Ct autopsy 2008 - 02 - 22 stan

PPOSTMORTEM OSTMORTEM UUSE SE OOF F AADVANCED DVANCED IIMAGING MAGING TTECHNIQUESECHNIQUES

IIS S AAUTOPSY UTOPSY GGOING OING DDIGITAL?IGITAL?

AANILNIL A AGGRAWALGGRAWAL, MD, MDS. P. SS. P. STAWICKITAWICKI, MD, MDBBRIANRIAN A. H A. HOEYOEY, MD, MD

FFEBRUARYEBRUARY 24, 2008 24, 2008

CCASE ASE PPRESENTATIONSRESENTATIONS

OOVERVIEWVERVIEW• HISTORY

• THE BASICS

• BACKGROUND

• SPECIFIC STUDIES & FINDINGS

• ROLE IN EDUCATION

• CONTROVERSIES

• FUTURE DIRECTIONS

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

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

HHISTORY: ISTORY: IIMAGING MAGING 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

HHISTORYISTORY

TTHEHE B BASICSASICS• 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?

IIMAGINGMAGING A AUTOPSYUTOPSY• 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?

• 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 A AUTOPSYUTOPSY

• 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)


• 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 A AUTOPSYUTOPSY I ISS C COMPLEMENTARYOMPLEMENTARY• 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)


• 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 F FINDINGS & INDINGS & SSTUDIESTUDIES

• 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


• 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


• 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


• 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


• 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



IIMAGINGMAGING: CT : CT VSVS MRI MRI • 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

IIMAGING MAGING AAUTOPSY:UTOPSY:MMEDICAL EDICAL EEDUCATIONDUCATION

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’

TTHE HE BBIG IG PPICTUREICTURE

PPOSTMORTEMOSTMORTEM U ULTRASONOGRAPHYLTRASONOGRAPHY• 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

IAIA: : FFUTURE UTURE 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?


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?

QQUESTIONS ?UESTIONS ?

Ct autopsy 2008 - 02 - 22 stan

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