Traumatic extra-axial hemorrhage: correlation of postmortem MSCT, MRI, and forensic-pathological findings

Automated detection of fatal cerebral haemorrhage in postmortem CT data

During the last years, the detection of different causes of death based on postmortem imaging findings became more and more relevant. Especially postmortem computed tomography (PMCT) as a non-invasive, relatively cheap, and fast technique is progressively used as an important imaging tool for supporting autopsies. Additionally, previous works showed that deep learning applications yielded robust results for in vivo medical imaging interpretation. In this work, we propose a pipeline to identify fatal cerebral haemorrhage on three-dimensional PMCT data. We retrospectively selected 81 PMCT cases from the database of our institute, whereby 36 cases suffered from a fatal cerebral haemorrhage as confirmed by autopsy. The remaining 45 cases were considered as neurologically healthy. Based on these datasets, six machine learning classifiers (k-nearest neighbour, Gaussian naive Bayes, logistic regression, decision tree, linear discriminant analysis, and support vector machine) were executed and two deep learning models, namely a convolutional neural network (CNN) and a densely connected convolutional network (DenseNet), were trained. For all algorithms, 80% of the data was randomly selected for training and 20% for validation purposes and a five-fold cross-validation was executed. The best-performing classification algorithm for fatal cerebral haemorrhage was the artificial neural network CNN, which resulted in an accuracy of 0.94 for all folds. In the future, artificial neural network algorithms may be applied by forensic pathologists as a helpful computer-assisted diagnostics tool supporting PMCT-based evaluation of cause of death.

A Comparative Study of Intravital CT and Autopsy Findings in Fatal Traumatic Injuries

Objectives: Traumatic injuries are one of the severe health problems of our time. In the 21st Century, approximately 4.5 million people worldwide die each year due to trauma. Computed tomography (CT) is widely used to diagnose injuries and offers information on the specific location and extent of organ and tissue damage. In cases of severe trauma, whole-body CT is increasingly used as a standard diagnostic technique. An autopsy is the final diagnostic examination and is still considered the gold standard in diagnostic methods in medicine. The aim of the study was to assess the reliability and accuracy of CT scan results, as well as limits in detecting trauma for forensic purposes. It aims to compare traumatic findings in the antemortem CT results to those observed at autopsy. Materials and Methods: We conducted a retrospective–prospective study involving 510 deaths due to trauma. We compared selected traumatic changes in the antemortem CT scan results with the autopsy findings. We obtained data with a detailed analysis of autopsy protocols, photographic documentation from the autopsies, and the interpretation of CT scans from medical documentation. In cases of discrepancies in the findings, we borrowed CT scans, which were repeatedly reviewed by clinical radiologists. Results: By comparing the findings of selected injuries detected by antemortem CT and autopsy, we found a correlation of findings in 75.3% and a discrepancy of findings in 24.7% in a set of 510 cases. After repeated targeted assessment of CT images by clinical radiologists in cases of discrepancies in the findings, which were detected by autopsy and undescribed by CT, the discrepancy decreased to 17%. Conclusions: The results of the study are comparable with data from many studies and professional publications. They show that CT compared to autopsy is a good method for diagnosing gunshot wounds to the head and bone fractures, with a limited diagnosis of cranial base fractures, while an autopsy is better for detecting minor injuries to organs and soft tissues.

Forensic imaging: a powerful tool in modern forensic investigation

Forensic imaging is a non-invasive examination process during the forensic investigation. It is mainly used in forensic pathology as an adjunct to the traditional autopsy. In the past two decades, forensic imaging has been vigorously developed by forensic experts from computed tomography (CT) to multiple augmented techniques through CT and magnetic resonance imaging (MRI). The application field of forensic imaging has also been broadened as its advantages are recognised by more forensic practitioners. In addition to the forensic pathology, this technique has been used in other forensic disciplines, including forensic anthropology, forensic odontology, forensic ballistics and wildlife forensics, etc. This article reviews the development of forensic imaging as the practice and research development in different forensic disciplines based on the relevant literature analysis.

Head and Brain Postmortem Computed Tomography-Autopsy Correlation in Hospital Deaths

The use of postmortem computed tomography (PMCT) to support autopsy pathology has increased in recent decades. To some extent, PMCT has also been contemplated as a potential alternative to conventional postmortem examination. The purpose of this study was to investigate the ability of PMCT to detect specific pathologic findings in the head and brain in natural hospital deaths.We examined postmortem CT images and autopsy data from 31 subjects who died at SUNY (State University of New York) Upstate University Hospital between 2013 and 2018. Each subject underwent a noncontrast PMCT and a traditional autopsy. A neuroradiologist analyzed PMCT images for head and brain abnormalities. The autopsies were performed by pathologists who were aware of the radiology results.In our series, PMCT was able to detect the majority of the significant space-occupying lesions, although it was not always reliable in ascertaining their nature. Postmortem computed tomography revealed findings usually challenging to detect at autopsy. Unfortunately, there were also situations in which PMCT was misleading, showing changes that were difficult to interpret, or that could be related to postmortem events. Therefore, we conclude PMCT should be used as an adjunct rather than a substitute to autopsy.

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.

Noninvasive 7 tesla MRI of fatal craniocerebral gunshots - a glance into the future of radiologic wound ballistics

Compared to computed tomography (CT), magnetic resonance imaging (MRI) provides superior visualization of the soft tissue. Recently, the first 7 Tesla (7 T) MRI scanner was approved for clinical use, which will facilitate access to these ultra-high-field MRI scanners for noninvasive examinations and scientific studies on decedents. 7 T MRI has the potential to provide a higher signal-to-noise ratio (SNR), a characteristic that can be directly exploited to improve image quality and invest in attempts to increase resolution. Therefore, evaluating the diagnostic potential of 7 T MRI for forensic purposes, such as assessments of fatal gunshot wounds, was deemed essential. In this article, we present radiologic findings obtained for craniocerebral gunshot wounds in three decedents. The decedents were submitted to MRI examinations using a 7 T MRI scanner that has been approved for clinical use and a clinical 3 T MRI scanner for comparison. We focused on detecting tiny injuries beyond the wound tract caused by temporary cavitation, such as microbleeds. Additionally, 7 T T₂-weighted MRI highlighted a dark (hypo intense) zone beyond the permanent wound tract, which was attributed to increased amounts of paramagnetic blood components in damaged tissue. Microbleeds were also detected adjacent to the wound tract in the white matter on 7 T MRI. Based on the findings of radiologic assessments, the advantages and disadvantages of postmortem 7 T MRI compared to 3 T MRI are discussed with regard to investigations of craniocerebral gunshot wounds as well as the potential role of 7 T MRI in the future of forensic science.

Traumatic Brain Injury: Imaging Patterns and Complications

While the diagnosis of traumatic brain injury (TBI) is a clinical decision, neuroimaging remains vital for guiding management on the basis of identification of intracranial pathologic conditions. CT is the mainstay of imaging of acute TBI for both initial triage and follow-up, as it is fast and accurate in detecting both primary and secondary injuries that require neurosurgical intervention. MRI is more sensitive for the detection of certain intracranial injuries (eg, axonal injuries) and blood products 24-48 hours after injury, but it has limitations (eg, speed, accessibility, sensitivity to motion, and cost). The evidence primarily supports the use of MRI when CT findings are normal and there are persistent unexplained neurologic findings or at subacute and chronic periods. Radiologists should understand the role and optimal imaging modality to use, in addition to patterns of primary brain injury and their influence on the risk of developing secondary brain injuries related to herniation. ^©RSNA, 2019 See discussion on this article by Mathur and Nicolaou.

Postmortem imaging findings and cause of death determination compared with autopsy: a systematic review of diagnostic test accuracy and meta-analysis

BACKGROUND

The aim of this study was to evaluate the sensitivity of postmortem computed tomography (PMCT), postmortem magnetic resonance imaging (PMMR) and PMCT angiography (PMCTA) compared with autopsy in cases of adult death investigations.

METHODS

For this systematic review and meta-analysis, Embase, PubMed, Scopus, Web of Science and Medline were searched for eligible studies in October 2016; a follow-up literature search was conducted in March 2018. Studies referring to PMCT, PMCTA and/or PMMR of more than 3 cases with subsequent autopsy were included. Data were extracted from published texts in duplicate. The extracted outcomes were categorized as follows: soft tissue and organ findings, skeletal injuries, haemorrhages, abnormal gas accumulations and causes of death. The summary measure was sensitivity, if 3 or more studies were available. To combine studies, a random effects model was used. Variability and heterogeneity within the meta-analysis was assessed.

RESULTS

Of 1053 studies, 66 were eligible, encompassing a total of 4213 individuals. For soft tissue and organ findings, there was a high pooled sensitivity with PMCTA (0.91, 95% CI 0.81-0.96), without evidence for between-study variability (Cochrane's Q test p = 0.331, I² = 24.5%). The pooled sensitivity of PMCT+PMMR was very high in skeletal injuries (0.97, CI 0.87-0.99), without evidence for variability (p = 0.857, I² = 0.0%). In detecting haemorrhages, the pooled sensitivity for PMCT+PMMR was the highest (0.88, 95% CI 0.35-0.99), with strong evidence of heterogeneity (p < 0.05, I² > 50%). Pooled sensitivity for the correct cause of death was the highest for PMCTA with 0.79 (95% CI 0.52-0.93), again with evidence of heterogeneity (p = 0.062, I² > 50%).

CONCLUSION

Distinct postmortem imaging modalities can achieve high sensitivities for detecting various findings and causes of death. This knowledge should lead to a reasoned use of each modality. Both forensic evidence and in-hospital medical quality would be enhanced.

Papilledema as a Diagnostic Sign of Cerebral Edema on Postmortem Magnetic Resonance Imaging

The purpose of this study was to investigate papilledema (PA) as a diagnostic criterion for the presence of antemortem or agonal cerebral edema despite normal postmortem brain swelling on postmortem magnetic resonance imaging (PMMR) in comparison with conventional autopsy.One hundred subjects with head PMMR and autopsy were included in this study. The sensitivities, spec icities, positive predictive values (PPVs), negative predictive values (NPVs), and accuracies were calculated in terms of the PA, PMMR, and cerebral edema on autopsy. Spearman r tests were used to analyze the linear correlations of PA and the radiological and autoptic determination of cerebral edema.In autopsy, the sensitivity regarding the presence of PA and cerebral edema was 66.2% (PPV, 70.5%), and specificity was 48.6% (NPV, 28.3%), with an overall accuracy of 60%. On PMMR, the sensitivity was 86.6% (PPV, 95%). The specificity was 90.9% (NPV, 34%), with an overall accuracy of 88%. The Spearman correlation revealed a statistically significant result (P < 0.001), which indicated a strong linear correlation of the presence of PA and cerebral edema with the autopsy results and the PMMR results.The presence of PA may aid in the diagnoses of cerebral edema despite normal postmortem brain swelling based on PMMR.

Brain Magnetic Resonance Imaging for Traumatic Brain Injury: Why, When, and How?

Conventional magnetic resonance imaging (MRI) and angiography (MRA) provide invaluable information in the evaluation of patients with all stages and grades of traumatic brain injury (TBI). The information obtained with MRI provides a more complete assessment of the patient's brain injury and possible long-term sequelae.

Diffusion tensor imaging of peripheral nerves in non-fixed post-mortem subjects

PURPOSE

While standard magnetic resonance imaging (MRI) sequences are increasingly employed in post-mortem (PM) examinations, more advanced techniques such as diffusion tensor imaging (DTI) remain unexplored in forensic sciences. Therefore, we studied the temporal stability and reproducibility of DTI and fiber tractography (FT) in non-fixed PM subjects. In addition, we investigated the lumbosacral nerves with PMDTI and compared their tissue characteristics to in vivo findings.

METHODS

MRI data were acquired on a 1.5T MRI scanner in seven PM subjects, consisting of six non-trauma deaths and one chronic trauma death, and in six living subjects. Inter-scan (within one session) and inter-session (between days) reproducibility of diffusion parameters, fractional anisotropy (FA), and mean diffusivity (MD), were evaluated for the lumbosacral nerves using Bland-Altman and Jones plots. Diffusion parameters in nerves L3-S2 were compared to living subjects using the non-parametric Mann-Whitney U test.

RESULTS

Reproducibility of diffusion values of inter-scan 95% limits of agreement ranged from -0.058 to 0.062 for FA, and (-0.037 to 0.052)×10(-3)mm(2)/s for MD. For the inter-session this was -0.0423 to 0.0423, and (-0.0442 to 0.0442)×10(-3)mm(2)/s for FA, and MD, respectively. Although PM subjects showed approximately four-fold lower diffusivity values compared to living subjects, FT results were comparable. The chronic trauma case showed disorganization and asymmetry of the nerves.

CONCLUSION

We demonstrated that DTI was reproducible in characterizing nervous tissue properties and FT in reconstructing the architecture of lumbosacral nerves in PM subjects. We showed differences in diffusion values between PM and in vivo and showed the ability of PMDTI and FT to reconstruct nerve lesions in a chronic trauma case. We expect that PMDTI and FT may become valuable in identification and documentation of PM nerve trauma or pathologies in forensic sciences.

Evaluation of post-mortem lateral cerebral ventricle changes using sequential scans during post-mortem computed tomography

In the present study, we evaluated post-mortem lateral cerebral ventricle (LCV) changes using computed tomography (CT). Subsequent periodical CT scans termed “sequential scans” were obtained for three cadavers. The first scan was performed immediately after the body was transferred from the emergency room to the institute of legal medicine. Sequential scans were obtained and evaluated for 24 h at maximum. The time of death had been determined in the emergency room. The sequential scans enabled us to observe periodical post-mortem changes in CT images. The series of continuous LCV images obtained up to 24 h (two cases)/16 h (1 case) after death was evaluated. The average Hounsfield units (HU) within the LCVs progressively increased, and LCV volume progressively decreased over time. The HU in the cerebrospinal fluid (CSF) increased at an individual rate proportional to the post-mortem interval (PMI). Thus, an early longitudinal radiodensity change in the CSF could be potential indicator of post-mortem interval (PMI). Sequential imaging scans reveal post-mortem changes in the CSF space which may reflect post-mortem brain alterations. Further studies are needed to evaluate the proposed CSF change markers in correlation with other validated PMI indicators.

Dating of Early Subdural Haematoma: A Correlative Clinico-Radiological Study

INTRODUCTION

Determination of post-traumatic interval remains one of the foremost important goals of any forensic investigation related to human crimes. The estimation of time since injury in cases of subdural haemorrhage has been studied only by a few investigators on the histological and radiological front.

AIM

The purpose of this study was to determine the post-traumatic interval of Subdural Haemorrhage (SDH) based on Hounsfield Unit measurements (HU) on Computed Tomography (CT) in surviving victims of head injury.

MATERIALS AND METHODS

The study included a total of 100 cases of closed head injury with subdural haemorrhage. The Post-traumatic Time Interval (PTI) varied from 0.5 hours to a maximum of 249 hours, with a mean of 54.2 hours.

RESULTS

Statistically significant results were obtained between the HU measurements of the SDH and the post-traumatic intervals and were found to be statistically significant. A rough attempt was made to determine the effect of haematoma volume on attenuation and was found out to be statistically insignificant.

CONCLUSION

The density of the subdural haematoma decreases with increase in the post-traumatic interval that concurs with the limited number of studies being conducted in the past. We concluded that further sorting of cases could be done according to its age with additional research and uniformity in the methodology.

Imaging of head trauma

Imaging is an indispensable part of the initial assessment and subsequent management of patients with head trauma. Initially, it is important for diagnosing the extent of injury and the prompt recognition of treatable injuries to reduce mortality. Subsequently, imaging is useful in following the sequelae of trauma. In this chapter, we review indications for neuroimaging and typical computed tomography (CT) and magnetic resonance imaging (MRI) protocols used in the evaluation of a patient with head trauma. We review the role of CT), the imaging modality of choice in the acute setting, and the role of MRI in the evaluation of patients with head trauma. We describe an organized and consistent approach to the interpretation of imaging of these patients. Important topics in head trauma, including fundamental concepts related to skull fractures, intracranial hemorrhage, parenchymal injury, penetrating trauma, cerebrovascular injuries, and secondary effects of trauma, are reviewed. The chapter concludes with advanced neuroimaging techniques for the evaluation of traumatic brain injury, including use of diffusion tensor imaging (DTI), functional MRI (fMRI), and MR spectroscopy (MRS), techniques which are still under development.

[Post-mortem perinatal imaging: State of the art and perspectives, with an emphasis on ultrasound]

The fields of application of post-mortem imaging have been exponentially growing for 10 years. Its potential to identify the cause of death in trauma and ballistic cases is now properly documented. In pediatric and perinatal practice, large significant series are less available, except for MRI and central nervous system analysis where scientific evidence is now robust. After a short historical and state-of-the-art review, we will try to depict the way we see the future of this sub-specialty of post-mortem imaging, especially in specific perinatal situations.

Post-mortem imaging compared with autopsy in trauma victims--A systematic review

BACKGROUND

Post-mortem imaging or virtual autopsy is a rapidly advancing field of post-mortem investigations of trauma victims. In this review we evaluate the feasibility of complementation or replacement of conventional autopsy by post-mortem imaging in trauma victims.

MATERIALS AND METHODS

A systematic review was performed in compliance with the PRISMA guidelines. MEDLINE, Embase and Cochrane databases were systematically searched for studies published between January 2008 and January 2014, in which post-mortem imaging was compared to conventional autopsy in trauma victims. Studies were included when two or more trauma victims were investigated.

RESULTS

Twenty-six studies were included, with a total number of 563 trauma victims. Post-mortem computer tomography (PMCT) was performed in 22 studies, post-mortem magnetic resonance imaging (PMMRI) in five studies and conventional radiography in two studies. PMCT and PMMRI both demonstrate moderate to high-grade injuries and cause of death accurately. PMCT is more sensitive than conventional autopsy or PMMRI in detecting skeletal injuries. For detecting minor organ and soft tissue injuries, autopsy remains superior to imaging. Aortic injuries are missed frequently by PMCT and PMMRI and form their main limitation.

CONCLUSION

PMCT should be considered as an essential supplement to conventional autopsy in trauma victims since it detects many additional injuries. Despite some major limitations, PMCT could be used as an alternative for conventional autopsy in situations where conventional autopsy is rejected or unavailable.

The future of pediatric and perinatal postmortem imaging

The field and applications of postmortem imaging are exponentially growing. Its potential to identify the cause of death in trauma and ballistic cases is now properly documented, as well as its use in drug mule identification. In pediatric and perinatal practice, large significant series are less available, except for MRI and central nervous system analysis where scientific evidence is now robust. In this review, after a short historical review and analysis of current problems and challenges, we will try to depict the way we see the future of this subspecialty of postmortem cross-sectional imaging, including all specific situations: terminations of pregnancy, intrauterine death, sudden unexpected infant death and identification issues.

Essentials of forensic post-mortem MR imaging in adults

Post-mortem MR (PMMR) imaging is a powerful diagnostic tool with a wide scope in forensic radiology. In the past 20 years, PMMR has been used as both an adjunct and an alternative to autopsy. The role of PMMR in forensic death investigations largely depends on the rules and habits of local jurisdictions, availability of experts, financial resources, and individual case circumstances. PMMR images are affected by post-mortem changes, including position-dependent sedimentation, variable body temperature and decomposition. Investigators must be familiar with the appearance of normal findings on PMMR to distinguish them from disease or injury. Coronal whole-body images provide a comprehensive overview. Notably, short tau inversion-recovery (STIR) images enable investigators to screen for pathological fluid accumulation, to which we refer as "forensic sentinel sign". If scan time is short, subsequent PMMR imaging may be focussed on regions with a positive forensic sentinel sign. PMMR offers excellent anatomical detail and is especially useful to visualize pathologies of the brain, heart, subcutaneous fat tissue and abdominal organs. PMMR may also be used to document skeletal injury. Cardiovascular imaging is a core area of PMMR imaging and growing evidence indicates that PMMR is able to detect ischaemic injury at an earlier stage than traditional autopsy and routine histology. The aim of this review is to present an overview of normal findings on forensic PMMR, provide general advice on the application of PMMR and summarise the current literature on PMMR imaging of the head and neck, cardiovascular system, abdomen and musculoskeletal system.

Postmortem CT compared to autopsy in children; concordance in a forensic setting

OBJECTIVES

The aim of this study is to assess the accuracy of postmortem CT (PMCT) in determining the cause of death in children who underwent a forensic autopsy because of a suspected nonnatural death.

METHODS

We selected forensic pediatric autopsies at the Netherlands Forensic Institute, whereby the subject underwent PMCT between 1-1-2008 and 31-12-2012. Cause of death was independently scored by a radiologist and a pathologist. Cause of death was classified (1) in categories being natural, unnatural, and unknown; (2) according to the ICD-10; and (3) according to institutional classification.

RESULTS

In the study period, 189 pediatric forensic autopsies were performed. Fifteen were excluded because of putrefaction. Of the remaining 174 autopsies, 98 (56%) underwent PMCT. PMCT and autopsy identified the same category in 69/98 cases (70%, kappa 0.49). They identified the same cause of death in 66/98 cases (67%, kappa 0.5) using ICD-10; in 71/98 (72%, kappa 0.62) using a forensic classification. PMCT performed better in unnatural deaths (59-67 % agreement) than in natural deaths (0 % agreement). If no cause of death was detected with autopsy, PMCT failed to identify a cause of death in 98% (39/40).

CONCLUSIONS

Pediatric PMCT does identify the majority of unnatural causes of death, but does not identify new diagnoses (true positives) if no cause of death is found during autopsy. Diagnostic accuracy in natural deaths is low.

KEY POINTS

• The case mix is an important predictor for the concordance between PMCT and autopsy. • In case of an unnatural death, 72--81% of PMCT results matches autopsy results. • In case of a natural death, 0% of PMCT results matches autopsy results. • If no cause of death is identified with autopsy, 98% of PMCT results concurs.

Comparison of computed tomography and autopsy in detection of injuries after unsuccessful cardiopulmonary resuscitation

AIM

Computed tomography (CT) has been suggested as an aid or even a replacement for autopsy. The aim of this trial was to study the conformity of the two methods in finding injuries in non-surviving patients after unsuccessful cardiopulmonary resuscitation.

METHODS

In this prospective study, 31 patients were submitted to a CT prior to autopsy after unsuccessful resuscitation attempts. Pathological findings were noted by both the radiologist and the pathologists in a specified protocol. The pathologists and radiologist were blinded from each other's results.

RESULTS

CT and autopsy revealed rib fractures in 22 and 24 patients respectively (kappa=0.83). In 8 patients, CT revealed more rib fractures than autopsy; and in 12 patients, autopsy revealed more rib fractures than CT. In 7 patients, neither method showed any rib fractures. The mean difference between the two methods in detecting rib fractures was 0.16 (S.D.: ± 3.174, limits of agreement: -6.19 to 6.51). The kappa value for sternal fractures was 0.49. A total of 260 pathological findings were noted by CT and 244 by autopsy. The average patient showed a median of 9 injuries (every fracture counted as one injury), independent of the method used in detecting the injuries.

CONCLUSIONS

There was a strong concordance between the two methods in finding rib fractures but not sternal fractures and these results support the concept of CT as a valuable complement to autopsy in detecting rib fractures after unsuccessful cardiopulmonary resuscitation but not as a replacement. Other injuries did not show the same concordance.

The effectiveness of postmortem multidetector computed tomography in the detection of fatal findings related to cause of non-traumatic death in the emergency department

OBJECTIVES

To investigate the diagnostic performance of postmortem multidetector computed tomography (PMMDCT) for the detection of fatal findings related to causes of non-traumatic death in the emergency department (ED).

METHODS

494 consecutive cases of clinically diagnosed non-traumatic death in ED involving PMMDCT were enrolled. The fatal findings were detected on PMMDCT and classified as definite or possible findings. These findings were confirmed by autopsy in 20 cases.

RESULTS

The fatal findings were detected in 188 subjects (38.1%) including 122 with definite (24.7%) and 66 with possible finding (13.4%). Definite findings included 21 cases of intracranial vascular lesions, 84 with intra-thoracic haemorrhage, 13 with retroperitoneal haemorrhage and one with oesophagogastric haemorrhage. In three patients who had initially been diagnosed with non-traumatic death, PMMDCT revealed fatal traumatic findings. Two definite findings (two haemopericardiums) and seven possible findings (two intestinal obstructions, one each of multiple liver tumours central pulmonary artery dilatation, pulmonary congestion, peritoneal haematoma, and brain oedema) were confirmed by autopsy. The causes of death were not determined in cases with possible findings without autopsy.

CONCLUSIONS

PMMDCT is a feasible tool for detecting morphological fatal findings in non-traumatic death in ED. It is important to know the ability and limitation of PMMDCT.

Forensic application of postmortem diffusion-weighted and diffusion tensor MR imaging of the human brain in situ

BACKGROUND AND PURPOSE

DWI and DTI of the brain have proved to be useful in many neurologic disorders and in traumatic brain injury. This prospective study aimed at the evaluation of the influence of the PMI and the cause of death on the ADC and FA for the application of DWI and DTI in forensic radiology.

MATERIALS AND METHODS

DWI and DTI of the brain were performed in situ in 20 deceased subjects with mapping of the ADC and FA. Evaluation was performed in different ROIs, and the influence of PMI and cause of death was assessed.

RESULTS

Postmortem ADC values of the brain were decreased by 49%-72% compared with healthy living controls. With increasing PMI, ADCs were significantly reduced when considering all ROIs together and, particularly, GM regions (all regions, P < .05; GM, P < .01), whereas there was no significant effect in WM. Concerning the cause of death, ADCs were significantly lower in mechanical and hypoxic brain injury than in brains from subjects having died from heart failure (traumatic brain injury, P < .005; hypoxia, P < .001). Postmortem FA was not significantly different from FA in living persons and showed no significant influence of PMI or cause of death.

CONCLUSIONS

Performing postmortem DWI and DTI of the brain in situ can provide valuable information for application in forensic medicine. ADC could be used as an indicator of PMI and could help in the assessment of the cause of death.

Quantitative analysis of intracranial hypostasis: comparison of early postmortem and antemortem CT findings

OBJECTIVE

The purpose of this study was to quantitatively analyze postmortem hypostasis in the intracranial venous sinus on head CT scans compared with the antemortem CT findings in the same patients with the aim of evaluating sedimentation in the heart and great vessels.

MATERIALS AND METHODS

A total of 50 patients on whom head CT was performed before and after death were enrolled. Attenuation in the dorsal part of the superior sagittal sinus was measured at the level of the basal ganglia on both antemortem and postmortem CT scans. Increased attenuation in the transverse sinus and cerebellar tentorium and sedimentation in the heart and great vessels were evaluated visually.

RESULTS

Attenuation in the dorsal part of the superior sagittal sinus increased significantly (p < 0.0001) between antemortem (42.77 ± 6.23 HU) and postmortem (49.72 ± 10.58 HU) CT in 80% of cases. Increased attenuation of the transverse sinus or cerebellar tentorium was observed in 48% of cases and sedimentation in the heart or great vessels in 62% of cases. Increased attenuation in the superior sagittal sinus was clearly evident in patients with sedimentation in the heart or great vessels (antemortem, 43.81 ± 6.17 HU; postmortem, 54.65 ± 8.51 HU) compared with the patients without evidence of sedimentation (antemortem, 41.06 ± 6.10 HU; postmortem, 41.66 ± 8.57 HU) (p < 0.0001).

CONCLUSION

Intracranial hypostasis is a common postmortem CT finding. Radiologists and physicians who interpret postmortem neurologic images should be aware of intracranial hypostasis and differentiate this phenomenon from intracranial hemorrhage.

Clinical radiology and postmortem imaging (Virtopsy) are not the same: Specific and unspecific postmortem signs

The aim of this article is to disclose the characteristics of postmortem forensic imaging; give an overview of the several possible findings in postmortem imaging, which are uncommon or new to clinical radiologists; and discuss the possible pitfalls. Unspecific postmortem signs are enlisted and specific signs shall be presented, which are typical for one cause of death. Unspecific signs. Livor mortis may not only be seen from the outside, but also inside the body in the lungs: in chest CT internal livor mortis appear as ground glass opacity in the dependent lower lobes. The aortic wall is often hyperdense in postmortem CT due to wall contraction and loss of luminal pressure. Gas bubbles are very common postmortem due to systemic gas embolism after major open trauma, artificial respiration or initial decomposition; in particular putrefaction produces gas bubbles globally. Specific signs. Intracranial bleeding is hyperattenuating both in radiology and in postmortem imaging. Signs of strangulation are hemorrhage in the soft tissue of the neck like skin, subcutaneous tissue, platysma muscle and lymph nodes. The "vanishing" aorta is indicative for exsanguination. Fluid in the airways with mosaic lung densities and emphysema (aquosum) is typical for fresh-water drowning.