Post-mortem use of advanced CT techniques in autopsy

1. PPOSTMORTEMOSTMORTEM UUSESE OOFF AADVANCEDDVANCED IIMAGINGMAGING TTECHNIQUESECHNIQUES
IISS AAUTOPSYUTOPSY GGOINGOING DDIGITAL?IGITAL?
AANILNIL AAGGRAWALGGRAWAL, MD, MD
S. P. SS. P. STAWICKITAWICKI, MD, MD
BBRIANRIAN A. HA. HOEYOEY, MD, MD
FFEBRUARYEBRUARY 24, 200824, 2008

2. CCASEASE PPRESENTATIONSRESENTATIONS

3. OOVERVIEWVERVIEW
• HISTORY
• THE BASICS
• BACKGROUND
• SPECIFIC STUDIES & FINDINGS
• ROLE IN EDUCATION
• CONTROVERSIES
• FUTURE DIRECTIONS

4. HHISTORYISTORY
• Ancient Egypt and Mesopotamia  Postmortem dissections
performed during embalming
• India  Autopsy and dissection were practiced by Sushruta
(sixth century B.C.), an early pioneer of ayurveda
• Third century B.C., Greece  Autopsy used for the purpose of
extending understanding of anatomy and disease
• Middle Ages and Renaissance, Europe  Autopsy re-emerged
with the work of Vesalius and others
• The seats and causes of diseases investigated by anatomy
 First organized treatise on pathological findings at autopsy
published in 1761 by Giovanni Batista Morgagni

5. HHISTORYISTORY
• End of the nineteenth century  Osler made autopsy one of
the cornerstones of his medical training and clinical method
• Students not only expected to attend autopsies on patients
who succumbed  They were trained to perform autopsies
• During this same period  Cabot reported on the autopsies
of thousands of patients
• First half of 20th
century  Autopsy rates steadily increase,
significant advances made through cadaveric investigations
• Second half of the 20th
century/early 21st
century  Steady
decline in autopsy rates noted around the globe

6. HHISTORY:ISTORY: IIMAGINGMAGING AAUTOPSYUTOPSY
• 1977 Wullenweber et al  first forensic application of CT to
describe radiographic patterns of gunshot injury to the head
• 1980s Flodmark et al  comparison study of premortem CT
and subsequent autopsy findings in neonates who suffered
perinatal asphyxia
• 1989 Kalender et al  spiral CT opens the door to 3D data
acquisition and processing
• 1990-2000  University of Bern Virtopsy project
• 1994 Donchin et al  postmortem CT in trauma victims
• 2007 Hoey et al  CATopsy study in trauma patients

7. HHISTORYISTORY

8. TTHEHE BBASICSASICS
• Autopsy  Examination of a cadaver to determine or confirm
the cause of death
• Greek for autos (self) and opsomei (I will see)  To see with
one’s own eyes….
• Imaging autopsy  High-definition CT and/or MRI scan of the
decedent prior to or in lieu of traditional autopsy
• How is it done  Decedent transported on a gourney in a
body bag to CT/MRI scanner (at times challenging)
• How is it interpreted  Patholigists and radiologists
collaborate in these investigations  Role of others?

9. IIMAGINGMAGING AAUTOPSYUTOPSY
• Advanced imaging used for some time in
forensic investigation
• CT and MRI are now being evaluated as
complementary or even as alternative means of
post-mortem examination
• Concurrent decline in traditional autopsy rates
worldwide  Is imaging autopsy a viable
alternative?
• Why should be bother?

10. • Why use postmortem imaging?
– Cause of death determination
– Gender identification
– Body length and individual decendent feature
identification
– Defining foreign bodies (bullets, etc)
– Injury identification and forensic reconstruction (3D
reconstruction, bullet tract)
– Education and performance improvement process
– Research (from medicine to history)
IIMAGINGMAGING AAUTOPSYUTOPSY

11. • Advantages of imaging autopsy
– Takes a few minutes on modern scanners
– Non-invasive  Radiation can’t hurt postmortem
– May be viewed remotely without loss of imaging detail
– Allows for ‘repeated’ autopsies during subsequent investigation
– Able to detect fractures that are difficult to detect during
traditional autopsy
– Able to readily detect foreign bodies (bullets) and their
trajectories  Used by the U. S. Military (DARPA)
IIMAGINGMAGING AAUTOPSYUTOPSY

12. • Limitations of imaging autopsy
– Death determination varies between 49% and 91%  depends on
the cause of death and the ease of radiographic ‘capture’ of relevant
pathologic findings
– Minor but critical findings have been reported to be ‘missed’ on
imaging autopsies  Less likely as modern radiologic techniques
evolve and accuracy improves
– Imaging autopsy lacks the ability to demonstrate active contrast
extravasation or any other processes that require active metabolic
and/or circulatory activity to be visualized
– Therefore, imaging autopsy not be as helpful in determining deaths
due to poisoning, metabolic disorders, other processes that do not
alter the structural or tissue appearance of the body
– Significance of some findings (i.e., intravascular/hepatic air)
unknown  More studies needed to elucidate
IIMAGINGMAGING AAUTOPSYUTOPSY

13. IIMAGINGMAGING AAUTOPSYUTOPSY IISS CCOMPLEMENTARYOMPLEMENTARY
• Imaging does not replace a standard autopsy, but it does offer
certain additional advantages
• Allows visualization of soft tissue patterns in cases of severe
putrefaction  Structural patterns may not be distinguishable
upon traditional autopsy
• Hoey et al - Over 40% of post-mortem CT studies had
clinically significant findings that were not identified on
traditional autopsy
• Very accurate  Good estimation of solid organ weights
(Jackowski et al); Excellent visualization of projectile tract
(Thali et al); Ability to match vehicle and occupant
characteristics in fatal vehicular crashes (Thali et al)

14. CCASEASE PPRESENTATIONSRESENTATIONS

15. • Donchin et al - J Trauma 1994;37:552-555
– Used CT imaging
– 25 trauma victims underwent CT within 6 hours of death
– Radiologist/pathologist blinded to each other’s findings
– Total 127 pathologic findings  45% seen on both traditional
and imaging autopsy  30% missed by CT  25% missed
by traditional autopsy
– CT better than traditional autopsy for skeletal injuries
– Overall  imaging autopsy revealed 70.5% of findings and
traditional autopsy revealed 74.8%
– Although not more effective than traditional autopsy 
imaging autopsy increases the overall yield when combined
with the traditional autopsy
SSPECIFICPECIFIC FFINDINGS &INDINGS & SSTUDIESTUDIES

16. • Thali et al - J Forensic Sci 2003;48:386-403
– Used both MSCT and MRI
– 55% of causes of death were found independently using only
radiographic data
– Radiography superior to autopsy in revealing certain cases of
cranial, skeletal, and soft tissue trauma
• Plattner et al - J Forensic Sci 2003;48:1347-1355
– Used both MSCT and MRI
– MSCT/MRI superior to autopsy in the demonstrating extent and
distribution of gas in intraparenchymal blood vessels of internal
organs and body regions inaccessible by standard biopsy
SSPECIFICPECIFIC FFINDINGS &INDINGS & SSTUDIESTUDIES

17. • Aghayev et al - Neuroradiology 2004;46:559-
564
– Used both MSCT and MRI in blunt head injury
– Imaging studies documented herniation of the cerebellar tonsils
prior to traditional autopsy
• Aghayev et al - J Forensic Sci 2004;49:809-813
– Used MSCT in head injured decedent
– Postmortem imaging is a good forensic visualization tool for
documentation and examination of injuries and pathology
SSPECIFICPECIFIC FFINDINGS &INDINGS & SSTUDIESTUDIES

18. • Jackowski et al - Forensic Sci Int 2005;149:11-23
– Used both MSCT and MRI
– Examined postmortem cardiac imaging for postmortem changes
– Ability to use more radiation (better image quality) without
concern for biologic effects of ionizing radiation
• Jackowski et al - Forensic Sci Int 2005;151:157-163
– Used both MSCT and MRI in a pediatric patient with fatal
streptococcus group A infection
– Postmortem imaging detected all relevant autopsy findings, as
verified by subsequent histological and microbiological
confirmation  support for the use of imaging autopsy
SSPECIFICPECIFIC FFINDINGS &INDINGS & SSTUDIESTUDIES

19. • Hayakawa et al – Int J Legal Med 2006;120:24-26
– Used mobile CT unit
– Postmortem examinations  quality control measure for traditional
autopsy
– In 25% of cases  CT demonstrated the cause of death to differ from
that determined by superficial postmortem exams
• Oyake et al – Radiat Med 2006;24:493-502
– Computed tomographic studies within 2 hours of death
– Determination of etiology for sudden death in infants and children
– Non-traumatic mechanism in 15 patients
– Imaging autopsy pointed to the cause of death in 14 of 15 when
radiographic information combined with premortem clinical and
laboratory data
SSPECIFICPECIFIC FFINDINGS &INDINGS & SSTUDIESTUDIES

20. • Levy et al – Isr Med Assoc J 2007;9:699-702
– Postmortem CT examinations of military air mishap victims
– Abnormally located air found in 24% of imaging autopsies
– Solid organ injury and superficial trauma detection significantly worse
on CT than on traditional autopsy
– Imaging autopsy  useful as a complementary examination
• Hoey et al – J Trauma 2007;9:699-702
– Postmortem CT examinations of trauma victims
– Comparison of imaging and traditional autopsy findings  imaging
correctly identified cause of death in 83% of decedents and revealed
40% of clinically significant findings not seen on traditional autopsy
– Imaging autopsy as a clinical performance improvement tool
SSPECIFICPECIFIC FFINDINGS &INDINGS & SSTUDIESTUDIES

21. CCASEASE PPRESENTATIONSRESENTATIONS

22. IIMAGINGMAGING: CT: CT VSVS MRIMRI
• CT
– Good for visualization of
bone, air
– Reasonable visualization of
soft tissues
– Ability to image vascular
structures with postmortem
contrast
– Less expensive
– Shorter scanning times
• MRI
– Excellent for soft tissue
imaging
– Very accurate imaging of
neurologic structures
– More expensive
– Longer scanning times
These two techniques may well be complementary

23. IIMAGINGMAGING AAUTOPSY:UTOPSY:
MMEDICALEDICAL EEDUCATIONDUCATION

24. CCONTROVERSIESONTROVERSIES
• Cost  Who will pay for imaging autopsies?
– Cost of imaging (CT/MRI) autopsy around $500-$1,000
– Cost of traditional autopsy around $1,700 to $3,500
• Name  Too much confusion ....
– Virtopsy
– CATopsy
– Virtual autopsy
– Imaging autopsy
• Medicolegal  Don't even go there ....
– Will imaging autopsy findings be 'discoverable'
– Performance improvement versus 'incrimination’

25. TTHEHE BBIGIG PPICTUREICTURE

26. PPOSTMORTEMOSTMORTEM UULTRASONOGRAPHYLTRASONOGRAPHY
• Easy to learn and use
• Ultrasonography is used extensively in resuscitative
clinical situations
• Trauma  FAST exam, pneumothorax assessment,
even extremity assessment
• Potential uses of ultrasound in postmortem setting
 Organ evaluation, pneumothorax, pericardial
tamponade, hemoperitoneum

27. IAIA:: FFUTUREUTURE DDIRECTIONSIRECTIONS
• Defining the ‘meaning’ of specific findings (i.e., hepatic gas,
intracardiac gas, etc)
• Further technological improvement
• Large-scale, prospective, multi-institutional studies
• Clarification of 'jurisdictions'
• Determination of medicolegal aspects  Does imaging
autopsy constitute legal evidence?
• Imaging autopsy as a screening tool for traditional autopsy 
Could it enhance the educational value of the few autopsies
that are being performed today?
• Forensic ‘telemedicine’ consultations?

28. CCASEASE PPRESENTATIONSRESENTATIONS

29. CCONCLUSIONSONCLUSIONS
• Imaging autopsy is here to stay
• Learning to appreciate advantages and limitations 
Imaging autopsy most likely to become a ‘screening’
tool or a complementary study
• Many issues remain unresolved
• What are the medico-legal implications
• Who is going to pay for these studies
• Who will interpret these studies  Will subspecialty
fellowship trained radiologists-pathologists be
needed?

30. QQUESTIONS ?UESTIONS ?