Postmortem angiography in computed tomography and magnetic resonance imaging in a case of fatal hemorrhage due to an arterio-venous malformation in the brain

The value of PMCTA in the diagnosis of coronary atherosclerosis in isolated human hearts

Postmortem computed tomography (PMCT) has a limited value in investigating coronary artery disease, despite several obvious advantages over the conventional autopsy. To address this issue, postmortem computed tomography angiography (PMCTA) has been introduced into various studies, where it has been used to investigate natural and unnatural deaths involving vascular damage, occlusion, or other pathologies of the vascular system. To investigate the application value of PMCTA in the diagnosis of coronary artery stenosis in ex situ hearts, the water-based contrast media were injected into isolated hearts, scaned, and finally compared with gold standards (autopsy and histology findings of the coronary artery). This study involved 16 subjects from the Academy of Forensic Science who were suspected to have died of sudden death without traumatic injuries. Unenhanced PMCT was performed first, followed by PMCTA using a water-based contrast agent, injected into the coronary arteries of isolated hearts using a self-designed angiography device. The image data were reconstructed into three-dimensional (3D) angiography images using software in the angiography facility. The 3D images were recorded and evaluated by two radiologists and then statistically analysed. The results of PMCTA were consistent with the gold standards for the diagnosis of coronary artery stenosis (P > 0.05). However, water-based contrast media can only be used to examine the pathological changes of blood vessels, which may have limitations in the diagnosis of causes of death such as myocardial oedema. PMCTA can be used as a new method to evaluate the degree of coronary atherosclerosis in addition to traditional autopsy. The 3D reconstruction technique reveals the coronary artery lesions more objectively and vividly and provides the opportunity to re-read the data at any time.

Key points

The methods and parameters for coronary angiography in isolated human hearts were standardized based on the previous researcher.PMCTA in isolated human hearts is including the 3D reconstruction technique that reveals the coronary artery lesions more objectively and vividly, and provides the opportunity to re-read the data at anytime.PMCTA could only be used to examine the pathological changes of blood vessels, which might have limitations for the diagnosis of causes of death.PMCTA in isolated human hearts can be viewed as an auxiliary method for establishing the cause of death, which can provide an assessment of degree and extent of arterial stenosis and accurately help determine the abnormal location.

Application of postmortem MRI for identification of medulla oblongata contusion as a cause of death: a case report

Whiplash injury is common in traffic accidents, and severe whiplash is characterized by cervical spinal cord injuries with cervical dislocation or fracture, that can be diagnosed by postmortem computed tomography (PMCT), postmortem magnetic resonance (PMMR), or conventional autopsy. However, for cervical spinal cord injury without fracture and dislocation, PMMR can be more informative because it provides higher resolution of soft tissues. We report the case of a 29-year-old male who died immediately following a traffic accident, in which the vehicle hit an obstacle at a high speed, causing deformation of the bumper and severe damage of the vehicle body. PMCT indicated no significant injuries or diseases related to death, but PMMR showed patchy abnormal signals in the medulla oblongata, and the lower edge of the cerebellar tonsil was herniated out of the foramen magnum. The subsequent pathological and histological results confirmed that death was caused by medulla oblongata contusion combined with cerebellar tonsillar herniation. Our description of this case of a rare but fatal whiplash injury in which there was no fracture or dislocation provides a better understanding of the potentially fatal consequences of cervical spinal cord whiplash injury without fracture or dislocation and of the underlying lethal mechanisms. Compared with PMCT, PMMR provides important diagnostic information in forensic practice for the identification of soft tissue injuries, and is therefore an important imaging modality for diagnosis of whiplash injury when there is no fracture or dislocation.

Gunshot wounds to the head: a comparison of postmortem magnetic resonance imaging, computed tomography, and autopsy

BACKGROUND

Postmortem imaging has become a powerful diagnostic tool in forensics. Postmortem computed tomography (PMCT) is often used currently to complement and sometimes even replace an autopsy.

PURPOSE

To compare PMCT, postmortem magnetic resonance imaging (PMMRI), and autopsy findings for gunshot wounds to the head.

MATERIAL AND METHODS

Cross-sectional study. We performed a retrospective analysis of 24 cases with gunshot wounds to the head that underwent both PMCT and PMMRI between 2011 and 2018 at the Institute of Forensic Medicine, University of Zurich (Switzerland).

RESULTS

Our study confirms that PMCT and, to a slightly lesser degree, PMMRI provide additional information that is valuable when combined with autopsy findings. Air embolism was solely detected in PMCT (67% vs. 0% at autopsy). A retained bullet or projectile and bone fragments were diagnosed more frequently with PMCT (42%, 67%, and 92%) than at autopsy (33%, 42%, and 46%). Soft tissue lesions were more often detected with PMMRI than with PMCT. With regard to autopsy, subdural hemorrhage and ventricular hemorrhage were slightly more frequently diagnosed with PMMRI (63% and 75% vs. 38% and 58% at autopsy). Intracerebral hemorrhage was by far most often diagnosed with PMMRI (92%) compared with both PMCT (38%) and autopsy (14%).

CONCLUSION

All three modalities should ideally be considered in cases of craniocerebral gunshot wounds. However, it might be conceivable that depending on the forensic query, PMCT and PMMRI may be an adequate replacement for an autopsy.

Diagnosis of Vascular Rupture Due to Arteriovenous Malformation Using Postmortem Angiography and 3-Dimensonal Printing: A Case Report

ABSTRACT

Postmortem computed tomography (PMCT), PMCT angiography, and 3-dimensonal (3D) printing technology are increasingly applied to forensic practice. Although their effectiveness is undeniably confirmed, their potential role in practice still needs to be further explored. Here, we report a typical case in which such 4 technologies were applied to a woman found dead with stomach content beneath the head on the pillow in her residence. At first, the cause of death was simply considered as hypertensive cerebral hemorrhage after preliminary examination. However, the initial judgment was questioned by her family for her devoid of hypertension history. As indicated by the targeted PMCT with cerebral angiography, the woman died of pathological cerebral hemorrhage due to arteriovenous malformation, which was still unconvincing enough for the family because in violent death, some cerebral hemorrhage could also be located in the same position. Finally, the family came to be convinced when the close connection between the deformed blood vessels and hematoma was perfectly demonstrated by the application of 3D printing technology. This study proved that it can be an efficient tool for identifying the cause of death when the integration is made of 3D printing technology and PMCT angiography, as a more intuitive evidence of forensic science.

Postmortem magnetic resonance imaging revealed bilateral globi pallidi lesions in a death associated with prolonged carbon monoxide poisoning: a case report

A man and a woman were found dead in the same car with a burned coal briquette. The cause of death of the woman was assigned to acute carbon monoxide (CO) poisoning without difficulty based on typical findings associated with this condition, including elevation of carboxyhaemoglobin (COHb). However, the man had an unremarkable elevation of COHb and a higher rectal temperature compared to that of the woman. Postmortem computed tomography (PMCT) revealed ambiguous low-density areas in the bilateral globi pallidi. Further analysis by postmortem magnetic resonance (PMMR) imaging showed these lesions more clearly; the lesions appeared as marked high signal intensity areas on both the T2-weighted images and the fluid-attenuated inversion recovery sequences. A subsequent autopsy revealed signs of pneumonia, dehydration, starvation, and hypothermia, suggesting that the man died from prolonged CO poisoning. Both globi pallidi contained grossly ambiguous lesions, and a detailed neuropathologic investigation revealed these lesions to be coagulative necrotic areas; this finding was compatible with a diagnosis of prolonged CO poisoning. This case report shows that postmortem imaging, especially PMMR, is useful for detecting necrotic lesions associated with prolonged CO poisoning. This report further exemplifies the utility of PMMR for detecting brain lesions, which may be difficult to detect by macroscopic analysis.

Post-mortem computed tomography angiography using left ventricle cardiac puncture: A whole-body, angiographic approach

Post-mortem computed tomography (PMCT) and PMCT angiography (PMCTA) are rapidly becoming effective and practical methods in forensic medicine. In this article, the authors introduce a whole-body PMCTA approach involving left ventricle cardiac puncture. This procedure was performed in 9 males and 3 females. PMCT was performed first. Then a biopsy core needle was used for a percutaneous puncture into the left ventricle through the intercostal area under CT guidance. 1000 mL of contrast media (diatrizoate meglumine and normal saline [0.9%] at 1:2 ratio) was injected at a rate of 50 mL/8 s, followed by CT scan. Visualization of systemic arteries was achieved in 11 cases, while only partial visualization was achieved in 1 case, which may have been related to incomplete thawing of the cadaver. PMCTA results revealed no vascular diseases and abnormalities in 10 victims. Among the 10 victims, 4 post-scan autopsies were performed and found no vascular abnormalities, consistent with the PMCTA results. Autopsy of the other 6 victims were refused by the relatives. PMCTA revealed signs of internal carotid artery aneurysm inside the sphenoid sinus in one victim, which was confirmed by autopsy. PMCTA results of another victim showed signs of stenosis and blockage of the distal part of the right vertebral artery and basilar artery. Thromboembolism of those arteries was found during autopsy. Compared with other existing PMCTA methods for examination of vascular injuries and diseases, this technique involves simple procedures, is less time consuming, has lower associated costs, does not require specialized equipment, provides adequate imaging quality, and is suitable for centres not equipped with cardiopulmonary bypass machines or other specialized equipment.

Diagnosis of a Cerebral Arteriovenous Malformation Using Isolated Brain Computed Tomography Angiography: Case Report

This report presents a case of a 40-year-old woman who was found dead in her house. The examination of the body revealed no external injuries. The whole body was scanned by multi-detector-row computed tomography (CT) before autopsy, revealing massive hemorrhage in the right frontal extending into the ventricular system. At autopsy, the brain parenchyma was removed. Then CT angiography was carried on the isolated brain. Computed tomography angiography suggested a mass of irregular, tortuous vessels in areas of hemorrhage in the right frontal lobe of the brain. Finally, histological examination confirmed the result of CT angiography due to an arteriovenous malformation. Hence, postmortem CT angiography played an important role in diagnosis of the cerebral arteriovenous malformation that was responsible for a massive hemorrhage in the skull.

A Fatal Case of a Ruptured Cerebral Aneurysm Detected by Postmortem Computed Tomography Angiography Using a New Contrast-Medium Solution

Forensic autopsy is still the criterion standard in legal investigations. Currently, notable transformation is occurring because postmortem imaging is being increasingly endorsed. This article highlights the effectiveness of postmortem computed tomography angiography by using a new contrast medium mixture as a solitary tool to define the cause and manner of death in a ruptured cerebral aneurysm case. Based on the imaging results, autopsy was not mandated and the case was closed.

Postmortem CT versus forensic autopsy: frequent discrepancies of tracheobronchial content findings

In their daily forensic casework, the authors experienced discrepancies of tracheobronchial content findings between postmortem computed tomography (PMCT) and autopsy to an extent previously unnoticed in the literature. The goal of this study was to evaluate such discrepancies in routine forensic cases. A total of 327 cases that underwent PMCT prior to routine forensic autopsy were retrospectively evaluated for tracheal and bronchial contents according to PMCT and autopsy findings. Hounsfield unit (HU) values of tracheobronchial contents, causes of death, and presence of pulmonary edema were assessed in mismatching and matching cases. Comparing contents in PMCT and autopsy in each of the separately evaluated compartments of the respiratory tract low positive predictive values were assessed (trachea, 38.2%; main bronchi, 40%; peripheral bronchi, 69.1%) indicating high discrepancy rates. The majority of tracheobronchial contents were viscous stomach contents in matching cases and low radiodensity materials (i.e., HU < 30) in mismatching cases. The majority of causes of death were cardiac related in the matching cases and skull/brain trauma in the mismatching cases. In mismatching cases, frequency of pulmonary edema was significantly higher than in matching cases. It can be concluded that discrepancies in tracheobronchial contents observed between PMCT and routine forensic autopsy occur in a considerable number of cases. Discrepancies may be explained by the runoff of contents via nose and mouth during external examination and the flow back of tracheal and main bronchial contents into the lungs caused by upright movement of the respiratory tract at autopsy.