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

Three-dimensional versus two-dimensional postmortem ultrasound: feasibility in perinatal death investigation

Three- and four-dimensional US techniques in antenatal screening are commonplace, but they are not routinely used for perinatal postmortem US. In this technical innovation, we performed both two-dimensional (2-D) and three-dimensional (3-D) postmortem US on 11 foetuses (mean gestation: 23 weeks; range: 15–32 weeks) to determine whether there was any benefit in 3-D over conventional 2-D methods. In one case of osteogenesis imperfecta, both 2-D and 3-D US images were non-diagnostic because of small foetal size. Of the remaining 10 foetuses, 7 were normal at imaging and autopsy, and 3 had abnormalities detected on both 2-D and 3-D US. There were no false-positive diagnoses by 2-D or 3-D US. Whilst 3-D postmortem US was a feasible technique, it did not provide additional information over 2-D US. Routine 3-D postmortem US cannot therefore be routinely recommended based on our findings

Diagnostic accuracy of postmortem ultrasound vs 1.5T postmortem MRI for non-invasive perinatal autopsies

Objectives: To determine the diagnostic accuracy of postmortem magnetic resonance imaging (PM-MRI) and postmortem ultrasound (PM-US) for perinatal autopsy in the same patient cohort, and to determine whether PM-US can provide the same anatomical information as PM-MRI. Methods: In this prospective, 5-year (July 2014–July 2019) single-center study, we performed 1.5-T PM-MRI and PM-US in an unselected cohort of perinatal deaths. The diagnostic accuracies of both modalities were calculated, using autopsy as the reference standard. As a secondary objective, the concordance rates between the two imaging modalities for the overall main diagnosis and for five anatomical regions (brain, spine, thorax, heart and abdomen) were calculated. Results: During the study period, 136 cases underwent both PM-US and PM-MRI, of which 88 (64.7%) also underwent autopsy. There was no significant difference in the rates of concordance with autopsy between the two modalities for overall diagnosis (PM-US, 86.4% (95% CI, 77.7–92.0%) vs PM-MRI, 88.6% (95% CI, 80.3–93.7%)) or in the sensitivities and specificities for individual anatomical regions. There were more non-diagnostic PM-US than PM-MRI examinations for the brain (22.8% vs 3.7%) and heart (14.7% vs 5.1%). If an ‘imaging-only’ autopsy had been performed, PM-US would have achieved the same diagnosis as 1.5-T PM-MRI in 86.8% (95% CI, 80.0–91.5%) of cases, with the highest rates of agreement being for spine (99.3% (95% CI, 95.9–99.9%)) and cardiac (97.3% (95% CI, 92.4–99.1%)) findings and the lowest being for brain diagnoses (85.2% (95% CI, 76.9–90.8%)). Conclusion: Although there were fewer non-diagnostic cases using PM-MRI than for PM-US, the high concordance rate for overall diagnosis suggests that PM-US could be used for triaging cases when PM-MRI access is limited or unavailable

Improving uptake of perinatal autopsy

PURPOSE OF REVIEW: Uptake of perinatal autopsy has declined in the West over the past 30 years, largely because of reduced parental acceptance of a traditional invasive autopsy. Several studies have recently investigated the decline to identify the key factors and how they may be mitigated. RECENT FINDINGS: Three main themes were identified that have been found to improve uptake of perinatal autopsy: improved communication, in particular ensuring the consent process was conducted as a conversation with time spent talking through the procedure and allowing time for questions; health professional training to ensure staff discussing autopsy with parents have adequate understanding of the procedure and are able to convey confidence and empathy; and availability of less invasive autopsy, including noninvasive as well as minimally invasive options. These should be offered alongside standard autopsy, which some parents may still prefer. SUMMARY: This review highlights that the discussions that take place, and the options that are available to parents, can profoundly impact whether or not they consent to autopsy investigation. Further research should focus on the impact of offering less invasive options as well as evaluating the training and support materials that have recently been developed

Multiple Cardiac Rhabdomyomas Visualised Using Micro-CT in a Case of Tuberous Sclerosis

Cardiac rhabdomyoma is the most common tumour of the heart in infancy and childhood, representing approximately 60% of all primary cardiac tumours in these age groups. Though they have a tendency to regress with advancing age and are histologically benign, rhabdomyomas may cause mechanical obstruction to blood flow, arrhythmia, congestive cardiac failure and death and may be associated with underlying genetic syndromes such as tuberous sclerosis. We present the case of a primigravida in her early 20s with no significant medical history who was referred to the Fetal Medicine Unit at 34 weeks' gestation following the detection of an irregular fetal heartbeat. An anomaly scan at 20 weeks had been reported as normal

Latest Developments in Post-Mortem Fetal 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 MRI, ultrasound, 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 fetuses. 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. 3D printing and augmented reality may help make imaging findings more accessible to parents, colleagues and trainees

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