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

Impact of non-invasive post-mortem micro-CT imaging on a fetal autopsy service: a single centre retrospective study

AIM

To evaluate the impact of a new, less-invasive micro-computed tomography (CT) service on autopsy service provision. We recorded parental consent, type of autopsy performed, autopsy reporting times and time taken for the body to be released from the mortuary.

MATERIALS AND METHODS

A retrospective, single-centre case series was conducted for all perinatal deaths since the introduction of our micro-CT service in 2016, with a detailed review of records extracted from 2019 and 2021. Fetal demographics (gestational age, weight), type of autopsy conducted, and the time taken from receiving the body to releasing the body and issuing a final report were recorded.

RESULTS

Micro-CT imaging uptake increased to over two hundred cases/year by 2021. Overall, invasive autopsies reduced from (45.8%, 196/428; 2019) to (32.1%, 125/390; 2021) with an equivalent rise in less-invasive autopsy from 54.2% (232/428;2019) to 67.9% (265/390;2019). Offering a micro-CT service resulted in an increase in consent to imaging-based autopsies from (76.9%, 329/428;2019) to (87.2%, 340/390;2021). Micro-CT has become the most common post-mortem imaging performed in our institution at 54.4% (212/251;2021), although the body preparation time from the tissue staining required has increased the time to provide an autopsy report to 17 days and release of the body to 18 days.

CONCLUSION

Our study shows that introducing a micro-CT post-mortem imaging service was associated with reduced use of conventional invasive procedures, despite a slight increase in turnaround times. Understanding these factors and continued improvements in micro-CT service delivery will help make this accessible to a wider population in the future.

Standardizing Minimally Invasive Tissue Sampling of Postmortem Brain Using Bard Monopty Needle in Newborns with Neurological Injury

INTRODUCTION

Minimally invasive tissue sampling of the brain in newborns using the Bard Monopty needle helps to diagnose various neurological conditions by obtaining relevant brain cores. We designed a modified procedure to provide maximum diagnostic utility in brain tissue biopsies.

METHOD

Twenty newborns underwent postmortem minimally invasive tissue sampling of the brain through the anterior fontanelle and posterior approach, using the engraved lines on the needle labeled from mark 0 to 13. The cores were correlated with conventional autopsy findings.

RESULTS

Meninges were best obtained at marks 0 and 1 from the anterior fontanelle and mark 1 from posterior fontenelle in 85% of cases. Periventricular brain parenchyma was best obtained from mark 3 and mark 1 from anterior and posterior fontanel, respectively in 90% cases. The sampling success in obtaining brain cores was 100%.

DISCUSSION

This modified technique increases the yield of meninges and brain tissue in newborns and aids in diagnosis.

Minimally invasive autopsy - endoscopic approach to post-mortem diagnostics

The noticeable decline in the number of autopsies performed in recent years requires investigation into the causes of the phenomenon and attempts to prevent it. One potential cause of this trend is fear of disfiguring the body. Carrying out autopsies using a minimally invasive method may reduce the decrease in the number of autopsies performed. The first work on the development of the method and its continuation gave promising results. This allows us to start a discussion on attempts to introduce the method. The solution seems especially justified when the alternative is to completely abandon post-mortem examinations using the traditional method. Laparoscopy and thoracoscopy are tools that allow for accurate imaging and analysis of organ changes. Enriching them with additional tests using endoscopic techniques may have a positive impact on the accuracy of autopsy diagnoses. The development of a clear protocol for minimally invasive post-mortem diagnosis requires further research to determine the accuracy of the method.

Minimally invasive autopsy in the evaluation of fetal malformations and stillbirths: A feasibility study

BACKGROUND

Minimally invasive autopsy (MIA) using post-mortem magnetic resonance imaging with ancillary investigations is reported as accurate as conventional autopsy. This study assesses MIA's feasibility and accuracy compared to conventional autopsy.

METHOD

MIA and/or conventional autopsy were performed on malformed fetuses (14-20 weeks gestation) and stillbirths (>20 weeks gestation), with/without malformation. Concordance in diagnostic accuracy (95% confidence interval [CI]) and agreement (Kappa coefficient [k]) were assessed in malformed cases where both MIA and autopsy were conducted.

RESULTS

We enrolled 200 cases, including 100 malformed fetuses (<20 weeks) and 100 stillbirths (with/without malformations). Concordance of 97.3% was observed between MIA and autopsy in 156 malformed cases. The overall diagnostic accuracy of MIA was 96.04%.

CONCLUSION

While conventional autopsy remains the gold standard, MIA is feasible in tertiary care settings. It can be considered a potential alternative for post-mortem assessment, particularly in settings with limited facility of conventional autopsy and parental refusal.

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.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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.

Prospective cohort study: Causes of stillbirth in Australia 2013-2018

BACKGROUND

Stillbirth is a major public health problem that is slow to improve in Australia. Understanding the causes of stillbirth through appropriate investigation is the cornerstone of prevention and important for parents to understand why their baby died.

AIM

The aim of this study is to assess compliance with the Perinatal Society of Australia and New Zealand (PSANZ) Perinatal Mortality Clinical Practice Guidelines (2009) for stillbirths.

METHODS

This is a prospective multi-centred cohort study of stillbirths at participating hospitals (2013-2018). Data were recorded into a purpose-built database. The frequency of the recommended core investigations was calculated, and χ² test was performed for subgroup analyses by gestational age groups and timing of fetal death. A 70% compliance threshold was defined for investigations. The cause of death categories was provided according to PSANZ Perinatal Death Classification.

RESULTS

Among 697 reported total stillbirths, 562 (81%) were antepartum, and 101 (15%) were intrapartum. The most common cause of death categories were 'congenital abnormality' (12.5%), 'specific perinatal conditions' (12.2%) and 'unexplained antepartum death' (29%). According to 2009 guidelines, there were no stillbirths where all recommended investigations were performed (including or excluding autopsy). A compliance of 70% was observed for comprehensive history (82%), full blood count (94%), cytomegalovirus (71%), toxoplasmosis (70%), renal function (75%), liver function (79%), external examination (86%), post-mortem examination (84%) and placental histopathology (92%). The overall autopsy rate was 52%.

CONCLUSIONS

Compliance with recommended investigations for stillbirth was suboptimal, and many stillbirths remain unexplained. Education on the value of investigations for stillbirth is needed. Future studies should focus on understanding the yield and value of investigations and service delivery gaps that impact compliance.

[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.

Postmortem microfocus computed tomography for noninvasive autopsies: experience in >250 human fetuses

Background

Noninvasive imaging autopsy alternatives for fetuses weighing <500 grams are limited. Microfocus computed tomography has been reported as a viable option in small case series with the potential to avoid an invasive autopsy. Implementation of postmortem microfocus computed tomography in a large cohort as part of routine clinical service has yet been unreported, and realistic “autopsy prevention rates” are unknown.

Objective

This study aimed to describe the range of abnormalities detectable on fetal microfocus computed tomography in a clinical setting and additional findings identified on the antenatal ultrasound and to estimate the invasive autopsy avoidance rate (ie, cases in which imaging was sufficient to deem autopsy unnecessary).

Study Design

A prospective observational case series of all fetuses referred for microfocus computed tomography imaging at a single institution was conducted for 3 years (2016–2019). Imaging was reported by 2 pediatric radiologists before autopsy, with “decision to proceed” based on the specialist perinatal pathologists’ judgment and parental consent. Agreement rates between microfocus computed tomography and antenatal ultrasound were evaluated, and where feasible, diagnostic accuracy for microfocus computed tomography was calculated using autopsy as a reference standard.

Results

A total of 268 fetuses were included (2–350 grams body weight; 11–24 weeks’ gestation), with cause for demise in 122 of 268 (45.5%). Of the 122 fetuses, 64 (52.5%) exhibited fetal anomalies. Although 221 of 268 (82.5%) fetuses had consent for invasive autopsy, only 29 of the 221 (13.1%) underwent this procedure, which implied an autopsy avoidance rate of 192 of 221 (86.9%). Complete agreement was present for all brain, thoracic, and abdominal pathologies, whereas sensitivity and specificity for cardiac anomalies were 66.7% and 91.7%, respectively. Microfocus computed tomography and antenatal ultrasound agreement was found in 219 of 266 cases (81.9%), with partial agreement in 21 of 266 (7.9%) and disagreement in 26 of 266 (10.5%), mostly because of additional cardiac, soft tissue, or genitourinary findings by microfocus computed tomography, which were not seen on the ultrasound.

Conclusion

Fetal microfocus computed tomography imaging is a viable and useful tool for imaging early gestational fetuses and can avoid the need for invasive autopsy. Confirmation of antenatal diagnoses is achieved in most cases, and additional anomalies may also be detected.

A structured collaborative approach to intervention design using a modified intervention mapping approach: a case study using the Management and Interventions for Asthma (MIA) project for South Asian children

BACKGROUND

To describe how using a combined approach of community-based participatory research and intervention mapping principles could inform the development of a tailored complex intervention to improve management of asthma for South Asian (SA) children; Management and Interventions for Asthma (MIA) study.

METHODS

A qualitative study using interviews, focus groups, workshops, and modified intervention mapping procedures to develop an intervention planning framework in an urban community setting in Leicester, UK. The modified form of intervention mapping (IM) included: systematic evidence synthesis; community study; families and healthcare professionals study; and development of potential collaborative intervention strategies. Participants in the community study were 63 SA community members and 12 key informants; in-depth semi-structured interviews involved 30 SA families, 14 White British (WB) families and 37 Healthcare Professionals (HCPs) treating SA children living with asthma; prioritisation workshops involved 145 SA, 6 WB and 37 HCP participants; 30 participants in finalisation workshops.

RESULTS

Two key principles were utilised throughout the development of the intervention; community-based participatory research (CBPR) principles and intervention mapping (IM) procedures. The CBPR approach allowed close engagement with stakeholders and generated valuable knowledge to inform intervention development. It accounted for diverse perceptions and experiences with regard to asthma and recognised the priorities of patients and their families/caregivers for service improvement. The 'ACT on Asthma' programme was devised, comprising four arms of an intervention strategy: education and training, clinical support, advice centre and raising awareness, to be co-ordinated by a central team.

CONCLUSIONS

The modified IM principles utilised in this study were systematic and informed by theory. The combined IM and participatory approach could be considered when tailoring interventions for other clinical problems within diverse communities. The IM approach to intervention development was however resource intensive. Working in meaningful collaboration with minority communities requires specific resources and a culturally competent methodology.

Does the medical autopsy still have a place in the current diagnostic process? A 6-year retrospective study in two French University hospitals

Medical autopsies have been in considerable decline for several decades, in France and worldwide. We aimed to determine whether a medical autopsy still currently has a role to play in diagnosis, by analyzing its performance and diagnostic limitations. This dual-centre retrospective descriptive study included all medical autopsies performed in the university hospitals of Lille and Marseille, France, between January 2007 and December 2012. Autopsies of fetuses or stillborn infants, or those related to sudden infant deaths and research protocols were excluded. 412 medical autopsies were included. The male:female ratio was 1.5:1 and mean age was 27.3 years. Half of all autopsies were pediatric. Regarding anatomical region and/or injury mechanism, a clinical diagnosis was suggested in 52.2% of cases, an autopsy diagnosis in 55.6% and a microscopic diagnosis in 81.8%. There was very low agreement between the clinician's suggested diagnosis and the final diagnosis, both for organ specific diseases and cause of death. Agreement was moderate between autopsy diagnoses and microscopic diagnoses for organ specific diseases and low for cause of death. From our findings we concluded that an autopsy associated with microscopic examination was still valuable in diagnosing cause of death. Microscopic examination was indispensable to determine certain causes of death.