The dead continue to teach the living: examining the role of computed tomography and magnetic resonance imaging in the setting of postmortem examinations

Traditional autopsy versus computed tomography imaging autopsy in trauma: A case of "synergistic disagreement"

BACKGROUND

Decreases in the rates of traditional autopsy (TA) negatively impact traumatology, especially in the areas of quality improvement and medical education. To help enhance the understanding of trauma-related mortality, a number of initiatives in imaging autopsy (IA) were conceived, including the postmortem computed tomography ("CATopsy") project at our institution. Though IA is a promising concept, few studies directly correlate TA and IA findings quantitatively. Here, we set out to increase our understanding of the similarities and differences between key findings on TA and IA in a prospective fashion with blinding of pathologist and radiologist evaluations.

METHODS

A prospective study of TA versus IA was conducted at an Academic Level I Trauma Center (June 2001-May 2010). All decedents underwent a postmortem, whole-body, noncontrast computed tomography that was interpreted by an independent, blinded, board-certified radiologist. A blinded, board-certified pathologist then performed a TA. Autopsy results were grouped into predefined categories of pathologic findings. Categorized findings from TA and IA were compared by determining the degree of agreement (kappa). The χ(2) test was used to detect quantitative differences in "potentially fatal" findings (eg, aortic trauma, splenic injury, intracranial bleeding, etc) between TA and IA.

RESULTS

Twenty-five trauma victims (19 blunt; 9 female; median age 33 years) had a total of 435 unique findings on either IA or TA grouped into 34 categories. The agreement between IA and TA was worse than what chance would predict (kappa = -0.58). The greatest agreement was seen in injuries involving axial skeleton and intracranial/cranio-facial trauma. Most discrepancies were seen in soft tissue, ectopic air, and "incidental" categories. Findings determined to be "potentially fatal" were seen on both TA/IA in 48/435 (11%) instances with 79 (18%) on TA only and 53 (12%) on IA only. TA identified more "potentially fatal" solid organ and heart/great vessel injuries, while IA revealed more spine injuries, "potentially fatal" procedure-related findings, and the presence of ectopic air/fluid.

CONCLUSION

This limited study does not support substitution of noncontrast, computed tomography-based IA for TA. Our quantitative analyses suggest that TA and IA evaluations may be complementary and synergistic when performed concurrently. There are potential benefits to using IA in trauma process/quality improvement and in educational settings. Further research should focus on the value (and limitations) of the information provided by IA in the absence of TA.

Postmortem imaging in congenital heart disease: preliminary experience

BACKGROUND

Despite the importance of the autopsy for quality improvement, autopsy rates have declined dramatically in recent decades due to poor acceptance by families and physicians and high costs to institutions.

PURPOSE

To compare postmortem imaging (PMI) with autopsy in patients with congenital heart defects to see if PMI could substitute in some or all cases and to compare costs of the two methods.

MATERIAL AND METHODS

Ten patients with congenital heart disease dying in hospital during the study period in whom an autopsy was planned underwent PMI using postmortem magnetic resonance imaging (PMMRI) (6 patients) and postmortem computed tomographic angiography (PMCTA) (10 patients) with permission of the family. Four patients were excluded from PMMR because of metal ECMO cannulas. PMI was interpreted before autopsy using an organ system checklist and results compared to autopsy. The costs of each method were tracked.

RESULTS

When both PMMR and PMCTA were performed the PMI findings corresponded closely with autopsy. PMI correctly diagnosed the principal heart defects in all six cases and correctly imaged central vessels, heart valves and chambers, brain, abdominal organs, and bone. Weak points were visualization of the coronary arteries and distinguishing postmortem pulmonary atelectasis from lung pathology. The cause of death by PMI matched autopsy findings in 5/6 cases in which both PMMR and PMCTA were performed and was incomplete in the other five cases. The cost of PMI was about 15% lower than the cost of autopsy.

CONCLUSION

PMI provided most gross anatomic cardiac diagnoses available by autopsy in our series of patients with congenital heart defects and the cost appears to be lower.

Virtual CT autopsy in clinical pathology: feasibility in clinical autopsies

For the past century, autopsy techniques in clinical pathology have not changed significantly, while autopsy rates are declining. Modern imaging techniques offer interesting prospects of supportive post-mortem diagnostic investigation. In a prospective study of 29 autopsy cases, complimentary virtual autopsy using unenhanced post-mortem computed tomography (pmCT) was performed. We analysed in a prospective cohort study 29 unenhanced pmCT scans, generated prior to autopsy. Clinical information regarding clinical history and circumstances of death were provided. The objective of the study was to find consistency and/or discrepancy between virtual autopsy and conventional autopsy findings regarding cause of death and death-related diagnoses, reconstruction of the pathogenetic mechanisms involved, side diagnoses and CPR (cardiopulmonary resuscitation)- or death-related post-mortem changes. Accuracy of pmCT for cause of death was 68 % and the positive predictive value (PPV) was 75 %. Regarding the pathogenetic mechanisms, accuracy of pmCT was 21 % and PPV was 29 %. The combined diagnostic yield of autopsy and pmCT was 133 % compared to autopsy only. Modern imaging techniques give an opportunity for post-mortem diagnostics to complete but not yet replace traditional autopsy. We could show that in two out of three cases, the cause of death found by pmCT matched the diagnosis from classical autopsy. While both disciplines, pathology and radiology, will profit from the mutual exchange of data, it seems a realistic aim to strive for virtual autopsy possibly further supported by biopsies and contrast-enhanced pmCT as an alternative to the classical clinical autopsy. A combination of both methods enhances diagnostic quality and completeness of the autopsy report.

Postmortem computed tomography images of a broken piece of a weapon in the skull

The use of post-mortem radiological imaging is becoming increasing widespread in forensic medicine. These images can help improve the quality and safety of autopsy. We report two cases of homicide victims that had broken pieces of a weapon in their skull. Postmortem multislice computed tomography (MSCT) demonstrated metal artifacts in the skull of two homicide cases. Autopsy showed that both artifacts were pieces broken off of a sharp instrument. Some possible benefits of postmortem MSCT include the ability to reconstruct visual images of weapons and the possible prevention of injury to autopsy personnel.