Letter to the Editor: Re: Gubbins K (2016) The hanging/hanged patient and relevance to pre-hospital care. Journal of Paramedic Practice 8(6): 290–3

Letter to the editor

How does post-mortem imaging compare to autopsy, is this a relevant question?

The rapid development of imaging techniques used for the investigation of death invites the question "how does imaging compare with autopsy". This paper is based on an invited talk given to the International Society of Forensic Radiology and Imaging in 2015 and attempts to show that this question cannot be answered, as it is in fact several questions depending on the circumstances of death. Review of the literature is fraught with difficulties due to the rapid evolution of technology, the varied circumstances of death investigation and the multiple possible post-mortem investigations that imaging can be compared with. The article focuses on the assessment of adult sudden natural death and suggests the questions that need to be answered

Positional Statement: Radiology Disaster Victim identification Reporting forms

Since the first application of radiology to Disaster Victim Identification (DVI) during the investigation of the SS Noronic ship disaster in 1949 [1] radiology has played an increasingly important role in DVI, particularly with the increasing utilisation of post mortem computed tomography (PMCT). There are now instances in DVI investigations where PMCT has been used as the substantial or even sole form of pathological body examination, i.e. replacing invasive (autopsy) examination. It is critical that the relevant radiological findings are conveyed accurately to those investigating the deaths irrespective of the radiological modality used. The communication of the findings will usually take the form of two separate reports. The first should be the completion of the newly introduced INTERPOL DVI Radiology Examination Record Form, either in paper or electronic format, to record the findings of the initial radiology examination. This report will inform the DVI investigation. In order to inform the pathological examination, a second detailed radiological report of the remains can be produced, either at the same time or later, (this will be incident and practitioner dependent) using an appropriate whole-body or partial remains reporting form or similar

Post-mortem computed tomography visualised fire related post-mortem changes of the head

As post-mortem computed tomography (PMCT) becomes more routinely utilised in day-to-day autopsy practice around the world it is important that those reporting the images are aware of changes that may not be encountered in clinical radiology that can result in the post-mortem period but resemble antemortem pathology. Two cases are presented to illustrate the PMCT findings of three of the four classical changes that occur to the head after death as a result of the effect of prolonged exposure to heat

PMCT images of a motorcycle helmet-associated fracture.

Case 1: A 44 year-old male was involved in a head-on collision with a car which was overtaking another vehicle at the time. After being thrown from the motorcycle the deceased impacted to the car’s nearside, then to the rear offside curtain of an oncoming lorry before coming to rest on the opposite verge of the road. He was declared dead at the scene. The full-face SHOEI brand helmet worn had a witness mark to the front center just above the visor edge. There were multiple areas of bruising and abrasion to the head but no lacerations. Blood was noted to issue from the left ear. Post-mortem computed tomography (PMCT) identified a fracture of the base of the skull centered at the pituitary fossa extending to both middle fossae. It extended to the temporal bone of the vault, and along the lambdoid suture. The fracture did not quite meet at the back of the head, preventing dissociation between two skull portion

Cardiothoracic Ratio (CTR) measured on Post-mortem computed tomography (PMCT) - pre and post-ventilation

The cardiothoracic ratio (CTR) is commonly used as an indicator of cardiomegaly in clinical radiology. CTR is generally calculated using measurements from chest radiographs. More recently, a number of studies have used computed tomography (CT). This has not been attempted using with post-mortem ventilation, which would more closely mimic the inspiratory breath hold phase chest radiograph used for clinical CTR. The aim of this study was to determine whether CTR can be measured on post-mortem CT (PMCT), whether it correlates with heart weight at autopsy and suggests cardiomegaly, and what effect ventilated PMCT (VPMCT) has on CTR measurements. CTR (%) was measured on PMCT scans pre and post ventilation using a method designed to mimic the deep inspiration and breath hold clinical thoracic CT, and compared with heart weights measured at autopsy with cardiomegaly defined from normal heart weight tables scaled for body size and sex. Forty-two cases with both PMCT and VPMCT were consented for research. Results showed excellent measurement repeatability. VPMCT reduced heart diameter and CTR. The best CTR threshold to correlate cardiomegaly was 50% for PMCT (sensitivity & specificity (S&S)=89 & 71%) and 44% for VPMCT (S&S=79 & 71%). The heart diameter thresholds were 130 mm for PMCT (S&S=89 & 93%) and 114 mm for VPMCT (S&S=93% & 86%). Both CTR and heart diameter, using both PMCT and VPMCT, correlated well with heart weight at autopsy. However, using VPMCT and CTR did not give any advantage to measuring heart size on standard PMCT in this study

Could Post-mortem Computed Tomography Angiography Inform Cardiopulmonary Resuscitation Research?

Aim: Firstly, to develop an optimised chest compression post mortem computed tomography angiography protocol in the adult human during closed chest compression to investigate cardiopulmonary resuscitation blood flow, and secondly to provide preliminary observations of post-mortem anatomical cardiac chamber movement using a novel radiolucent static chest compression device. Methods: Variable volumes of radiological contrast agent were injected intravenously into a series of consented human cadavers. Each cadaver had chest compressions delivered with a LUCAS™2 mechanical chest compressor. Following each cycle of chest compressions, each cadaver was imaged with a Toshiba Aquilion CXL 128 slice computed tomography (CT) scanner to investigate the extent of contrast distribution. A chest compression simulator was then designed and built to allow static CT imaging of 1 cm incremental cadaver chest compressions to a depth of 5 cm. Results: Mechanical compressions: Ten cases were recruited for the CT angiography component of the study. Two were subsequently excluded from the study at the time of the initial, non-contrast PMCT scan. A further case was recruited in Emergency Department (ED). CT demonstrable antegrade arterial contrast distribution was achieved in 2 cases. The other 7 cases, including that undertaken in ED shortly after death, showed venous retrograde flow. Incremental compressions: Five new cases underwent incremental chest compression imaging. All cases demonstrated compression of the sternum, ribs, atria and great vessels. The right and left ventricles were not compressed, but moved laterally and inferiorly, further into the left chest cavity. The left hemi-diaphragm, stomach and liver moved inferiorly. The sternum, ventricles, hemi-diaphragm, stomach and liver all moved back to their original position on incremental release. Conclusion: The study suggests that with further protocol modification and access to human cadavers as near to death as possible, chest compression post mortem computed angiography (CCPMCTA) could be used as a model for the study of human vascular flow and heart movement during CPR

An investigation of juvenile cranial thickness-analysis of skull morphometrics across the complete developmental age range

Current methods for measuring skull thickness in adults involve taking measurements from the skull at set points during autopsy. The aim of this study was to develop a reproducible method for measuring skull thickness in juveniles using Post-mortem Computed Tomography (PMCT). Thirty-nine juveniles underwent computed tomography scans as part of the autopsy examination. In those cases where the head scans showed no skull pathology they were made anonymous and entered into this study. One of the methods used at autopsy which is reported to yield the most consistent results was replicated using PMCT. A novel PMCT method was also developed using multi-plane reconstructions (MPR). Each PMCT method produced a set of results that showed a statistically significant positive correlation between age and the average skull thickness. This study shows that PMCT can be used to produce a standardised method for measuring juvenile skull thickness and could form an important component of forensic examinations in children

Adult post-mortem imaging in traumatic and cardiorespiratory death and its relation to clinical radiological imaging

The use of post-mortem imaging is expanding throughout the world with increasing use of advanced imaging techniques, such as contrast-enhanced CT and MRI. The questions asked of post-mortem imaging are complex and can be very different, for example for natural sudden death investigation will focus on the cause, whereas for trauma the cause of death is often clear, but injury patterns may be very revealing in investigating the background to the incident. Post-mortem imaging is different to clinical imaging regarding both the appearance of pathology and the information required, but there is much to learn from many years of clinical research in the use of these techniques. Furthermore, it is possible that post-mortem imaging research could be used not only for investigating the cause of death but also as a model to conduct clinically relevant research. This article reviews challenges to the development of post-mortem imaging for trauma, identification and cardiorespiratory death, and how they may be influenced by current clinical thinking and practice

The Future of Pediatric and Perinatal Post-mortem 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