New pitfalls of high-density postmortem computed tomography

Thirty-day clinical outcome of traumatic brain injury patients with acute extradural and subdural hematoma: a cohort study at Mulago National Referral Hospital, Uganda

Background

Increasing traumatic brain injury (TBI) has paralleled the need for decompression surgery for acute subdural (ASDH) and acute extradural haematoma (AEDH). Knowledge of key determinants of clinical outcomes of such patients is mandatory to guide treatment protocols.

Objective

To determine the 30-day clinical outcomes and predictor variables for patients with extra-axial hematomas at Mulago National Referral Hospital in Uganda.

Methods

Prospective observational cohort study of 109 patients with computed tomography (CT) confirmed extra-axial hematomas. Ethical clearance was obtained from the School of Medicine Research and Ethics Committee of College of Health Sciences, Makerere University (REC REF. 2018-185). Admitted patients were followed-up and reassessed for Glasgow Outcome Scale (GOS) and final disposition. Multivariate regression analysis was performed using Stata 14.0 (StataCorp. 2015) at 95% confidence interval, regarding p < 0.05 as statistically significant.

Results

The overall proportion of favorable outcome was 71.7% (n = 71), with 42.3% (n = 11) and 81.7% (n = 58) for ASDH and AEDH, respectively (p = 0.111). Factors associated with a favorable outcome were admission systolic BP > 90 mmHg [IRR = 0.88 (0.26–0.94) 95%CI, p = 0.032), oxygen saturation > 90% [IRR = 0.5 (0.26–0.94) 95%CI, p = 0.030] and diagnosis AEDH [IRR = 0.53 (0.30–0.92) 95%CI, p = 0.025). Moderate TBI [IRR = 4.57 (1.15–18.06) 95%CI, p = 0.03] and severe TBI [IRR = 6.79 (2.32–19.86) 95%CI, p < 0.001] were significantly associated with unfavorable outcomes.

Conclusion

The study revealed that post resuscitation GCS, systolic BP, oxygen circulation, and diagnosis of AEDH at admission are the most important determinants of outcome for patients with extra-axial intracranial hematomas. These findings are valuable for the triaging teams in resource-constrained settings.

Empty Delta Sign on Unenhanced Postmortem Computed Tomography Scan in Cerebral Venous Thrombosis

Cerebral venous thrombosis is a rare condition which constitutes 0.5% to 2% of all types of stroke and carries a mortality of up to 20% to 50%. It leads to cerebral edema, infarction, hemorrhage and venous hypertension. Clinically the diagnosis is confirmed using enhanced computed tomography (CT) angiography which demonstrates an empty delta sign in cerebral veins, particularly in the superior sagittal sinus. However, postmortem CT (PMCT) findings on cerebral venous thrombosis have not been documented in the literature. We present a case report of a 69-year-old man who on unenhanced PMCT scan showed an empty delta sign in the cerebral veins. The empty delta sign was able to be demonstrated in unenhanced PMCT which can be explained by hyper attenuation of the dural veins at postmortem forming an internal contrast highlighting the thrombus.

Total-body CT and MR features of postmortem change in in-hospital deaths

OBJECTIVES

To evaluate the frequency of total-body CT and MR features of postmortem change in in-hospital deaths.

MATERIALS AND METHODS

In this prospective blinded cross-sectional study, in-hospital deceased adult patients underwent total-body postmortem CT and MR followed by image-guided biopsies. The presence of PMCT and PMMR features related to postmortem change was scored retrospectively and correlated with postmortem time interval, post-resuscitation status and intensive care unit (ICU) admittance.

RESULTS

Intravascular air, pleural effusion, periportal edema, and distended intestines occurred more frequently in patients who were resuscitated compared to those who were not. Postmortem clotting was seen less often in resuscitated patients (p = 0.002). Distended intestines and loss of grey-white matter differentiation in the brain showed a significant correlation with postmortem time interval (p = 0.001, p<0.001). Hyperdense cerebral vessels, intravenous clotting, subcutaneous edema, fluid in the abdomen and internal livores of the liver were seen more in ICU patients. Longer postmortem time interval led to a significant increase in decomposition related changes (p = 0.026).

CONCLUSIONS

There is a wide variety of imaging features of postmortem change in in-hospital deaths. These imaging features vary among clinical conditions, increase with longer postmortem time interval and must be distinguished from pathologic changes.

Experimental evaluation of freezing preparation for the macroscopic inspection in putrefied brain

PURPOSE

To evaluate the usefulness of freezing preparation for macroscopic investigation in advanced putrefied brain.

MATERIALS AND METHODS

After sealing in individual plastic bags, 10 pig heads were stored at 20°C for 5days allow postmortem change (putrefaction) to progress. After an observation period, they were divided into 2 groups to evaluate the usefulness of the freezing effect in macroscopic investigation. The process over the postmortem period and the freezing process were examined.

RESULTS

At day-5, the presence of air density was detected between the inner surface of the cranium and the brain parenchyma. Intra-cranial air accumulation presented on CT in all heads. In the control group, the brain parenchyma leaked out from the hole in the meninges, and the gray-white matter difference was clear in 3/72 (4.2%), moderate in 7/72 (9.7%), ambiguous in 17/72 (23.6%), and poor in 45/72 (62.5%). In the freezing group, the brain parenchyma presented homogeneous low density after more than 14h freezing. On opening the cranium, the entire brains were frozen, and the gray-white matter difference was clear in 33/72 (46.0%), moderate in 17/72 (24.0%), ambiguous in 15/72 (21.0%), and poor in 7/72 (10.0%). The freezing group afforded greater clarity in the gray-white matter inspection (p<0.05).

CONCLUSION

Freezing preparation was useful for the macroscopic investigation of putrefied brain compared with the ordinary autopsy.

Freezing effect on brain density in postmortem CT

Two 60-year-old males were found at their homes whose bodies had deteriorated due to putrefaction. To prevent worm invasion and minimize deterioration, dry ice was used prior to the autopsy investigation. Prior to autopsy, postmortem CT demonstrated a decreased density in brain parenchyma at the dry-iced side, and autopsy revealed deteriorated brain parenchyma with frozen effect (presented like sherbet). Moreover, the deteriorated cerebral parenchyma maintained their structure and they were evaluated by cutting. When lower CT density presents in postmortem CT, the freezing effect may need to be considered and the physician should evaluate the cadaver's postmortem condition to prevent misdiagnoses.

Classification of hemopericardium on postmortem CT

Postmortem CT (PMCT) is increasingly used in forensic practice, and knowledge and classification of typical hemopericardium on PMCT would help to assure correct radiological interpretation. The goal of this study was to evaluate the pericardial and pleural space fluid volumetry, and to evaluate the signs on PMCT pointing to cardiac tamponade as the cause of death, and their pitfalls. Fourteen cadavers (eleven male, three female, 49-87 [mean, 70.9] years) were examined by PMCT. The pericardial volume and pericardial findings with/without pleural space fluid collection were compared with autopsy findings. In addition, the appearance of pericardial lesions on PMCT was documented and compared with the autopsy findings. The respective volumes of pericardial space, and right and left pleural space fluid showed as 172.0-711.0 (mean 368.7) ml, 0-1830.0 (266.1) ml, 0-231.0 (75.2) ml on PMCT, and were 136.0-652.0 (311.1) ml, 0-2100 (299.0) ml, and 0-300.0 (61.3) ml on autopsy. In statistical evaluation, the pericardial space volume was significantly greater on PMCT (p<0.05), but there was no significant difference in pleural space fluid volume. The hemopericardium PMCT showed 3 patterns: double band, single band, and horizontal level, and the former two patterns presented as coagulated blood at autopsy. Single band and horizontal level patterns were thought to result from CPR-related causes and/or postmortem manipulation. In conclusion, double and single band patterns on PMCT were indicative findings of cardiac tamponade. An understanding of the pericardial PMCT appearance and its significance can help to avoid misreading, and is important for making correct radiological interpretation.

CT-guided percutaneous needle placement in forensic medicine

We have developed a technique of CT-guided needle placement in the destructed human body in forensic practice. A sixty-year-old male was found in a burned car and he was also destructed severely. Although blood was needed for the external examination, it was difficult to approach the vessels because of the severely burned condition of the cadaver. Thus, we attempted to obtain a blood sample from a vessel using a CT-guided technique. Postmortem CT demonstrated the presence of blood-containing vessels in the pelvis. Indeed, CT-guided needle placement had no difficulty with surface markers, table location, or depth measurement from the surface. CT-guide needle placement is a feasible and reliable technique, so that when the tissue/blood sample is at risk of being spoiled, CT-guided needle placement could be a substitute for conventional sampling techniques.