Common Postmortem Computed Tomography Findings Following Atraumatic Death: Differentiation between Normal Postmortem Changes and Pathologic Lesions

Abstract

Computed tomography (CT) is widely used in postmortem investigations as an adjunct to the traditional autopsy in forensic medicine. To date, several studies have described postmortem CT findings as being caused by normal postmortem changes. However, on interpretation, postmortem CT findings that are seemingly due to normal postmortem changes initially, may not have been mere postmortem artifacts. In this pictorial essay, we describe the common postmortem CT findings in cases of atraumatic in-hospital death and describe the diagnostic pitfalls of normal postmortem changes that can mimic real pathologic lesions.

Keywords: Autopsy imaging; Forensic radiology; Postmortem CT; Postmortem imaging.

Fig. 1. Hypostasis and hemorrhagic lesion in brain in 35-year-old deceased woman (case 1).

A. CT scan obtained 8 hours and 35 minutes after death shows obscure hypostasis in dorsal superior sagittal sinus (arrowhead) in case 1. Linear and curving high density lesions are present along falx cerebri and cerebral sulcus (arrows). B. Subsequent autopsy reveals diffuse subarachnoid hemorrhage. CT = computed tomography

Fig. 2. Three lesion patterns on postmortem CT images of brain.

A. Pattern 1. CT scan of 53-year-old deceased woman obtained 1 hour and 35 minutes after death shows unremarkable postmortem changes (case 2). B. Pattern 2. CT scan of 39-year-old deceased woman obtained 9 hours and 9 minutes after death shows diffuse brain swelling (case 3). C. Pattern 3. CT scan of 78-year-old deceased man obtained 14 hours and 41 minutes after death shows both diffuse brain swelling and loss of distinction between gray and white matter (case 4). CT = computed tomography

Fig. 3. Hypostasis and thrombosis in great vessels in 45-year-old deceased man (case 5).

CT scan obtained 2 hours and 8 minutes after death shows hypostasis in thoracic aorta (A, arrow). Hyperdense cast is present within left pulmonary artery (A, arrowheads), which is later diagnosed as pulmonary thrombus on autopsy (B, arrow). CT = computed tomography

Fig. 4. Dissection and hypostasis in ascending aorta in 76-year-old deceased woman (case 6).

CT scan obtained 14 hours and 30 minutes after death shows both flap (arrow) separating two lumens and hypostasis (arrowhead) in ascending aorta. Increased density and thickening of aortic wall, which are normal postmortem changes, are also observed (dotted arrow). CT = computed tomography

Fig. 5. Hypostasis and pathologic lesion in lung in 73-year-old deceased man (case 7).

A. CT scan obtained 16 hours and 48 minutes after death shows increased density lesion with horizontal border in dependent region of left upper lobe, which is attributed to hypostasis (arrows). Endotracheal fluid, thought to be normal postmortem change, is also observed (arrowhead). B. Asymmetrical and segmental consolidation is simultaneously observed in right lower lobe (arrows). C, D. Pathological examination with hematoxylin and eosin on subsequent autopsy indicates pulmonary congestion (C; low-power view) and inflammatory cellular infiltration (pneumonia) (D; low-power view). Images C and D correspond to A and B, respectively. CT = computed tomography

Fig. 6. Hyperdense lung lesion not attributed to normal postmortem change in 18-year-old deceased man (case 8).

CT scan obtained 3 hours and 32 minutes after death shows multiple areas of consolidation and randomly distributed nodules. Subsequent autopsy revealed pneumonia. CT = computed tomography

Fig. 7. Broad intraorganic/vascular gas unassociated with cardiopulmonary resuscitation (CPR) in 65-year-old deceased man (case 9).

CT scan obtained 12 hours and 20 minutes after death shows intraorganic/vascular gas throughout body (A-C, arrows). Gas is observed within lumens of right atrium and ventricle (A), and left femoral artery and vein (C). Intrahepatic gas is also observed (B), which is considered to be in hepatic vascular system. CPR was not performed because patient had do-not-resuscitate order. CT = computed tomography

Fig. 8. Hemorrhagic hyperdense fluid in stomach in 65-year-old deceased woman with liver cirrhosis and esophagogastric varices (case 10).

CT scan obtained 13 hours and 33 minutes after death shows content with two different densities in gastric lumen. Higher density material in gastric lumen (arrows) is clumped, covers lower density material, and is suspected to be caused by rupture of esophagogastric varices. This was proven on subsequent autopsy. CT = computed tomography

Fig. 9. Hemorrhagic hyperdense fluid in colon in 50-year-old deceased woman (case 11).

CT scan obtained 2 hours and 17 minutes after death shows hyperdense contents, which fill colon (arrows) and were diagnosed as hemorrhagic on autopsy. Upon reviewing patient's medical history, we found that he was receiving anticoagulant medication and thus was at risk of hemorrhage. CT = computed tomography

Fig. 10. Non-hemorrhagic hyperdense fluid in colon in 72-year-old deceased woman (case 12).

CT scan obtained 1 hours and 48 minutes after death shows hyperdense content in colon (arrow) similar to case 11. However, this material was not hemorrhagic on subsequent autopsy. It was unclear based on patient's medical history whether she was administered oral contrast medium or other oral medication, such as laxative. Residual contrast material is also observed in kidneys of cases 12 and 16 because contrast-enhanced CT was performed immediately before death. CT = computed tomography

Fig. 11. Hyperdense wall of GI tract in 74-year-old deceased woman (case 13).

A. CT scan obtained 2 hours and 34 minutes after death shows hyperdense walls throughout GI tract (arrows). B, C. Autopsy revealed that hyperdense GI wall was intramural hemorrhage (B, macroscopic image; C, microscopic low-power view image with hematoxylin and eosin stain). CT = computed tomography, GI = gastrointestinal

Fig. 12. Intraluminal gas in GI tract unassociated with CPR in 64-year-old deceased man (case 14).

CT scan obtained 3 hours and 57 minutes after death shows widespread distension of GI tract. Although this finding can be caused by CPR, in this patient, CPR was not performed due to DNR order. This finding is considered nonspecific. CPR = cardiopulmonary resuscitation, CT = computed tomography, DNR = do-not-resuscitate, GI = gastrointestinal

Fig. 13. Intramural gas in GI tract caused by antemortem condition in 75-year-old deceased man who underwent CPR (case 15).

CT scan obtained 4 hours and 21 minutes after death shows intramural gas throughout GI tract (arrows). Although there may have some contribution from CPR, autopsy proved that he had pneumatosis cystoides intestinalis. CT = computed tomography, GI = gastrointestinal

Fig. 14. Intramural gas in GI tract unassociated with CPR in 72-year-old deceased woman who did not undergo CPR (case 16).

CT scan obtained 1 hour and 48 minutes after death shows intramural gas throughout GI tract (arrows) similar to case 15. CPR was not performed before death due to patient's DNR order. However, autopsy did not reveal any pathology associated with this postmortem CT finding. Therefore, intramural gas was attributed to mucosal injury, which is normal postmortem change. CPR = cardiopulmonary resuscitation, CT = computed tomography, DNR = do-not-resuscitate, GI = gastrointestinal

Fig. 15. Dilatation of right heart in 50-year-old deceased man (case 17).

CT scan obtained 17 hours and 18 minutes after death shows dilatation of right heart (A, arrows). Although this is known to be normal postmortem change caused by blood congestion, it became clear with in autopsy that finding in this case was caused by pulmonary veno-occlusive disease. Other lesions related to this disease are also present: pulmonary artery dilation (B, arrows) and pulmonary edema (C). CT = computed tomography