Postmortem CT (PMCT) can be useful for evaluating traumatic injuries in deceased individuals. PMCT can detect a wide range of injuries, particularly craniofacial fractures, brain hemorrhages, thoracic injuries like hemothorax and pneumothorax, and skeletal fractures. It is often more sensitive than autopsy for bone injuries. However, PMCT has limitations and cannot replace autopsy, as it may miss some soft tissue injuries and natural causes of death. While complementary to autopsy, in some situations PMCT can provide sufficient information to determine cause of death without an invasive autopsy.

1. Postmortem CT in Trauma
Rathachai Kaewlai, MD

2. BG Gil Brogdon, MD
It is believed that forensic scientists in other
disciplines would find radiologists in their
area interested in cooperative efforts
Sharing of interdisciplinary skills and
knowledge would
• Improve the economy and effectiveness of
investigative efforts
• Prevent some false starts and/or
reinventions of well-worn wheels, and most
important,
• Expand scientific horizons
Gil Brogdon, MD
Father of Forensic Radiology
1929-2014

3. Outline
Postmortem imaging techniques
Role of PMCT in trauma
Normal PMCT findings
Traumatic pathologies on PMCT
Current status at Ramathibodi
Q & A

4. Death Investigation
Situation peaceful
No injuries
Medical history and ID cleared
Liberation for funeral

5. Death Investigation
Situation suspicious?
Possible malpractice?
Legal inspection for MOD,TOD and triage
If cannot answer
Autopsy
(usually head, thorax, abdomen)
Postmortem imaging
Radiography
CT
CT angiography
MRI
MOD = mode of death,TOD = time of death

6. “Virtopsy”
Virtual autopsy
Began in Germany, now settled in Switzerland
What it covers:
PMCT, PMCTA, PMMR
Biopsy
Surface scanning
Virtual reconstruction of trauma events
Virtopsy.com

7. PM Imaging: Filling the Void of
Traditional Autopsy
Traditional autopsy = reference standard
But
Invasive
Certain body parts difficult to dissect
Require permission from relatives of trauma victims
Religious issue

8. Focusing on Trauma and PMCT
Very common
Every 5s, a person in the world dies from trauma
Major cause of death worldwide
2nd in Thailand
1st in age group of 1-45 years in developing
countries
Proven usefulness of PMCT
New technology allows fast imaging in seconds
3D reconstruction for visualization

9. PMCT to Answer
Key Forensic Questions
Identity
Time of death
Injuries:
Self inflicted or 3rd party, priority, vitality, survival time
Type, severity, instrument, direction
Concomitant injuries
Reconstruction of events

10. PMCT: Advantages
To physicians
Analysis of organs in situ
Info added to autopsy
Less time consuming in certain
body parts than autopsy
(neck, spine, pelvis)
Stored images for years
Trauma care evaluation
Education
Research
To victims’ relatives
Less invasive
Less rejection
No religious issue

11. PMCT: Techniques
Coverage
Head/neck
Body to knees or lower
No IV contrast
Arms on side
High dose for image quality
2D reformations
3D imaging

12. PMCT: Supporting Evidence
Systematic review in Forensic Science International
Jalalzadeh H, et al. (2015) from The Netherlands
26 studies, 563 trauma victims
“PMCT demonstrated moderate to high-grade injuries
and COD accurately”
“PMCT more sensitive than conventional autopsy in
detecting skeletal injuries”

13. Normal PM Changes Seen on CT
Livor mortis
Rigor mortis
Algor mortis
Decomposition
Putrefaction

14. Livor Mortis
Seen in all fluid
compartments, internal
organs, soft tissues of
body
Increased attenuation in
subcutaneous tissues,
lungs, and solid organs
with AP gradient in
dependent part

15. Livor Mortis
Separation of components
of blood in vascular
compartment
“Hematocrit effect”

16. Postmortem Decomposition
Dependent on multiple variables
Early in warmer temperatures and humid conditions
Imaging “lag time” = a few hours after death
Obvious within 24-48 hours
“Severe decomposition” images from Levy AD et al. Radiology 2007

17. Autolysis of Brain Parenchyma
Loss of gray-white differentiation (within 6 hrs)
Effacement of sulci
Normal

18. Putrefaction
Accumulation of air within
brain, subQ, internal
organs (such as liver,
pancreas, kidneys),
vessels (mesenteric/
portal system, aorta,
celiac trunk, SMA)

19. Putrefactive Hepatic Gas
Most common in portal syst
As early as 4-7 hr after death
First seen in nondependent
anterior liver (LL), then
diffusely within 24 hours
In hepatic veins, hepatic
arteries and biliary tree, air
is usually due to trauma or
other pathologies

20. Putrefactive
Pneumatosis Intestinalis
Intramural bowel wall air
–nonspecific sign
should not be mistaken
for bowel injury

21. Pathologies: Skeleton
PMCT detects more skeletal
injuries than autopsy
Especially better than autopsy
for AIS 1-3 injuries
PMCT good for areas not
easily accessible for
dissection (facial skeleton,
pelvis)

22. Soft Tissues
Hematomas often overlook with PMCT
Autopsy superior to PMCT
For soft tissue and vascular injuries
Even with AIS 3+ injuries
Exception is abnormal gas collections
PMCT far better than autopsy even with under
water technique

23. Calvarial Fractures
PMCT ~ autopsy

24. Facial and Skull Base Fractures
Facial fractures – PMCT better or equal to autopsy
Skull base fractures – autopsy better

25. Brain Hemorrhages
In general, brain lesions better with autopsy
Brain hemorrhages – PMCT ~ autopsy
But small ones can be missed on PMCT
IVH – PMCT better
SAH, IVH, subgaleal hematomas

26. PMCT Explanation on Cause of
Death in the Brain
Decebration
Traumatic external brain
herniation
Crush fractures of skulls
Extensive IVH
Cerebral venous gas
emboli 2/2 open-skull
fractures
External brain herniation

27. Cerebral Venous Air Embolism
Air in cerebral ven sinuses
Air in supracardiac neck veins
Air in right side of heart, PA
and branches
Retrograde air filling in IVC,
hepatic veins, renal veins
Images from Panda A et al. Curr Probl Diagnost Radiol 2015

28. Traumatic Intraocular
Hemorrhage
May be a/w orbital and
skull base fractures
Potentially missed on
autopsy
Right intraocular hemorrhage

29. Hemothorax
PMCT better, small fluid easily detected with PMCT
Including blood in mediastinum/pericardium
Mediastinal shift better with PMCT
*

30. Pneumothorax
Gas-related injuries difficult to
detect with autopsy
PMCT better, including gas in
mediastinum/pericardium
Mediastinal shift better with
PMCT
Tension can be a cause of death
and lead to pneumorachis and
pneumocephalus,
subsequently causing death
*
*

31. Lung Lesions (in general)
Autopsy better
PMCT problem
Hypostasis (normal PM change)
Trauma: contusions, lacerations
Non-trauma: aspiration, infective pneumonia, edema
Need correlation with time and mechanism of injury

32. Pulmonary Injuries
Large lacerations may be COD
Pulmonary alveolo-venous fistula formation
Systemic arterial gas emboli
Open chest wall injury + lacerations +

33. Aspiration
Fluid in airways (*),
esophagus and stomach
Opacities in dependent
portions of lung (*)
*
*
*

34. Heart and Mediastinum Lesions
In general, autopsy better
Only large lesions can be seen on PMCT
Pneumopericardium – PMCT better
Hemopericardium – PMCT ~ autopsy

35. Vanishing Aorta Sign
Specific PMCT sign for
exsanguination (of any
origin) as a cause of death
Small and indiscernible aorta
Images from Panda A et al. Curr Probl Diagnost Radiol 2015

36. Cardiac Clues
Giving clues to nontraumatic
cardiac cause of death even
in patients with history of
trauma and without other
obvious signs of injury
Cardiac hypertrophy
Atherosclerotic aortic and
coronary calcifications
Valvular calcifications
Coronary calcification

37. Abdomen/pelvis Organ Injuries
Autopsy better than PMCT
Only high-grade injuries may be found at PMCT
Poor detection for spleen, kidney injuries
Retroperitoneal hemorrhage

38. C-spine – PMCT better or ~ autopsy
Dislocations – PMCT ~ autopsy
T-spine – PMCT ~ autopsy
L-spine – PMCT better or ~ autopsy
Spine Fracture/Dislocation
Spine fracture/dislocation

39. Pneumorachis
Potential cause of cord
compression leading to death
Pneumorachis

40. Strangulation
Pneumomediastinum and cervical emphysema with
abrupt cutoff at level of strangulation
Suggestive of antemortem hanging
Hyoid bone fractures
Autopsy better
Cervical soft tissue injuries

41. Gunshot Wound
Delineate number and location of entry/exit wounds,
position, size/number of pellets, trajectory of bullets,
internal injuries, likely cause of death

42. Cause of Death
Few PMCT studies investigated cause of trauma deaths
Exsanguination
Central respiratory paralysis
Hemopericardium
Concurrent gas embolisms
Reports of limited no. of cases – most COD given by
PMCT were correct

43. Pitfalls
Common in soft tissues, heart, mediastinum, vessels and
abdomen (missed diagnosis)
Unable to differentiate causes of pulmonary opacities

44. Setting up PMCT: Prerequisites
Curiosity
Cooperation between imaging and forensic teams
Both physicians and non-physicians
Role understanding
Readiness to learn
Availability of scanner
A little knowledge on forensic pathology, imaging
technique, interpretation and limitations

45. Summary
PMCT in trauma can detect wide spectrum of injuries
Most useful in detecting craniofacial, cerebral, thoracic
and osseous injuries
Complementary to autopsy
Can obviate need for autopsy in specific situations
Limitations include inability to obtain toxologic samples,
hypothermia/burn as COD, pulmonary and fat
emboli, myocardial infarctions, other natural COD