapped the locations and numbers of bridging veins onto a 3D model of the surface of a representative infant brain. We have also recorded the in situ diameter of 79 bridging veins from two neonatal, one infant and two young children at post-mortem examination. Large numbers of veins, both distant from and directly entering the dural venous sinuses, were discovered travelling between the brain and dural membrane, with the mean number of veins per brain being 54.1 and the largest number recorded as 94. The mean diameter of the bridging veins was 0.93 mm, with measurements ranging from 0.05 to 3.07 mm. These data demonstrate that some veins are extremely small and subjectively, and they appear to be delicate. Characterisation of infant bridging veins will contribute to the current understanding of potential vascular sources of subdural bleeding and could also be used to further develop computational models of infant head injury.

Post-mortem computed tomography coaxial cutting needle biopsy to facilitate the detection of bacterioplankton using PCR probes as a diagnostic indicator for drowning.

We report for the first time the use of coaxial cutting needle biopsy, guided by post-mortem computed tomography (PMCT), to sample internal body tissues for bacterioplankton PCR analysis to investigate drowning. This technical report describes the biopsy technique, the comparison of the needle biopsy and the invasive autopsy sampling results, as well as the PMCT and autopsy findings. By using this new biopsy sampling approach for bacterioplankton PCR, we have developed on previous papers describing the minimally invasive PMCT approach for the diagnosis of drowning. When such a system is used, the operator must take all precautions to avoid contamination of the core biopsy samples due to the sensitivity of PCR-based analytic systems.

Post-mortem imaging of the infant and perinatal dura mater and superior sagittal sinus using optical coherence tomography.

Infants and young children are likely to present with subdural haemorrhage (SDH) if they are the victims of abusive head trauma. In these cases, the most accepted theory for the source of bleeding is the bridging veins traversing from the surface of the brain to the dura mater. However, some have suggested that SDH may result from leakage of blood from a dural vascular plexus. As post-mortem examination of the bridging veins and dura is challenging, and imaging modalities such as magnetic resonance and computed tomography do not have the resolution capabilities to image small blood vessels, we have trialled the use of intravascular and benchtop optical coherence tomography (OCT) systems for imaging from within the superior sagittal sinus (SSS) and through the dura during five infant/perinatal autopsies. Numerous vessel-like structures were identified using both OCT systems. Measurements taken with the intravascular rotational system indicate that the approximate median diameters of blood vessels entering anterior and posterior segments of the SSS were 110 µm (range 70 to 670 µm, n = 21) and 125 µm (range 70 to 740 µm, n = 23), respectively. For blood vessels close to the wall of the SSS, the median diameters for anterior and posterior segments of the SSS were 80 µm (range 40 to 170 µm, n = 25) and 90 µm (range 30 to 150 µm), respectively. Detailed characterisation of the dural vasculature is important to aid understanding of the source of SDH. High resolution 3-dimensional reconstructions of the infant dural vasculature may be possible with further development of OCT systems.

Perimortem trauma in King Richard III: a skeletal analysis.

BACKGROUND: Richard III was the last king of England to die in battle, but how he died is unknown. On Sept 4, 2012, a skeleton was excavated in Leicester that was identified as Richard. We investigated the trauma to the skeleton with modern forensic techniques, such as conventional CT and micro-CT scanning, to characterise the injuries and establish the probable cause of death. METHODS: We assessed age and sex through direct analysis of the skeleton and from CT images. All bones were examined under direct light and multi-spectral illumination. We then scanned the skeleton with whole-body post-mortem CT. We subsequently examined bones with identified injuries with micro-CT. We deemed that trauma was perimortem when we recorded no evidence of healing and when breakage characteristics were typical of fresh bone. We used previous data to identify the weapons responsible for the recorded injuries. FINDINGS: The skeleton was that of an adult man with a gracile build and severe scoliosis of the thoracic spine. Standard anthropological age estimation techniques based on dry bone analysis gave an age range between 20s and 30s. Standard post-mortem CT methods were used to assess rib end morphology, auricular surfaces, pubic symphyseal face, and cranial sutures, to produce a multifactorial narrower age range estimation of 30-34 years. We identified nine perimortem injuries to the skull and two to the postcranial skeleton. We identified no healed injuries. The injuries were consistent with those created by weapons from the later medieval period. We could not identify the specific order of the injuries, because they were all distinct, with no overlapping wounds. Three of the injuries-two to the inferior cranium and one to the pelvis-could have been fatal. INTERPRETATION: The wounds to the skull suggest that Richard was not wearing a helmet, although the absence of defensive wounds on his arms and hands suggests he was still otherwise armoured. Therefore, the potentially fatal pelvis injury was probably received post mortem, meaning that the most likely injuries to have caused his death are the two to the inferior cranium. FUNDING: The University of Leicester.

Estimation of postmortem interval using vitreous potassium levels in cases of fatal road traffic collision

AIM OF THE STUDY: To produce a formula that can accurately predict postmortem interval (PMI) based on vitreous potassium levels using road traffic collision fatalities. MATERIAL AND METHODS: Vitreous humour samples were taken from 78 individuals who had died following road traffic collisions between 2010 and 2015. Samples were obtained from both eyes and were sent for on-site analysis. Measurement of potassium was by an indirect ion-specific electrode Siemens diagnostics ADVIA 2400 chemistry system. Exact time of death was known from police reports, the time of postmortem was recorded and the postmortem interval was calculated. Linear regression was then used to analyse the relationship between the two. The impact of age was also assessed. RESULTS: PMI was between 6 and 162 hours. As vitreous potassium increases, the PMI also increases; exhibiting a linear relationship. This is illustrated by a regression equation of PMI = 6.42[K+] - 40.94, R = 0.67 (p < 0.001). This produced a formula closely comparable with three other studies proposed in previous literature and produces estimates that may exceed one calendar day. When both age and medical intervention are accounted for there is an insignificant improvement in prediction. CONCLUSIONS: Validated methods have been used to produce a formula for prediction of PMI using vitreous potassium. Although this is specific to road traffic collisions, the methods are transferable and can be seen to be comparable with other recently published methods. Nonetheless, if greater levels of accuracy are required it is suggested that biomarkers delivering a higher level of precision should still be sought.

Visualisation of the intact dura mater and brain surface in infant autopsies: a minimally destructive technique for the post-mortem assessment of head injury.

During the post-mortem examination of babies and young children, it is important to be able to visualise the brain and its coverings, particularly in cases where a head injury is likely to have occurred. In this paper, we present an improved method for removal of the calvarial bones in infant autopsies to enable viewing of the dura mater and brain. In contrast to the standard post-mortem procedure for observing and removing the brain, this novel technique is minimally disruptive, allowing the dura mater to remain undamaged. Specialised paediatric neurosurgical tools were used to remove the skull bones from 23 neonates, infants and young children during post-mortem examination. In 21 of our 23 cases, the calvarial bones were removed successfully with the dura mater remaining intact. In one case, there was a thickening of the dura mater which created a strong adherence of this membrane to the bone. In another case, the dura mater was slightly damaged due to the inexperience of the operator in using the neurosurgical tools. This method of calvarial bone removal reduces the degree of post-mortem artefact and enhances the ability to observe and photographically document autopsy findings, including the artefact-free detection of signs of injury such as epidural or subdural haematoma, and brain swelling. This technique has now become a routine practise in both of our units to remove the skull bones in infant/young children post-mortem examinations.

Ventilated post-mortem computed tomography through the use of a definitive airway.

Ventilated post-mortem computed tomography (VPMCT) has been shown to achieve lung expansion in cadavers and has been proposed to enhance the diagnosis of lung pathology. Two key problems of the method of ventilation have been identified: firstly, the presence of head and neck rigor making airway insertion challenging and, secondly, air leak, if there is not a good seal around the airway, which diminishes lung expansion and causes inflation of the stomach. Simple procedures to insert a 'definitive' cuffed airway, which has a balloon inflated within the trachea, are therefore desirable. This study aims to test different procedures for inserting cuffed airways in cadavers and compare their ventilation efficacy and to propose a decision algorithm to select the most appropriate method. We prospectively tested variations on two ways of inserting a cuffed airway into the trachea: firstly, using an endotracheal tube (ET) approach, either blind or by direct visualisation, and, secondly, using a tracheostomy incision, either using a standard tracheostomy tube or shortened ET tube. We compare these approaches with a retrospective analysis of a previously reported series using supraglottic airways. All techniques, except 'blind' insertion of ET tubes, were possible with adequate placement of the airway in most cases. However, achieving both adequate insertion and a complete tracheal seal was better for definitive airways with 56 successful cases from 59 (95 %), compared with 9 cases from 18 (50 %) using supraglottic airways (p < 0.0001). Good lung expansion was achieved using all techniques if the airway was adequately positioned and achieved a good seal, and there was no significant chest pathology. We prefer inserting a shortened ET tube via a tracheostomy incision, as we find this the easiest technique to perform and train. Based on our experience, we have developed a decision algorithm to select the most appropriate method for VPMCT.

The future of pediatric and perinatal postmortem imaging.

The field and applications of postmortem imaging are exponentially growing. Its potential to identify the cause of death in trauma and ballistic cases is now properly documented, as well as its use in drug mule identification. In pediatric and perinatal practice, large significant series are less available, except for MRI and central nervous system analysis where scientific evidence is now robust. In this review, after a short historical review and analysis of current problems and challenges, we will try to depict the way we see the future of this subspecialty of postmortem cross-sectional imaging, including all specific situations: terminations of pregnancy, intrauterine death, sudden unexpected infant death and identification issues.