Accuracy of non-contrast PMCT for determining cause of death

Enhanced autopsy triage (EA-Triage) in drug-related deaths: integrating quick toxicological analysis and postmortem computed tomography

The objective was to assess the diagnostic accuracy of an enhanced autopsy triage (EA-Triage) setup consisting of postmortem computed tomography (PMCT), simulated quick toxicological analysis (sQTA), external examination, and case information in determining cause of death (COD) in persons with past or current use of illegal drugs (drug-related deaths). Information on drug-related deaths selected for medico-legal autopsy in 2020-2021 at the Department of Forensic Medicine, Aarhus University, Denmark, was analyzed retrospectively. The included cases underwent conventional autopsy, PMCT, and systematic toxicological analysis. A board-certified forensic pathologist, who was blinded to the internal examination and COD from the medico-legal autopsy, determined COD based on the EA-Triage setup. 154 cases with a median age of 40.6 years (range 17-70 years, 82% males) were included. The COD determined by medico-legal autopsy and that determined by EA-Triage matched in 113 cases (73%), including those with an unknown COD. EA-Triage and medico-legal autopsy determined unknown COD in 45 (29%) and 5 cases (3%), respectively. Excluding cases with an unknown COD, EA-Triage predicted COD in 109 cases (71%); of those, 72 (66%) had no unexplained case circumstances or suspicion of a criminal act. In these 72 cases, the CODs determined by EA-Triage and medico-legal autopsy matched in 71 cases (99%), and the sensitivity and specificity for detecting lethal intoxication were 100% and 90%, respectively. EA-Triage showed strong diagnostic accuracy for determining COD in drug-related deaths. This method may be suitable for enhancing preautopsy triage and guiding police investigations at an early stage.

Efficacy of postmortem CT and tissue sampling in establishing the cause of death in clinical practice: a prospective observational study

AIMS

The aim of this study is to evaluate whether agreement with autopsy-determined cause of death (COD) increases by use of postmortem CT (PMCT) or PMCT in combination with postmortem sampling (PMS), when compared with clinical assessment only.

METHODS

This prospective observational study included deceased patients from the intensive care unit and internal medicine wards between October 2013 and August 2017. The primary outcome was percentage agreement on COD between the reference standard (autopsy) and the alternative postmortem examinations (clinical assessment vs PMCT or PMCT+PMS). In addition, the COD of patient groups with and without conventional autopsy were compared with respect to involved organ systems and pathologies.

RESULTS

Of 730 eligible cases, 144 could be included for analysis: 63 underwent PCMT without autopsy and 81 underwent both PMCT and autopsy. Agreement with autopsy-determined COD was significantly higher for both PMCT with PMS (42/57, 74%), and PMCT alone (53/81, 65%) than for clinical assessment (40/81, 51%; p=0.007 and p=0.03, respectively). The difference in agreement between PMCT with PMS and PMCT alone was not significant (p=0.13). The group with autopsy had a significantly higher prevalence of circulatory system involvement and perfusion disorders, and a lower prevalence of pulmonary system involvement.

CONCLUSION

PMCT and PMS confer additional diagnostic value in establishing the COD. Shortcomings in detecting vascular occlusions and perfusion disorders and susceptibility to pulmonary postmortem changes could in future be improved by additional techniques. Both PMCT and PMS are feasible in clinical practice and an alternative when autopsy cannot be performed.

Postmortem computed tomography plus forensic autopsy for determining the cause of death in child fatalities

BACKGROUND

Postmortem computed tomography (CT) and magnetic resonance imaging have been gradually introduced to forensic pathology centres over the past two decades, with varying results in comparison to autopsy.

OBJECTIVE

The purpose of this study was to determine the accuracy of postmortem CT in determining a cause of death in children who died of unnatural causes.

MATERIALS AND METHODS

This was a prospective recruitment of 30 children (< 18 years) who underwent postmortem CT and a forensic autopsy. A cause of death was independently assigned by two experienced paediatric radiologists and compared to that of the forensic autopsy.

RESULTS

A correct cause of death was assigned by reviewers 1 and 2 in 70% (n = 21/30) and 67% (n = 20/30) of cases, respectively. For gunshot injuries and blunt force head injuries, there was 91% (n = 10/11) and 100% (n = 6/6) agreement between forensic autopsy and both reviewers, respectively. No cause of death could be assigned by reviewers 1 and 2 in 27% (n = 8) and 30% (n = 9) of cases, respectively. An incorrect cause of death was assigned by both reviewers in one case (3%). The Cohen Kappa level of agreement between the forensic autopsy and reviewers 1 and 2 was k = 0.624 (95% confidence interval [CI]: 0.45-0.80, P = 0) and k = 0.582 (95% CI 0.41-0.76, P = 0), respectively. There was near perfect agreement between reviewers 1 and 2 (k = 0.905) (95% CI 0.78-1.00, P = 0).

CONCLUSION

Postmortem CT has good diagnostic accuracy for identifying a cause of death related to trauma, but it has poor accuracy for children dying from causes not associated with apparent physical injury.

Use of Post-Mortem Computed Tomography During the COVID-19 Pandemic: The Malaysian Experience

Background

COVID-19 was declared a pandemic by the World Health Organization (WHO). COVID-19 is highly contagious, making it a threat to healthcare workers, including those working in mortuaries. Therefore, it is important to determine if the cause of death (COD) could be identified using limited autopsy, diagnostic tests and post-mortem imaging modalities instead of full autopsy. This study aims to examine the effectiveness of post-mortem imaging, specifically post-mortem computed tomography (PMCT) at determining the COD during a pandemic.

Methods

This cross-sectional study included 172 subjects with suspected or unknown COVID-19 status brought in dead to the institute's mortuary during the pandemic in Malaysia. PMCT images reported by forensic radiologists and their agreement with conventional autopsy findings by forensic pathologists regarding COD were analysed to look at the effectiveness of PMCT in determining COD during a pandemic.

Results

Analysis showed that 78.7% (133) of cases reported by forensic radiologists concurred with the COD certified by forensic pathologists. Of these cases, 85 (63.9%) had undergone only external examination and real-time reverse transcriptase polymerase chain reaction (rRT-PCR) COVID-19 testing, meaning that imaging was the sole method used to determine the COD besides history from available medical records and the investigating police officer.

Conclusion

PMCT can be used as a complement to medicolegal autopsies in pandemic contexts, as it provides significant information on the possible COD without jeopardising the safety of mortuary health care workers.

Usefulness of a tissue optical clearing technique for forensic autopsy

Forensic pathologists are required to investigate lethal trauma or disease at autopsy. In addition to massive contusions of various organs, a number of small features with potentially fatal implications also need to be sought. Since such lesions may need microscopic examinations for detailed evaluation, it is important to select suitable anatomic locations for tissue sampling. For practical screening of small lesions, we have developed a tissue optical clearing (TOC) technique for forensic autopsy. The technique involves clearing with a non-toxic organic solvent, ethyl cinnamate, which renders excised organs transparent, while hemorrhages or blood-containing vessels remain opaque. Using this technique, tiny hemorrhages in the spinal cord were able to be identified by gross examination, allowing proper selection of locations for tissue sampling. Subsequent histopathological evaluation was successfully performed with no apparent artifacts related with the TOC procedure. In addition, a combination of TOC and targeted CT angiography allowed feasible examination of the arterial occlusive lesion in the superior mesenteric artery, and when combined with micro-CT scanning it was useful for evaluating the lumen of the coronary artery with stent implantation. The results obtained so far indicated that TOC could complement routine forensic autopsy procedures when detailed evaluation of small lesions is required.

Synergistic Effects of Forensic Medicine and Traumatology: Comparison of Clinical Diagnosis Autopsy Findings in Trauma-Related Deaths

BACKGROUND

Trauma is the third leading cause of death worldwide after cardiovascular and oncologic diseases. Predominant causes of trauma-related death (TD) are severe traumatic brain injury (sTBI), hemorrhagic shock, and multiple organ failure. An analysis of TD is required in order to review the quality of trauma care and grasp how well the entire trauma network functions, especially for the most severely injured patients. Furthermore, autopsies not only reveal hidden injuries, but also verify clinical assumed causes of death.

MATERIAL

During the study period of 3 years, a total of 517 trauma patients were admitted to our supraregional University Centre of Orthopaedics and Traumatology in Dresden. 13.7% (71/517) of the patients died after trauma, and in 25 cases (35.2%), a forensic autopsy was instructed by the federal prosecutor. The medical records, death certificates, and autopsy reports were retrospectively evaluated and the clinical findings matched to autopsy results.

RESULTS

The observed mortality rates (13.7%) were 4.2% less than expected by the calculated RISC II probability of survival (mortality rate of 17.9%). The most frequent trauma victims were due to falls >3 m (n = 29), followed by traffic accidents (n = 28). The median ISS was 34, IQR 25, and the median New ISS (NISS) was 50, IQR 32. Locations of death were in emergency department (23.9%), ICU (73.2%), OR and ward (1.4%, respectively). Clinicians classified 47.9% of deaths due to sTBI (n = 34), followed by 9.9% thoracic trauma and multiple organ failure (n = 7), 8.4% multiple trauma (n = 6), and 2.8% hypoxia and exsanguination (n = 2). In 18.3%, cases were unspecific or other causes of death recorded on the death certificates. Evident differences with evident clinical consequences were ascertained in 4% (n = 1) and marginal clinical consequences in 24% (6/25). In 16% (4/25), marginal differences with minor forensic consequences were revealed.

CONCLUSIONS

Even in a supraregional trauma center, specialized in multiple trauma management (4.2% survival benefit), room for improvement exists in more than a quarter of all casualties. This underlines the need for higher autopsy rates to uncover missed injuries and to understand the pathomechanism in each trauma fatality. This would also help to uncover potential insufficiencies in clinical routines with regard to diagnostics. The interdisciplinary cooperation of trauma surgeons and forensic pathologists can increase the quality of trauma patient care.

Oleic Acid (OA), A Potential Dual Contrast Agent for Postmortem MR Angiography (PMMRA): A Pilot Study

Choosing proper perfusates as contrast agents is an important aspect for postmortem magnetic resonance angiography (PMMRA). However, in this emerging field, the number of suitable kinds of liquid is still very limited. The objective of this research is to compare MR images of oleic acid (OA) with paraffin oil (PO) in vitro and in ex situ animal hearts, in order to evaluate the feasibility to use OA as a novel contrast agent for PMMRA. In vitro, OA, PO and water (control) were introduced into three tubes separately and T₁weighted-spin echo (T₁w-SE) and T₂w-SE images were acquired on a 1.5T MR scanner. In the second experiment, OA and PO were injected into left coronary artery (LCA) and left ventricle (LV) of ex situ bovine hearts and their T₁w-SE, T₂w-SE, T₁w-multipoint Dixon (T₁w-mDixon) and 3DT₂w-mDixon images were acquired. The overall results indicate that OA may have a potential to be used as a dual (T₁ and T₂ based) contrast agent for PMMRA when proper sequence parameters are utilized. However, as the pilot study was based on limited number of animal hearts, more researches using OA in cadavers are needed to validate our findings.

Corpse dismemberment: A case series. Solving the puzzle through an integrated multidisciplinary approach

The finding of corpse parts poses several challenges for the forensic pathologist presenting implications for identification, diagnosis of death and determination of wounds vitality. Further interpretative difficulties in cases of cadaveric dismemberment derive from the scarcity of tanatochronological parameters useful to estimate the post-mortem interval (PMI) and the absence of uniform investigative protocols in the different centres of forensic pathology. The present study proposes an investigation protocol for the cadaveric dismemberment through the discussion of a case series. The study group consisted of cases in which the dismemberment was performed after the murder. For all cases, a study protocol based on crime scene investigation, post-mortem computed tomography (PMCT), autopsy, toxicological, histological, immunohistochemical and genetic investigations was implemented. In particular, the standardised use of radiographic study before the autopsy allows all to have information that can guide the forensic pathologist during the autopsy. The use of immunohistochemistry allows an assessment of the vitality of the lesions possibly involved in the determinism of death, as well as of the surfaces of dismemberment, representing a tool of considerable utility for forensic purposes. The genetic investigations allow the identification of the victims, while the toxicological ones highlight the possible abuse of substances. The implemented protocol presents a demonstrated usefulness in improving diagnostic accuracy in corpse dismemberment cases.

Post-mortem CT vs necropsy in feline medicine

OBJECTIVES

The aim of this study was to compare post-mortem CT findings with necropsy findings in domestic cats.

METHODS

Post-mortem CT and necropsies were performed in 20 cadavers of domestic cats. The sensitivity, specificity and agreement between the post-mortem CT and necropsy findings were determined.

RESULTS

There were a total of 315 post-mortem findings; 183 were identified by post-mortem CT and 132 were identified by necropsy. Post-mortem CT demonstrated a higher sensitivity to identify the findings mainly in bones. The higher indices of agreement between post-mortem CT and necropsy were related to abnormalities of pleural space, bones and joints.

CONCLUSIONS AND RELEVANCE

This study demonstrated that post-mortem CT and necropsy provided different information. Thus, their use in conjunction with each other might improve the understanding of the cause of death and the identification of post-mortem lesions.

Postmortem imaging findings and cause of death determination compared with autopsy: a systematic review of diagnostic test accuracy and meta-analysis

BACKGROUND

The aim of this study was to evaluate the sensitivity of postmortem computed tomography (PMCT), postmortem magnetic resonance imaging (PMMR) and PMCT angiography (PMCTA) compared with autopsy in cases of adult death investigations.

METHODS

For this systematic review and meta-analysis, Embase, PubMed, Scopus, Web of Science and Medline were searched for eligible studies in October 2016; a follow-up literature search was conducted in March 2018. Studies referring to PMCT, PMCTA and/or PMMR of more than 3 cases with subsequent autopsy were included. Data were extracted from published texts in duplicate. The extracted outcomes were categorized as follows: soft tissue and organ findings, skeletal injuries, haemorrhages, abnormal gas accumulations and causes of death. The summary measure was sensitivity, if 3 or more studies were available. To combine studies, a random effects model was used. Variability and heterogeneity within the meta-analysis was assessed.

RESULTS

Of 1053 studies, 66 were eligible, encompassing a total of 4213 individuals. For soft tissue and organ findings, there was a high pooled sensitivity with PMCTA (0.91, 95% CI 0.81-0.96), without evidence for between-study variability (Cochrane's Q test p = 0.331, I² = 24.5%). The pooled sensitivity of PMCT+PMMR was very high in skeletal injuries (0.97, CI 0.87-0.99), without evidence for variability (p = 0.857, I² = 0.0%). In detecting haemorrhages, the pooled sensitivity for PMCT+PMMR was the highest (0.88, 95% CI 0.35-0.99), with strong evidence of heterogeneity (p < 0.05, I² > 50%). Pooled sensitivity for the correct cause of death was the highest for PMCTA with 0.79 (95% CI 0.52-0.93), again with evidence of heterogeneity (p = 0.062, I² > 50%).

CONCLUSION

Distinct postmortem imaging modalities can achieve high sensitivities for detecting various findings and causes of death. This knowledge should lead to a reasoned use of each modality. Both forensic evidence and in-hospital medical quality would be enhanced.

Nasal Septum Defects Detected on Postmortem Computed Tomography

Nasal septum defects may have forensic relevance because they are associated with various mechanisms, including trauma and cocaine abuse. Like all human body tissues, the nasal septum may be affected by maggots' infestation during postmortem decomposition. Postmortem computed tomography (PMCT) can reveal small findings and related details. Three cases of early postmortem period and 2 cases of advanced decomposition, where external examination of the nasal cavities and PMCT revealed nasal septum defect, are presented. In the early postmortem period cases, the lesions' edges appeared smoother on PMCT, whereas in the advanced decomposed cases, the edges were irregular and maggots were infested. Postmortem computed tomography can detect nasal septum defects and may help differentiate the preexisting from the postmortem ones based on their edges' radiological appearance. Such findings may indicate possible chronic cocaine abuse (cocaine nose), trauma, or other nasal pathology. It is important to note that such defects may be altered or caused by advanced decomposition.

Fatal gunshot injuries in the common buzzard Buteo buteo L. 1758 - imaging and ballistic findings

The conservation of the common buzzard is assured by the European Union law. In Poland, this wild bird is under strict species protection and it is used as a bioindicator for heavy metals in the environment. A case of the fatal shooting of a buzzard with a firearm by an unidentified shooter is described here. Macroscopic evaluation, X-ray imaging, post-mortem computed tomography, ballistic examination of the isolated bullets and finally a simulation of the assumed position of the bird at the time of the shot were performed. Numerous pellets were found inside the body, together with multiple bone fractures and central nervous system trauma. The buzzard died most probably as a result of spinal cord injury from a single shot that was fired from a smoothbore hunting gun. Collected evidence was insufficient to identify the shooter, which sadly confirms that identification of the perpetrator in wildlife forensics remains low.

Can virtual autopsy with postmortem CT improve clinical diagnosis of cause of death? A retrospective observational cohort study in a Dutch tertiary referral centre

OBJECTIVE

To investigate whether virtual autopsy with postmortem CT (PMCT) improves clinical diagnosis of the immediate cause of death.

DESIGN

Retrospective observational cohort study.

INCLUSION CRITERIA

inhospital and out-of-hospital deaths over the age of 1 year in whom virtual autopsy with PMCT and conventional autopsy were performed.

EXCLUSION CRITERIA

forensic cases, postmortal organ donors and cases with incomplete scanning procedures. Cadavers were examined by virtual autopsy with PMCT prior to conventional autopsy. The clinically determined cause of death was recorded before virtual autopsy and was then adjusted with the findings of virtual autopsy. Using conventional autopsy as reference standard, we investigated the increase in sensitivity for immediate cause of death, type of pathology and anatomical system involved before and after virtual autopsy.

SETTING

Tertiary referral centre.

PARTICIPANTS

86 cadavers that underwent conventional and virtual autopsy between July 2012 and June 2016.

INTERVENTION

PMCT consisted of brain, cervical spine and chest-abdomen-pelvis imaging. Conventional autopsy consisted of thoracoabdominal examination with/without brain autopsy.

PRIMARY AND SECONDARY OUTCOME MEASURES

Increase in sensitivity for the immediate cause of death, type of pathology (infection, haemorrhage, perfusion disorder, other or not assigned) and anatomical system (pulmonary, cardiovascular, gastrointestinal, other or not assigned) involved, before and after virtual autopsy.

RESULTS

Using PMCT, the sensitivity for immediate cause of death increased with 12% (95% CI 2% to 22%) from 53% (41% to 64%) to 64% (53% to 75%), with 18% (9% to 27%) from 65% (54% to 76%) to 83% (73% to 91%) for type of pathology and with 19% (9% to 30%) from 65% (54% to 76%) to 85% (75% to 92%) for anatomical system.

CONCLUSION

While unenhanced PMCT is an insufficient substitute for conventional autopsy, it can improve diagnosis of cause of death over clinical diagnosis alone and should therefore be considered whenever autopsy is not performed.