Normal perinatal and paediatric postmortem magnetic resonance imaging appearances

Fetal and neonatal post-mortem imaging referral template: recommendations from the European Society of Paediatric Radiology Post-mortem Task Force

BACKGROUND

In post-mortem (PM) fetal and neonatal imaging, relevant clinical information is crucial for accurate interpretation and diagnosis; however, it is usually incomplete.

OBJECTIVE

To propose a standardized template for PM fetal and neonatal imaging referrals to enhance communication between referring clinicians and reporting radiologists.

MATERIALS AND METHODS

A modified Delphi approach was conducted amongst members of the European Society of Paediatric Radiology (ESPR) PM Task Force and other recommended PM imaging specialists worldwide to determine consensus on necessary information. These were based on three pre-existing referral templates already in use across a variety of centers. The study ran for 4 months (December 2023-April 2024).

RESULTS

Nineteen specialists from 17 centers worldwide formed our expert panel. The final agreed referral template information includes the patient's identification details (mother and fetus when available), fetal/neonatal information (gestational age, sex, type of demise (including type of termination of pregnancy (i.e., surgical or medical)), date and time of fetal demise (+ delivery) or neonatal death, singleton/multiple pregnancy, clinical information (obstetrical history, prenatal imaging findings, amniocentesis findings, physical external examination findings), provisional clinical diagnosis, and ordering physician's information.

CONCLUSION

A comprehensive referral template has been created, representing expert consensus on the minimum data required for the conduct of quality PM fetal and neonatal imaging, with the goal of facilitating accuracy of image interpretation.

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.

Disparities Between Prenatal Ultrasound and Autopsy Findings in Pregnancies Resulting in Fetal Loss

OBJECTIVES

This retrospective study aimed to assess disparities between prenatal ultrasound and autopsy findings in pregnancies that resulted in fetal loss, and to evaluate the diagnostic performance of prenatal ultrasound using postmortem examinations as a gold standard.

METHODS

Our study included 136 autopsy cases following a fetal loss that occurred at our tertiary medical center for 8 years. A comparison between the prenatal ultrasound and autopsy findings was made, and all cases were classified according to the degree of agreement. The diagnostic performance of prenatal ultrasound was calculated at the level of organ system and specific malformations.

RESULTS

The primary sonographic diagnosis was confirmed in 91.9% of the cases (n = 125). General agreement was highest among central nervous system (CNS), cardiovascular and musculoskeletal systems (85.7%, n = 36, 18, and 12, respectively) and lowest among facial, multiple anomalies, genitourinary and gastrointestinal systems (50.0%, 74.3%, 78.6%, and 80.0%, n = 2, 26, 11, and 4, respectively). The sensitivity of ultrasound was highest in the CNS (93.2%) and musculoskeletal (87.0%) and lowest in the facial (32.3%) and pulmonary (13.0%) systems. Specifically, low diagnostic rates were noted in detecting ventriculomegaly, valvular anomalies, renal dysplasia, spleen and adrenal anomalies, and digital and facial defects.

CONCLUSIONS

Our study observed an overall high agreement between prenatal ultrasound and autopsy while contributing to our comprehensive understanding of its strengths and limitations across various types of organ systems and specific malformations.

Postmortem MR in termination of pregnancy for central nervous system (CNS) anomalies

OBJECTIVES

To evaluate the concordance of conventional autopsy (CA) and postmortem magnetic resonance (MR) after termination of pregnancy (TOP) in fetuses with prenatally detected central nervous system (CNS) anomalies. Second, to determine the most informative postmortem investigation in parental counseling.

METHODS

All TOPs between 2006 and 2016 with prenatally detected CNS involvement and having a postmortem MR and CA as postmortem examinations were retrospectively analyzed and concordance levels were established.

RESULTS

Of 764 TOPs, 255 cases had a CNS anomaly detected prenatally (33.4%). Fetal genetic anomalies (n = 40) and cases without both postmortem MR and CA were excluded, leaving 68 cases for analysis.Disagreement between postmortem MR and CA was observed in 22 cases (32.4%). In eight cases (11.8%), more information was obtained by CA compared with MR. However, only two cases with major additional findings were found when compared with prenatal diagnosis. In 14 cases (20.6%), MR was superior to CA either because of additional cerebral anomalies undetected by CA (n = 5) and/or because of severe autolysis hindering pathology of the CNS (n = 9).

CONCLUSIONS

Our data point out that an adequate postmortem evaluation, valuable in parental counseling, can be provided by a postmortem MR in 97% of the cases.Key PointsAn adequate postmortem evaluation, valuable in parental counseling, can be provided by a postmortem (PM) magnetic resonance (MR) in the majority of cases.PM MR is an excellent postmortem imaging tool for the brain.In cases with brain autolysis, PM MR is often the only informative PM investigation tool.PM MR is an essential adjunct to CA in the PM evaluation of pregnancies terminated for a central nervous system (CNS) anomaly.

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.

Essence of postmortem computed tomography for in-hospital deaths: what clinical radiologists should know

Postmortem computed tomography (CT) is an essential tool for investigating the causes of death. Postmortem CT has characteristic imaging findings and should not be interpreted in the same manner as clinical antemortem images. In analyzing the cause of death in in-hospital death cases using postmortem images, it is crucial to understand early postmortem and post-resuscitation changes. In addition, it is essential to understand the limitations of diagnosing the cause of death or significant pathology relating to death on non-contrast-enhanced postmortem CT. In Japan, there has also been social demand to establish a system for postmortem imaging at the time of death. To facilitate such a system, clinical radiologists should be prepared to interpret postmortem images and assess the cause of death. This review article provides comprehensive information regarding unenhanced postmortem CT for in-hospital death cases in daily clinical practice in Japan.

Postmortem Magnetic Resonance Imaging of In Utero Fetuses and Its Relationship With Postmortem Interval: A Multi-Organ Observational Study on Reduced Fetuses of Complicated Multiple Pregnancies

BACKGROUND

Despite technological advancements in perinatal imaging, autopsy examination is still regarded as the reference standard to determine the time and reason of the fetal death.

PURPOSE

This study was conducted to identify the intrauterine postmortem magnetic resonance imaging (PMMR) findings of fetuses, who underwent radiofrequency ablation (RFA).

STUDY TYPE

Prospective.

POPULATION

Fifty-three twin/triplet complicated pregnancies scheduled for selective reduction of one of the fetuses by RFA were included.

FIELD STRENGTH/SEQUENCE

The imaging methods used are T1-weighted gradient-echo imaging (T1 GRE), T2 half-Fourier acquisition single-shot turbo spin-echo (SSTSE), and diffusion-weighted imaging (DWI) sequences.

ASSESSMENT

The MRIs were interpreted by three radiologists.

STATISTICAL TESTS

Data were analyzed using the software package SPSS Statistics Version 22.0. The used tests included one-way analysis of variance (ANOVA) and Duncan tests (significance level: P value <0.05). This analysis was performed with scikit-learn library (version 1.1.1) in Python version 3.9.

RESULTS

Average PMMR scores of orbit, brain, and abdomen showed significant differences among different PM interval subgroups. The brain apparent diffusion coefficient (ADC) numbers of reduced and living fetuses were significantly different at any PM interval. To determine which findings are closely associated with the timing of fetal death, five different methods of feature selection were employed. The top eight selected features achieved the highest area under the curve (AUC) of 78.19%.

DATA CONCLUSION

In utero, PMMR findings may be associated with the time of fetal death. Among different fetal organs evaluated, particularly PMMR top eight features specifically scores of orbits were associated with PM intrauterine time after death.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 2.

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.

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.

Pictorial review of the postmortem computed tomography in neonaticide cases

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

A pragmatic evidence-based approach to post-mortem perinatal imaging

Post-mortem imaging has a high acceptance rate amongst parents and healthcare professionals as a non-invasive method for investigating perinatal deaths. Previously viewed as a 'niche' subspecialty, it is becoming increasingly requested, with general radiologists now more frequently asked to oversee and advise on appropriate imaging protocols. Much of the current literature to date has focussed on diagnostic accuracy and clinical experiences of individual centres and their imaging techniques (e.g. post-mortem CT, MRI, ultrasound and micro-CT), and pragmatic, evidence-based guidance for how to approach such referrals in real-world practice is lacking. In this review, we summarise the latest research and provide an approach and flowchart to aid decision-making for perinatal post-mortem imaging. We highlight key aspects of the maternal and antenatal history that radiologists should consider when protocolling studies (e.g. antenatal imaging findings and history), and emphasise important factors that could impact the diagnostic quality of post-mortem imaging examinations (e.g. post-mortem weight and time interval). Considerations regarding when ancillary post-mortem image-guided biopsy tests are beneficial are also addressed, and we provide key references for imaging protocols for a variety of cross-sectional imaging modalities.

MRI signs of intrauterine fetal demise

Intrauterine fetal demise (IUFD) is an uncommon but serious event that may occasionally be encountered on fetal MRI. Compared to the more florid signs of fetal demise which has occurred some time ago, recent IUFD is associated with more subtle findings that may be missed or misinterpreted. The two main MRI sequences used in imaging the fetus are T2-like two-dimensional balanced steady-state free-precession (SSFP), a white blood sequence, or T2-weighted single-shot fast spin-echo (SSFSE), a black blood sequence. The most reliable and specific signs of a recent IUFD are a constricted heart with poorly delineated cardiac chambers and signal abnormality in the heart and aorta, which will have different features depending on the MRI sequence used. Secondary signs of IUFD include global brain ischemia, abnormal globes, effusions, body wall edema and umbilical cord thrombosis. Unlike fetal ultrasound examinations where cardiac activity is routinely assessed, fetal MRI requires careful scrutiny of the fetal heart for assessment of fetal life.

Navigating the perils and pitfalls of pediatric forensic postmortem imaging in the United States

Postmortem CT is widely used in the general adult and military populations. It is used extensively in pediatric death investigations in Europe and Asia, but distinctive challenges are encountered when launching a postmortem imaging program in the United States. We describe the issues we have encountered specific to establishing a pediatric postmortem imaging service in this country and propose potential solutions.

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.

Maceration determines diagnostic yield of fetal and neonatal whole body post-mortem ultrasound

OBJECTIVES

To determine factors in nondiagnostic fetal and neonatal post-mortem ultrasound (PMUS) examinations.

METHODS

All fetal and neonatal PMUS examinations were included over a 5-year study period (2014-2019). Nondiagnostic image quality by body parts (brain, spine, thorax, cardiac, and abdomen) was recorded and correlated with patient variables. Descriptive statistics and logistic regression analyses were performed to identify significant factors for nondiagnostic studies.

RESULTS

Two hundred sixty-five PMUS examinations were included, with median gestational age of 22 weeks (12-42 wk), post-mortem weight of 363 g (16-4033 g), and post-mortem interval of 8 days (0-39 d). Diagnostic imaging quality was achieved for 178/265 (67.2%) studies. It was high for abdominal (263/265, 99.2%), thoracic (264/265, 99.6%), and spine (265/265, 100%) but lower for brain (210/265, 79.2%) and cardiac imaging (213/265, 80.4%). Maceration was the best overall predictor for nondiagnostic imaging quality (P < .0001). Post-mortem fetal weight was positively associated with cardiac (P = .0133) and negatively associated with brain imaging quality (P = .0002). Post-mortem interval was not a significant predictor.

CONCLUSIONS

Fetal maceration was the best predictor for nondiagnostic PMUS, particularly for brain and heart. Fetuses with marked maceration and suspected cardiac or brain anomalies should be prioritised for post-mortem MRI.

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.

Perinatal post-mortem ultrasound (PMUS): radiological-pathological correlation

There has been an increasing demand and interest in post-mortem imaging techniques, either as an adjunct or replacement for the conventional invasive autopsy. Post-mortem ultrasound (PMUS) is easily accessible and more affordable than other cross-sectional imaging modalities and allows visualisation of normal anatomical structures of the brain, thorax and abdomen in perinatal cases. The lack of aeration of post-mortem foetal lungs provides a good sonographic window for assessment of the heart and normal pulmonary lobulation, in contrast to live neonates.In a previous article within this journal, we published a practical approach to conducting a comprehensive PMUS examination. This covered the basic principles behind why post-mortem imaging is performed, helpful techniques for obtaining optimal PMUS images, and the expected normal post-mortem changes seen in perinatal deaths. In this article, we build upon this by focusing on commonly encountered pathologies on PMUS and compare these to autopsy and other post-mortem imaging modalities.

Diagnostic assessment of foetal brain malformations with intra-uterine MRI versus perinatal post-mortem MRI

PURPOSE

To evaluate differences in diagnostic yield of intra-uterine foetal (iuMR) and post-mortem MRI (PMMR) for complex brain malformations, using autopsy as the reference standard.

METHODS

In this retrospective, multicentre study spanning 2 years, we reviewed 13 terminated singleton pregnancies with a prenatal ultrasound finding of complex foetal cerebral abnormalities, referred for both iuMR and PMMR. The iuMR and PMMR studies of the brain were reported independently by two groups of radiologists, blinded to each other's reports. Descriptive statistics were used to compare differences in intracranial abnormalities with autopsy (and genetic testing, where present) as reference standard.

RESULTS

The median gestational age at termination was 24.6 weeks (IQR 22-29) with median time between delivery and PMMR of 133 h (IQR 101-165). There was full concordance between iuMR and PMMR findings and autopsy in 2/13 (15.3%) cases. Partial concordance between both imaging modalities was present in 6/13 (46.2%) and total discordance in the remainder (5/13, 38.5%). When compared to autopsy, PMMR missed important key findings specifically for neuronal migration and cerebellar anomalies, whereas iuMR appeared to overcall CSF space abnormalities which were less crucial to reaching the final overall diagnosis.

CONCLUSIONS

iuMR should be performed to improve foetal phenotyping where there is a prenatal ultrasound for complex foetal brain abnormalities. Reliance on PMMR alone is likely to result in misdiagnosis in a majority of cases.

Pediatric postmortem computed tomography: initial experience at a children's hospital in the United States

Postmortem CT might provide valuable information in determining the cause of death and understanding disease processes, particularly when combined with traditional autopsy. Pediatric applications of postmortem imaging represent a new and rapidly growing field. We describe our experience in establishing a pediatric postmortem CT program and present a discussion of the distinct challenges in developing this type of program in the United States of America, where forensic practice varies from other countries. We give a brief overview of recent literature along with the common imaging findings on postmortem CT that can simulate antemortem pathology.

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.

Is traditional perinatal autopsy needed after detailed fetal ultrasound and post-mortem MRI?

OBJECTIVE

To determine the additional yield from autopsy following prenatal ultrasound and post-mortem magnetic resonance imaging (PMMR) for structural abnormalities.

METHOD

PMMR was performed on consecutive fetuses over a 6-year period. Prenatal ultrasound and PMMR findings were categorised as concordant, partially concordant or discordant findings. The yield of new and clinically significant information from autopsy was assessed. Diagnostic accuracies for both modalities were calculated, using autopsy as reference standard.

RESULTS

Our study consisted of 81 fetuses. PMMR and prenatal ultrasound findings were concordant in 44/81 (54.3%), partially concordant in 26/81 (32.1%) and discordant in 11/81 (13.6%) cases. In 19/81 cases (23%), autopsy provided additional information, which appeared clinically significant in 12 cases. In 10 of those 12 cases, there was discordance between PMMR and ultrasound. In only 2 of 44 cases where ultrasound and PMMR were concordant, did autopsy provide clinically significant information. Diagnostic accuracy rates for ultrasound were sensitivity of 76.8% (66.6%, 84.6%), specificity of 92.5% (88.9%, 95.0%). For PMMR the sensitivity was 79.0% (68.9%, 86.5%), specificity 97.9% (95.5%, 99.0%). PMMR had a significantly higher concordance rate with autopsy than ultrasound (89.0 vs 93.8%; P < .001).

CONCLUSION

Where PMMR and ultrasound are concordant, there is little additional yield from autopsy.

Perinatal post mortem ultrasound (PMUS): a practical approach

Declining rates of consent for standard perinatal autopsy has led to a rise in interest for postmortem imaging as an alternative, non-invasive method for investigation of childhood and perinatal deaths. Whilst much interest has focussed on cross-sectional techniques such as postmortem CT (PMCT) or MRI (PMMR), other modalities including postmortem ultrasound (PMUS) have been shown to have reasonable diagnostic accuracy rates, with the added benefit of being more readily accessible and affordable. There is little published information or formal guidance available on preparation for postmortem perinatal ultrasound, views to be obtained and differentiating normal postmortem change from potential abnormalities.

This article will focus on the role of perinatal postmortem ultrasound as an alternative imaging method for non-invasive autopsy, with emphasis on imaging technique, practical considerations and commonly encountered case examples.

Postmortem magnetic resonance imaging vs autopsy of second trimester fetuses terminated due to anomalies

Introduction

Our aim was to investigate the accuracy of postmortem fetal magnetic resonance imaging (MRI) compared with fetal autopsy in second trimester pregnancies terminated due to fetal anomalies. A secondary aim was to compare the MRI evaluations of two senior radiologists.

Material and methods

This was a prospective study including 34 fetuses from pregnancies terminated in the second trimester due to fetal anomalies. All women accepted a postmortem MRI and an autopsy of the fetus. Two senior radiologists performed independent evaluations of the MRI images. A senior pathologist performed the fetal autopsies. The degree of concordance between the MRI evaluations and the autopsy reports was estimated as well as the consensus between the radiologists.

Results

Thirty‐four fetuses were evaluated. Sixteen cases were associated with the central nervous system (CNS), five were musculoskeletal, one cardiovascular, one was associated with the urinary tract, and 11 cases had miscellaneous anomalies such as chromosomal aberrations, infections and syndromes. In the 16 cases related to the CNS, both radiologists reported all or some, including the most clinically significant anomalies in 15 (94%; CI 70%‐100%) cases. In the 18 non‐CNS cases, both radiologists reported all or some, including the most clinically significant anomalies in six (33%; CI 5%‐85%) cases. In 21 cases (62%; CI 44%‐78%), both radiologists held opinions that were consistent with the autopsy reports. The degree of agreement between the radiologists was high, with a Cohen's Kappa of 0.87.

Conclusions

Postmortem fetal MRI can replace autopsy for second trimester fetuses with CNS anomalies. For non‐CNS anomalies, the concordance is lower but postmortem MRI can still be of value when autopsy is not an option.

Diagnostic accuracy of perinatal post-mortem ultrasound (PMUS): a systematic review

OBJECTIVE

Ultrasound is ubiquitous in live paediatric imaging; however, its usage in post-mortem setting is less established. This systematic review aims to evaluate the diagnostic accuracy of paediatric post-mortem ultrasound (PMUS).

DESIGN

MEDLINE, Embase and Cochrane Library databases were queried for studies published between 1998 and 2018 assessing PMUS diagnostic accuracy rates in children<18 years old, using autopsy as reference standard. Risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies 2. A bivariate random-effects model was used to obtain combined mean estimates of sensitivity and specificity for different body systems.

RESULTS

Four studies were included, all relating to ultrasound for perinatal deaths. The mean diagnostic sensitivity and specificity for neurological abnormalities were 84.3% (95% CI: 70.8% to 92.2%) and 96.7% (95% CI: 86.5% to 99.3%); for cardiothoracic abnormalities 52.1% (95% CI: 27.6% to 75.5%,) and 96.6% (95% CI: 86.8% to 99.2%); and for abdominal abnormalities 78.4% (95% CI: 61.0% to 89.4%) and 97.3% (95% CI: 88.9% to 99.4%). Combining all body systems, the mean sensitivity and specificity were 73.3% (95% CI: 59.9% to 83.5%) and 96.6% (95% CI: 92.6% to 98.4%).

CONCLUSIONS

PMUS demonstrates a reasonable diagnostic accuracy, particularly for abdominal and neurological abnormalities, although cardiac anomalies were less readily identified.

TRIAL REGISTRATION NUMBER

CRD42018106968.

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.

Total-body CT and MR features of postmortem change in in-hospital deaths

OBJECTIVES

To evaluate the frequency of total-body CT and MR features of postmortem change in in-hospital deaths.

MATERIALS AND METHODS

In this prospective blinded cross-sectional study, in-hospital deceased adult patients underwent total-body postmortem CT and MR followed by image-guided biopsies. The presence of PMCT and PMMR features related to postmortem change was scored retrospectively and correlated with postmortem time interval, post-resuscitation status and intensive care unit (ICU) admittance.

RESULTS

Intravascular air, pleural effusion, periportal edema, and distended intestines occurred more frequently in patients who were resuscitated compared to those who were not. Postmortem clotting was seen less often in resuscitated patients (p = 0.002). Distended intestines and loss of grey-white matter differentiation in the brain showed a significant correlation with postmortem time interval (p = 0.001, p<0.001). Hyperdense cerebral vessels, intravenous clotting, subcutaneous edema, fluid in the abdomen and internal livores of the liver were seen more in ICU patients. Longer postmortem time interval led to a significant increase in decomposition related changes (p = 0.026).

CONCLUSIONS

There is a wide variety of imaging features of postmortem change in in-hospital deaths. These imaging features vary among clinical conditions, increase with longer postmortem time interval and must be distinguished from pathologic changes.

Perinatal death investigations: What is current practice?

Perinatal death (PD) is a devastating obstetric complication. Determination of cause of death helps in understanding why and how it occurs, and it is an indispensable aid to parents wanting to understand why their baby died and to determine the recurrence risk and management in subsequent pregnancy. Consequently, a perinatal death requires adequate diagnostic investigation. An important first step in the analysis of PD is to identify the case circumstances, including relevant details regarding maternal history, obstetric history and current pregnancy (complications are evaluated and recorded). In the next step, placental examination is suggested in all cases, together with molecular cytogenetic evaluation and fetal autopsy. Investigation for fetal-maternal hemorrhage by Kleihauer is also recommended as standard. In cases where parents do not consent to autopsy, alternative approaches such as minimally invasive postmortem examination, postmortem magnetic resonance imaging, and fetal photographs are good alternatives. After all investigations have been performed it is important to combine findings from the clinical review and investigations together, to identify the most probable cause of death and counsel the parents regarding their loss.

Learning effect on perinatal post-mortem magnetic resonance imaging reporting: single reporter diagnostic accuracy of 200 cases

OBJECTIVE

The objective of the study is to compare diagnostic accuracy of perinatal post-mortem magnetic resonance (PMMR) imaging against conventional autopsy, when reported by a single-blinded observer for all organ systems following a period of initial experience.

METHODS

We compared pre-autopsy PMMR with conventional autopsy for the detection of (1) major pathological abnormalities related to the cause of death and (2) all diagnostic findings in five different body organ systems. PMMR was reported blinded to autopsy findings.

RESULTS

In 201 cases, 123/146 (84.2%) of major abnormalities were identified by PMMR. Overall diagnostic accuracy of PMMR was 89.6% [95% confidence interval (CI): 84.3, 93.2%] across all cases, with high concordance 91.8% (95% CI: 89.9, 93.4%) across most organ systems. Our study showed higher concordance than single reporter statistics previously reported in neurological [92.2% vs 73.8%; diff 18.4% (95% CI: 11.0, 25.4%) p < 0.01] and thoracic systems [93.7% vs 81.2%; diff 12.5% (95% CI: 6.3, 18.4%) p < 0.01] and slightly better overall [91.8% vs 87.1%; diff 4.7% (95% CI: 2.1, 7.3%) p < 0.01].

CONCLUSION

The PMMR examinations can be reliably reported by a single radiologist, following a period of experience and training with this specific modality, with high-diagnostic accuracy for all organ systems. © 2017 John Wiley & Sons, Ltd.

Current issues in postmortem imaging of perinatal and forensic childhood deaths

Perinatal autopsy practice is undergoing a state of change with the introduction of evidence-based cross-sectional imaging, driven primarily by parental choice. In particular, the introduction of post mortem magnetic resonance imaging (PMMR) has helped to advance less-invasive perinatal autopsy in the United Kingdom (UK) and Europe. However, there are limitations to PMMR and other imaging techniques which need to be overcome, particularly with regard to imaging very small fetuses. Imaging is also now increasingly used to investigate particular deaths in childhood, such as suspected non-accidental injury (NAI) and sudden unexpected death in infancy (SUDI). Here we focus on current topical developments the field, with particular emphasis on the application of imaging to perinatal autopsy, and pediatric forensic deaths. Different imaging modalities and their relative advantages and disadvantages are discussed, together with other benefits of more advanced cross-sectional imaging which currently lie in the research domain. Whilst variations in local imaging service provision and need may determine different practice patterns, and access to machines and professionals with appropriate expertise and experience to correctly interpret the findings may limit current practices, we propose that gold standard perinatal and pediatric autopsy services would include complete PMMR imaging prior to autopsy, with PMCT in suspicious childhood deaths. This approach would provide maximal diagnostic yield to the pathologist, forensic investigator and most importantly, the parents.

ESPR postmortem imaging task force: where we begin

A new task force on postmortem imaging was established at the annual meeting of the European Society of Paediatric Radiology (ESPR) in Graz, Austria, in 2015. The postmortem task force is separate from the child abuse task force as it covers all aspects of fetal, neonatal and non-forensic postmortem imaging. The main focus of the task force is the guidance and standardization of non-radiographic postmortem imaging, particularly postmortem CT and postmortem MRI. This manuscript outlines the starting point of the task force, with a mission statement, outline of current experience, and short- and long-term goals.

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.

Indications, advantages and limitations of perinatal postmortem imaging in clinical practice

Just as there is a range of paediatric imaging techniques available during life, a similar repertoire is available as part of the foetal and perinatal postmortem examination. In this article, we review the literature regarding the diagnostic utility of postmortem radiography, US, CT and MRI in this clinical setting. There is limited direct evidence on the diagnostic utility of any of these techniques, apart from postmortem MRI, which when combined with other noninvasive investigations, has been shown to be highly sensitive and specific for many foetal postmortem diagnoses. The main disadvantages of postmortem MRI include the longer duration of imaging, the need for appropriate training in the interpretation of normal postmortem changes, and possible non-diagnostic imaging examinations in early gestation foetuses. As less-invasive autopsy becomes increasingly available, the true utility of these techniques will evolve, and clinical guidelines for maximal diagnostic yield can be developed.