The value of post-mortem CT in neonaticide in case of severe decomposition: description of 12 cases

The micro CT evaluation of crown and root pulp volume versus dentin thickness in teeth in postmortem interval (PMI)

Determining the postmortem interval (PMI) is one of the main study subjects of forensic sciences. The main purpose of this prospective in vitro study that was the Micro-CT evaluation of teeth crown and root pulp volume versus dentin thickness in terms of PMI determination. The study involved 60 female Wistar rats, with weights ranging from 270 to 320 g. These rats were grouped into six different post-mortem period categories. Following the animals' sacrifice, they were subjected to a natural putrefaction period, with a control group, in the grounds of a sheltered garden. Hemi-mandible samples were then extracted and placed in glass tubes for Micro-CT evaluations, following the progression of putrefaction processes. The pulp volume and dentin thickness were assessed using Micro-CT, and the gathered data underwent statistical analysis. Micro-CT was employed to analyze sixty right mandibular second molar teeth in the hemi-mandible. The crown pulp volume exhibited a reduction in group 6, with a value of 0.239 mm3 after a three-month period of natural putrefaction (p < 0.001). There is statistically differences among groups in case of pairwise comparison (p < 0.05). However, the root pulp volume and dentin thickness variables did not display any statistically significant changes. Despite certain limitations associated with this study, the Micro-CT findings concerning teeth pulp volume can serve as an objective parameter, especially for late postmortem investigations and the estimation of time of death.

Usefulness of virtual autopsy in diagnosing pathologies in the paediatric population: A systematic review

Objective

Virtual autopsy is a non-invasive/minimally invasive method for conducting an autopsy, with the assistance of imaging techniques. We aim to review the benefits of virtual autopsy in detecting pathologies in the paediatric population.

Method

The procedure adhered to Institute of Medicine and Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. Seven databases including MEDLINE and SCOPUS were searched for articles published 2010-2020 worldwide in English. A narrative synthesis of the findings of included studies was carried out to discuss and summarize the results of the review.

Results

From 686 studies on paediatric deaths, 23 met selection/quality criteria. Virtual autopsy was better than conventional autopsy in detecting skeletal lesions and bullet trajectory, thus a crucial tool in the investigation of traumatic and firearm deaths. Virtual autopsy was superior to conventional autopsy in identifying the point of bleeding in postoperative deaths and objectively quantifying air/fluid in body cavities. Virtual autopsy was a useful adjunct for detecting pulmonary thrombo-embolism, foreign body aspiration, drowning and metastatic malignancies. The use of non-contrast imaging in investigating natural paediatric deaths did not offer more information than conventional autopsy. Misinterpretation of normal post-mortem changes as pathological findings was another disadvantage of virtual autopsy leading to erroneous conclusions. But accuracy may be improved with contrast enhancement and post-mortem magnetic resonance imaging.

Conclusion

Virtual autopsy is a crucial tool in the investigation of traumatic and firearm deaths in the paediatric population. Virtual autopsy will be useful as an adjunct to conventional autopsy in asphyxial deaths, stillbirths and decomposed bodies. Virtual autopsy has limited value in differentiating antemortem and post-mortem changes with the added risk of misinterpretations, therefore should be used with caution in natural deaths.

Pictorial review of the postmortem computed tomography in neonaticide cases

Neonaticide is defined by the deliberate killing or homicide of a child within 24 h of its birth. In this context, three fundamental questions are generally asked of the forensic pathologist: what is the cause of death of the neonate? Was the child viable (i.e., what is the gestational age of the neonate)? Finally, was the neonate stillborn or liveborn?Postmortem imaging can help answer these questions by conducting (1) a complete lesional analysis of the body and the placenta, (2) an estimation of the gestational age by measuring the lengths of the diaphyseal long bones, and (3) an analysis of the aeration of the lungs and intestines. Using the details of 18 cases, we illustrate aspects of neonaticide cases in postmortem computed tomography (PMCT), offering detailed examples of notable postmortem changes and abnormalities, especially in the analysis of the pulmonary parenchyma. This article presents a useful iconography for the radiologist confronted with this rare yet complex forensic situation.

Assessment of neonaticide in the setting of concealed and denied pregnancies

It is known that concealed and denied pregnancy are both associated with increased health risks to the mother and infant. Whilst there is literature surrounding management and safeguarding in these instances, we are not aware of a case review of post-mortem findings in infants with a history of concealed or denied pregnancy. We performed a retrospective review of all coronial post-mortems performed between 2003 and 2018 on infants and fetuses with a history of concealment or denial of pregnancy. Maternal demographics, delivery information, post-mortem findings and results of ancillary investigations were analyzed. Twenty cases (1.8% of total coronial workload in the period of the study) were included. Four women admitted to concealing their pregnancy, eleven denied their pregnancy and in the remaining five cases the bodies of the infants had been abandoned and the mother was not traceable. The bodies of these infants were found in waste disposal sites, wooded areas and in a drainpipe. Only six infants in total were judged to have survived delivery, all others were stillborn or unascertained. Perinatal hypoxia, large subdural hemorrhage and congenital pneumonia were the reported causes of death in those infants that were liveborn. In one case there was suspicion of neonaticide. Concealment and denial of pregnancy occur in a wider demographic than perhaps anticipated and is not limited to teenage primigravids. Mothers with concealed and denied pregnancy hid the body of their deceased infant out of fear of prosecution. In many circumstances, viability at birth cannot be ascertained.

Lung density measurement in postmortem computed tomography: a new tool to assess immediate neonatal breath in suspected neonaticides

INTRO

Evidence of breath after birth is one of the main forensic issues in suspected neonaticide. Hydrostatic test (HT) and pathological examination are currently used to assess it, but they are not entirely reliable or immediately available.

OBJECTIVE

To determine the performance of postmortem computed tomography (PMCT) to assess neonatal breath in suspected neonaticide, by comparing lung CT attenuation values between live birth and stillbirth cases, in correlation with HT and pathology.

METHOD

Cases of suspected neonaticides who underwent a PMCT and complete forensic autopsy with an HT were retrospectively selected from the databases of four French Forensic Medicine Departments. The diagnosis of vitality (i.e., stillbirth or live birth) was based on the pathological examination and/or a combination of arguments, including HT result. Lung density on CT was measured in Hounsfield units (HU) by ROIs drawn in both pulmonary parenchymas.

RESULTS

Eleven patients were included, six live birth and five stillbirth cases. The result of HT was concordant with pathological examination when available (seven cases). Mean lung densities in live birth cases (- 173 HU [- 255; - 91 CI 95%]) were significantly lower than in stillbirth cases (40 HU [28; 52 CI 95%]) (p < 0.05), with a very high degree of interobserver reproducibility (ICC = 0.998 (CI 95% 0.991-0.999; p < 0.001).

CONCLUSION

PMCT and especially lung CT attenuation measurement is a reliable and easy-to-use method for assessing neonatal breath in suspected neonaticides.

"Was the Infant Born Alive?" A Review of Postmortem Techniques Used to Determine Live Birth In Cases of Suspected Neonaticide

The question of whether an infant was born alive has received much attention in the forensic literature. The volume of literature reflects the degree of controversy surrounding the techniques employed and their varied interpretation and utility. The majority of the investigation has been focused on the question "Has the infant breathed?" to determine if an infant was born alive by utilizing techniques that assess aeration of the lungs. However, caution must be employed when interpreting these techniques due to the well-recognized limitations in their interpretation, particularly in the presence of gaseous decomposition and/or resuscitation efforts. Although in some instances there may be irrefutable evidence that the infant was born alive, there is no single finding that can reliably be utilized to answer the question "Was the infant born alive?" in every case. Hence, the approach to postmortem investigation continues to include a wide range of observations, dissections, special techniques, and ancillary tests to assist the pathologist to form a considered opinion. There are a number of more recently described techniques which show great promise in assisting to answer this question including advanced imaging and immunohistochemical studies of the umbilical cord. It remains, though, that in many cases it is not possible to definitively answer this question and stillbirth should be assumed due to the potential legal implications of determining that an infant was born alive.

Towards multi-phase postmortem CT angiography in children: a study on a porcine model

PURPOSE

Multi-phase postmortem computed tomography angiography (MPMCTA) is a growing technique, which is standardized for adults. Application of this protocol for a children population is not so well defined. Our study aims to adapt the adult's protocol to children, using a porcine model.

MATERIAL AND METHODS

Three groups of 18 pigs were studied, with a weight distribution between 4 and 48 kg. Different pump devices were used. Pigs of group I were studied using the Virtangio® machine, whereas pigs of groups II and III were studied using used the Medrad® machine. Study of vascular opacification was possible using a semi-quantitative method based on 26 arterial and 26 venous segments that were distributed over the entire body from the cephalic extremity to the posterior pawns.

RESULTS

While thoracic, abdominal, and pelvic vascular opacification were complete for each individual pig in a group, group III showed better vascular opacification for the cephalic extremity. This was also true for anterior and posterior pawns vascular opacification. Spearman correlation tests showed a significant relationship between anthropometric characteristics of pigs, injection parameters, and percentage of opacified segments. A higher percentage of opacification was obtained for individuals of lower weights, with comparatively lower quantities of contrast agent injected.

CONCLUSION

Postmortem computed tomography angiography (PMCTA) was possible for all the individuals, particularly for small weights (4 kg) using the Medrad® machine. However, further studies are needed to better understand the procedure.

Dutch guideline for clinical foetal-neonatal and paediatric post-mortem radiology, including a review of literature

Clinical post-mortem radiology is a relatively new field of expertise and not common practice in most hospitals yet. With the declining numbers of autopsies and increasing demand for quality control of clinical care, post-mortem radiology can offer a solution, or at least be complementary. A working group consisting of radiologists, pathologists and other clinical medical specialists reviewed and evaluated the literature on the diagnostic value of post-mortem conventional radiography (CR), ultrasonography, computed tomography (PMCT), magnetic resonance imaging (PMMRI), and minimally invasive autopsy (MIA). Evidence tables were built and subsequently a Dutch national evidence-based guideline for post-mortem radiology was developed. We present this evaluation of the radiological modalities in a clinical post-mortem setting, including MIA, as well as the recently published Dutch guidelines for post-mortem radiology in foetuses, neonates, and children. In general, for post-mortem radiology modalities, PMMRI is the modality of choice in foetuses, neonates, and infants, whereas PMCT is advised in older children. There is a limited role for post-mortem CR and ultrasonography. In most cases, conventional autopsy will remain the diagnostic method of choice.

CONCLUSION

Based on a literature review and clinical expertise, an evidence-based guideline was developed for post-mortem radiology of foetal, neonatal, and paediatric patients. What is Known: • Post-mortem investigations serve as a quality check for the provided health care and are important for reliable epidemiological registration. • Post-mortem radiology, sometimes combined with minimally invasive techniques, is considered as an adjunct or alternative to autopsy. What is New: • We present the Dutch guidelines for post-mortem radiology in foetuses, neonates and children. • Autopsy remains the reference standard, however minimal invasive autopsy with a skeletal survey, post-mortem computed tomography, or post-mortem magnetic resonance imaging can be complementary thereof.

Postmortem-computed tomography and postmortem-computed tomography-angiography: a focused update

The use of multidetector CT (MDCT) represents a reality routinely used in several forensic institutes, for the numerous advantages that this diagnostic tool can provide; costs are becoming increasingly lower; data acquisition is always faster and once acquired may be revalued at any time. However, there are also some diagnostic limitations, for example, the visualization of the vascular system or a limited soft tissue contrast. In order to overcome these limitations, in recent years, contrast medium has been introduced in postmortem cases, with the development of several techniques of PMCT angiography (PMCTA) and standardized protocols to make them easily reproducible. The aim of this review is to highlight the advantages and pitfalls of PMCT and PMCTA in forensic investigation, taking into consideration the broad spectrum of applications both for natural and unnatural deaths and the numerous methods currently used. Secondly, in the light of the considerable progress in this field and the attempt to develop standardized protocols of PMCTA, the authors aim to evaluate the diagnostic value of PMCTA in comparison both to PMCT and conventional autopsy.

Normal pediatric postmortem CT appearances

Postmortem radiology is a rapidly developing specialty that is increasingly used as an adjunct to or substitute for conventional autopsy. The goal is to find patterns of disease and possibly the cause of death. Postmortem CT images bring to light processes of decomposition most radiologists are unfamiliar with. These postmortem changes, such as the formation of gas and edema, should not be mistaken for pathological processes that occur in living persons. In this review we discuss the normal postmortem thoraco-abdominal changes and how these appear on CT images, as well as how to differentiate these findings from those of pathological processes.

Imaging for homicide investigations

The authors present the opportunities of the application of post-mortem imaging, focusing on post-mortem computed tomography and post-mortem computed tomography angiography in modern forensic investigation of homicide cases. The paper is based on scientific publications related to the subject from ca. the past 10 years, supplemented by the authors' own experiences. The article is illustrated with reconstructions based on the authors' own cases related to homicide due to ballistic/sharp/blunt trauma. As is shown, the results of evaluation of post-mortem computed tomography allow better diagnosis, documentation and visualisation of forensic examinations.

Normal cranial postmortem CT findings in children

INTRODUCTION

Postmortem imaging (both CT and MRI) has become a widely used tool the last few years, both for adults and children. If it would be known which findings are normal postmortem changes, interpretation of abnormal findings becomes less ambiguous. Our aim was to describe postmortem intracranial radiological findings on postmortem CT (PMCT) in children, which did not have a relationship with the cause of death, and to determine whether these findings have a relationship with the postmortem interval or with medical interventions.

MATERIALS AND METHODS

We selected all consecutive pediatric autopsies that were performed at the Netherlands Forensic Institute in the period 1-1-2008 to 31-12-2011, whereby the subject underwent total body PMCT. We collected data on age at death, gender, cause of death determined by forensic autopsy and time between death and PMCT. Normal findings that were scored were: gray-white differentiation of the brain, collapse of the ventricles, air in the orbit, fluid accumulation in the frontal and maxillary sinuses, and air in vessels of head and neck.

RESULTS

One-hundred-fifty-nine forensic pediatric autopsies were performed in the 4 year study period at the NFI; 77 underwent a total body PMCT, of which 68 were included in the analyses. Fluid accumulation in the sinuses was present 30-40% of the cases in which the sinuses were developed. In 22% of all children intravascular intracranial air, either arterial or venous, was detected. We did not find a relationship between the duration of the postmortem interval and the appearance of any of the findings. Intravenous infusion is not significantly associated with the presence of intravascular air, except for air in the left and right common carotid artery (B=2.9, P=0.05).

CONCLUSIONS

By demonstrating the intracranial abnormalities that appear postmortem, we have tried to provide more insight in the range of findings that can be seen with pediatric PMCT. As these findings resemble antemortem pathology, it is important that the radiologist who interprets PMCT has knowledge of these normal postmortem findings.

Postmortem CT compared to autopsy in children; concordance in a forensic setting

OBJECTIVES

The aim of this study is to assess the accuracy of postmortem CT (PMCT) in determining the cause of death in children who underwent a forensic autopsy because of a suspected nonnatural death.

METHODS

We selected forensic pediatric autopsies at the Netherlands Forensic Institute, whereby the subject underwent PMCT between 1-1-2008 and 31-12-2012. Cause of death was independently scored by a radiologist and a pathologist. Cause of death was classified (1) in categories being natural, unnatural, and unknown; (2) according to the ICD-10; and (3) according to institutional classification.

RESULTS

In the study period, 189 pediatric forensic autopsies were performed. Fifteen were excluded because of putrefaction. Of the remaining 174 autopsies, 98 (56%) underwent PMCT. PMCT and autopsy identified the same category in 69/98 cases (70%, kappa 0.49). They identified the same cause of death in 66/98 cases (67%, kappa 0.5) using ICD-10; in 71/98 (72%, kappa 0.62) using a forensic classification. PMCT performed better in unnatural deaths (59-67 % agreement) than in natural deaths (0 % agreement). If no cause of death was detected with autopsy, PMCT failed to identify a cause of death in 98% (39/40).

CONCLUSIONS

Pediatric PMCT does identify the majority of unnatural causes of death, but does not identify new diagnoses (true positives) if no cause of death is found during autopsy. Diagnostic accuracy in natural deaths is low.

KEY POINTS

• The case mix is an important predictor for the concordance between PMCT and autopsy. • In case of an unnatural death, 72--81% of PMCT results matches autopsy results. • In case of a natural death, 0% of PMCT results matches autopsy results. • If no cause of death is identified with autopsy, 98% of PMCT results concurs.