Postmortem Magnetic Resonance Imaging Research Articles

Ex vivo magnetic resonance imaging of the human fetal brain.

The fetal brain undergoes a dynamic process of development during gestation, marked by well-orchestrated events such as neuronal proliferation, migration, axonal outgrowth, and dendritic arborization, mainly elucidated through histological studies. Ex vivo magnetic resonance imaging (MRI) has emerged as a useful tool for 3D visualization of the developing fetal brain, serving as a complementary tool to traditional histology. In this review, we summarized the commonly employed ex vivo MRI techniques and their advances in fetal brain imaging, as well as a standard protocol for postmortem fetal brain specimen collection and fixation. We then provided an overview of ex vivo MRI-based studies on the fetal brain. According to our review, ex vivo T1- or T2-weighted structural MRI has contributed to the characterization of the anatomy of transient neuronal proliferative zones, the basal ganglia, and the cortex. Diffusion MRI related techniques, such as diffusion tensor imaging and tractography, have helped to investigate the microstructural patterns of fetal brain tissue, as well as the early emergence and development of neuronal migration pathways and white matter bundles. Ex vivo MRI findings have shown strong histological correlations, supporting the potential of MRI in evaluating the developmental events in the fetal brain. Postmortem MRI examinations have also demonstrated comparable, and in certain cases, superior performance to traditional autopsy in revealing fetal brain abnormalities. In conclusion, ex vivo fetal brain MRI is an invaluable tool that provides unique insights into the early stages of brain development.

Whole-body non-forensic fetal virtopsy using postmortem magnetic resonance imaging at 7 Tesla vs classical autopsy.

To determine the diagnostic accuracy of virtual autopsy using whole-body postmortem ultra-high field magnetic resonance imaging (MRI) at 7 Tesla (T), using a short T2-weighted imaging (T2-WI) protocol, compared with classical autopsy, for detecting structural abnormalities in small second-trimester fetuses. Thirty consecutive fetuses at 13-19 weeks' gestation (weight, 17-364 g) were included following spontaneous pregnancy loss or termination of pregnancy. After fixation in 10% formaldehyde solution (48 h to 1 week), all fetuses were scanned using a two-dimensional turbo high-resolution T2-WI protocol with multislice relaxation time, followed by an invasive autopsy. The diagnostic accuracy of virtual autopsy vs classical autopsy was calculated for 990 anatomical structures (30 fetuses × 33 items). Sensitivity, specificity, positive and negative predictive values and Cohen's κ coefficient of agreement, with their 95% CIs, as well as the McNemar test, were used to evaluate the accuracy and agreement of the two diagnostic methods. Analysis was stratified by anatomical segment (nervous, pulmonary, cardiovascular, digestive, renal, facial and skeletal) and across three gestational-age intervals (13-14, 15-16 and 17-19 weeks). Considering classical autopsy as the gold standard, virtual autopsy had a sensitivity of 92.04% (95% CI, 85.42-96.29%) and a specificity of 97.87% (95% CI, 94.64-99.42%), with a positive predictive value of 96.30% (95% CI, 90.78-98.56%) and a negative predictive value of 95.34% (95% CI, 91.61-97.45%), achieving a diagnostic accuracy of 95.68% (95% CI, 92.73-97.68%) for detecting structural abnormalities in second-trimester fetuses. Cohen's κ for virtual vs classical autopsy was 0.907. The diagnostic ability of virtual autopsy at 7 T for malformed fetuses was superior to that of classical autopsy for analyzing the nervous system in small fetuses with pronounced autolysis, equivalent to that of classical autopsy when analyzing pulmonary, cardiovascular and renal systems and inferior when evaluating the fetal intestines. The sensitivity of virtual autopsy at 7 T for describing structural abnormalities increased with gestational age. Virtual fetal autopsy using 7-T MRI and a turbo high-resolution T2-WI protocol with multislice relaxation time is a feasible postmortem diagnostic tool for the identification of fetal structural anomalies. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

The Douglas-Bell Canada Brain Bank Post-mortem Brain Imaging Protocol

Magnetic resonance imaging (MRI) is a valuable non-invasive tool that has been widely used for in vivo investigations of brain morphometry and microstructural characteristics. Post-mortem MRIs can provide complementary anatomical and microstructural information to in vivo imaging and ex vivo neuropathological assessments without compromising the sample for future investigations. We have developed a post-mortem MRI protocol for the brain specimens of the Douglas-Bell Canada Brain Bank (DBCBB), the largest brain bank in Canada housing over 3000 neurotypical and diseased brain specimens, that allows for acquisition of high-resolution 3T and 7T MRIs. Our protocol can be used to scan DBCBB specimens with minimal tissue manipulation, allowing for feasibly scanning large numbers of post-mortem specimens while retaining the quality of the tissue for downstream histology and immunohistochemistry assessments. We demonstrate the robustness of this protocol despite the dependency of image quality on fixation by acquiring data on the first day of extraction and fixation, to over twenty years post fixation. The acquired images can be used to perform volumetric segmentations, cortical thickness measurements, and quantitative analyses which can be potentially used to link MRI-derived and ex vivo histological measures, assaying both the normative organization of the brain and ex vivo measures of pathology.

Blunt force trauma in forensic radiology

Description of the main forensic radiological examination modalities and findings in blunt force trauma in living and deceased adults. Elaboration of the essential points based on the authors' own experiences and relevant literature. Injury-related consequences of blunt force are frequently observed in forensic radiological diagnostics, especially in the context of accidents and suicides, and less frequently in homicides. The method of choice for radiological imaging of blunt force in deceased persons is native postmortem computed tomography (PMCT). In principle, the radiological effects of blunt force in PMCT do not differ significantly from those in living persons. Postmortem magnetic resonance imaging (PMMRI) is very suitable for imaging blunt soft tissue injuries in the shorter postmortem interval. In the case of living individuals with the consequences of blunt force trauma, imaging is primarily indicated for clinical diagnostic reasons. Common indications are domestic violence, violence against the elderly, and disputes in public spaces. The choice of radiological examination method depends on the clinical history and symptoms, and the radiological examinations can be subjected to aforensic assessment.

A postmortem high-resolution MRI study of the development of cochlear nerve-related structures in the second and third trimesters of pregnancy.

Magnetic resonance imaging (MRI) is used to determine whether cochlear nerve development is normal in infants and adults, but it has not yet been used to evaluate cochlear nerve development or measure cochlear nerve-related structures in the fetus. This study sought to provide imaging data for clinical evaluations concerning cochlear nerve development in the fetus using MRI. Postmortem 3.0-Tesla MRI of inner ear was performed in 51 fetuses with normal temporal bones at 25 to 40 weeks of gestation. The continuous scanning protocol incorporated axial three-dimensional (3D) sampling perfection with application-specific contrasts using different flip angle evolution sequences. The images were evaluated to measure the structures of the cochlear aperture (CA), internal auditory canal (IAC), and vestibulocochlear and facial nerves in the cerebellopontine angle (CPA), which have been reported to be associated with cochlear nerve development. We also calculated the ratio between the diameters of the vestibulocochlear and facial nerves. The measurable parameters were compared between the right and left sides. The threshold for statistical significance was set at P<0.05. The inner ear anatomy was discernible on MRI in all the fetal specimens, and growth of the CA, IAC, vestibulocochlear nerve, and facial nerve in the CPA was observed as fetal age increased. There was no significant difference in the measurements of these structures between the right and left sides (all P>0.05). MRI can be used to help evaluate the anatomy and development of the cochlear nerve in the fetus. These normative measurements could be valuable for clinical evaluations of the cochlear nerve.

Synthetic MRI and MR Fingerprinting-Derived Relaxometry of Antenatal Human Brainstem Myelination: A Postmortem-Based Quantitative Imaging Study.

The radiologic evaluation of ongoing myelination is currently limited prenatally. Novel quantitative MR imaging modalities provide relaxometric properties that are linked to myelinogenesis. In this retrospective postmortem imaging study, the capability of Synthetic MR imaging and MR fingerprinting-derived relaxometry for tracking fetal myelin development was investigated. Moreover, the consistency of results for both MR approaches was analyzed. In 26 cases, quantitative postmortem fetal brain MR data were available (gestational age range, 15 + 1 to 32 + 1; female/male ratio, 14/12). Relaxometric measurements (T1-/T2-relexation times) were determined in the medulla oblongata and the midbrain using Synthetic MR imaging/MR fingerprinting-specific postprocessing procedures (Synthetic MR imaging and MR Robust Quantitative Tool for MR fingerprinting). The Pearson correlations were applied to detect relationships between T1-relaxation times/T2-relaxation times metrics and gestational age at MR imaging. Intraclass correlation coefficients were calculated to assess the consistency of the results provided by both modalities. Both modalities provided quantitative data that revealed negative correlations with gestational age at MR imaging: Synthetic MR imaging-derived relaxation times (medulla oblongata [r = -0.459; P = .021]; midbrain [r = -0.413; P = .040]), T2-relaxation times (medulla oblongata [r = -0.625; P < .001]; midbrain [r = -0.571; P = .003]), and MR fingerprinting-derived T1-relaxation times (medulla oblongata [r = -0.433; P = .035]; midbrain [r = -0.386; P = .062]), and T2-relaxation times (medulla oblongata [r =-0.883; P < .001]; midbrain [r = -0.890; P < .001]).The intraclass correlation coefficient analysis for result consistency between both MR approaches ranged between 0.661 (95% CI, 0.351-0.841) (T2-relaxation times: medulla oblongata) and 0.920 (95% CI, 0.82-0.965) (T1-relaxation times: midbrain). There is a good-to-excellent consistency between postmortem Synthetic MR imaging and MR fingerprinting myelin quantifications in fetal brains older than 15 + 1 gestational age. The strong correlations between quantitative myelin metrics and gestational age indicate the potential of quantitative MR imaging to identify delayed or abnormal states of myelination at prenatal stages of cerebral development.

Four-Hour-Delayed Gadolinium 3D REAL IR and SPACE FLAIR MRI Correlated to Meniere Disease Histology.

Objectives: This study aims to showcase the complementary nature of utilizing both histopathology and magnetic resonance imaging (MRI) in understanding the otologic pathophysiology of Meniere disease. In addition, it seeks to raise awareness of the value of preserving and curating historical temporal bone collections which continue to inform our understanding of otologic diseases. Methods: The essential anatomical feature of Meniere disease-the distended membranous labyrinth-is explored through a comparison of early temporal bone studies with contemporary MRI techniques. The histopathologic photomicrographs are of inner ear specimens from deceased patients with symptoms consistent with Meniere disease. The MRI sequences from living patients exhibiting classic Meniere disease symptoms during life are captured 4 hours post-administration of gadolinium. Results: Both histopathologic examination and MRI imaging reveal consistent distention of the saccule, utricle, and scala media in patients with Meniere disease. The study shows the histologic photomicrographs of actual Meniere patients compared to the MRIs and successfully demonstrates the correlation between postmortem histological findings and MRI evidence of distension in living patients. Conclusions: A corresponding distension of the membranous labyrinth is seen in both the histologic specimens and the Meniere MRIs. This correlation suggests the potential utility of utilizing MRI to aid in diagnosing atypical Meniere disease and distinguishing it from other disease processes, such as migraine equivalent vertigo. The integration of historical temporal bone studies with modern MRI techniques offers valuable insights into the pathophysiology of otologic diseases. In addition, it emphasizes the importance of preserving and curating historical temporal bone collections for continued research and medical education purposes. Previous studies of delayed MRIs did not use Meniere disease temporal bone histopathology images.

Gray–white matter contrast reversal on T1-weighted spin-echo in postmortem brain

PurposeThe image contrast of postmortem magnetic resonance imaging (MRI) may differ from that of antemortem MRI because of circulator arrest, changes in postmortem tissue, and low-body-temperature scanning conditions. In fact, we have found that the signal intensity of white matter (WM) on T1-weighted spin-echo (T1WSE) images of the postmortem brain was lower than that of gray matter (GM), which resulted in image contrast reversal between GM and WM relative to the living brain. However, the reason for this phenomenon is unclear. Therefore, the aim of this study is to clarify the reason why image contrast reversal occurs between GM and WM of the postmortem brain. Materials and methodsTwenty-three corpses were included in the study (mean age, 60.6 years; range: 19–60 years; mean rectal temperature at scan, 6.9℃; range: 4–11℃). On a 1.5 T MRI system, postmortem T1W-SE MRI of the brain was conducted in the 23 corpses prior to medico-legal autopsy. Next, T1 and T2 of the GM and WM at the level of the basal ganglia were determined in the same participants using inversion recovery and multiple SE sequences, respectively. The proton density (PD) was also calculated from the T1 and T2 images (in the same slice). ResultsT1W-SE image contrast between the GM and WM of all postmortem brains was inverted relative to the living brain. T1 (579 ms in GM and 307 ms in WM) and PD (64 in GM and 44 in WM) of the postmortem brain decreased compared with the living brain. While T1 of WM/GM remained below 1 even postmortem, the PD of WM/GM decreased. T2 (110 ms in GM and 98 ms in WM) of the postmortem brain did not differ from the living brain. ConclusionThe decrease in PD of WM/GM in the postmortem brain may be the major driver of contrast reversal between the GM and WM relative to the living brain.

Comparative Study of Postmortem MRI and Pathological Findings in Malignant Brain Tumors.

This study compared magnetic resonance imaging (MRI) findings of postmortem brain specimens with neuropathological findings to evaluate the value of postmortem MRI. Postmortem MRI was performed on five formalin-fixed whole brains with malignant tumors. Postmortem T2-weighted images detected all neuropathological abnormalities as high-signal regions but also showed histological tumor invasion in areas without edema. Tumor lesions with high necrosis and edema showed high signal intensity on T2-weighted images; in three cases, lesion enlargement was detected on the final prenatal imaging and postmortem MRI. Disease progression immediately before death may have contributed to this difference. In conclusion, the correlation between MRI and neuropathological findings facilitates understanding of the mechanisms responsible for MRI abnormalities. Increased free water due to edema, necrosis, and brain tissue injury can explain the increased signal intensity observed on T2-weighted images. Postmortem MRI may contribute to effective pathology by identifying subtle abnormalities prior to brain dissection.

Ultrasonography and Postmortem Magnetic Resonance Imaging of Bilateral Ocular Disease in a Heifer

Bovine ocular diseases are typically characterized by the concurrent appearances of both macroscopic and intraocular abnormalities. This study examines the diagnostic efficacy of a combination of ultrasonography and magnetic resonance imaging (MRI) for the bilateral ocular disease observed in a 9-month-old Japanese Black heifer. This case presented with bilateral strabismus and a white-colored lens structure in the right eye. A combination of ultrasonography and MRI revealed formations of corn-like and V-shaped membranous structures within the vitreous cavities of the left and right eyeballs, respectively. In the right eye, a cataract was suspected on both ultrasonogram and MRI. This case involved bilateral retinal detachments and strabismus similar to the signs of an autosomal recessive hereditary ocular disease; however, the cataract in the right eye differed from that hereditary disease. Finally, in genetic analysis, a known mutation of the WFDC1 gene was not detected. Ultrasonography is superior to MRI in demonstrating intraocular pathological changes. On the other hand, MRI is helpful for evaluating invasiveness of the ocular lesions to the peripheral structures. Thus, the combined use of these imaging modalities is recommended for diagnosing various bovine ocular diseases.

Forensic age estimation of the knee by post-mortem DR, CT, and MR imaging: a comparative study

It is believed by many that reference data for age estimation purposes must be imaging-modality specific. A study from our department has however proven otherwise. We therefore found it interesting to investigate this further by looking at the level of agreement between different imaging modalities. The aim of this study was to investigate the level of agreement between the three radiological modalities, computed tomography (CT), magnetic resonance imaging (MRI), and digital radiography (DR), in assessing the ossification of the epiphyses of the knee. A total of 34 deceased individuals of 10–25 years of age, brought in for a medicolegal autopsy at our department, were scanned by CT, MRI, and DR. The ossification stages of the three bones of the right knee, distal femoral, proximal tibial, and proximal fibular epiphysis were assessed using the established combined staging method by Schmeling et al. and Kellinghaus et al. Analysis of the results by Cohen’s weighted kappa showed a good agreement between CT and DR (K = 0.61–0.70), and MRI and DR (K = 0.68–0.79) but only moderate agreement between CT and MRI (K = 0.55–0.57). This leads us to conclude that different radiological images cannot be used interchangeably for age estimation purposes, so reference material needs to be imaging-modality specific. However, to make a more general conclusion research on a larger population is needed.

A toolkit for stroke infarct volume estimation in rodents

Stroke volume is a key determinant of infarct severity and an important metric for evaluating treatments. However, accurate estimation of stroke volume can be challenging, due to the often confined 2-dimensional nature of available data. Here, we introduce a comprehensive semi-automated toolkit to reliably estimate stroke volumes based on (1) whole brains ex-vivo magnetic resonance imaging (MRI) and (2) brain sections that underwent immunofluorescence staining. We located and quantified infarct areas from MRI three days (acute) and 28 days (chronic) after photothrombotic stroke induction in whole mouse brains. MRI results were compared with measures obtained from immunofluorescent histologic sections of the same brains. We found that infarct volume determined by post-mortem MRI was highly correlated with a deviation of only 6.6 % (acute) and 4.9 % (chronic) to the measurements as determined in the histological brain sections indicating that both methods are capable of accurately assessing brain tissue damage (Pearson r > 0.9, p < 0.001). The Dice similarity coefficient (DC) showed a high degree of coherence (DC > 0.8) between MRI-delineated regions of interest (ROIs) and ROIs obtained from histologic sections at four to six pre-defined landmarks, with histology-based delineation demonstrating higher inter-operator similarity compared to MR images. We further investigated stroke-related scarring and post-ischemic angiogenesis in cortical peri‑infarct regions and described a negative correlation between GFAP+fluorescence intensity and MRI-obtained lesion size.

A novel reconstruction model for thoracic spinal cord injury in swine.

Spinal cord (SC) reconstruction (process to reestablish the severed neural continuity at the injury site) may provide better recovery from blunt SC injury (SCI). A miniature swine model of blunt SC compression was used to test the hypothesis that reconstruction of the SC with sural nerve in combination with surgical decompression and stabilization improves functional, macro- and microstructural recovery compared to decompression and stabilization alone. Following blunt T9-T11 SC compression injury, five adult Yucatan gilts randomly received laminectomy and polyethylene glycol (as fusogen) with (n = 3) or without (n = 2) sural nerve graft SC reconstruction. Fusogens are a heterogeneous collection of chemicals that fuse the axon membrane and are currently used to augment epineural coaptation during peripheral nerve graft reconstruction. Outcome measures of recovery included weekly sensory and motor assessments, various measurements obtained from computed tomography (CT) myelograms up to 12 weeks after injury Measurements from postmortem magnetic resonance imaging (MRI) and results from spinal cord histology performed 12 weeks after injury were also reported. Vertebral canal (VC), SC and dural sac (DS) dimensions and areas were quantified on 2-D CT images adjacent to the injury. Effort to stand and response to physical manipulation improved 7 and 9 weeks and 9 and 10 weeks, respectively, after injury in the reconstruction group. Myelogram measures indicated greater T13-T14 VC, smaller SC, and smaller DS dimensions in the reconstruction cohort, and increased DS area increased DS/VC area ratio, and higher contrast migration over time. Spinal cord continuity was evident in 2 gilts in the reconstruction cohort with CT and MRI imaging. At the SCI, microstructural alterations included axonal loss and glial scarring. Better functional outcomes were observed in subjects treated with sural nerve SC reconstruction. Study results support the use of this adult swine model of blunt SCI. Long-term studies with different nerve grafts or fusogens are required to expand upon these findings.

Noninvasive estimation of heart organ mass by postmortem magnetic resonance imaging and computed tomography compared to conventional autopsy in fetuses: a pilot study

ObjectivesThe purpose of this pilot study is to investigate the accuracy of mass estimation of the heart using postmortem MRI and CT in this population. MethodsThe mass of the heart was estimated using three different methods: sequential segmentation of the right and left ventricles by MRI in 30 patients; sequential segmentation of the left ventricle chamber using CT and an ellipsoid method of the left ventricle (LV) using CT in 6 patients. The estimated mass by each method was compared to conventional autopsy mass using linear regression. ResultsThe correlation between estimated and measured cardiac mass using postmortem MRI measurements of the right and left ventricles, CT derived volumes of the left ventricle, or by the LV ellipsoid CT method are as follows: y = 0.87744x - 0.74813 (R2 = 0.958); y = 0.6004x - 2.16 (R2 = 0.8681); y = 0.6019 - 2.1615 (R2 = 0.8599), respectively. When separating the fetuses evaluated by pmMRI into a ≤20 weeks subset or >20 weeks subset, the correlation are as follows: y = 0.5176x + 0.2428 (R2 = 0.645) and y = 0.91237x - 1.53647 (R2 = 0.9475), respectively. ConclusionMass of the heart at autopsy modestly correlates with MRI derived volumes measuring the right and left ventricles. The small sample in the CT derived volume of the left ventricle alone or by the simplified estimated method using the ellipsoid measurements of the left ventricle by CT compared to autopsy weights make it difficult to conclude CT's utility using these methods.

Detection of pulmonary thrombembolism and postmortem clotting on postmortem magnetic resonance imaging

The purpose of this study was to develop a feasible imaging protocol superior to postmortem computed tomography (PMCT) and to establish diagnostic parameters for diagnosing pulmonary thromboembolism (PE) on postmortem magnetic resonance imaging (PMMR).The study collective of 113 subjects was prospectively investigated by PMMR for the presence of PE and / or postmortem clotting (cruor). PE was detected in 20 cases; the remaining 93 cases were investigated for the morphology of cruor. Age grading was performed by PMMR, autopsy and histology. The postmortem sedimentation effect was used for the applied imaging protocol on PMMR (supine and prone position). Visual distension of the pulmonary arteries in PE was seen in all cases, but not in the controls. Re-positioning of the corpse from supine in prone position proved to be beneficial in 90 %. Postmortem motion artifacts are firstly described in 20.4 %. Hyperacute PE (grade 1) presented with a homogenous and hypointense signal on T2w images, acute PE (grade 2) with slightly heterogeneous, but still homogenous hypointense signal, subacute PE (grade 3) was with heterogeneous and slightly hyperintense signal and chronic PE (grade 4) with predominately homogenous with scarce portions of heterogeneous but hyperintense signal. PMMR allowed for the detection of PE and for in situ depiction of combined age grading.

Multimodal analytical tools for the molecular and elemental characterisation of lesions in brain tissue of multiple sclerosis patients

Multiple sclerosis (MS) is a prevalent immune-mediated inflammatory disease of the central nervous system inducing a widespread degradation of myelin and resulting in neurological deficits. Recent advances in molecular and atomic imaging provide the means to probe the microenvironment in affected brain tissues at an unprecedented level of detail and may provide new insights. This study showcases state-of-the-art spectroscopic and mass spectrometric techniques to compare distributions of molecular and atomic entities in MS lesions and surrounding brain tissues.MS brains underwent post-mortem magnetic resonance imaging (MRI) to locate and subsequently dissect MS lesions and surrounding white matter. Digests of lesions and unaffected white matter were analysed via ICP-MS/MS revealing significant differences in concentrations of Li, Mg, P, K, Mn, V, Rb, Ag, Gd and Bi. Micro x-ray fluorescence spectroscopy (μXRF) and laser ablation – inductively coupled plasma – time of flight – mass spectrometry (LA-ICP-ToF-MS) were used as micro-analytical imaging techniques to study distributions of both endogenous and xenobiotic elements. The essential trace elements Fe, Cu and Zn were subsequently calibrated using in-house manufactured gelatine standards. Lipid distributions were studied using IR-micro spectroscopy and matrix assisted laser desorption/ionisation mass spectrometry imaging (MALDI-MSI). MALDI-MSI was complemented with high-resolution tandem mass spectrometry and trapped ion mobility spectroscopy for the annotation of specified phospho- and sphingolipids, revealing specific lipid species decreased in MS lesions compared to surrounding white matter.This explorative study demonstrated that modern molecular and atomic mapping techniques provide high-resolution imaging for relevant bio-indicative entities which may complement our current understanding of the underlying pathophysiological processes.

Caudal regression syndrome type 1 with minimally invasive computed tomography and magnetic resonance imaging autopsy: a case report

BackgroundCaudal regression syndrome is a rare complex congenital anomaly with reduced penetrance and phenotypic variability characterized by osseous defects of the caudal spine, lower limb anomalies, and accompanying genitourinary, gastrointestinal/anorectal, and cardiac system soft tissue defects. We report a rare presentation of type 1 caudal regression syndrome in a pregnant woman with preexisting diabetes, in which early recognition of severe fetal anomalies on routine antenatal ultrasound facilitated confirmation with fetal magnetic resonance imaging to characterize extent of disease and prognosticate fetal outcome.Case presentationThis case of type 1 caudal regression syndrome in the setting of maternal pregestational diabetes mellitus resulted in stillbirth. The mother was a 29-year-old Caucasian primigravida female with past medical history of poorly controlled type 2 diabetes managed with metformin prior to pregnancy, prompting admission for glucose management and initiation of insulin at 13 weeks. Baseline hemoglobin A1c was high at 8.0%. Fetal ultrasound at 22 weeks was notable for severe sacral agenesis, bilateral renal pelvis dilatation, single umbilical artery, and pulmonary hypoplasia. Fetal magnetic resonance imaging at 29 weeks showed absent lower two-thirds of the spine with corresponding spinal cord abnormality compatible with type 1 caudal regression syndrome. The mother delivered a male stillborn at 39 and 3/7 weeks. Minimally invasive postmortem magnetic resonance imaging and computed tomography autopsy were performed to confirm clinical findings when family declined conventional autopsy. Etiology of sacral agenesis was attributed to poorly controlled maternal diabetes early in gestation.ConclusionMaternal preexisting diabetes is a known risk factor for development of congenital malformations. This rare case of type 1 caudal regression syndrome in a mother with preexisting diabetes with elevated hemoglobin A1c highlights the importance of preconception glycemic control in diabetic women and the utility of fetal magnetic resonance imaging for confirmation of ultrasound findings to permit accurate prognostication. Additionally, minimally invasive postmortem magnetic resonance imaging and computed tomography autopsy can facilitate diagnostic confirmation of clinical findings in perinatal death due to complex congenital anomalies while limiting the emotional burden on bereaved family members who decline conventional autopsy.

Diagnostic accuracy of coronary artery stenosis and thrombosis assessment using unenhanced multiplanar 3D post-mortem cardiac magnetic resonance imaging

BackgroundA 3D sequence was introduced to unenhanced post-mortem cardiac magnetic resonance imaging (PMCMR) to enable multiplanar coronary artery image analysis and to investigate its diagnostic accuracy for the diagnosis of coronary artery stenosis and thrombosis. Materials and MethodsN = 200 forensic cases with suspected coronary artery pathology underwent 3 Tesla PMCMR (sequence used: T2 weighted transversal 3D turbo spin echo) before autopsy. Main coronary artery stenosis and thrombosis were assessed in PMCMR by multiplanar image analysis by two observers. Coronary artery histology was determined as the gold standard and compared to PMCMR. Sensitivity, specificity, negative (NPV) and positive predictive values (PPV) with 95% confidence intervals were calculated. ResultsFor all coronary arteries combined, sensitivity was 75% (PPV 73%) for the diagnosis of stenosis and 72% (PPV 71%) for the diagnosis of thrombosis. Specificity was 92% (NPV 90%) for correct diagnosis of non-existing stenosis and 97% (NPV 97%) for non-existing thrombosis. Sensitivity for correct diagnosis of different degrees of stenosis ranged between 67% and 80% (PPVs 67–82%); specificity ranged between 96% and 99% (NPVs 96–99%). ConclusionMultiplanar PMCMR coronary artery stenosis and thrombosis assessment based on an unenhanced T2 weighted 3D sequence provide moderate sensitivity and high specificity for the diagnosis of coronary artery stenosis and/or thrombosis. Hence, 3D T2w PMCMR cannot reliably detect existing coronary artery stenosis and thrombosis but may be particularly useful for the exclusion of stenosis or thrombosis of the main coronary arteries.

Twenty Years of Managed Epilepsy for a Stranded Male Guadalupe Fur Seal (Arctocephalus townsendi) Secondary to Suspect Domoic Acid Toxicosis

Many wild otariids (sea lions and fur seals) strand along the California coast annually with seizures following presumed exposure to harmful algal blooms (HABs). This is a long-term case study of a stranded subadult male Guadalupe fur seal (Arctocephalus townsendi) that stranded in 2001 and within days after admission began demonstrating seizure activity. The epilepsy was stabilized with antiepileptic drug (AED) therapy and advanced imaging was performed. Magnetic resonance (MR) scans showed signs of encephalopathy consistent with domoic acid (DA) toxicosis. This fur seal was deemed “non-releasable” and over the following 19 years, he received supportive veterinary care and AED treatment at a permitted facility. In the summer of 2020, the fur seal showed progressive behavioral and functional deterioration whereupon humane euthanasia was performed. Post-mortem MR and diffusion tensor images (DTI) were acquired. A volumetric comparison with historic scans showed evidence of severe progressive unilateral right hippocampal atrophy. Histopathology confirmed severe chronic right and mild left hippocampal atrophy. The progressive degenerative brain changes demonstrate how adaptive brain function can be with neuronal atrophy secondary to DA exposure. This case highlights some considerations and decision-making processes needed for the rehabilitation and placement of wild stranded otariids with acquired epilepsy secondary to DA toxicity.

Postmortem radiology studies in global and national healthcare: literature analysis and perspectives of Russian specialists

Despite the significant importance of autopsies for determining the cause of death and the evaluating the effectiveness of treatments, there is a progressive decrease in their number across all countries. At the same time, there is an active introduction of postmortem radiological studies to analyze the bodies of deceased patients.&#x0D; The article presents literature analysis summarizing the results of surveys from foreign specialists, as well as the opinions of Russian specialists, regarding the possibilities and features of postmortem radiological studies, mainly focusing on deceased newborns and infants. It is noted that postmortem radiological studies are carried out as part of both pathoanatomical autopsy and forensic medical examination. Postmortem computed tomography in cases of violent death and postmortem magnetic resonance imaging in cases of death from diseases were performed more often. General clinical equipment located in clinical radiology departments was more frequently used than those located in the mortuary, pathology department, or forensic facility. The analysis of the results of postmortem radiological examinations was predominantly carried out by radiologists, with a joint analysis involving a radiologist and a pathologist being less common. It is emphasized that in the Russian Federation, postmortem radiological studies are mostly of a single nature. According to Russian researchers, in the current era of advancing personalized medicine, radiation techniques, and information technologies, there arises a need to use postmortem radiological studies to objectify and improve the accuracy of traditional autopsies. Postmortem radiological studies, which are objective operator-independent methods of examining the bodies of dead people, should be considered as a highly effective stage of pathology and, especially, forensic autopsy.