Visualization of myocardial infarction by post-mortem single-organ coronary computed tomography: a feasibility study

Identification of sudden cardiac death from human blood using ATR-FTIR spectroscopy and machine learning

OBJECTIVE

The aim of this study is to identify a rapid, sensitive, and non-destructive auxiliary approach for postmortem diagnosis of SCD, addressing the challenges faced in forensic practice.

METHODS

ATR-FTIR spectroscopy was employed to collect spectral features of blood samples from different cases, combined with pathological changes. Mixed datasets were analyzed using ANN, KNN, RF, and SVM algorithms. Evaluation metrics such as accuracy, precision, recall, F1-score and confusion matrix were used to select the optimal algorithm and construct the postmortem diagnosis model for SCD.

RESULTS

A total of 77 cases were collected, including 43 cases in the SCD group and 34 cases in the non-SCD group. A total of 693 spectrogram were obtained. Compared to other algorithms, the SVM algorithm demonstrated the highest accuracy, reaching 95.83% based on spectral biomarkers. Furthermore, by combing spectral biomarkers with age, gender, and cardiac histopathological changes, the accuracy of the SVM model could get 100%.

CONCLUSION

Integrating artificial intelligence technology, pathology, and physical chemistry analysis of blood components can serve as an effective auxiliary method for postmortem diagnosis of SCD.

Bleeding-Source Exploration in Subdural Hematoma: Observational Study on the Usefulness of Postmortem Computed Tomography Angiography

In a few cases, postmortem computed tomography angiography (PMCTA) is effective in postmortem detection of cortical artery rupture causing subdural hematoma (SDH), which is difficult to detect at autopsy. Here, we explore the usefulness and limitations of PMCTA in detecting the sites of cortical arterial rupture for SDH. In 6 of 10 cases, extravascular leakage of contrast material at nine different places enabled PMCTA to identify cortical arterial rupture. PMCTA did not induce destructive arterial artifacts, which often occur during autopsy. We found that, although not in all cases, PMCTA could show the site of cortical arterial rupture causing subdural hematoma in some cases. This technique is beneficial for cases of SDH autopsy, as it can be performed nondestructively and before destructive artifacts from the autopsy occur.

State of the Art on the Role of Postmortem Computed Tomography Angiography and Magnetic Resonance Imaging in the Diagnosis of Cardiac Causes of Death: A Narrative Review

The need of a minimally invasive approach, especially in cases of cultural or religious oppositions to the internal examination of the body, has led over the years to the introduction of postmortem CT (PMCT) methodologies within forensic investigations for the comprehension of the cause of death in selected cases (e.g., traumatic deaths, acute hemorrhages, etc.), as well as for personal identification. The impossibility to yield clear information concerning the coronary arteries due to the lack of an active circulation to adequately distribute contrast agents has been subsequently overcome by the introduction of coronary-targeted PMCT Angiography (PMCTA), which has revealed useful in the detection of stenoses related to calcifications and/or atherosclerotic plaques, as well as in the suspicion of thrombosis. In parallel, due to the best ability to study the soft tissues, cardiac postmortem MR (PMMR) methodologies have been further implemented, which proved suitable for the detection and aging of infarcted areas, and for cardiomyopathies. Hence, the purpose of the present work to shed light on the state of the art concerning the value of both coronary-targeted PMCTA and PMMR in the diagnosis of coronary artery disease and/or myocardial infarction as causes of death, further evaluating their suitability as alternatives or complementary approaches to standard autopsy and histologic investigations.

[A retrospective mortality analysis of natural deaths of the 65+ generation based on postmortem autopsies performed at the Institute of Legal Medicine in Frankfurt am Main during two periods]

BACKGROUND AND AIM OF THE STUDY

In Germany, a constant demographic change is taking place, which leads to an increasing aging of the society. The present study aimed to analyze natural deaths occurring at an age of ≥ 65 years, since health vulnerability in this age group is gaining importance.

MATERIAL AND METHODS

Autopsy reports of the Institute of Forensic Medicine, University Hospital of the Goethe University Frankfurt/Main, Germany, were retrospectively evaluated regarding natural death cases of ≥ 65-year-olds in a time comparison (period I: 2000-2002; period II: 2013-2015).

RESULTS

During both periods, a total of 1206 autopsies concerning this age group were performed. Among these, 404 cases (33.5%) of unnatural death and 39 cases (3.2%) of a combination of natural and unnatural death were recorded; in 94 cases (7.8%), the manner of death could not be elucidated. The majority (n = 669; 55.5%) included cases of natural death. In the largest group of these (n = 350; 52.3%), cardiac causes of death were predominant, followed by 132 (19.7%) respiratory and 47 (7.0%) abdominal causes of death. In addition, 37 (5.5%) cases of malignant neoplasms, 33 (4.9%) of ruptures of large vessels, 33 (4.9%) of cerebral, and 37 (5.5%) other cases of natural death were noted. A significant decrease of cardiac causes of death was observed in the comparison of periods I and II. In particular, there was a significant decrease in high-grade occlusive coronary sclerosis. Moreover, there were significant differences between both sexes. Men had significantly more bypasses, stents and heart scars and suffered a myocardial infarction about 10 years earlier than women.

CONCLUSION

The results of the present study are largely consistent with the literature. The decrease in numbers of cardiac deaths may be attributed to increasingly better medical care and to a significantly higher rate of stent implantation. Especially in times of pandemics, the role of forensic gerontology will become more important.

Impact of increasing levels of adaptive statistical iterative reconstruction on image quality in oil-based postmortem CT angiography in coronary arteries

Introduction

Postmortem multi-detector computed tomography (PMCT) has become an important part in forensic imaging. Modern reconstruction techniques such as iterative reconstruction (IR) are frequently used in postmortem CT angiography (PMCTA). The image quality of PMCTA depends on the strength of IR. For this purpose, we aimed to investigate the impact of different advanced IR levels on the objective and subjective PMCTA image quality.

Material and methods

We retrospectively analyzed the coronary arteries of 27 human cadavers undergoing whole-body postmortem CT angiography between July 2017 and March 2018 in a single center. Iterative reconstructions of the coronary arteries were processed in five different level settings (0%; 30%; 50%; 70%; 100%) by using an adaptive statistical IR method. We evaluated the objective (contrast-to-noise ratio (CNR)) and subjective image quality in several anatomical locations.

Results

Our results demonstrate that the increasing levels of an IR technique have relevant impact on the image quality in PMCTA scans in forensic postmortem examinations. Higher levels of IR have led to a significant reduction of image noise and therefore to a significant improvement of objective image quality (+ 70%). However, subjective image quality is inferior at higher levels of IR due to plasticized image appearance.

Conclusion

Objective image quality in PMCTA progressively improves with increasing level of IR with the best CNR at the highest IR level. However, subjective image quality is best at low to medium levels of IR. To obtain a “classic” image appearance with optimal image quality, PMCTAs should be reconstructed at medium levels of IR.

Can post-mortem coronary artery calcium scores aid diagnosis in young sudden death?

This study sought to explore the feasibility and utility of post-mortem coronary artery calcium (CAC) scoring in identifying patients with ischemic heart disease as cause of sudden death. 100 deceased patients aged 18-50 years underwent post-mortem examination in the setting of sudden death. At post-mortem, fifty cases were determined to have ischemic heart disease, and fifty had death attributed to trauma or unascertained causes. The CAC score was calculated in a blinded manner from post-mortem CTs performed on all cases. CAC scores were assessable in 97 non-decomposed cases (feasibility 97%). The median CAC score was 88 Agatston units [IQR 0-286] in patients deceased from ischemic heart disease vs 0 [IQR 0-0] in patients deceased from other causes (p < 0.0001). Presence of any coronary calcification differed significantly between ischemic heart disease and non-ischemic groups (adjusted odds ratio 10.7, 95% CI 3.2-35.5). All cases with a CAC score > 100 (n = 22) had ischemic heart disease as the cause of death. Fifteen cases had a CAC score of zero but severe coronary disease at post-mortem examination. Post-mortem CAC scoring is highly feasible. An elevated CAC score in cases 18-50 years old with sudden death predicts ischemic heart disease at post-mortem examination. However, a CAC score of zero does not exclude significant coronary artery disease. Post-mortem CAC score may be considered as a further assessment tool to help predict likely cause of death when there is an objection to or unavailability of post-mortem examination.

Post-mortem computed tomography for forensic applications: A systematic review of gunshot deaths

The first reported application of computed tomography (CT) to the field of forensic medicine was in 1977 for the study of gunshot injuries to the head. Since then, CT scanning has shown increased uses within the field of forensic practice. In this study a systematic literature search was carried out by consulting 17 electronic scientific databases. This systematic review considers studies published to date concerning the use of post-mortem CT (PMCT) in gunshot injury cases; this review shows variability between the PMCT and autopsy examination findings. Furthermore we identify the technical differences between the selected studies, emphasizing the specific findings obtainable with PMCT, in order to support forensic research towards shared and validated practices, whose results are used as evidence in the courtroom.

Postmortem computed tomography angiography (PMCTA) and traditional autopsy in cases of sudden cardiac death due to coronary artery disease: a systematic review and meta-analysis

INTRODUCTION

Several studies have been performed to assess the efficacy of postmortem computed tomography angiography (PMCTA) in solving cases of sudden cardiac death, even in comparison with the traditional autopsy. However, the results were often inconsistent and inconclusive. Therefore, a global discussion on the subject through a systematic review of the literature and a meta-analysis is necessary.

METHODS

A systematic search of PubMed was performed up to April 23, 2018. Studies exploring the role of PMCTA in cases of sudden cardiac death and the accuracy of this method in diagnosing the cause of death compared to traditional autopsy were included.

RESULTS

The overall sensitivity and specificity of the seven included studies, using conventional autopsy as a reference standard, were 92% and 95%, respectively. The positive and negative likelihood ratios were, respectively, 20.76 (95% CI 1.16-370.2) and 0.08 (95% CI 0.03-0.17), showing that PMCTA represents a strong indicator of the posttest probability of disease. The diagnostic odds ratio and the area under the curve were, respectively, 261.54 (95% CI 1.87-5760.53) and 0.93 (95% CI 0.90-0.95), indicating a high diagnostic power of the test.

CONCLUSION

PMCTA demonstrated a high accuracy in the diagnosis of parietal and luminal coronary changes but was less effective in detecting myocardial ischemia and necrosis. Therefore, the only radiological investigation is often insufficient to determine the cause of sudden death and the conventional autopsy remains the gold standard. However, PMCTA can improve the performance of the autopsy, serving as an aid and guide in the sampling phase for histopathological investigations.

Friar Leopold Mandic (1866-1942): the computed tomography of the body of a saint

PURPOSE

In forensic clinical anatomy computed tomography (CT) is used in post-mortem radiological investigation as an objective nondestructive documentation of the body surface and of the interior of the body. This technique is applied also in paleopathology, in particular in mummy studies, with the aim of providing a permanent record of the mummy's features, investigating the embalming procedure employed and analyzing the extent of the preservation in detail.

METHODS

For the Extraordinary Jubilee of Mercy, the mortal remains of Saint Leopold Mandic and Saint Pio da Pietralcina, as examples of Mercy known by everyone, have been brought to Rome in February 2016. During the survey that preceded the preparation for transport to Rome, a whole-body CT was performed on the mummified corpse of Leopold Mandic, Capuchin Saint of Padova, Italy.

RESULTS

The CT examination demonstrated the presence of osteoarthritis at the level of the vertebral column, of the left knee and of the left hand. Moreover, CT showed the preservation of skeleton and partial preservation of the some viscera, such as remnants of the brain, heart, oesophagus, urinary bladder, plexuses and spinal nerves, ear ossicles, major arterial vessels (aorta and carotid arteries). It is to emphasize the fact that Saint Leopold was not subjected before the CT to any conservative treatment.

CONCLUSIONS

Computed tomography demonstrated to be a non-destructive method to investigate Saint Leopold, in order to maintain the integrity of the body and to acquire data on his pathologies and on his preservation. CT allows not only the acquisition of sectional images but also, thanks to dedicated software, the post-processing and reconstruction of three-dimensional models, that can be used also for public displays.

Identification of Pulmonary Edema in Forensic Autopsy Cases of Sudden Cardiac Death Using Fourier Transform Infrared Microspectroscopy: A Pilot Study

Many studies have proven the usefulness of biofluid-based infrared spectroscopy in the clinical domain for diagnosis and monitoring the progression of diseases. Here we present a state-of-the-art study in the forensic field that employed Fourier transform infrared microspectroscopy for postmortem diagnosis of sudden cardiac death (SCD) by in situ biochemical investigation of alveolar edema fluid in lung tissue sections. The results of amide-related spectral absorbance analysis demonstrated that the pulmonary edema fluid of the SCD group was richer in protein components than that of the neurologic catastrophe (NC) and lethal multiple injuries (LMI) groups. The complementary results of unsupervised principle component analysis (PCA) and genetic algorithm-guided partial least-squares discriminant analysis (GA-PLS-DA) further indicated different global spectral band patterns of pulmonary edema fluids between these three groups. Ultimately, a random forest (RF) classification model for postmortem diagnosis of SCD was built and achieved good sensitivity and specificity scores of 97.3% and 95.5%, respectively. Classification predictions of unknown pulmonary edema fluid collected from 16 cases were also performed by the model, resulting in 100% correct discrimination. This pilot study demonstrates that FTIR microspectroscopy in combination with chemometrics has the potential to be an effective aid for postmortem diagnosis of SCD.

Evolution of post-mortem coronary imaging: from selective coronary arteriography to post-mortem CT-angiography and beyond

Since the 1970s, remarkable efforts have been made in the post-mortem coronary study, especially by angiography, as an added tool to diagnose heart-related deaths. In more recent times, post-mortem CT (PMCT) and post-mortem CT-angiography (PMCTA) have become an established practice in numerous forensic units, because of the undeniable advantages these diagnostic instruments can offer: data acquisition times are increasingly fast, costs have become lower and, once acquired, data can be re-utilized and re-evaluated at any given time. This review aims to chart the history of post-mortem cardiac imaging, highlighting its evolution both in terms of methodology and technology as well as the contribution that forensic radiology has been able to offer to forensic pathology, not as an alternative to autopsy but as a guide and aid when performing one. Finally, the latest advances in the study of cardiac deaths are explored, namely by cardiac post-mortem MRI (PMMR), able to visualize all the various stages of a myocardial infarction, post-mortem MRI-angiography (PMMRA), useful in investigating coronary artery pathology and post-mortem cardiac micro-CT, able to provide near-histological levels of myocardial, coronary and valvular detail.