Is acute subdural hematoma reduced during the agonal stage and postmortem?

Distinguishing true from pseudo hematoma in the cervical spinal canal using postmortem computed tomography

Spinal cord injury is difficult to detect directly on postmortem computed tomography (PMCT) and it is usually diagnosed by indirect findings such as a hematoma in the spinal canal. However, we have encountered cases where the hematoma-like high-attenuation area in the cervical spinal canal was visible on PMCT, while no hematoma was observed at autopsy; we called it a "pseudo hematoma in the cervical spinal canal (pseudo-HCSC)." In this retrospective study, we performed statistical analysis to distinguish true from pseudo-HCSC. The cervical spinal canal was dissected in 35 autopsy cases with a hematoma-like high-attenuation area (CT values 60-100 Hounsfield Unit (HU)) in the spinal canal from the first to the fourth cervical vertebrae in axial slices of PMCT images. Of these 22 had a hematoma and 13 did not (pseudo-HCSC). The location and length of the hematoma-like high-attenuation and spinal cord areas were assessed on reconstructed PMCT images, true HCSC cases had longer the posterior hematoma-like area and shorter the spinal cord area in the midline of the spinal canal (P < 0.05). Furthermore, we found that true HCSC cases were more likely to have fractures and gases on PMCT while pseudo-HCSC cases were more likely to have significant facial congestion (P < 0.05). We suggest that pseudo-HCSC on PMCT is related to congestion of the internal vertebral venous plexus. This study raises awareness about the importance of distinguishing true HCSC from pseudo-HCSC in PMCT diagnosis, and it also presents methods for differentiation between these two groups.

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.

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.

Smaller but denser: postmortem changes alter the CT characteristics of subdural hematomas

PURPOSE

The aim of this study was to investigate if (1) the volume of subdural hematomas (SDH), midline shift, and CT density of subdural hematomas are altered by postmortem changes and (2) if these changes are dependent on the postmortem interval (PMI).

MATERIALS AND METHODS

Ante mortem computed tomography (AMCT) of the head was compared to corresponding postmortem CT (PMCT) in 19 adults with SDH. SDH volume, midline shift, and hematoma density were measured on both AMCT and PMCT and their differences assessed using Wilcoxon-Signed Rank Test. Spearman's Rho Test was used to assess significant correlations between the PMI and the alterations of SDH volume, midline shift, and hematoma density.

RESULTS

Mean time between last AMCT and PMCT was 109 h, mean PMI was 35 h. On PMCT mean midline displacement was decreased by 57% (p < 0.001); mean SDH volume was decreased by 38% (p < 0.001); and mean hematoma density was increased by 18% (p < 0.001) in comparison to AMCT. There was no correlation between the PMI and the normalization of the midline shift (p = 0.706), the reduction of SDH volume (p = 0.366), or the increase of hematoma density (p = 0.140).

CONCLUSIONS

This study reveals that normal postmortem changes significantly affect the extent and imaging characteristics of subdural hematoma and may therefore affect the interpretation of these findings on PMCT. Radiologists and forensic pathologists who use PMCT must be aware of these phenomena in order to correctly interpret PMCT findings in cases of subdural hemorrhages.

Pre-autopsy computed tomography accurately detected cerebral hemorrhage in highly decomposed bodies: report of two cases

Diagnosis of cerebral hemorrhage as a cause of death is often difficult when bodies are in a highly decomposed state. Postmortem imaging can be useful for estimating cause of death in cerebral hemorrhage cases, but the effects of decomposition on imaging findings have not been well studied. We report here two cases in which pre-autopsy computed tomography (CT) accurately detected cerebral hemorrhage in highly decomposed bodies and consequently allowed for careful autopsy dissection. We found that the CT attenuation value of hematoma remained high in intracranial hemorrhagic lesions, probably due to a postmortem increase in the density of hematomas. The high contrast against the background parenchyma enabled the hematomas to be discriminated from the surrounding cerebral parenchyma even in considerably decomposed bodies. However, dispersion and breakdown of the hematomas over time with decomposition appeared to result in contrast reduction. In such cases, hematomas may be missed or their size underestimated on CT. Thus, a comprehensive approach involving autopsy is necessary to determine cause of death for highly decomposed bodies.