Postmortem Magnetic Resonance Imaging Research Articles

Postmortem Neuroimaging of Cetacean Brains Using Computed Tomography and Magnetic Resonance Imaging

In the course of the pioneering virtopsy-driven cetacean stranding response program in the Hong Kong waters, postmortem computed tomography (PMCT) and postmortem magnetic resonance (PMMR) imaging (PMMRI) have been implemented to provide supplementary or complementary information for conventional necropsy. Stranded carcasses are often badly degraded and susceptible to rapid cerebral autolysis and putrefaction. Necropsy on decomposed brains with limited sample analysis often defy a specific diagnosis. Studies on PMMR neuroimaging have been focused on neuroanatomy and brain morphology in freshly deceased or preserved specimens. The literature is devoid of any reference on the potential value of PMMRI examination of decomposed cetacean brains. This project evaluated the benefits of PMMR neuroimaging in situ in decomposed carcasses in comparison to PMCT. A total of 18 cetacean carcasses were studied by PMCT and PMMRI examinations. Anatomical brain structures and visible brain pathologies were evaluated and scored using Likert-scale rating. Intracranial gas accumulation was clearly depicted in all cases by all radiological techniques. Other features were more clearly depictable in PMMRI than in PMCT images. The results of the present study indicated that superiority of PMMRI compared to PMCT increased with advancing putrefaction in brain. The preservation of structural integrity was visualized by PMMRI due to its superior ability to depict soft tissue. PMMRI brain should be incorporated in postmortem investigation of decomposed stranded cetaceans.

Skin temperature increase after whole body postmortem magnetic resonance imaging

• 1.5 T whole body postmortem magnetic resonance (PMMR) imaging was taken for 1 h. • The causes of skin temperature increase ( T inc ) after PMMR imaging was investigated. • Average specific absorption rates of PMMR imaging were within the safe range. • T inc is hardly influenced by radiofrequency heating but rather by room temperature. • 1.5 T whole body PMMR imaging for 1 h does not significantly warm up a cadaver. To investigate causes for skin temperature increase after whole body postmortem magnetic resonance (PMMR) imaging. We performed PMMR imaging using a 1.5 T clinical scanner on 28 deceased human adults. The corpses were kept in cold storage at 4 ℃ before MRI and the scan room was maintained at 23 ℃. Skin temperatures of corpses before and after MRI were measured and average specific absorption rates (SAR) of the measured points were calculated. Average skin temperature before and after PMMR imaging was 11.8 ± 5.8 ℃ and 15.0 ± 5.1 ℃, respectively. Average skin temperature increase was 3.2 ± 1.4 ℃, and whole-body average SAR in all sequences was 0.97 ± 0.94 W/kg. The skin temperature increase correlated significantly with the difference between the average initial skin temperature before PMMR imaging and the room temperature ( R 2 = 0.388, P = 0.002), but did not correlate significantly with whole-body average SAR in all sequences ( R 2 = 0.032, P = 0.662 > 0.05). The skin temperature increase during whole body PMMR imaging is more likely influenced by room temperature than by RF energy-induced heating effect. RF heating effect in PMMR imaging is minimal, and it appears to be no significant issue to conduct 1.5 T PMMR imaging prior to autopsy.

Mapping the trigeminal root entry zone and its pontine fibre distribution patterns.

IntroductionRecently, an additional trigeminothalamic tract – the dorsal trigeminothalamic tract – has been described in human brainstems by our group next to the known ventral trigeminothalamic tract. As various elements of the trigeminal system are known to be organised in a somatotopic fashion, the question arose whether the fibres within the trigeminal root show specific distributions patterns in their contribution to the ventral trigeminothalamic tract and dorsal trigeminothalamic tract specifically.MethodsThis study investigated the arrangement of the fibres in the trigeminal root by combining various imaging methods in the pons of 11 post-mortem specimens. The pons were investigated by polarised light imaging (PLI) (n = 4; to quantify fibre orientation; 100 µm interslice distance), histochemical staining methods (n = 3; to visualise the internal myeloarchitecture; 60 µm) and ultra-high field, post-mortem magnetic resonance imaging (MRI) (n = 4; for tractography; 500 µm interslice distance).ResultsThis study shows that the fibres, from the point where the trigeminal root enters the brainstem, are distinctly arranged by their contribution to the ventral trigeminothalamic tract and dorsal trigeminothalamic tract. This finding is supported by both post-mortem, ultra-high dMRI and different light microscopy techniques.ConclusionThe data from this study suggest that the fibres in the superior half of the root contribute mainly to the ventral trigeminothalamic tract, whereas the fibres in the inferior half mainly contribute to the dorsal trigeminothalamic tract. Such a somatotopic organisation could possibly create new insights into the anatomical origin of trigeminal neuralgia and the clinical relevance of this somatotopic organisation should therefore be further explored.

Skeletal muscular relaxation time from postmortem MR imaging of adult humans

Abstract Purpose To measure T1, and T2 values of the skeletal muscle by postmortem magnetic resonance (PMMR) imaging in adult humans at 1.5 T, and to compare them with those of living human subjects. Materials and methods We performed skeletal muscular PMMR imaging on 45 deceased adults (31 men, 14 women; mean age, 55.6 years). We measured T1 and T2 values of the right and left erector spinae muscles. The PMMR imaging data were compared with those from the corresponding sites in 13 healthy subjects. The association among rectal temperature, age and sex in T1 and T2 values was assessed by multiple regression analysis. Results By skeletal muscular PMMR imaging (clinical MR imaging), the average T1 values were: right:745 ± 107 ms (820 ± 108 ms); left:930 ± 133 ms (1022 ± 116 ms), and the average T2 values were: right:62± 9 ms (43± 5 ms); left:59 ± 7 ms (42 ± 5 ms). The left-right T1 difference was due to B1 inhomogeneity. Compared with clinical skeletal muscular MR imaging, PMMR imaging demonstrated significantly shorter T1 values and longer T2 values. On PMMR imaging, T1 values were significantly influenced by rectal temperature, whereas T2 values were significantly influenced by age and sex, but not by rectal temperature. Conclusion In the skeletal muscle, PMMR imaging shows shorter T1 values and longer T2 values than clinical MR imaging. T1 values decrease with lower rectal temperature and T2 values increase with female and elder age.

The Subplate Layers: The Superficial and Deep Subplate Can be Discriminated on 3 Tesla Human Fetal Postmortem MRI.

The subplate (SP) is a transient structure of the human fetal brain that becomes the most prominent layer of the developing pallium during the late second trimester. It is important in the formation of thalamocortical and cortico-cortical connections. The SP is vulnerable in perinatal brain injury and may play a role in complex neurodevelopmental disorders, such as schizophrenia and autism. Nine postmortem fetal human brains (19-24 GW) were imaged on a 3 Tesla MR scanner and the T2-w images in the frontal and temporal lobes were compared, in each case, with the histological slices of the same brain. The brains were confirmed to be without any brain pathology. The purpose of this study was to demonstrate that the superficial SP (sSP) and deep SP (dSP) can be discriminated on postmortem MR images. More specifically, we aimed to clarify that the observable, thin, hyperintense layer below the cortical plate in the upper SP portion on T2-weighted MR images has an anatomical correspondence to the histologically established sSP. Therefore, the distinction between the sSP and dSP layers, using clinically available MR imaging methodology, is possible in postmortem MRI and can help in the imaging interpretation of the fetal cerebral layers.

Approaching the forensic significance of possible PMMR correlates in a case of assumed cardiac rigor mortis

Abstract We demonstrate a left ventricular subendocardial ring as low signal intensity (SI) findings in a T2-weighted image (T2WI) sequence in postmortem magnetic resonance (PMMR) imaging. As plausible explanation, we propose rigor mortis of the heart muscle and discuss the implications of that. An 18-year-old man with a previous history of arrhythmia suddenly went into cardiopulmonary arrest while eating. Although cardiopulmonary resuscitation was performed for 120 min, death was confirmed. Autopsy revealed the cause of death to be sudden cardiac death due to arrhythmia induced by arrhythmogenic right ventricular cardiomyopathy. In this case, PMMR imaging performed before autopsy demonstrated a low SI area in the subendocardial region, suggesting a cardiac rigor mortis on the short-axial T2WI, apparent diffusion coefficient (ADC) map, and diffusion-weighted image (DWI). Low SI on T2WI is considered to be lesser interstitial fluids distribution in more-pressured subendocardial region, low SI on ADC map to be higher viscosity in subendocardial region, and low SI on DWI to be T2 blackout effect. PMMR imaging may delineate a correlate for assumed cardiac rigor mortis, which seems to be practically impossible to reliably identify macroscopically.

Ex Vivo MRI Analytical Methods and Brain Pathology in Preterm Lambs Treated with Postnatal Dexamethasone †.

Postnatal glucocorticoids such as dexamethasone are effective in promoting lung development in preterm infants, but are prescribed cautiously due to concerns of neurological harm. We developed an analysis pipeline for post-mortem magnetic resonance imaging (MRI) to assess brain development and hence the neurological safety profile of postnatal dexamethasone in preterm lambs. Lambs were delivered via caesarean section at 129 days’ (d) gestation (full term ≈ 150 d) with saline-vehicle control (Saline, n = 9), low-dose tapered dexamethasone (cumulative dose = 0.75 mg/kg, n = 8), or high-dose tapered dexamethasone (cumulative dose = 2.67 mg/kg, n = 8), for seven days. Naïve fetal lambs (136 d gestation) were used as end-point maturation controls. The left-brain hemispheres were immersion-fixed in 10 % formalin (24 h), followed by paraformaldehyde (>6 months). Image sequences were empirically optimized for T1- and T2-weighted MRI and analysed using accessible methods. Spontaneous lesions detected in the white matter of the frontal cortex, temporo-parietal cortex, occipital lobe, and deep to the parahippocampal gyrus were confirmed with histology. Neither postnatal dexamethasone treatment nor gestation showed any associations with lesion incidence, frontal cortex (total, white, or grey matter) or hippocampal volume (all p > 0.05). Postnatal dexamethasone did not appear to adversely affect neurodevelopment. Our post-mortem MRI analysis pipeline is suitable for other animal models of brain development.

Postmortem Magnetic Resonance Imaging and Postmortem Computed Tomography in Ligature and Manual Strangulation.

The aim of this study was to evaluate magnetic resonance imaging (MRI) findings in cases of fatal manual or ligature strangulation. Verification of strangulation by computed tomography (CT), MRI, and at autopsy as well as its detectability in each modality was assessed. We retrospectively analyzed 6 manual and ligature strangulation cases between 2013 and 2019 who all underwent a whole-body CT, head and neck MRI, and an autopsy. Two radiologists examined head and neck imaging data and compared the data to autopsy findings. Magnetic resonance imaging showed a high efficiency in verifying intramuscular hemorrhages, which were confirmed in autopsy. Moreover, in one case without a visible strangulation mark, soft tissue injuries associated with strangulation were detected. Fractures, especially thyroid cartilage fractures, were successfully diagnosed by CT. As MRI showed a successful detection of soft tissue lesions in relation to strangulation, it can serve as an alternative method or provide additional value to an autopsy. Intramuscular hemorrhages are a common finding in manual and ligature strangulation, providing a useful sign of applied pressure on the neck. However, to evaluate fractures, an additional CT or autopsy is recommended.

Full virtual autopsy in a case of a suicidal transthoracic gunshot injury

Abstract In a case of a single penetrating gunshot injury to the chest, all of the available imaging and imaging-related methods that are routinely used and indicated for reconstructive purposes were applied. These methods included postmortem computed tomography (PMCT), PMCT-angiography, PMCT with postmortem ventilation, postmortem magnetic resonance imaging (PMMR), PMMR-angiography, postmortem magnetic resonance spectroscopy, and three-dimensional surface documentation. This report offers a broad spectrum of imaging data of the same case; therefore, this report constitutes a case-based overview of contemporary postmortem imaging.

Post-mortem 7 Tesla MRI detection of white matter hyperintensities: A multidisciplinary voxel-wise comparison of imaging and histological correlates

White matter hyperintensities (WMH) occur in normal aging and across diagnostic categories of neurodegeneration. Ultra-high field imaging (UHF) MRI machines offer the potential to improve our understanding of WMH. Post-mortem imaging using UHF magnetic resonance imaging (MRI) is a useful way of assessing WMH, however, the responsiveness of UHF-MRI to pathological changes within the white matter has not been characterized. In this study we report post-mortem MRI sequences of white matter hyperintensities in normal aging, Alzheimer’s disease, and cerebrovascular disease. Seven Tesla post-mortem MRI reliably detected periventricular WMH using both FLAIR and T2 sequences and reflects underlying pathology of myelin and axon density despite prolonged fixation time. Co-registration of histological images to MRI allowed for direct voxel- wise comparison of imaging findings and pathological changes. Myelin content and cerebrovascular pathology were the most significant predictors of MRI white matter intensity as revealed by linear mixed models. Future work investigating the utility of UHF- MRI in studying cell-specific changes within WMH is required to better understand radio-pathologic correlations.

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.

Internal Subdivisions of the Marmoset Claustrum Complex: Identification by Myeloarchitectural Features and High Field Strength Imaging.

There has been a surge of interest in the structure and function of the mammalian claustrum in recent years. However, most anatomical and physiological studies treat the claustrum as a relatively homogenous structure. Relatively little attention has been directed toward possible compartmentalization of the claustrum complex into anatomical subdivisions, and how this compartmentalization is reflected in claustrum connections with other brain structures. In this study, we examined the cyto- and myelo-architecture of the claustrum of the common marmoset (Callithrix jacchus), to determine whether the claustrum contains internal anatomical structures or compartments, which could facilitate studies focused on understanding its role in brain function. NeuN, Nissl, calbindin, parvalbumin, and myelin-stained sections from eight adult marmosets were studied using light microscopy and serial reconstruction to identify potential internal compartments. Ultra high resolution (9.4T) post-mortem magnetic resonance imaging was employed to identify tractographic differences between identified claustrum subcompartments by diffusion-weighted tractography. Our results indicate that the classically defined marmoset claustrum includes at least two major subdivisions, which correspond to the dorsal endopiriform and insular claustrum nuclei, as described in other species, and that the dorsal endopiriform nucleus (DEnD) contains architecturally distinct compartments. Furthermore, the dorsal subdivision of the DEnD is tractographically distinguishable from the insular claustrum with respect to cortical connections.

Minimally invasive perinatal and pediatric autopsy with laparoscopically assisted tissue sampling: feasibility and experience of the MinImAL procedure.

Less invasive autopsy techniques in cases of fetal or infant death have good acceptability among parents, but the published sampling adequacy in needle biopsy studies is generally poor. Minimally Invasive Autopsy with Laparoscopically assisted sampling (MinImAL) has the potential to increase the diagnostic yield of less invasive autopsy by improving the quality and quantity of tissue samples obtained, whilst permitting visualization, extraction and examination of internal organs through a small incision. The aim of this study was to present the findings of our experience with the MinImAL procedure in cases of fetal, neonatal and pediatric death. This was a retrospective analysis of 103 prospectively recruited unselected cases of fetal, neonatal or pediatric death that underwent the MinImAL procedure at a tertiary referral center over a 5-year period. Following preprocedure 1.5-T whole-body postmortem magnetic resonance imaging, MinImAL autopsy was performed. Procedure duration, sampling adequacy and cause of death were assessed. Chi-square analysis was used to compare the 'unexplained' rate of intrauterine deaths in the cohort with that in a previously published cohort of > 1000 cases of intrauterine death examined by standard autopsy. MinImAL autopsy was performed successfully in 97.8% (91/93) of the cases undergoing a complete procedure. There was a satisfactory rate of adequate histological sampling in most major organs; heart (100%, 91 cases), lung (100%, 91 cases), kidney (100%, 91 cases), liver (96.7%, 88 cases), spleen (94.5%, 86 cases), adrenal glands (89.0%, 81 cases), pancreas (82.4%, 75 cases) and thymus (56.0%, 51 cases). Procedure duration was similar to that of standard autopsy in a previously published cohort of intrauterine deaths. The unexplained rate in stillbirths and intrauterine fetal deaths that underwent MinImAL autopsy was not significantly different from that following standard autopsy. The MinImAL procedure provides good histological yield from major organs with minimal cosmetic damage and can be learned by an autopsy practitioner. The MinImAL procedure is an appropriate minimally invasive alternative for the investigation of perinatal and pediatric deaths in which consent to full autopsy is withheld, and may have applications in both high- and low/middle-income settings. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Communicating 3D data-interactive 3D PDF documents for expert reports and scientific publications in the field of forensic medicine.

Modern forensic investigations increasingly revert to 3D imaging techniques, such as computed tomography, magnetic resonance imaging, and 3D surface imaging. Findings are therefore often based on 3D data sets; however, this information is commonly reported and communicated within 2D imagery. The use of interactive 3D PDFs is already established in the scientific community but has yet to be implemented in the field of forensic medicine. Three example cases were chosen to serve as exemplary data for the most commonly applied imaging techniques in postmortem imaging. 3D surface models were created from postmortem magnetic resonance imaging (PMMR), postmortem computed tomography (PMCT), and 3D surface imaging data sets. PMMR revealed a space-occupying subdural hemorrhage that led to ipsilateral compression of the brain tissue of the right hemisphere. PMCT displayed a defect in the skull on the left side of the temporal bone. 3D surface imaging data displayed a patterned discoloration on the inside of the left forearm. Interactive 3D PDFs offer the possibility to communicate 3D information to the reader while maintaining all the benefits of a regular 2D PDF. With Adobe Acrobat, the reader can interactively navigate through 3D data sets and create sufficient depth cues to generate a realistic 3D perception of the data. The interactive 3D PDF is a useful extension of standard 2D PDFs and has the potential to communicate 3D data to the reader in a more complete, more comprehensible, and less subjective manner than 2D PDFs.

EP16.30: Fetal triventricular hydrocephalus associated with different findings in pre‐ and postmortem fetal magnetic resonance imaging: a case report

We present a case of fetal triventricular hydrocephalus associated with distinct different findings in the fetal cerebellum and liver when comparing pre- and postmortem fetal magnetic resonance imaging (MRI). A 34-year-old, gravid 2, para 1, woman underwent prenatal ultrasound examination at 22+4 weeks of gestation which showed a triventrucular hydrocephalus, along with hepatic calcification, a hyperechogenic intestine, ascites, mild pericardial effusion, and a white spot in the left ventricle without hemodynamic significance. The ultrasound examination at 13 weeks gestation had been completely normal. TORCH infection screen was negative. The couple declined invasive diagnostic screening for genetic analysis. The prenatal fetal MRI that showed suspicion of cerebellar infarction as the cause of the triventricular hydrocepalus. The liver calcification, with a hyperechogenic intestine, ascites, moderate pericardial effusion, and white spots in the left ventricle were confirmed. After intensive interdisciplinary counselling, the couple opted termination of pregnancy. After delivery the fetus underwent post-mortem fetal MRI, 6 days following the initial scan. This MRI suggested a cerebellar vascular malformation with minimal bleeding and subarachnoid hemorrhage but also showed a novel finding: hemangiomatosis of the liver with minimal bleeding and under perfused liver parenchyma. In conclusion, the use of post-mortem fetal MRI may be useful to identify pathological findings not evident in pre-mortem MRI due in part to the greater precision of the examination. Postmortem examination of the brain is often inconclusive. The use of post mortem MRI instead of autopsy offers a non-invasive way to identify the cause of fetal malformations. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

OC21.07: The diagnostic value of postmortem magnetic resonance imaging of the fetal heart compared to conventional autopsy and ultrasound

OC21.07: The diagnostic value of postmortem magnetic resonance imaging of the fetal heart compared to conventional autopsy and ultrasound

Relating diffusion tensor imaging measurements to microstructural quantities in the cerebral cortex in multiple sclerosis.

To investigate whether the observed anisotropic diffusion in cerebral cortex may reflect its columnar cytoarchitecture and myeloarchitecture, as a potential biomarker for disease‐related changes, we compared postmortem diffusion magnetic resonance imaging scans of nine multiple sclerosis brains with histology measures from the same regions. Histology measurements assessed the cortical minicolumnar structure based on cell bodies and associated axon bundles in dorsolateral prefrontal cortex (Area 9), Heschl's gyrus (Area 41), and primary visual cortex (V1). Diffusivity measures included mean diffusivity, fractional anisotropy of the cortex, and three specific measures that may relate to the radial minicolumn structure: the angle of the principal diffusion direction in the cortex, the component that was perpendicular to the radial direction, and the component that was parallel to the radial direction. The cellular minicolumn microcircuit features were correlated with diffusion angle in Areas 9 and 41, and the axon bundle features were correlated with angle in Area 9 and to the parallel component in V1 cortex. This may reflect the effect of minicolumn microcircuit organisation on diffusion in the cortex, due to the number of coherently arranged membranes and myelinated structures. Several of the cortical diffusion measures showed group differences between MS brains and control brains. Differences between brain regions were also found in histology and diffusivity measurements consistent with established regional variation in cytoarchitecture and myeloarchitecture. Therefore, these novel measures may provide a surrogate of cortical organisation as a potential biomarker, which is particularly relevant for detecting regional changes in neurological disorders.

Post-mortem 11.7 Tesla Magnetic Resonance Imaging vs. Polarized Light Imaging Microscopy to Measure the Angle and Orientation of Dorsal Root Afferents in the Human Cervical Dorsal Root Entry Zone.

Background: Destruction of the afferents by dorsal root entry zone (DREZ) surgery may be an effective treatment of intractable neuropathic pain, though it remains a high-risk surgical intervention. Potential complications due to the lesioning of structures within the cervical spinal cord other than the DREZ can be minimized by accurate knowledge of the optimal insertion angle [i.e., the angle between the DREZ and the posterior median sulcus (PMS)]. The employed insertion angle was based on measurements between the DREZ and the PMS on post-mortem transverse slices. However, new, more sophisticated imaging techniques are currently available and are thought to yield higher spatial resolution and more accurate images.Obejctive: This article measures the angle between the DREZ and the PMS on 11.7T post-mortem magnetic resonance images and compares these findings with polarized light imaging (PLI) microscopy images of the same specimens in order to quantify fiber orientation within the DREZ.Methods: To visualize the anatomy of the cervical DREZ, magnetic resonance imaging (MRI), diffusion-weighted MRI (dMRI), probabilistic tractography, and PLI were performed on three post-mortem human cervical spinal cords at level C5–C6. The MR data was used to measure the angle between the DREZ and the PMS. MR images were complemented by probabilistic tractography results. Then, the orientation of fibers within the DREZ was quantified by use of PLI microscopy.Results: Median angle between the DREZ and the PMS, as measured on MR-images, was found to be 40.1° (ranging from 34.2° to 49.1°) and 39.8° (ranging from 31.1° to 47.8°) in the left and right hemicord, respectively. Median fiber orientation within the DREZ, as quantified by PLI, was 28.5° (ranging from 12.0° to 44.3°) and 27.7° (ranging from 8.5° to 38.1°) in the left and right hemicord, respectively.Conclusion: Our study, which provides an improved understanding of the anatomy of the DREZ, the angle between the DREZ and the PMS and the median fiber orientation within the DREZ, could contribute to safer DREZ-lesioning surgery to treat chronic neuropathic pain in the future.

Automated data extraction and report analysis in computer-aided radiology audit: practice implications from post-mortem paediatric imaging

To determine local departmental adherence to the paediatric post-mortem magnetic resonance imaging (MRI) protocols, using a customised automated computational approach. A retrospective review of 460 whole-body post-mortem MRI examinations performed at Great Ormond Street Hospital for Children over a 5.5-year period was assessed for adherence to a full or abbreviated imaging sequence protocol. A simple computer program was developed to batch process DICOM (digital imaging and communications in medicine) files, extracting imaging sequence details, followed by natural language processing (NLP) of authorised reports to automate information extraction of diagnostic image quality. The program was able to extract study parameters from the entire dataset (approximately 80 GB of data) in a few hours, and retrieve information on diagnostic image quality using NLP with an overall diagnostic accuracy for data extraction of 96.7% (445/460, 95% confidence interval [CI]: 94.7-98%). The full imaging protocol was adhered to in 305/460 (66.3%) cases, and an abbreviated protocol in 140/460 (30.4%) cases. Overall, 423/460 (91.9%) of studies were of diagnostic quality. These included 298/305 (97.7%) of the full protocol, 111/140 (79.3%) of the abbreviated protocol. In only five cases were the examinations non-diagnostic for all body systems, all of whom weighed <100 g (24.7-72 g) and imaged using the abbreviated protocol. The present study demonstrated a successful application of an automated approach for data collection for audit and quality assessment purposes using paediatric post-mortem imaging as a specific example. Re-audit of these data following change implementation will be straightforward now that the automated workflow is clearly established.

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

To determine the additional yield from autopsy following prenatal ultrasound and post-mortem magnetic resonance imaging (PMMR) for structural abnormalities. 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. 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). Where PMMR and ultrasound are concordant, there is little additional yield from autopsy.