Post-mortem MRI as an alternative to non-forensic autopsy in foetuses and children: from research into clinical practice

MRI changes observed in a case of atypical scrapie in a 7-year-old Herdwick ewe

Atypical scrapie is a transmissible spongiform encephalopathy that is rarely diagnosed in living animals. In March 2022, a 7-y-old Herdwick ewe was referred to the Scottish Centre for Production Animal Health and Food Safety because of circling behavior and ill thrift. The ewe had a low body condition score, was obtunded, with a wide-based stance of the pelvic limbs, and was circling to the left. Hematologic, biochemical, and CSF analyses were unremarkable, but postmortem magnetic resonance imaging (MRI) findings were consistent with diffuse, bilateral, and symmetrical atrophy of the forebrain and ventriculomegaly. The clinical signs, the involvement of an individual older ewe, and the MRI results led to the clinical diagnosis of scrapie. Immunohistochemistry on the fixed brain, performed by the U.K. Animal and Plant Health Agency, revealed deposits of PrPSc, which is a specific disease marker of transmissible spongiform encephalopathies, mainly in the cerebellum and at lower concentrations in the cerebrum and obex, consistent with the diagnosis of atypical scrapie. MRI findings in a sheep with atypical scrapie have not been described previously, to our knowledge. Scrapie should be included in the list of clinical differential diagnoses when veterinarians are presented with sheep with progressive neurologic signs of several weeks' duration.

Imaging of sudden unexpected death in infancy: a comprehensive nationwide French survey

RATIONALE AND OBJECTIVES

Introduction of post-mortem imaging has helped improve sudden unexpected death in infancy (SUDI) management in Europe. French guidelines were issued in 2007 to homogenise SUDI investigations including imaging. The aim of this study was to evaluate current imaging management of SUDI in France.

MATERIAL AND METHODS

Between January 2022 and July 2022, all 35 SUDI French referral centres were invited to answer an e-mailed online survey including 29 questions divided into four different sections covering imaging practices for SUDI including radiology department organisation, imaging modalities performed, methods of reading, and current training resources. Partial responses were secondarily completed by a personal call to the SUDI imaging consultant. The current implementation of the 2007 recommendations was compared with a previous evaluation from 2015 and with current North American practices.

RESULTS

The participation rate of centres performing SUDI imaging was 100% (35/35). Imaging was systematically performed in 94.3% (33/35) of the centres: 74.3% (26/35) using radiography; 5.7% (2/35) using ultrasound; 94.3% (33/35) using computed tomography (CT), including 89% (31/35) whole-body CT and 5.7% (2/35) brain CT; and 20% (7/35) using magnetic resonance imaging (MRI). Two centres (5.7%, 2/35) did not systematically perform brain imaging. One (2.9%, 1/35) used ultrasound-guided biopsy. In comparison with 2015, rates of brain imaging increased by 25.4% (P=0.008). There was no significant difference in the number of forensic MRIs performed between France and North America (P=0.663).

CONCLUSION

Despite improvements since 2015, full compliance with French guidelines for SUDI investigations remains incomplete. The use of imaging, particularly CT and brain imaging, has increased. Further efforts are needed to standardise imaging practices for optimal SUDI investigations.

Added value of postmortem mri in sudden unexpected infant death cases

We aimed to investigate the potential added value of postmortem MRI (PMMRI) in sudden unexpected infant death (SUID) cases referred to our center between September 2020 and June 2023. Ultimately, 19 SUID cases underwent PMMRI alongside standard autopsy procedures, which included technical examinations such as postmortem CT (PMCT). Four radiologists, two with prior PMMRI experience, provided structured reports following consensus. For each case, the responsible forensic medicine specialist documented the cause of death before and after reviewing the PMMRI report. Additionally, they assessed the overall impact of the PMMRI report and had the opportunity to provide written comments. The results of our study indicate that none of the PMMRI reports altered the prior determined cause of death, which included cases of infection, asphyxia, and sudden infant death syndrome (SIDS). However, we observed a moderate impact in one case and a low impact in 10 cases. The moderate impact arose from the PMMRI report identifying hypoxic-ischemic changes, where histologic examination of the brain was perceived as normal. Conversely, in the 10 cases with a low impact, the PMMRI reports supported the autopsy findings, specifically indicating brain injury and intra-alveolar cellular infiltrates. In conclusion, our study suggests that while PMMRI may not be pivotal in determining the cause of death in SUID cases, it could aid in detecting hypoxic-ischemic changes and reinforcing brain and lung observations. However, distinguishing genuine lung pathology from postmortem changes using PMMRI remains challenging. Further research is warranted to clarify the role of PMMRI in forensic SUID investigations.

Body weight-based iodinated contrast immersion timing for human fetal postmortem microfocus computed tomography

Objectives

The aim of this study was to evaluate the length of time required to achieve full iodination using potassium tri-iodide as a contrast agent, prior to human fetal postmortem microfocus computed tomography (micro-CT) imaging.

Methods

Prospective assessment of optimal contrast iodination was conducted across 157 human fetuses (postmortem weight range 2-298 g; gestational age range 12-37 weeks), following micro-CT imaging. Simple linear regression was conducted to analyse which fetal demographic factors could produce the most accurate estimate for optimal iodination time.

Results

Postmortem body weight (r2 = 0.6435) was better correlated with iodination time than gestational age (r2 = 0.1384), producing a line of best fit, y = [0.0304 × body weight (g)] - 2.2103. This can be simplified for clinical use whereby immersion time (days) = [0.03 × body weight (g)] - 2.2. Using this formula, for example, a 100-g fetus would take 5.2 days to reach optimal contrast enhancement.

Conclusions

The simplified equation can now be used to provide estimation times for fetal contrast preparation time prior to micro-CT imaging and can be used to manage service throughput and parental expectation for return of their fetus.

Advances in knowledge

A simple equation from empirical data can now be used to estimate preparation time for human fetal postmortem micro-CT imaging.

Less-invasive autopsy for early pregnancy loss

Autopsy investigations provide valuable information regarding fetal death that can assist in the parental bereavement process, and influence future pregnancies, but conventional autopsy is often declined by parents because of its invasive approach. This has led to the development of less-invasive autopsy investigations based on imaging technology to provide a more accessible and acceptable choice for parents when investigating their loss. Whilst the development and use of more conventional clinical imaging techniques (radiographs, CT, MRI, US) are well described in the literature for fetuses over 20 weeks of gestational age, these investigations have limited diagnostic accuracy in imaging smaller fetuses. Techniques such as ultra-high-field MRI (>3T) and micro-focus computed tomography have been shown to have higher diagnostic accuracy whilst still being acceptable to parents. By further developing and increasing the availability of these more innovative imaging techniques, parents will be provided with a greater choice of acceptable options to investigate their loss, which may in turn increase their uptake. We provide a narrative review focussing on the development of high-resolution, non-invasive imaging techniques to evaluate early gestational pregnancy loss.

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 maceration score on postmortem magnetic resonance imaging vs. conventional autopsy

BACKGROUND

Postmortem fetal magnetic resonance imaging (MRI) has been on the rise since it was proven to be a good alternative to conventional autopsy. Since the fetal brain is sensitive to postmortem changes, extensive tissue fixation is required for macroscopic and microscopic assessment. Estimation of brain maceration on MRI, before autopsy, may optimize histopathological resources.

OBJECTIVE

The aim of the study is to develop an MRI-based postmortem fetal brain maceration score and to correlate it with brain maceration as assessed by autopsy.

MATERIALS AND METHODS

This retrospective single-center study includes 79 fetuses who had postmortem MRI followed by autopsy. Maceration was scored on MRI on a numerical severity scale, based on our brain-specific maceration score and the whole-body score of Montaldo. Additionally, maceration was scored on histopathology with a semiquantitative severity scale. Both the brain-specific and the whole-body maceration imaging scores were correlated with the histopathological maceration score. Intra- and interobserver agreements were tested for the brain-specific maceration score.

RESULTS

The proposed brain-specific maceration score correlates well with fetal brain maceration assessed by autopsy (τ = 0.690), compared to a poorer correlation of the whole-body method (τ = 0.452). The intra- and interobserver agreement was excellent (correlation coefficients of 0.943 and 0.864, respectively).

CONCLUSION

We present a brain-specific postmortem MRI maceration score that correlates well with the degree of fetal brain maceration seen at histopathological exam. The score is reliably reproduced by different observers with different experience.

Postmortem Diffusion-Weighted Magnetic Resonance Imaging of the Brain in Perinatal Death: An Animal Control Study to Detect the Influence of Postmortem Interval

OBJECTIVES

Diffusion-weighted imaging may be useful as part of a postmortem magnetic resonance imaging protocol. However, apart from the effect of temperature on apparent diffusion coefficient (ADC), normal postmortem ADC changes can influence the interpretation. Therefore, this study was conducted to evaluate the correlation between normal ADC changes and postmortem intervals (PMIs) and develop a reference standard for postmortem changes after temperature correction.

MATERIALS AND METHODS

Six premature lambs were scanned at different PMIs. ADC values were measured at different parenchymal locations. Correlation and linear regression between ADC values and PMI were analyzed for all locations, both uncorrected and corrected for temperature.

RESULTS

All locations showed a significant negative correlation between the PMI and ADC value, with (R2 = 0.581-0.837, P < 0.001) and without (R2 = 0.183-0.555, P < 0.001-0.018) temperature correction.

CONCLUSIONS

The postmortem interval is negatively correlated with ADC values in the brain. A correlation coefficient for the PMI can be calculated after temperature correction to predict ADC changes. However, further research is required to evaluate its clinical application in humans.

Postmortem Fetal Temperature Estimation with Magnetic Resonance Imaging: Apparent Diffusion Coefficient Measurements in the Vitreous Body and Cerebrospinal Fluid

OBJECTIVES

Magnetic resonance imaging (MRI) is increasingly used in postmortem fetal imaging. Several factors influence the quality of MRI in this setting, such as small size, autolytic and maceration changes, and temperature. Knowing the fetal temperature at the time of scanning can improve the MRI interpretation. Temperature can be calculated using diffusion-weighted imaging with measurements of the apparent diffusion coefficient (ADC) in the cerebrospinal fluid (CSF). However, this is complicated by small ventricle size and hemorrhage and, therefore, may be unreliable in postmortem imaging. The current study evaluated the feasibility and reliability of using the ADC for temperature measurements of the vitreous body compared to that of CSF.

MATERIALS AND METHODS

Two lambs were scanned postmortem at five different time points over 28 hours. Furthermore, 10 stillborn fetuses were scanned once, at 4 to 62 hours after birth. The temperature was measured with a digital thermometer and calculated using the ADCs of the vitreous body (lambs and fetuses) and CSF (fetuses).

RESULTS

There was an excellent correlation between measured and calculated temperatures in vitreous bodies of lambs (r = 0.997, P < 0.001) and fetuses (r = 0.970, P < 0.001). The correlation between measured and calculated temperatures in the CSF was poor (r = 0.522, P = 0.122).

CONCLUSION

The calculation of the temperature based on the ADC of the vitreous body is feasible and reliable for postmortem fetal imaging.

Sudden Cardiac Death and Ex-Situ Post-Mortem Cardiac Magnetic Resonance Imaging: A Morphological Study Based on Diagnostic Correlation Methodology

During the last years, post-mortem imaging has gradually been assumed within research in the field of forensic pathology. This role appears to be clearly and simply applied in the trauma field with the use of conventional radiography or Post Mortem Computed Tomography (PMCT). Recently, particular attention was paid to cardiovascular imaging using Post Mortem Magnetic Resonance Imaging (PMMRI). The present experimental study aims to: (i) confirm the efficacy of a Post Mortem Cardiac Resonance Imaging (PMCRI) study protocol for the study of human hearts collected during the autopsy; (ii) apply the defined protocol on subjects who died of “SCD (sudden cardiac death)”, to identify alterations that could guide subsequent sampling. Two hearts of healthy subjects (A: male 22 years; B: female 26 years), who died from causes other than SCD were collected and compared to hearts that belonged to SCD individuals (C: male, 47 years old; D: female, 44 years old; E: male; 72 years old). The exams were performed on a 1.5 T scanner (Philips Intera Achieva, Best, the Netherlands) on hearts collected during autopsy and after a 30-day formalin fixation. Two readers analyzed the obtained images blindly and after randomization. From the comparison between the data from imaging and the macroscopic and histological investigations carried out, the present study proved the effectiveness of a PMMRI protocol to study ex-situ hearts. Moreover, it suggested the following semeiology in post-mortem SCD cases: the hyperintense area with indistinct margins in the Short Tau Inversion Recovery (STIR) sequence was linked to edema or area of pathological fibers, whereas the hypointense area in the T2-FFE sequences was linked to fibrosis. PMMRI can provide a valuable benefit to post-mortem investigations, helping to distinctly improve the success rate of histological sampling and investigations, which remains the gold standard in the diagnosis of sudden death.

3Tesla post-mortem MRI quantification of anatomical brain structures

Quantitative post-mortem magnetic resonance imaging (PMMR) allows for measurement of T1 and T2 relaxation times and proton density (PD) of brain tissue. Quantitative PMMR values may be used for advanced post-mortem neuro-imaging diagnostics such as computer aided diagnosis. So far, the quantitative T1, T2 and PD post-mortem values of regular anatomical brain structures were unknown for a 3 Tesla PMMR application. The goal of this basic research study was to evaluate the quantitative values of post-mortem brain structures for a 3 T post-mortem magnetic resonance application with regard to various corpse temperatures. In 50 forensic cases, a quantitative PMMR brain sequence was applied prior to autopsy. Measurements of T1 (in ms), T2 (in ms), and PD (in %) values of cerebrum (Group 1: frontal grey matter, frontal white matter, thalamus, caudate nucleus, globus pallidus, putamen, internal capsule) brainstem and cerebellum (Group 2: cerebral peduncle, substantia nigra, red nucleus, pons, middle cerebellar peduncle, cerebellar hemisphere, medulla oblongata) were conducted in synthetically calculated axial PMMR brain images. Assessed quantitative values were corrected for corpse temperature. Temperature dependence was observed mainly for T1 values. ANOVA testing resulted in significant differences of quantitative values between the investigated anatomical brain structures in both groups. It can be concluded that temperature corrected 3 Tesla PMMR T1, T2 and PD values are feasible for characterization and discrimination of regular anatomical brain structures. This may provide a base for future advanced diagnostics of forensically relevant brain lesions and pathology.

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.

[Technical and methodological support for postmortem radiation examinations in the pathological departments and the forensic bureau]

The purpose of the work is to analyze the technical and methodological features of postmortem radiation studies based on literature data and the results of our own experience. To designate such studies, the term thanatoradiology has been proposed. The basis for the effective conduct of a thanatodiological examination is adequate technical support, which equally consists of the capabilities of the equipment for obtaining radiographs, CT and MR tomograms (type and generation of the device, technical features of a particular model), as well as the capabilities of the radiologist's workstation with the help of which the computer processing of the obtained images is carried out, three-dimensional reconstructions are performed, the calculation of planar and volumetric parameters and additional information is obtained. The use of an X-ray unit allows one to assess only pronounced pathology and the presence of foreign objects. The effectiveness of a computed tomography device depends on the choice of the slice thickness and the step of the examination table. Research on a magnetic resonance imager is effective at certain magnetic induction strength, the form of a magnetic coil and the used mode of recording a pulse sequence. The objectivity and efficiency of digital processing of tomograms consists of the type of a radiologist's workstation and installed programs for post-processing tomograms, including for modeling three-dimensional images and color mapping. The choice of a specific method of postmortem radiation research should be determined mainly by the research objectives. Research should be carried out taking into account age, body weight, individual characteristics and the state of body tissues. Today, it is advisable to use radiation methods as part of a comprehensive pathological and anatomical or forensic medical research to improve the quality and shorten the autopsy duration. The development of a unified protocol for postmortem CT and MRI studies that meets the pathological, anatomical and forensic requirements remains an urgent task.

Microbiology in minimally invasive autopsy: best techniques to detect infection. ESGFOR (ESCMID study group of forensic and post-mortem microbiology) guidelines

This manuscript aims to: 1) provide specific guidelines on PMM techniques in the setting of minimally invasive autopsy (MIA), both for pathologists collecting samples and for microbiologists advising pathologists and interpreting the results and 2) introduce standardization in PMM sampling at MIA. Post-mortem microbiology (PMM) is crucial to identify the causative organism in deaths due to infection. MIA including the use of post-mortem (PM) computed tomography (CT) and PM magnetic resonance imaging (MRI), is increasingly carried out as a complement or replacement for the traditional PM. In this setting, mirroring the traditional autopsy, PMM aims to: detect infectious organisms causing sudden unexpected deaths; confirm clinically suspected but unproven infection; evaluate the efficacy of antimicrobial therapy; identify emergent pathogens; and recognize medical diagnostic errors. Meaningful interpretation of PMM results requires careful evaluation in the context of the clinical history, macroscopic and microscopic findings. These guidelines were developed by a multidisciplinary team with experts in various fields of microbiology and pathology on behalf of the ESGFOR (ESCMID – European Society of Clinical Microbiology and Infectious Diseases - Study Group of Forensic and Post-mortem Microbiology, in collaboration with the ESP -European Society of Pathology-) based on a literature search and the author’s expertise. Microbiological sampling methods for MIA are presented for various scenarios: adults, children, developed and developing countries. Concordance between MIA and conventional invasive autopsy is substantial for children and adults and moderate for neonates and maternal deaths. Networking and closer collaboration among microbiologists and pathologists is vital to maximize the yield of PMM in MIA.

Visualisation of fetal meconium on post-mortem magnetic resonance imaging scans: a retrospective observational study

Background

Less invasive techniques for fetal post-mortems are increasingly used to correlate with parental wishes. With the use of post-mortem magnetic resonance imaging (MRI), normal appearance of the organs must be established.

Purpose

To investigate the after death appearance of the fetal meconium throughout gestation using the hyperintense appearance of meconium on T1 weighted MRI.

Material and Methods

This was a retrospective study that took place in a tertiary referral centre radiology department. Sixty-two fetal body post-mortem MRI scans (January 2014 to May 2018) between 12 and 41 weeks gestation were reviewed. Signal intensity of meconium at the rectum, sigmoid colon, splenic flexure and hepatic flexure was evaluated and correlated with gestational age. Interrater reliability was calculated.

Results

Meconium did not consistently have high signal intensity on T1 scans and was not always obvious. Rectal meconium had the highest intensity, and the more proximal the bowel the lower the intensity. The meconium had higher intensity at earlier gestations. Interrater reliability for rectal meconium gradings was excellent.

Conclusion

This study provides the first published primary research on the appearance of fetal meconium on post-mortem MRI. Overall, results were variable and suggest an alteration of bowel contents after death, but further investigation is needed to effectively inform practice.

Minimally invasive autopsy for fetuses and children based on a combination of post-mortem MRI and endoscopic examination: a feasibility study

BACKGROUND

Less invasive perinatal and paediatric autopsy methods, such as imaging alongside targeted endoscopy and organ biopsy, may address declining consent rates for traditional autopsy, but their acceptability and accuracy are not known.

OBJECTIVES

The aims of this study were to provide empirical data on the acceptability and likely uptake for different types of autopsy among key stakeholders (study 1); and to analyse existing autopsy data sources to provide estimates of the potential efficacy of less invasive autopsy (LIA) and its projected utility in clinical practice (study 2).

REVIEW METHODS

Study 1: this was a mixed-methods study. Parents were involved in research design and interpretation of findings. Substudy 1: a cross-sectional survey of 859 parents who had experienced miscarriage, termination of pregnancy for fetal anomaly, stillbirth, infant or child death, and interviews with 20 responders. Substudy 2: interviews with 25 health professionals and four coroners. Substudy 3: interviews with 16 religious leaders and eight focus groups, with 76 members of the Muslim and Jewish community. Study 2: a retrospective analysis of national data in addition to detailed information from an existing in-house autopsy database of > 5000 clinical cases that had undergone standard autopsy to determine the proportion of cases by clinical indication group for which tissue sampling of specific internal organs significantly contributed to the diagnosis.

RESULTS

Substudy 1: 91% of participants indicated that they would consent to some form of LIA, 54% would consent to standard autopsy, 74% to minimally invasive autopsy (MIA) and 77% to non-invasive autopsy (NIA). Substudy 2: participants viewed LIA as a positive development, but had concerns around the limitations of the technology and de-skilling the workforce. Cost implications, skills and training requirements were identified as implementation challenges. Substudy 3: religious leaders agreed that NIA was religiously permissible, but MIA was considered less acceptable. Community members indicated that they might consent to NIA if the body could be returned for burial within 24 hours. Study 2: in 5-10% of cases of sudden unexplained death in childhood and sudden unexplained death in infants, the final cause of death is determined by routine histological sampling of macroscopically normal organs, predominantly the heart and lungs, and in this group routine histological sampling therefore remains an important aspect of investigation. In contrast, routine histological examination of macroscopically normal organs rarely (< 0.5%) provides the cause of death in fetal cases, making LIA and NIA approaches potentially highly applicable.

LIMITATIONS

A key limitation of the empirical research is that it is hypothetical. Further research is required to determine actual uptake. Furthermore, because of the retrospective nature of the autopsy data set, findings regarding the likely contribution of organ sampling to final diagnosis are based on extrapolation of findings from historical autopsies, and prospective data collection is required to validate the conclusions.

CONCLUSIONS

LIA is viable and acceptable (except for unexplained deaths), and likely to increase uptake. Further health economic, performance and implementation studies are required to determine the optimal service configuration required to offer this as routine clinical care.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

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.

Surveillance for variant CJD: should more children with neurodegenerative diseases have autopsies?

OBJECTIVES

To report investigations performed in children with progressive neurodegenerative diseases reported to this UK study.

DESIGN

Since 1997 paediatric surveillance for variant Creutzfeldt-Jakob disease (vCJD) has been performed by identifying children aged less than 16 years with progressive intellectual and neurological deterioration (PIND) and searching for vCJD among them.

SETTING

The PIND Study obtains case details from paediatricians who notify via the British Paediatric Surveillance Unit.

PARTICIPANTS

Between May 1997 and October 2017, a total of 2050 cases meeting PIND criteria had been notified and investigated.

RESULTS

Six children had vCJD. 1819 children had other diagnoses, made in 12 cases by antemortem brain biopsy and in 15 by postmortem investigations. 225 children were undiagnosed: only 3 had antemortem brain biopsies and only 14 of the 108 who died were known to have had autopsies; postmortem neuropathological studies were carried out in just 10% (11/108) and only two had prion protein staining of brain tissue. Of the undiagnosed cases 43% were known to come from Asian British families.

CONCLUSIONS

Most of the notified children had a diagnosis other than vCJD to explain their neurological deterioration. None of the undiagnosed cases had the clinical phenotype of vCJD but brain tissue was rarely studied to exclude vCJD. Clinical surveillance via the PIND Study remains the only practical means of searching for vCJD in UK children.

The Value of Autopsy in Neonates in the 21st Century

BACKGROUND

Autopsy rates in neonatal intensive care unit (NICU) patients who died are declining worldwide. Postmortem magnetic resonance imaging (MRI) is suggested as adjunct to or substitute for autopsy.

OBJECTIVE

The aim of this paper was to determine the additional diagnostic value of autopsy in NICU patients and whether autopsy findings were potentially detectable using postmortem MRI.

METHODS

From 2008 to 2015, 298 infants died during admission to our NICU. Permission for unrestricted, nonforensic autopsy was obtained in 100 (33.6%) of these 298 infants. Retrospectively, autopsy reports and medical records of NICU patients were compared. Additional autopsy findings were graded according to the Goldman system, grading the clinical relevance of additional findings. In addition, the potential detectability of these additional findings on postmortem MRI was assessed.

RESULTS

Additional findings obtained by autopsy were found in 48% of the cases, divided into major (Goldman I/II, 24%) and minor (Goldman III/IV, 24%) additional findings. Major additional findings were significantly more often found in patients with a lower gestational age, and minor additional findings in patients with a higher postnatal age at death. Of all patients with additional findings determined by autopsy, 56.3% would most likely not have been detected using postmortem MRI.

CONCLUSIONS

Our results emphasize the still very important role of autopsy in the NICU setting and show that conventional autopsy could probably not be completely substituted by postmortem MRI.

Intrauterine fetal MR versus postmortem MR imaging after therapeutic termination of pregnancy: evaluation of the concordance in the detection of brain abnormalities at early gestational stage

BACKGROUND AND PURPOSE

Fetal postmortem MR Imaging (pmMRI) has been recently used as an adjuvant tool to conventional brain autopsy after termination of pregnancy (TOP). Our purpose was to compare the diagnostic performance of intrauterine MRI (iuMRI) and pmMRI in the detection of brain anomalies in fetuses at early gestational age (GA).

MATERIAL AND METHODS

We retrospectively collected 53 fetuses who had undergone iuMRI and pmMRI for suspected brain anomalies. Two pediatric neuroradiologists reviewed iuMRI and pmMRI examinations separately and then together. We used Cohen's K to assess the agreement between pmMRI and iuMRI. Using the combined evaluation iuMRI+pMRI as the reference standard, we calculated the "correctness ratio." We used Somers' D to assess the cograduation between postmortem image quality and time elapsed after fetus expulsion.

RESULTS

Our data showed high agreement between iuMRI and pmMRI considering all the categories together, for both observers (K1 0.84; K2 0.86). The correctness ratio of iuMRI and pmMRI was 79% and 45% respectively. The major disagreements between iuMRI and pmMRI were related to postmortem changes as the collapse of liquoral structures and distorting phenomena. We also found a significant cograduation between the time elapsed from expulsion and pmMRI contrast resolution and distortive phenomena (both p < 0.001).

CONCLUSIONS

Our study demonstrates an overall high concordance between iuMRI and pmMRI in detecting fetal brain abnormalities at early GA. Nevertheless, for the correct interpretation of pmMRI, the revision of fetal examination seems to be crucial, in particular when time elapsed from expulsion is longer than 24 h.

KEY POINTS

• IuMRI and pmMRI showed overall high concordance in detecting fetal brain abnormalities at early GA. • PmMRI corroborated the antemortem diagnosis and it could be a valid alternative to conventional brain autopsy, only when the latter cannot be performed. • Some caution should be taken in interpreting pmMR images when performed after 24 h from fetal death.

Conventional Autopsy versus Minimally Invasive Autopsy with Postmortem MRI, CT, and CT-guided Biopsy: Comparison of Diagnostic Performance

Purpose To compare the diagnostic performance of minimally invasive autopsy with that of conventional autopsy. Materials and Methods For this prospective, single-center, cross-sectional study in an academic hospital, 295 of 2197 adult cadavers (mean age: 65 years [range, 18-99 years]; age range of male cadavers: 18-99 years; age range of female cadavers: 18-98 years) who died from 2012 through 2014 underwent conventional autopsy. Family consent for minimally invasive autopsy was obtained for 139 of the 295 cadavers; 99 of those 139 cadavers were included in this study. Those involved in minimally invasive autopsy and conventional autopsy were blinded to each other's findings. The minimally invasive autopsy procedure combined postmortem MRI, CT, and CT-guided biopsy of main organs and pathologic lesions. The primary outcome measure was performance of minimally invasive autopsy and conventional autopsy in establishing immediate cause of death, as compared with consensus cause of death. The secondary outcome measures were diagnostic yield of minimally invasive autopsy and conventional autopsy for all, major, and grouped major diagnoses; frequency of clinically unsuspected findings; and percentage of answered clinical questions. Results Cause of death determined with minimally invasive autopsy and conventional autopsy agreed in 91 of the 99 cadavers (92%). Agreement with consensus cause of death occurred in 96 of 99 cadavers (97%) with minimally invasive autopsy and in 94 of 99 cadavers (95%) with conventional autopsy (P = .73). All 288 grouped major diagnoses were related to consensus cause of death. Minimally invasive autopsy enabled diagnosis of 259 of them (90%) and conventional autopsy 224 (78%); 200 (69%) were found with both methods. At clinical examination, the cause of death was not suspected in 17 of the 99 cadavers (17%), and 124 of 288 grouped major diagnoses (43%) were not established. There were 219 additional clinical questions; 189 (86%) were answered with minimally invasive autopsy and 182 (83%) were answered with conventional autopsy (P = .35). Conclusion The performance of minimally invasive autopsy in the detection of cause of death was similar to that of conventional autopsy; however, minimally invasive autopsy has a higher yield of diagnoses. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by Krombach in this issue.

[History of the anatomical and clinical autopsy]

The history of the autopsy is naturally also a part of the history of anatomy and pathology and spans over about 2300 years. The first documented autopsies were conducted in about 300 B.C. Thereafter, due to the prohibition of dissections due to religious, social, or hygienic reasons, a long period of stagnation took place. With the onset of the Renaissance in the 15th and 16th century, interest in the ancient sciences such as anatomy began to rise and consequently an increasing number of dissections for anatomical studies were conducted. Nevertheless, it took nearly 200 years until clinical symptoms and/or causes of disease and death were correlated with anatomical findings. In the second half of the 19th century, the clinical autopsy based on the combination of macroscopic and microscopic findings became more and more important as a precondition for the systematic description of diseases. Based on autopsy findings and together with several new techniques, modern pathology could be established at the beginning of the 20th century as a source of scientific knowledge for the clinical medicine and as a theoretical discipline of its own.

Postmortem fetal magnetic resonance imaging: where do we stand?

Abstract

Postmortem fetal magnetic resonance imaging (PMFMRI) is increasingly used thanks to its good overall concordance with histology paralleling the rising incidence of parental refusal of autopsy. The technique could become a routine clinical examination but it needs to be standardized and conducted by trained radiologists. Such radiologists should be aware of not only the (congenital and acquired) anomalies that can involve the fetus, but also of the “physiological” postmortem changes. In this article, we intend to focus on the contribution of PMFMRI based on the existing literature and on our own experience, as we presently perform the technique routinely in our clinical practice.

Key Points

• Concordance rates between PMFMRI and autopsy are high for detecting fetal pathologies.

• PMFMRI is more acceptable for parents than traditional autopsy.

• PMFMRI is becoming widely used as a part of the postmortem investigations.

• A dedicated radiologist needs to learn to interpret correctly a PMFMRI.

• PMFMRI can be easily realized in daily clinical practice.

Conventional vs virtual autopsy with postmortem MRI in phenotypic characterization of stillbirths and fetal malformations

OBJECTIVE

To compare virtual autopsy using postmortem magnetic resonance imaging (MRI) with conventional autopsy with respect to phenotypic characterization of stillbirths and malformed fetuses, and acceptability to parents.

METHODS

This was a prospective diagnostic evaluation study, conducted from June 2013 to June 2015, including stillbirths and pregnancies terminated owing to fetal malformation at ≥ 20 weeks' gestation, for which parental consent to both conventional autopsy and postmortem MRI was obtained. Cases of maternal and obstetric cause of fetal demise were excluded. Whole-body postmortem MRI (at 1.5 T) was performed prior to conventional autopsy. Taking conventional autopsy as the diagnostic gold standard, postmortem MRI findings alone, or in conjunction with other minimally invasive prenatal and postmortem investigations, were assessed and compared for diagnostic accuracy.

RESULTS

Parental consent for both conventional autopsy and postmortem MRI was obtained in 52 cases of which 43 were included in the analysis. In 35 (81.4%) cases, the final diagnosis based on virtual autopsy with postmortem MRI was in agreement with that of conventional autopsy. With conventional autopsy as the reference standard, sensitivity, specificity, positive and negative predictive values of postmortem MRI were, respectively: 77.7%, 99.8%, 97.4% and 98.0% for whole-body assessment; 93.1%, 99.0%, 87.1% and 99.5% for the nervous system; 61.0%, 100.0%, 100.0% and 96.7% for the cardiovascular system; 91.1%, 100.0%, 100.0% and 98.0% for the pulmonary system; 80.6%, 99.8%, 96.7% and 98.7% for the abdomen; 96.2%, 99.7%, 96.2% and 99.7% for the renal system; and 66.7%, 100.0%, 100.0% and 97.2% for the musculoskeletal system. Virtual autopsy was acceptable to 96.8% of families as compared with conventional autopsy to 82.5%.

CONCLUSIONS

Virtual autopsy using postmortem MRI and other minimally invasive investigations can be an acceptable alternative to conventional autopsy when the latter is refused by the parents. Postmortem MRI is more acceptable to parents and can provide additional diagnostic information on brain and spinal cord malformations. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

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.

[Fetal autopsies : Relic or still a gold standard?]

BACKGROUND

Fetal autopsy rates are decreasing in Western countries although post-mortem examinations render important information for the parents concerning the cause of abortion and risk of recurrence in future pregnancies.

OBJECTIVE

The intention of the presented study was to analyze the development of fetal autopsies in Germany during the last decade and to review accessible information obtained by fetal autopsy.

MATERIAL AND METHODS

Reports of fetal autopsies conducted in two German university Institutes of pathology between 2005 and 2014 were evaluated retrospectively. Demographic data and the correlation between clinical diagnoses and autopsy findings were assessed. In addition, differences between spontaneous and induced cases of abortion and differences between the institutes were also documented.

RESULTS

Overall, 428 fetal autopsies were performed, whereby the number of autopsies decreased by 24.2% during the study period. Of the examined fetuses 29.7% were induced abortions which as expected exhibited different malformations compared to cases of spontaneous abortion (p < 0.001). There was no evidence of a malformation or other cause of death in 27.1% of the cases and 95.7% of these abortions occurred spontaneously. A discrepancy between clinical and autopsy findings was evident in 6.8% of cases and 3.5% of the autopsy examinations revealed at least one additional malformation compared to the prenatal clinical data.

CONCLUSION

Despite improvements in prenatal diagnostics, fetal autopsies remain an important diagnostic tool even today contributing additional information in a considerable number of cases potentially revising clinical diagnoses.

Neonatal imaging using an on-site small footprint MR scanner

With its soft-tissue definition, multiplanar capabilities and advanced imaging techniques, magnetic resonance imaging (MRI) for neonatal care can provide better understanding of pathology, allowing for improved care and counseling to families. However, MR imaging in neonates is often difficult due to patient instability and the complex support necessary for survival. In our institution, we have installed a small footprint magnet in the neonatal intensive care unit (NICU) to minimize patient risks and provide the ability to perform MR imaging safely in this population. With this system, we have been able to provide more information with regard to central nervous system disorders, abdominal pathology, and pulmonary and airway abnormalities, and have performed postmortem imaging as an alternative or supplement to pathological autopsy. In our experience, an MR scanner situated within the NICU has allowed for safer and more expedited imaging of this vulnerable population.

Modern post-mortem imaging: an update on recent developments

Modern post-mortem investigations use an increasing number of digital imaging methods, which can be collected under the term "post-mortem imaging". Most methods of forensic imaging are from the radiology field and are therefore techniques that show the interior of the body with technologies such as X-ray or magnetic resonance imaging. To digitally image the surface of the body, other techniques are regularly applied, e.g. three-dimensional (3D) surface scanning (3DSS) or photogrammetry. Today's most frequently used techniques include post-mortem computed tomography (PMCT), post-mortem magnetic resonance imaging (PMMR), post-mortem computed tomographic angiography (PMCTA) and 3DSS or photogrammetry. Each of these methods has specific advantages and limitations. Therefore, the indications for using each method are different. While PMCT gives a rapid overview of the interior of the body and depicts the skeletal system and radiopaque foreign bodies, PMMR allows investigation of soft tissues and parenchymal organs. PMCTA is the method of choice for viewing the vascular system and detecting sources of bleeding. However, none of those radiological methods allow a detailed digital view of the body's surface, which makes 3DSS the best choice for such a purpose. If 3D surface scanners are not available, photogrammetry is an alternative. This review article gives an overview of different imaging techniques and explains their applications, advantages and limitations. We hope it will improve understanding of the methods.

Factors affecting uptake of postmortem examination in the prenatal, perinatal and paediatric setting

Background

Postmortem examination is the single most useful investigation in providing information to parents about why their baby or child died. Despite this, uptake remains well below the recommended 75%.

Objective

To address the question ‘what are the barriers and motivators to perinatal, prenatal and paediatric PM examination?’

Search strategy

Key databases including Pubmed and CINAHL; Cochrane library, websites of relevant patient organisations, hand search of key journals, first and last authors and references.

Selection criteria

Peer‐reviewed qualitative, quantitative or mixed methods research examining factors affecting uptake or decline of perinatal or paediatric postmortem examination.

Data collection and analysis

Narrative synthesis; findings were compared across studies to examine interrelations.

Main results

Seven major themes describing barriers to postmortem uptake were identified: dislike of invasiveness, practicalities of the procedure, organ retention issues, protective parenting, communication and understanding, religion and culture and professional or organisational barriers. Six major themes related to factors which facilitated parental consent were identified: desire for information, contributing to research, coping and well‐being, respectful care, minimally invasive options, and policy and practice. There were a number of themes in the literature that reflected best practice.

Conclusion

Findings highlight the need for better health professional education and the fact some concerns may be mitigated if less invasive methods of postmortem were routinely available. New consent packages and codes of practice may have a positive impact on perception of examination after death. The landscape is changing; further research is necessary to assess the impact on postmortem uptake rates.

Tweetable abstract

Systematic review to explore the barriers and motivators to perinatal, prenatal and paediatric postmortem examination.

Systematic review to explore the barriers and motivators to perinatal, prenatal and paediatric postmortem examination.

Whole-Body MRI Virtual Autopsy Using Diffusion-weighted Imaging With Background Suppression (DWIBS) at 3 T in a Child Succumbing to Chordoma

BACKGROUND

We report the use of diffusion-weighted imaging with background suppression (DWIBS) in pediatric virtual magnetic resonance imaging (MRI) autopsy of a child who succumbed to chordoma.

CASE DESCRIPTION

A 10-year-old girl who succumbed to relapse of a chordoma underwent whole-body virtual MRI autopsy 12 hours postmortem with short Tau inversion recovery (STIR) and DWIBS on 3 T, which demonstrated the primary mass, local and cardiac invasion, and metastatic disease to the thorax, abdomen, head/neck, and musculoskeletal system.

CONCLUSIONS

Postmortem virtual MRI autopsy including DWIBS successfully demonstrated the transthoracic spread of chordoma and invasion of the heart, resulting in blood-borne metastases. Motion and respiratory artifact were not factors during virtual autopsy using DWIBS on 3 T, making ideal use of this technology.

FORENSIC RADIOLOGY AND IMAGING FOR VETERINARY RADIOLOGISTS

Imaging studies are often of evidentiary value in medicolegal investigations involving animals and the role of the veterinary radiologist is to interpret those images for courts as an expert or opinion witness. With progressing interest in prosecuting animal crimes and strengthening of penalties for crimes against animals, the participation of veterinary radiologists in medicolegal investigations is expected to increase. Veterinary radiologists who are aware of radiographic and imaging signs that result in animal suffering, abuse, or neglect; knowledgeable in ways radiology and imaging may support cause of death determinations; conversant in postmortem imaging; comfortable discussing mechanisms and timing of blunt or sharp force and projectile trauma in imaging; and prepared to identify mimics of abuse can assist court participants in understanding imaging evidence. The goal of this commentary review is to familiarize veterinary radiologists with the forensic radiology and imaging literature and with the advantages and disadvantages of various imaging modalities utilized in forensic investigations. Another goal is to provide background information for future research studies in veterinary forensic radiology and imaging.

The possibilities of studying human embryos and foetuses using micro-CT: a technical note

The purpose of the study was to discover a way to study the internal structure and evolution of human embryos noninvasively. The human embryo was stained with phosphotungstic acid solution (PTA) in ethanol (EPTA) and scanned using a micro computed tomography (micro-CT) scanner. Using appropriate software, a three-dimensional image of the embryo was created, which could be further exploited. The methodology described could be used for the non-destructive examination of the internal structure of the human embryo, and the resulting data can be used as a resource for medical students, gynaecologists, and paediatricians.

A Fatal Case of a Ruptured Cerebral Aneurysm Detected by Postmortem Computed Tomography Angiography Using a New Contrast-Medium Solution

Forensic autopsy is still the criterion standard in legal investigations. Currently, notable transformation is occurring because postmortem imaging is being increasingly endorsed. This article highlights the effectiveness of postmortem computed tomography angiography by using a new contrast medium mixture as a solitary tool to define the cause and manner of death in a ruptured cerebral aneurysm case. Based on the imaging results, autopsy was not mandated and the case was closed.

Post-mortem magnetic resonance foetal imaging: a study of morphological correlation with conventional autopsy and histopathological findings

The aim of the present study is to offer our experience concerning post-mortem magnetic resonance (PMMR) in foetal death cases and an evaluation of the differences between the findings acquired by PMMR and by forensic autopsy. Fifteen foetuses were recruited from July 2014 to December 2015. These had suffered intrauterine death in women in the 21st to 38th week of gestation who were treated in the emergency department for non-perception of foetal movements. We performed a PMMR on foetuses, 3 ± 1 days on average from the time of death, and then a complete forensic autopsy was performed. All 15 foetuses were examined with a whole-body study protocol, starting from the skull, down to and including the lower limbs. The total time of examination ranged from 20 to 30 min in each case. The external evaluation and description of post-mortem phenomena (maceration), record of the weight and detection and the various measurements of foetal diameters were evaluated before performing autopsy. A complete histopathological study was performed in each case. Out of 15 cases examined, eight were negative for structural anatomical abnormalities and/or diseases, both in the preliminary radiological examination and the traditional autopsy. In the remaining seven cases, pathological findings were detected by PMMR with corresponding results at autopsy. PMMR can provide useful information on foetal medical conditions and result in improved diagnostic classification. It may enable the planning of a more suitable technique before proceeding to autopsy, including focusing on certain aspects of organ pathology otherwise not detectable. The association between PMMR, post-mortem examination and related histological study of the foetus-placenta unit could help reduce the percentage of cases in which the cause of foetal death remains unexplained. Lastly, it may allow a selective sampling of the organ in order to target histological investigations.

Quantification of maceration changes using post mortem MRI in fetuses

BACKGROUND

Post mortem imaging is playing an increasingly important role in perinatal autopsy, and correct interpretation of imaging changes is paramount. This is particularly important following intra-uterine fetal death, where there may be fetal maceration. The aim of this study was to investigate whether any changes seen on a whole body fetal post mortem magnetic resonance imaging (PMMR) correspond to maceration at conventional autopsy.

METHODS

We performed pre-autopsy PMMR in 75 fetuses using a 1.5 Tesla Siemens Avanto MR scanner (Erlangen, Germany). PMMR images were reported blinded to the clinical history and autopsy data using a numerical severity scale (0 = no maceration changes to 2 = severe maceration changes) for 6 different visceral organs (total 12). The degree of maceration at autopsy was categorized according to severity on a numerical scale (1 = no maceration to 4 = severe maceration). We also generated quantitative maps to measure the liver and lung T2.

RESULTS

The mean PMMR maceration score correlated well with the autopsy maceration score (R(2) = 0.93). A PMMR score of ≥4.5 had a sensitivity of 91%, specificity of 64%, for detecting moderate or severe maceration at autopsy. Liver and lung T2 were increased in fetuses with maceration scores of 3-4 in comparison to those with 1-2 (liver p = 0.03, lung p = 0.02).

CONCLUSIONS

There was a good correlation between PMMR maceration score and the extent of maceration seen at conventional autopsy. This score may be useful in interpretation of fetal PMMR.

Perinatal and paediatric post-mortem magnetic resonance imaging (PMMR): sequences and technique

As post-mortem MRI (PMMR) becomes more widely used for investigation following perinatal and paediatric deaths, the best possible images should be acquired. In this article, we review the most widely used published PMMR sequences, together with outlining our acquisition protocol and sequence parameters for foetal, perinatal and paediatric PMMR. We give examples of both normal and abnormal appearances, so that the reader can understand the logic behind each acquisition step before interpretation, as a useful day-to-day reference guide to performing PMMR.

Brain volume estimation from post-mortem newborn and fetal MRI

Objective

Minimally invasive autopsy using post-mortem magnetic resonance imaging (MRI) is a valid alternative to conventional autopsy in fetuses and infants. Estimation of brain weight is an integral part of autopsy, but manual segmentation of organ volumes on MRI is labor intensive and prone to errors, therefore unsuitable for routine clinical practice. In this paper we aim to show that volumetric measurements of the post-mortem fetal and neonatal brain can be accurately estimated using semi-automatic techniques and a high correlation can be found with the weights measured from conventional autopsy results.

Methods

The brains of 17 newborn subjects, part of Magnetic Resonance Imaging Autopsy Study (MaRIAS), were segmented from post-mortem MR images into cerebrum, cerebellum and brainstem using a publicly available neonate brain atlas and semi-automatic segmentation algorithm. The results of the segmentation were averaged to create a new atlas, which was then used for the automated atlas-based segmentation of 17 MaRIAS fetus subjects. As validation, we manually segmented the MR images from 8 subjects of each cohort and compared them with the automatic ones. The semi-automatic estimation of cerebrum weight was compared with the results of the conventional autopsy.

Results

The Dice overlaps between the manual and automatic segmentations are 0.991 and 0.992 for cerebrum, 0.873 and 0.888 for cerebellum and 0.819 and 0.815 for brainstem, for newborns and fetuses, respectively. Excellent agreement was obtained between the estimated MR weights and autopsy gold standard ones: mean absolute difference of 5 g and 2% maximum error for the fetus cohort and mean absolute difference of 20 g and 11% maximum error for the newborn one.

Conclusions

The high correlation between the obtained segmentation and autopsy weights strengthens the idea of using post-mortem MRI as an alternative for conventional autopsy of the brain.

•

We segment the cerebrum of 17 newborns and 17 fetuses from postmortem MR.

•

There is high correlation between the autopsy and MR segmentation brain volumes.

•

Postmortem MR can be a non-invasive alternative to conventional autopsy of infants.

Parental acceptance of minimally invasive fetal and neonatal autopsy compared with conventional autopsy

OBJECTIVE

To determine parental acceptance of minimally invasive autopsy (MIA) involving postmortem imaging and organ tissue sampling compared with conventional autopsy and to compare the acceptability of percutaneous versus laparoscopic-guided biopsy.

METHODS

Following termination of pregnancy parents were offered the option of traditional autopsy and subsequently interviewed about their acceptance of MIA. The McNemar test for paired samples was used to assess the difference in acceptance of MIA and conventional autopsy. The Wilcoxon signed-rank test for paired samples was used to compare the acceptance score for percutaneous versus laparoscopic-guided biopsy. Logistic regression was selected to study the association of parental acceptance of conventional autopsy and MIA with different variables.

RESULTS

Conventional autopsy was accepted by 42 (60.0%) of the 70 parents. Regression analysis showed that non-Muslim faith was the only factor significantly associated with acceptance of conventional autopsy (p = 0.030). Of 28 parents who initially refused conventional autopsy, 13(46.4%) subsequently accepted MIA, increasing acceptance to 78.6% (p < 0.001). Regression analysis showed that none of the factors significantly affected MIA acceptance. Parents expressed no preference between postmortem percutaneous versus laparoscopic-guided biopsy (p = 0.061).

CONCLUSION

Post-mortem imaging combined with systematic organ biopsies is highly acceptable among all parents independent of their religion and the method used for organ biopsy.