Materials swelling revealed through automated semantic segmentation of cavities in electron microscopy images.

Accurately quantifying swelling of alloys that have undergone irradiation is essential for understanding alloy performance in a nuclear reactor and critical for the safe and reliable operation of reactor facilities. However, typical practice is for radiation-induced defects in electron microscopy images of alloys to be manually quantified by domain-expert researchers. Here, we employ an end-to-end deep learning approach using the Mask Regional Convolutional Neural Network (Mask R-CNN) model to detect and quantify nanoscale cavities in irradiated alloys. We have assembled a database of labeled cavity images which includes 400 images, > 34 k discrete cavities, and numerous alloy compositions and irradiation conditions. We have evaluated both statistical (precision, recall, and F1 scores) and materials property-centric (cavity size, density, and swelling) metrics of model performance, and performed targeted analysis of materials swelling assessments. We find our model gives assessments of material swelling with an average (standard deviation) swelling mean absolute error based on random leave-out cross-validation of 0.30 (0.03) percent swelling. This result demonstrates our approach can accurately provide swelling metrics on a per-image and per-condition basis, which can provide helpful insight into material design (e.g., alloy refinement) and impact of service conditions (e.g., temperature, irradiation dose) on swelling. Finally, we find there are cases of test images with poor statistical metrics, but small errors in swelling, pointing to the need for moving beyond traditional classification-based metrics to evaluate object detection models in the context of materials domain applications.

Genetically determined cardiomyopathies at autopsy: the pivotal role of the pathologist in establishing the diagnosis and guiding family screening.

Cardiomyopathies (CMP) comprise a heterogenous group of diseases affecting primarily the myocardium, either genetic and/or acquired in origin. While many classification systems have been proposed in the clinical setting, there is no internationally agreed pathological consensus concerning the diagnostic approach to inherited CMP at autopsy. A document on autopsy diagnosis of CMP is needed because the complexity of the pathologic backgrounds requires proper insight and expertise. In cases presenting with cardiac hypertrophy and/or dilatation/scarring with normal coronary arteries, a suspicion of inherited CMP must be considered, and a histological examination is essential. Establishing the actual cause of the disease may require a number of tissue-based and/or fluid-based investigations, be it histological, ultrastructural, or molecular. A history of illicit drug use must be looked for. Sudden death is frequently the first manifestation of disease in case of CMP, especially in the young. Also, during routine clinical or forensic autopsies, a suspicion of CMP may arise based on clinical data or pathological findings at autopsy. It is thus a challenge to make a diagnosis of a CMP at autopsy. The pathology report should provide the relevant data and a cardiac diagnosis which can help the family in furthering investigations, including genetic testing in case of genetic forms of CMP. With the explosion in molecular testing and the concept of the molecular autopsy, the pathologist should use strict criteria in the diagnosis of CMP, and helpful for clinical geneticists and cardiologists who advise the family as to the possibility of a genetic disease.

Fatal Intoxications from a Combination of 4-Fluoroamphetamine and 25C-NBOMe.

Six fatalities have occurred from the ingestion of a combination of new psychoactive substances (NPSs), 4-fluoroamphetamine (4FA) and 2-(4-chloro-2,5-dimethoxyphenyl)-N-[(2-methoxyphenyl)methyl]ethanamine (25C-NBOMe) over a 9-month period. Four of these fatalities (one older female and three young males) were from direct adverse effects of drugs, and one each from a fall while being intoxicated and during restraint. All cases were subject to full postmortem examinations that included collection of femoral blood. The four drug-caused fatalities had postmortem blood concentrations for 4FA and 25C-NBOMe of 330-682 ng/L (median 417) and 1.4-12 ng/mL (median 4.3), respectively. The other two cases (both young males) where death was considered to have been caused indirectly by drug intoxication had 4FA and 25C-NBOMe postmortem concentrations of 21 and 123 ng/mL, and 1.8 and 4.5 ng/mL, respectively. None of these cases showed concentrations of drugs that suggested use of high recreational doses. In one drug-caused death, capsules and a brown powder obtained from the scene were found to contain a mixture of these two NPSs. With the exception of one drug-caused death, other drugs were detected; however, the effects of the two NPSs together were regarded as the primary triggers for the deaths. There were no consistent symptoms or pathology in these cases; however, agitation/aggression was observed in two cases prior to their collapse, with seizures in possibly three cases. Pulmonary and/or cerebral edema was noted in three cases. Potentially significant natural disease (a mildly enlarged heart) was only observed in one drug-caused case. These cases illustrate a possible increased risk of sudden death with this combination of drugs, both of which can elevate serotonin concentrations as well as act as strong stimulants. These cases also illustrate the difficulty in detecting NPS in cases where no prior information is available that might suggest their use.

The role of post-mortem imaging in preliminary examinations under the Coroners Act 2008 (Vic): a forensic pathologist's perspective.

Changing community attitudes and expectations, allied to the recent incorporation of sophisticated clinical imaging techniques into the medico-legal death investigation process, have presented significant challenges for Coroners and pathologists alike. The traditional functions of coronial systems have expanded from the relatively narrow confines of a judicial determination as to the cause of death on the basis of autopsy findings. Today they include broader responsibilities in death and disease prevention and a more enlightened approach to the social and familial consequences of a death. The Coroners Act 2008 (Vic) reflects this evolution with the introduction of a so-called preliminary examination process allowing for the performance of certain initial processes and procedures in relation to the medical investigation into a death, and with the aim of increasing the quality and robustness of the pathologist's advice to the Coroner before a decision is made as to whether the Coroner will order an autopsy. The post-mortem computed tomography scan (PMCT) is an important component of the preliminary examination process and significantly increases the information available in the early stages of a death investigation. The use of such new technology carries with it the necessity for a re-evaluation of the roles and responsibilities of the participants in the coronial death investigation system, including those of the next of kin. Three coronial case studies are presented to illustrate the impact and consequences of these developments.

Sudden unexpected death in the setting of undiagnosed Graves' disease.

Graves' disease is the most common cause of hyperthyroidism and is classically characterized by the clinical triad of diffuse toxic goiter, infiltrative ophthalmopathy with exophthalmos and an infiltrative dermopathy. While the name of the Irishman Robert Graves has received the eponymous honor, the first description of the condition in the English language can be attributed to the Englishman Caleb Perry, while in continental Europe the entity in name once honored Karl von Basedow. We present the case of a previously well 43 year old woman who presented in supraventricular tachycardia and acute pulmonary edema and died despite treatment and without a diagnosis for cause of death. At autopsy the significant positive macroscopic findings were confined to the lungs (acute pulmonary edema) and thyroid (diffusely enlarged). Histology revealed features typical of Graves' disease while post mortem thyroid function tests supported a diagnosis of thyrotoxic crisis in the setting of undiagnosed Graves' disease.

Rupture of a splenic artery aneurysm during pregnancy with maternal and foetal death: a case report.

Aneurysms of the splenic artery are rare although they are the most common of the so-called visceral artery aneurysms. First described by Beaussier in 1770, approximately 400 cases have now been reported in the literature. There is a strong association with pregnancy and since Corson's first description of the death of a mother in the third trimester from rupture of a splenic artery aneurysm, some 25% of reported cases have involved pregnant women. Arterial rupture is an obstetric emergency and associated with maternal and foetal mortality rates approaching 75% and 95% respectively. There are only 14 reported instances where both mother and baby survived. The clinical presentation is protean and in most cases splenic artery aneurysm is identified unexpectedly at angiography, laparotomy or post-mortem examination.

Sudden death due to aortic rupture complicating undiagnosed coarctation of the aorta in a teenager - a case report and review of the literature.

Coarctation of the aorta is one of the more common congenital cardiac defects accounting for between 5 and 10% of cases of congenital heart disease. It has traditionally been divided into infantile (pre-ductal) and adult (ductal) types. Prior to the development of surgical treatment for coarctation, the condition was associated with significant morbidity and mortality with the most common causes of death being aortic rupture, congestive cardiac failure, endocarditis and intracerebral haemorrhage. Presentation of undiagnosed aortic coarctation as sudden and unexpected death is today a distinctly uncommon phenomenon. We report one such case, that of an adolescent male who at autopsy was noted to have coarctation of ductal type with aortic dissection and haemopericardium. The presence of this condition should be considered by the forensic pathologist confronted with aortic dissection, particularly in a young person.

Fatality due to amisulpride toxicity: a case report.

Amisulpride is an atypical antipsychotic agent effective in the treatment of schizophrenia. There are few cases in the literature relating to the toxicity of this agent and reported fatalities are rare. Drug induced prolongation of the QT interval of the electrocardiograph (ECG) is increasingly recognised with various classes of drugs and in particular with antipsychotics. Cardiotoxicity can manifest as ventricular tachyarrhythmia, including torsades de pointes (TdP), complicating QT prolongation. We report a case of fatal amisulpride toxicity where the post-mortem blood concentration was 48 mg/L. Hitherto under-recognised toxic effects of novel chemotherapeutic agents can pose challenges for the forensic pathologist charged with performing medico-legal autopsies in cases of sudden unexpected death in young adults and particularly in those with schizophrenia. A knowledge of the ability of antipsychotic agents to induce fatal cardiac arrhythmias should inform the approach to the autopsy (including determination of the cause and mechanism of death) in such cases, as should an appreciation of the dangers inherent in the interpretation of post-mortem toxicology.

Fatality complicating agranulocytosis in the setting of carbimazole therapy.

Carbimazole is an antithyroid drug of the thionamide class which is used in the treatment of hyperthyroidism. Rarely, use of this drug may be associated with the development of agranulocytosis and neutropenia with the consequent risk of sepsis. We present the case of a 50-year-old female who developed rapidly progressive Pseudomonas aeruginosa septicemia in the setting of panycytopenia approximately 4 weeks following the commencement of carbimazole therapy for Graves' disease. She died shortly after presentation to hospital and the case was referred to the coroner as the death was unexpected and the clinical course was considered unusual. Relatively sudden, unexpected deaths resulting from hematological/endocrine causes are uncommonly encountered by forensic pathologists and this case serves to illustrate the enduring value of the autopsy in providing important clinicopathological correlation to clinicians.

Objections to medico-legal autopsy--recent developments in case law.

Medico-legal autopsies can be directed by coroners. However, in a number of jurisdictions family members can lodge objections with coroners against such procedures taking place. The authors analyse the objections, successful and unsuccessful, taken in Australia. Reviewing recent Victorian developments, they emphasise the public interest in autopsies which reveal medical causes of death. They identify the ongoing importance of coroners being able to exercise their statutory function to undertake death investigations effectively and to make informed recommendations to reduce the incidence of avoidable deaths.

Distal trapezius musculocutaneous flap for upper thoracic back wounds associated with spinal instrumentation and radiation.

Upper thoracic wounds with exposed hardware from spinal instrumentation and previous radiation presents a subset of back wound coverage problems that lend themselves to a unique opportunity to use the distal trapezius musculocutaneous flap. The unradiated, healthy skin paddle can be transposed between the radiated skin edges to seal and cover the exposed hardware and achieve early primary healing of the back wound without the need for a skin graft. The authors review their series of the upper back radiated wounds reconstructed with the trapezius musculocutaneous flaps, immediately at the time of the spinal surgery and secondarily after the incisional wound breakdown, to cover the exposed hardware. Their contiguous skin flap design strategy, results, and complications are discussed.

Postmortem concentrations of citalopram.

The postmortem concentrations of citalopram in blood, bile, liver, and vitreous humour were investigated in 14 cases using a specially developed high performance liquid chromatography assay. Concentrations from drug and non-drug related deaths were categorized to determine a postmortem therapeutic and toxic range. Therapeutic citalopram concentrations for blood, bile, liver, and vitreous humour ranged to 0.4 mg/L, 2.1 mg/l, 6.6 mg/kg, and 0.2 mg/L, respectively. In one potentially fatal response to citalopram, concentrations were 0.8 mg/L, 6.0 mg/L, 0.3 mg/L for blood, bile and vitreous humour, respectively.

The autopsy: legal and ethical principles.

Recent controversies both in Australia and overseas have focused public attention on autopsy practice. It has become apparent that there is an increasing expectation amongst the public for more detailed information concerning autopsy procedures and, in particular, tissue retention. This article attempts to review the legal and ethical issues with respect to postmortem examination in Australia and to contemplate potential offences and penalties should such obligations be breached.