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

VIRTual autOPSY-applying CT and MRI for modern forensic death investigations

Virtual autopsy, an advanced forensic technique, utilizes cutting-edge imaging technologies such as computed tomography (CT) and magnetic resonance imaging (MRI) to investigate the cause and manner of death without the need for physical dissection. By creating detailed, three-dimensional data of the entire body or specific areas of interest, these post-mortem imaging modalities provide a comprehensive, non-invasive approach to examining decedents. This article explores the historical development of virtual autopsy, its current applications in forensic medicine, and its promising future. It highlights the crucial roles of CT and MRI in forensic death investigations, while also addressing the challenges and limitations associated with these imaging techniques in post-mortem examinations.

The current state of forensic imaging - post mortem imaging

Over the last few decades, forensic imaging has become an essential part of current forensic practice. The aim of this 4-part review is to provide a comprehensive overview of forensic imaging over the first 25 years of this century. After a brief historic review, this first part details the advantages and limitations of post-mortem imaging for the indications most frequently encountered in daily practice.

Post-Mortem Imaging to Investigate the Causes of Stillbirth in Australia: Views of Parents, Midwives and Obstetricians

INTRODUCTION

There is increasing interest regarding the role and value of post-mortem imaging in identifying the causes of stillbirth. We sought to understand the experiences of parents and the perceptions and practices of midwives and obstetricians regarding post-mortem imaging (computed tomography [CT], magnetic resonance imaging [MRI], ultrasound and X-rays of the baby), in the investigation of stillbirths, and how its use and perceived value compares to that of other stillbirth investigations.

METHODS

Cross-sectional, web-based surveys of parents who experienced stillbirth in Australia from 2018 to 2022 and midwives and obstetricians involved in the care of parents who experienced stillbirth in the same 5 years. Data were analysed descriptively.

RESULTS

Data from 68 parents and 94 midwives and obstetricians were included. According to parents, post-mortem imaging (CT, MRI, ultrasound and X-ray) were the least discussed (1%-16%) and performed (0%-13%) stillbirth investigations. Twenty-eight percent of midwives and obstetricians had recommended the option of post-mortem imaging to parents, while 45% felt that doing so was beyond their scope of practice. Relative to autopsy, midwives and obstetricians were often unsure of the value of MRI across a range of clinical scenarios, and CT, MRI, ultrasound and X-ray were the investigations least often discussed (17%-47%) with parents.

CONCLUSIONS

Post-mortem imaging is currently underutilised in the investigation of stillbirths. Education and training are needed to enhance maternity care professionals' awareness of the role and value of imaging for identifying the causes of stillbirths, and how best to discuss these investigations with families.

The current state of forensic imaging - recommended radiological tools and international guidelines

The last few decades have seen the emergence of forensic imaging, both clinical and post-mortem. Year after year, the scientific community has refined the radiological tools that can be used for post-mortem and clinical forensic purposes. As a result, scientific societies have published recommendations that are essential for the daily work of forensic imaging. This third part of the review of the current state of forensic imaging describes these recommended radiological tools and also presents an overview of the various international guidelines dealing with post mortem imaging that can be found in the literature or that have been written by scientific societies.

The Current Status of Virtual Autopsy Using Combined Imaging Modalities: A Scoping Review

Background/Objectives: Virtual autopsy (virtopsy) is a new domain of research for interdisciplinary teams of radiologists and forensic specialists. This scoping review aims to underline the current state-of-the-art research using combined imaging modalities. Methods: We searched the PubMed database using the term virtopsy for articles that are available in free full text, indexed in the Medline Database, and published in English. The query returned 49 articles on this subject that have been published since 2002. Results: The main imaging modalities used for postmortem imaging were computed tomography (PMCT), angiography (PMCTA), magnetic resonance imaging (PMMRI), and ultrasonography (PMUS). PMCT is highly effective for detecting complex osseous injuries, tracing bullet trajectories, or identifying characteristic findings in drowning cases. PMCTA is valuable for evaluating vascular lesions, particularly in natural death cases. PMMRI is superior in analyzing soft tissues, including brain and spinal structures, cerebrospinal fluid, microbleeds, and laryngohyoid lesions, and identifying cardiomyopathies in young individuals. PMUS serves as an alternative, and its portability also allows for use in forensic settings. One specific situation observed was the increased number of studies published about virtopsy during the COVID-19 pandemic. Another aspect is the increased focus on this alternative to conventional autopsy in the regions where maneuvering of the deceased is limited according to cultural and social customs. Conclusions: We underline the advantages and limitations of each imaging modality used for virtopsy. Further studies need to be developed in order to gather supplementary data regarding the use of these imaging modalities in the new era of artificial intelligence in medicine.

Post-mortem radiology in fetal and neonatal death: the diagnostic value of post-mortem MRI versus autopsy regarding non-cardiac thoracic and abdominal abnormalities

AIM

To compare the diagnostic value and accuracy of post-mortem magnetic resonance imaging (PMMRI) and autopsy for non-cardiac thoracic and abdominal abnormalities in fetal death.

MATERIALS AND METHODS

This single-institution retrospective study included all consecutive cases of fetal and perinatal death between January 2015 and December 2021 for which PMMRI followed by autopsy was conducted. These cases comprised fetuses at >18 weeks of gestation and preterm and term neonates who lived for <24 h. All PMMRI and autopsy reports were re-assessed and scored for seven non-cardiac thoracic and 52 abdominal abnormalities, and concordance between autopsy and PMMRI findings was determined as the primary outcome.

RESULTS

Eighty cases were included in this study. Fetal loss was caused by termination of pregnancy in 80% of cases. Further, the mean gestational age was 166 days (23 weeks and 5 days, range 126-283 days). The concordance between PMMRI and autopsy for non-cardiac thoracic and abdominal abnormalities was 83.1% (95% confidence interval [CI] 71.3-83.3) and 76.3% (95% CI 65.8-84.2%), respectively, with a substantial and moderate strength of agreement (Cohen's kappa = 0.63 and 0.51 respectively).

CONCLUSION

PMMRI exhibited good overall diagnostic value for non-cardiac thoracic and abdominal abnormalities, specifically large structural abnormalities. PMMRI may offer parents and physicians a valuable addition to autopsy for the detection of non-cardiac thoracic and abdominal abnormalities, or even an alternative option when parents do not consent to autopsy.

Forensic post-mortem CT in children

Post-mortem computed tomography (PMCT) imaging is gaining popularity and acceptance for use alongside forensic autopsies of children, predominantly to aid in the detection of traumatic injuries. Recent research on this topic has provided a breadth of new information regarding the appropriate usage, imaging guidance, and diagnostic accuracy for the identification of different paediatric pathologies. Additionally, advanced CT imaging techniques, such as PMCT angiography or ventilated PMCT, have been trialled, and post-mortem micro-CT is now being used in specialist centres for the assessment of subtle fractures in extracted bone specimens. Various image post-processing methods (e.g., three-dimensional printing from PMCT imaging data) are being used for the illustration of injuries in the medicolegal setting to a lay audience and provide another avenue for the future of forensic radiology research. In this review, the evidence-based principles and benefits of post-mortem imaging for forensic investigation in childhood deaths are presented, with a particular focus on PMCT and current practices. Variations in forensic imaging strategies around the world, published diagnostic accuracy rates, and expected normal post-mortem imaging findings are discussed, as well as potential future applications and research in this area.

Current utilization of pediatric postmortem imaging in North America: a questionnaire-based survey

BACKGROUND

Postmortem imaging is used more widely as the number of conventional autopsies has decreased over the last several decades. It is widely accepted in Europe, Asia and Oceania, but there has been a delay in acceptance in North America. Education, scanning protocols, resourcing and clinical incentives are needed to support this emerging field.

OBJECTIVE

To determine the use of postmortem imaging and define perceived barriers to its implementation with the goal of expanding postmortem imaging in the United States and Canada.

MATERIALS AND METHODS

We sent an online survey to active members of the Society for Pediatric Radiology (SPR) addressing the use of postmortem imaging, indications, readers, practical aspects, anticipated barriers and potential solutions to more widespread use.

RESULTS

More than 50% of the 50 institutions that returned surveys used postmortem computed tomography; 24% used postmortem magnetic resonance imaging. Most postmortem imaging cases were read by radiologists. Fewer than 50% had formal correlation with autopsy results or an established relationship with the local medical examiner. Seven institutions reported reimbursement for postmortem imaging. Major barriers to postmortem imaging included lack of funding and lack of interest among clinicians. Funding and education were seen as important issues requiring attention.

CONCLUSION

While most responding institutions provide pediatric postmortem imaging, the modalities, protocols, reporting procedures and clinical correlation vary widely. A lack of funding and few opportunities for education are limiting factors. Attention to these issues along with active support from the SPR are seen as potential solutions to recognize the value and promote widespread acceptance of postmortem imaging.

Current and future funding streams for paediatric postmortem imaging: European Society of Paediatric Radiology survey results

BACKGROUND

Perinatal and childhood postmortem imaging has been accepted as a noninvasive alternative or adjunct to autopsy. However, the variation in funding models from institution to institution is a major factor prohibiting uniform provision of this service.

OBJECTIVE

To describe current funding models employed in European and non-European institutions offering paediatric postmortem imaging services and to discuss the perceived barriers to future postmortem imaging service provision.

MATERIALS AND METHODS

A web-based 16-question survey was distributed to members of the European Society of Paediatric Radiology (ESPR) and ESPR postmortem imaging task force over a 6-month period (March-August 2021). Survey questions related to the radiologic and autopsy services being offered and how each was funded within the respondent's institute.

RESULTS

Eighteen individual responses were received (13/18, 72.2% from Europe). Only one-third of the institutions (6/18, 33.3%) have fully funded postmortem imaging services, with the remainder receiving partial (6/18, 33.3%) or no funding (5/18, 27.8%). Funding (full or partial) was more commonly available for forensic work (13/18, 72%), particularly where this was nationally provided. Where funding was not provided, the imaging and reporting costs were absorbed by the institute.

CONCLUSION

Increased access is required for the expansion of postmortem imaging into routine clinical use. This can only be achieved with formal funding on a national level, potentially through health care commissioning and acknowledgement by health care policy makers and pathology services of the value the service provides following the death of a fetus or child. Funding should include the costs involved in training, equipment, reporting and image acquisition.

Fetal Brain Tumors, a Challenge in Prenatal Diagnosis, Counselling, and Therapy

Fetal brain tumors are a rare entity with an overall guarded prognosis. About 10% of congenital brain tumors are diagnosed during fetal life. They differ from the postnatally encountered pediatric brain tumors with respect to location and tumor type. Fetal brain tumors can be benign or malignant and infiltrate or displace adjacent brain structures. Due to their high mitotic rate, they can show rapid growth. Outcome depends on age of diagnosis, size, and histological tumor type. Findings like polyhydramnios and macrocephaly encountered on routine ultrasound are frequently associated. Detailed prenatal anomaly scan and subsequent fetal magnetic resonance imaging (MRI) may identify the brain tumor and its severity. Both maternal and fetal prognosis should be included in prenatal counselling and decision making.

The Practicality of Post-mortem Imaging in Prenatal, Perinatal, and Pediatric Cases

The essential role of the autopsy is seen in its contributions to medical care, scientific research, and family counseling. Major contributions are also noted in forensic pathology as a means to determine cause-of-death for legal and medical experts. However, autopsy acceptance rates are quite low due to an array of reasons including delayed burials, faith, and moral burdening. Thus, non-invasive post-mortem imaging strategies are becoming increasingly popular. The objective of this literature review is to evaluate the strengths and weaknesses of numerous post-mortem imaging modalities and consider their benefits over the traditional autopsy. The need for expertise in image interpretation for pediatric and perinatal cases is also discussed. A variety of publications, totaling 32 pieces, were selected from available literature on the basis of relevance. These articles studied various perinatal and pediatric post-mortem imaging strategies and their applications in clinical practice. Key strategies include post-mortem MRI, post-mortem CT, fetal post-mortem sonography, post-mortem computed tomographic angiography, and three-dimensional surface scanning. There is a general consensus that no standard model for post-mortem imaging currently exists in the United States and European countries. Amongst the imaging modems studied, post-mortem MRI has been acknowledged to show the greatest promise in diagnostic accuracy for fetal age groups. Most studies demonstrated that post-mortem CT had limited use for autopsy. Post-mortem imaging strategies for autopsy have high potential given their minimal invasiveness and increasing popularity. Furthermore, it is vital to crafting a global standard procedure for post-mortem imaging for prenatal, perinatal, and pediatric cases to better understand the cause of death, decomposition factors, and effects in-utero, and to provide an alternative to traditional autopsy.

Accuracy and clinical utility of standard postmortem radiological imaging after early second trimester termination of pregnancy

OBJECTIVE

This study aims to assess accuracy and clinical utility of postmortem radiological exams [Magnetic Resonance Imaging (MRI), Computed Tomography (CT) and Radiography (XR)] after termination of pregnancy at <23 weeks' gestation for congenital fetal malformations in comparison to autopsy.

STUDY DESIGN

This a prospective single-center study on fetuses underwent termination of pregnancy for fetal defects. Overall concordance between any radiological exam and autopsy was evaluated. For postmortem MRI only, the following subgroups were analyzed: 1) total agreement; 2) agreement for main findings; 3) agreement for main findings but major relevant additional findings at autopsy; 4) total disagreement.

RESULTS

174 cases were collected. The overall concordance with autopsy for main findings was 71% (115/163) for postmortem MRI and 99% (173/174) for prenatal ultrasound (US). Postmortem MRI detection rate was high for central nervous system (CNS) defects (98%), gastrointestinal, genitourinary and respiratory defects (100%), while it was poor for cardiovascular and musculoskeletal defects (25% and 42%, respectively). For musculoskeletal abnormalities, the performance of postmortem XR and postmortem CT exams improved the detection rate from 42% for postmortem MRI alone to 92%.

CONCLUSIONS

Postmortem MRI has a good overall concordance for fetal defects after termination of pregnancy performed at <23 weeks. Along with autopsy, postmortem MRI may be offered for all cases of CNS defects in order to prevent inconclusive exams due to autolysis of the brain tissue, while postmortem CT and postmortem XR are indicated for musculoskeletal defects. In the presence of multiple abnormalities or cardiac defects the couple should be counseled on the poor performance of radiological investigations.

Post-mortem perinatal imaging: what is the evidence?

Post-mortem imaging for the investigation of perinatal deaths is an acceptable tool amongst parents and religious groups, enabling a less invasive autopsy examination. Nevertheless, availability is scarce nationwide, and there is some debate amongst radiologists regarding the best practice and optimal protocols for performing such studies. Much of the published literature to date focusses on single centre experiences or interesting case reports. Diagnostic accuracy studies are available for a variety of individual imaging modalities (e.g. post-mortem CT, MRI, ultrasound and micro-CT), however, assimilating this information is important when attempting to start a local service.In this article, we present a comprehensive review summarising the latest research, recently published international guidelines, and describe which imaging modalities are best suited for specific indications. When the antenatal clinical findings are not supported by the post-mortem imaging, we also suggest how and when an invasive autopsy may be considered. In general, a collaborative working relationship within a multidisciplinary team (consisting of radiologists, radiographers, the local pathology department, mortuary staff, foetal medicine specialists, obstetricians and bereavement midwives) is vital for a successful service.

Virtual segmentation of three-dimensional ultrasound images of morphological structures of an ex vivo ectopic pregnancy inside a fallopian tube

Ex vivo ultrasound (US) of human tissues has been used for decades on the study of the acoustic physical aspects of the US, to the study of the morphology of the organs. Using three-dimensional (3D) US, we demonstrate the possibilities to study surgical specimens from gynecological conditions. 3D images of the surgical specimen were collected and virtually segmented according to the contrast of its images, providing a 3D image of the ectopic pregnancy and its effects on the fallopian tube.

Diagnostic assessment of traumatic brain injury by vacuum extraction in newborns: overview on forensic perspectives and proposal of operating procedures

BACKGROUND

Traumatic brain injury (TBI) during birth constitutes one of the most relevant causes of mortality and morbidity in newborns worldwide. Although improvements in obstetrical management and better indications for caesarean section have led to a consistent decrease in the incidence of perinatal mechanical injury, vacuum extraction is still associated with a high complications rate leading to several forensic issues in the evaluation of healthcare professional management.

METHODS

Vacuum-associated lesions may be topographically distinguished as extracranial or intracranial injuries. In order to achieve a correct assessment, diagnostic procedure should include post-mortem computed tomography and magnetic resonance imaging, autopsy examination, brain sampling and histological/immunohistochemical examination.

RESULTS

Post-mortem imaging represents a valid aid to guarantee preliminary evidence and direct subsequent investigations. An appropriate autopsy sampling must include several areas of cortex and underlying white matter; moreover, any visceral hemorrhages or other lesions should be sampled for the histological and immunohistochemical assessment of vitality and timing.

CONCLUSIONS

This study aimed to promote a validated step-by-step procedure to be adopted in order to standardize and to make easier the post-mortem framing and timing of vacuum-associated pediatric brain injuries.

High prevalence of non-accidental trauma among deceased children presenting at Level I trauma centers in the Netherlands

Purpose

Between 0.1—3% of injured children who present at a hospital emergency department ultimately die as a result of their injuries. These events are typically reported as unnatural causes of death and may result from either accidental or non-accidental trauma (NAT). Examples of the latter include trauma that is inflicted directly or resulting from neglect. Although consultation with a forensic physician is mandatory for all deceased children, the prevalence of fatal inflicted trauma or neglect among children is currently unclear.

Methods

This is a retrospective study that included children (0–18 years) who presented and died at one of the 11 Level I trauma centers in the Netherlands between January 1, 2014, and January 1, 2019. Outcomes were classified based on the conclusions of the Child Abuse and Neglect team or those of forensic pathologists and/or the court in cases referred for legally mandated autopsies. Cases in which conclusions were unavailable and there was no clear accidental cause of death were reviewed by an expert panel.

Results

The study included 175 cases of childhood death. Seventeen (9.7%) of these children died due to inflicted trauma (9.7%), 18 (10.3%) due to neglect, and 140 (80%) due to accidents. Preschool children (< 5 years old) were significantly more likely to present with injuries due to inflicted trauma and neglect compared to older children (44% versus 6%, p < 0.001, odds ratio [OR] 5.80, 95% confidence interval [CI] 2.66–12.65). Drowning accounted for 14 of the 18 (78%) pediatric deaths due to neglect, representing 8% of the total cases. Postmortem radiological studies and autopsies were performed on 37 (21%) of all cases of childhood death.

Conclusion

One of every five pediatric deaths in our nationwide Level I trauma center study was attributed to NAT; 44% of these deaths were the result of trauma experienced by preschool-aged children. A remarkable number of fatal drownings were due to neglect. Postmortem radiological studies and autopsies were performed in only one-fifth of all deceased children. The limited use of postmortem investigations may have resulted in missed cases of NAT, which will result in an overall underestimation of fatal NAT experienced by children.

Supplementary information

The online version contains supplementary material available at 10.1007/s12024-021-00416-7.

Micro-CT yields high image quality in human fetal post-mortem imaging despite maceration

BACKGROUND

Current clinical post-mortem imaging techniques do not provide sufficiently high-resolution imaging for smaller fetuses after pregnancy loss. Post-mortem micro-CT is a non-invasive technique that can deliver high diagnostic accuracy for these smaller fetuses. The purpose of the study is to identify the main predictors of image quality for human fetal post-mortem micro-CT imaging.

METHODS

Human fetuses were imaged using micro-CT following potassium tri-iodide tissue preparation, and axial head and chest views were assessed for image quality on a Likert scale by two blinded radiologists. Simple and multivariable linear regression models were performed with demographic details, iodination, tissue maceration score and imaging parameters as predictor variables.

RESULTS

258 fetuses were assessed, with median weight 41.7 g (2.6-350 g) and mean gestational age 16 weeks (11-24 weeks). A high image quality score (> 6.5) was achieved in 95% of micro-CT studies, higher for the head (median = 9) than chest (median = 8.5) imaging. The strongest negative predictors of image quality were increasing maceration and body weight (p < 0.001), with number of projections being the best positive imaging predictor.

CONCLUSIONS

High micro-CT image quality score is achievable following early pregnancy loss despite fetal maceration, particularly in smaller fetuses where conventional autopsy may be particularly challenging. These findings will help establish clinical micro-CT imaging services, addressing the need for less invasive fetal autopsy methods.

Differences in Postmortem Investigation Following Perinatal Death

OBJECTIVE

 The study aimed to describe the postmortem investigation patterns for perinatal deaths and compare the degree of investigation between stillbirths and early neonatal deaths.

STUDY DESIGN

 We conducted a single-center retrospective review of all perinatal deaths from 2011 to 2017. Perinatal death was defined as intrauterine fetal death at ≥20 weeks' gestation, plus neonatal deaths within the first 7 days of life. Rates of postmortem investigation were compared.

RESULTS

 There were 97 perinatal deaths, with 54 stillbirths (56%) and 43 neonatal deaths (44%). Stillbirths were significantly more likely to receive autopsy (p = 0.013) and postmortem genetic testing (p = 0.0004) when compared with neonatal deaths. Maternal testing was also more likely in stillbirths than neonatal deaths. A total of 32 deaths (33%) had no postmortem evaluation beyond placental pathology.

CONCLUSION

 Investigation following perinatal death is more likely in stillbirths than neonatal deaths. Methods to improve postmortem investigation following perinatal death are needed, particularly for neonatal deaths.

KEY POINTS

· Investigation into perinatal death is recommended.. · Rates of investigation remain low.. · Neonatal deaths with less investigation than stillbirths..

Human fetal whole-body postmortem microfocus computed tomographic imaging

Perinatal autopsy is the standard method for investigating fetal death; however, it requires dissection of the fetus. Human fetal microfocus computed tomography (micro-CT) provides a generally more acceptable and less invasive imaging alternative for bereaved parents to determine the cause of early pregnancy loss compared with conventional autopsy techniques. In this protocol, we describe the four main stages required to image fetuses using micro-CT. Preparation of the fetus includes staining with the contrast agent potassium triiodide and takes 3-19 d, depending on the size of the fetus and the time taken to obtain consent for the procedure. Setup for imaging requires appropriate positioning of the fetus and takes 1 h. The actual imaging takes, on average, 2 h 40 min and involves initial test scans followed by high-definition diagnostic scans. Postimaging, 3 d are required to postprocess the fetus, including removal of the stain, and also to undertake artifact recognition and data transfer. This procedure produces high-resolution isotropic datasets, allowing for radio-pathological interpretations to be made and long-term digital archiving for re-review and data sharing, where required. The protocol can be undertaken following appropriate training, which includes both the use of micro-CT techniques and handling of postmortem tissue.

Current state of perinatal postmortem magnetic resonance imaging: European Society of Paediatric Radiology questionnaire-based survey and recommendations

BACKGROUND

Postmortem magnetic resonance imaging (MRI) in perinatal and childhood deaths is increasingly used as a noninvasive adjunct or alternative to autopsy. Imaging protocols vary between centres and consensus guidelines do not exist.

OBJECTIVE

Our aim was to develop practical, standardised recommendations for perinatal postmortem MRI.

MATERIALS AND METHODS

Recommendations were based on the results of two surveys regarding local postmortem MRI practices sent electronically to all 14 members of the European Society of Paediatric Radiology (ESPR) Postmortem Imaging Task Force and 17 members of the International Society of Forensic Radiology and Imaging Task Force (25 different centres).

RESULTS

Overall, 11/14 (78.6%) respondents from different institutions perform postmortem MRI. All of these centres perform postmortem MRI for perinatal and neonatal deaths, but only 6/11 (54.5%) perform imaging in older children.

CONCLUSION

We propose a clinical standard for postmortem MRI sequences plus optional sequences for neuroimaging and cardiac anatomy depending on available scanning time and referral indications.

Clinical Application of Postmortem Magnetic Resonance Imaging in Neonates

BACKGROUND

Recent reports advocate the use of MRI either as a substitute for postmortem examinations or for a more targeted autopsy.

METHODS

A full-body postmortem MRI (pMRI) of infants was performed as early as possible after death, and findings were compared to clinical premortem diagnoses.

RESULTS

Thirty-one infants were scanned during the study period. Median gestation at birth was 34 weeks (ranges: 24-43). In 3 (10%) cases, no new findings were detected. In 2 (6%), new minor findings not related to the cause of death were detected, and in 17 (55%), new minor findings related to the cause of death were detected. New major findings related to the cause of death were detected in 4 (13%) cases, and new major findings not related to the cause of death were detected in 5 (16%) cases. In 3 (10%), findings thought to alter the perceived cause of death were detected. Overall, in 23 (74%) cases, pMRI findings reinforced the clinical premortem diagnoses.

CONCLUSIONS

pMRI is a culturally accepted alternative when autopsy is not performed and can either reinforce, refute, or add to premortem clinical diagnoses.

Fetal postmortem imaging: an overview of current techniques and future perspectives

Fetal death because of miscarriage, unexpected intrauterine fetal demise, or termination of pregnancy is a traumatic event for any family. Despite advances in prenatal imaging and genetic diagnosis, conventional autopsy remains the gold standard because it can provide additional information not available during fetal life in up to 40% of cases and this by itself may change the recurrence risk and hence future counseling for parents. However, conventional autopsy is negatively affected by procedures involving long reporting times because the fetal brain is prone to the effect of autolysis, which may result in suboptimal examinations, particularly of the central nervous system. More importantly, fewer than 50%-60% of parents consent to invasive autopsy, mainly owing to the concerns about body disfigurement. Consequently, this has led to the development of noninvasive perinatal virtual autopsy using imaging techniques. Because a significant component of conventional autopsy involves the anatomic examination of organs, imaging techniques such as magnetic resonance imaging, ultrasound, and computed tomography are possible alternatives. With a parental acceptance rate of nearly 100%, imaging techniques as part of postmortem examination have become widely used in recent years in some countries. Postmortem magnetic resonance imaging using 1.5-Tesla magnets is the most studied technique and offers an overall diagnostic accuracy of 77%-94%. It is probably the best choice as a virtual autopsy technique for fetuses >20 weeks' gestation. However, for fetuses <20 weeks' gestation, its performance is poor. The use of higher magnetic resonance imaging magnetic fields such as 3-Tesla may slightly improve performance. Of note, in cases of fetal maceration, magnetic resonance imaging may offer diagnoses in a proportion of brain lesions wherein conventional autopsy fails. Postmortem ultrasound examination using a high-frequency probe offers overall sensitivity and specificity of 67%-77% and 74%-90%, respectively, with the advantage of easy access and affordability. The main difference between postmortem ultrasound and magnetic resonance imaging relates to their respective abilities to obtain images of sufficient quality for a confident diagnosis. The nondiagnostic rate using postmortem ultrasound ranges from 17% to 30%, depending on the organ examined, whereas the nondiagnostic rate using postmortem magnetic resonance imaging in most situations is far less than 10%. For fetuses ≤20 weeks' gestation, microfocus computed tomography achieves close to 100% agreement with autopsy and is likely to be the technique of the future in this subgroup. The lack of histology has always been listed as 1 limitation of all postmortem imaging techniques. Image-guided needle tissue biopsy coupled with any postmortem imaging can overcome this limitation. In addition to describing the diagnostic accuracy and limitations of each imaging technology, we propose a novel, stepwise diagnostic approach and describe the possible application of these techniques in clinical practice as an alternative or an adjunct or for triage to select cases that would specifically benefit from invasive examination, with the aim of reducing parental distress and pathologist workload. The widespread use of postmortem fetal imaging is inevitable, meaning that hurdles such as specialized training and dedicated financing must be overcome to improve access to these newer, well-validated techniques.

Utility of unenhanced postmortem computed tomography for investigation of in-hospital nontraumatic death in children up to 3 years of age at a single Japanese tertiary care hospital

To evaluate the utility of unenhanced postmortem computed tomography (PMCT) for the investigation of in-hospital nontraumatic death in children up to 3 years of age.This study included the cadavers of children who died from intrinsic diseases before 3 years of age. The major underlying disease and the main organ-disease systems associated with the immediate causes of death were determined by clinical evaluation, PMCT, and autopsy, which were used as a reference standard. The rates of concordance between the former two methods and autopsy were calculated for all cases.In total, 22 cadavers (12 male and 10 female; mean age, 6.1 ± 8.2 months) were included. The rates of concordance between clinical evaluation/PMCT and autopsy for diagnosis of the major underlying disease and main organ-disease systems associated with the immediate causes of death were 100%/36% (P = .0015) and 59%/41% (P = .37), respectively. In cases where the respiratory system was associated with the immediate cause of death, PMCT showed greater diagnostic sensitivity (90%) than did clinical evaluation (20%). In contrast, the diagnostic sensitivity of PMCT was lower than that of clinical evaluation in cases involving disorders of the cardiac system and multiple organ systems (0% vs 100% for both).The findings of this study suggest that the use of unenhanced PMCT with clinical evaluation can result in improved detection of the immediate cause of death in select cases of in-hospital nontraumatic death before 3 years of age.

Latest developments in post-mortem foetal imaging

A sustained decline in parental consent rates for perinatal autopsies has driven the development of less-invasive methods for death investigation. A wide variety of imaging modalities have been developed for this purpose and include post-mortem whole body magnetic resonance imaging (MRI), ultrasound, computed tomography (CT) and micro-focus CT techniques. These are also vital for "minimally invasive" methods, which include potential for tissue sampling, such as image guidance for targeted biopsies and laparoscopic-assisted techniques. In this article, we address the range of imaging techniques currently in clinical practice and those under development. Significant advances in high-field MRI and micro-focus CT imaging show particular promise for smaller and earlier gestation foetuses. We also review how MRI biomarkers such as diffusion-weighted imaging and organ volumetric analysis may aid diagnosis and image interpretation in the absence of autopsy data. Three-dimensional printing and augmented reality may help make imaging findings more accessible to parents, colleagues and trainees.

Comparing dental identifier charting in cone beam computed tomography scans and panoramic radiographs using INTERPOL coding for human identification

According to INTERPOL, the comparison of antemortem and postmortem dental identifiers is a scientifically reliable approach for human identification. This study aimed to quantify the prevalence of corresponding INTERPOL coded dental identifiers in cone beam computed tomography (CBCT) scans and panoramic radiographs (PR). The sample consisted of 100 CBCT scans and 100 PR taken the same day from the same patients (35 males and 65 females). Randomly and independently, forty-one INTERPOL coded dental identifiers were searched in each image. Wilcoxon test compared the prevalence of codes in CBCT scans and PR, Chi-square tested the dependence between codes and teeth; and multiple correspondence analyses (MCA) explored the association between codes and teeth in color maps for CBCT scans and PR. No statistically significant differences between the prevalence of identifiers in CBCT scans and PR were detected (p=0.693). In CBCT scans and PR, dependence between teeth and codes was detected (p<0.05). In the study sample, the strongest associations were found between the codes unerupted (UNE), partially erupted (ERU) and impacted (IMV) and third molars, both in CBCT scans and PR. INTERPOL coded dental identifiers registered on CBCT scans and PR can be exchanged during human identification.

Diagnostic Accuracy of Postmortem CT of Children: A Retrospective Single-Center Study

OBJECTIVE. The objective of our study was to determine the diagnostic accuracy of postmortem CT in children compared with standard autopsy. MATERIALS AND METHODS. This single-center retrospective study reviewed un-enhanced whole-body postmortem CT examinations of children less than 16 years old with corresponding autopsy reports irrespective of the clinical indication for referral for postmortem CT. Perinatal deaths were excluded. Postmortem CT was reported by experienced postmortem radiologists who were blinded to autopsy findings, with the primary outcome being concordance for the main pathologic diagnosis or findings leading to a cause of death. Autopsy performed by pediatric pathologists was the reference standard. RESULTS. One hundred thirty-six patients (74 [54.4%] male and 62 [45.6%] female patients) were included. The mean age of the 136 patients was 2 years 1 month (range, 2 days-14.7 years). A cause of death at autopsy was found for 77 of the 136 (56.6%) patients. Postmortem CT depicted a correct cause of death in 55 of 77 (71.4%) patients; (55/136 overall [40.4%]), with the majority attributable to traumatic brain or body injuries. For major pathologic findings, diagnostic accuracy rates were a sensitivity of 71.4% (95% CI, 60.5-80.3%), specificity of 81.4% (95% CI, 69.6-89.3%), positive predictive value of 83.3% (95% CI, 72.6-90.4%), negative predictive value of 68.6% (95% CI, 57.0-78.2%), and concordance rate of 75.7% (95% CI, 67.9-82.2%). The sensitivity of postmortem CT versus autopsy was highest for intracranial (75.6%; 95% CI, 60.7-86.2%) and musculoskeletal (98.4%; 95% CI, 91.4-99.7%) abnormalities and lowest for cardiac (31.3%; 95% CI, 14.2-55.6%) and abdominal (53.8%; 95% CI, 29.1-78.6%) findings. CONCLUSION. Postmortem CT gives an acceptable diagnostic concordance rate with autopsy of 71.4%, although identification of the cause of death overall was low at 40.4%. The highest accuracy rates were for intracranial and musculoskeletal abnormalities.

Joint European Society of Paediatric Radiology (ESPR) and International Society for Forensic Radiology and Imaging (ISFRI) guidelines: paediatric postmortem computed tomography imaging protocol

Postmortem CT for investigating childhood deaths is increasingly utilised as a noninvasive adjunct or alternative to standard autopsy; however there are no standardised published imaging protocols. This article describes a standardised imaging protocol that has been developed based on current practices of international postmortem imaging practitioners and experts. This recommendation is expected to be useful for postmortem imaging centres wishing to update their existing practices and for those starting paediatric postmortem CT as a new service.