1. Recent Advances in Forensic Pathology: Post-mortem CT imaging
Criminal Bar Association of NZ
Saturday 5 August, 2017
Recent Advances in Forensic Pathology: Post-mortem CT imaging
DR JOANNA GLENGARRY, FORENSIC PATHOLOGIST
Victorian Institute of Forensic Medicine
Melbourne, Australia

2. Post-mortem CT imaging
Fluoroscopy
CT scans
X-rays
Ultrasound
MRI
Using radiology to image the deceased

3. So why is Post-mortem CT Imaging important?
The autopsy has been thought of as a low-tech tool in death investigation…
But forensic pathology is joining the 21st century
Emergence of the use of post-mortem CT scans (PMCT) in forensic pathology cases.
Routine use in suspicious cases and homicides
Changing how we investigate death
It will change how we present evidence
Now part of the NZ Coroner’s Act1
UK Chief Coroner has issued guidelines on its use2
Coroner’s Amendment Act 2016 S21A

4. So is this just a new fad?
PMCT has emerged from experimental and novel to established and validated tool in the forensic pathology toolbox:
its utility and place in the process is no longer in question

5. Question: What group was responsible for the development of the clinical CT machine?

6. According to some3 the development of the CT scanner was a result of the Beatles’ success.
The Beatles’ success enabled EMI to fund one of their engineers, Sir Godfrey Hounsfield’s research which ended with developing the first CT scanner.
While on an outing in the country, Hounsfield came up with the idea that one could determine what was inside a box by taking X-rays at all angles around the object.
He then constructed a computer that could take data from such X-rays to create an image of the object in "slices".
In 1979 he was awarded the 1979 Nobel prize in Medicine with Allan Cormack4
3. Dr B Timmis - Beatles greatest gift... is to science
4. "The Nobel Prize in Physiology or Medicine 1979". Nobelprize.org. Nobel Media AB Web. 3 Jul 2017.

7. What is CT? CT – Computed tomography
CAT – Computed Axial Tomography, Computer Aided Tomography
From the Greek tomos (slice) and graphein (to write).
Computer-processed combinations of many X-ray measurements taken from different angles to produce cross-sectional (tomographic) images (virtual "slices") of specific areas of a scanned object, allowing the user to see inside the object without cutting.

8. CT Scanner
Auckland Mortuary

12. Forensic Pathology_Glengarry
25 June 2015
CIB Induction_RNZPC

13. Forensic Pathology_Glengarry
25 June 2015
CIB Induction_RNZPC

14. Forensic Pathology_Glengarry
25 June 2015
CIB Induction_RNZPC

15. Why do we do it? Why must we do it?

16. Why must we do it? Medical history:
Prerequisite for death investigation and autopsy
In forensic pathology casework, the history is often incomplete, inaccurate or of poor relevancy
The PMCT can provide important ancillary information prior to autopsy, mitigating a lack of history

17. Why must we do it? Planning the autopsy:
Provisional location of disease and trauma allows the pathologist to plan the physical approach or special dissection
Hazard detection
Needles, knife tip, medical equipment
Unexploded ordnance
Foreign bodies/projectiles

18. Finding bullets

19. Finding bullets

20. Why must we do it? Finding disease and trauma:
Obscure sites of skeletal injuries
Roof of mouth
Pelvis
Spine
Limbs
Complex injury depiction
Abnormal air / gas
Air embolism
Pneumothorax, pneumoperitoneum
Occult skull base fracture
Diagnosing disease

21. Obscure sites of trauma
Roof of the mouth

22. Complex Injuries

23. When the family object? Haemopericardium – cause?
Family do not want an autopsy
Angiography shows aortic dissection
No requirement for autopsy

24. Why must we do it? Documentation / Legal transparency:
Document both the presence of and absence of findings
Full 3D volumetric record:
Complete surface record
Clothing, medical devices, property, items in hair
Skin breaches
Condition of body before autopsy
Permanent record of internal injury, disease
Retrospective review of wound tracks
Quality review, medical corroboration
Once the body is cremated, it’s a tad challenging to go back…

25. Permanent digital record

26. Wound track

27. Wound track

28. Why must we do it? Identification:
Visual, dental, fingerprints and DNA identification are not able to be used in every case
Medical information to assist ID
Age estimation
Evidence of prior surgery, fractures
Medical devices, prostheses or implants
Disaster Victim Identification5
Triage of cases
Identify comingling and non-human remains
Sex and age
Guide pathologist to sources of ID
5. O’Donnell et al. Contribution of postmortem multidetector CT scanning to identification of the deceased in a mass disaster: experience gained from the 2009 Victorian bushfire disaster. For Sci Int 2011; 205: 15-28

29. Why must we do it? Disaster Victim Identification:

30. Why must we do it? Presenting evidence:
To students or trainees
To peers
To the Court

31. Case Study 1 - Homicide
23M found at his residence with multiple injuries

32. Case Study 1 - Homicide

33. Case Study 1 - Homicide

34. Case Study 1 - Homicide
A great many injuries in keeping with both mattock and knife as weapons of infliction
Problematic come Court time:
Cannot show external photos due to extreme facial injuries
Still need to demonstrate injuries and patterns to jury
CT 3D renders were used in lieu of external photos

35. Case Study 2 – Homicide

36. Case Study 2 – Homicide

37. Disadvantages Pathologists are not radiologists…yet Cost
Learning curve
Shades of grey
Optical mileage
Cost
Massive data storage requirements
Need to retrain technicians
Not all disease states are shown

38. Radiology doesn’t show everything
Soft tissue injuries poorly revealed
Fine/small injuries
Causes of death not revealed
Histological diagnoses
Metabolic or biochemical processes
Toxicology
Fires

39. What does the literature say?

40. Does it work for Natural Disease?
Roberts (UK) et al6 examined discrepancies between PMCT diagnosis and autopsy diagnosis in cases of natural disease
Discrepancy between PMCT when a radiologic COD was evident: 16%
Comparable to the 15% error rate cited for Death Certificates
Problem: The most common causes of death seen in FP practise are not seen with PMCT
6. Roberts ISD et al. Post-mortem imaging as an alternative to autopsy in the diagnosis of adult deaths: a validation study. Lancet 2012; 379:

41. What about trauma?
Scholing (Netherlands) et al7 evaluated PMCT for determining COD and identification of specific injuries in trauma cases:
Agreement on COD between PMCT and the autopsy was %
In some cases, PMCT detected more injuries than autopsy
In some cases the PMCT missed injuries seen at autopsy
My experience? With appropriate case selection and experience
in using PMCT, many trauma cases can be examined by PMCT
plus a careful external examination without critical loss of information
7. Scholing M et al. The value of postmortem computed tomography as an alternative to autopsy in trauma victims: a systematic review. European Radiology 2009; 19:

42. Children?
Sieswerda-Hoogendororn (Netherlands) et al8 evaluated PMCT for determining COD in children:
PMCT identified the same COD as autopsy in 67% of unnatural deaths
But 0% agreement between CT and autopsy in natural disease
My experience? Imaging is an essential adjunct to autopsy,
particularly to exclude non-accidental injury.
But you need an autopsy to diagnose natural disease in children.
8. Sieswerda-Hoogendoorn T et al. Postmortem CT compared to autopsy in children; concordance in a forensic setting. International Journal of Legal Medicine 2014; 128:

43. Oh yeah? Show me how this actually works…

44. The NZ capability
Ability to perform the scan depends on an authority to do so from the Coroner
Auckland has in-house CT scanner
Scan all suspicious deaths, homicides
Scan trauma deaths, decomposed cases, shooting, hanging, diving deaths
Natural disease cases at pathologist discretion
Other forensic centres in Palmerston North, Wellington, Christchurch depend on goodwill of hospital clinical CT scanner
Logistical issues regarding timing, body transport, cultural acceptability
Initially the adult scans viewed and interpreted by forensic pathologist, later a report is provided by a radiologist is requested
Auckland has dedicated radiologists with an interest in PMCT
Paediatric autopsies have immediate report provided by paediatric radiologist

45. Case Study 3 - Suicide 56F witnessed standing on the side of the road
Truck passing felt a “bump” as its trailer rolled over an object
The female found deceased on road behind trailer
Medical records show history of depression
Police visit to her house revealed a suicide note

46. Case Study 3 - Suicide

47. Case Study 3 - Suicide

48. Case Study 3 - Suicide Circumstances and scene suggestive of suicide
Police report no suspicious features
External examination and CT scan showed severe injuries incompatible with life
Pattern of injuries consistent with a rollover mechanism
No evidence of a standing pedestrian impact on CT or external examination
No injuries inconsistent with the scenario as currently known
Dilemma:
What will a full autopsy examination add to this case?
Detection of natural disease
Full documentation of injuries
Coroner’s Decision:
No autopsy
Cause and manner of death can be determined from above information

49. Case Study 4 – Trauma vs Natural
82M found unconscious at home – collapse or fall?
Conveyed to hospital but deteriorated in the emergency department before investigations could be performed
Palliated at family’s request and died later that day
Medical history includes heart disease with previous bypass grafting, previous stroke, high blood pressure
Hospital doctors unable to write death certificate as COD unknown and possibly due to fall
Family opposed to autopsy

50. Case Study 4 – Trauma vs Natural
Issues arising before CT:
Unclear if death due to a fall with head trauma
Unclear if death due to underlying disease with a collapse
Has more than sufficient a burden of natural disease to account for sudden death
Was there a treatable cause that the hospital should have diagnosed?
Family do not want an invasive investigation
Coroner needs to determine cause and manner of death

51. Case Study 4 – Trauma vs Natural
Blood in the brain

52. Case Study 4 – Trauma vs Natural
Does the CT help resolve the issues?
Intracerebral haemorrhage
Unfiltered diagnostic possibilities: trauma, tumour, hypertensive bleed, vascular malformation, amyloid angiopathy, warfarin therapy
The appearances in a man of this age are classic for a condition known as amyloid angiopathy – an age related degenerative change in the blood vessels of the brain predisposing to rupture and catastrophic bleeding
No evidence of trauma  collapse rather than fall
A fatal process diagnosed
A cause of death available
Manner of death is natural
Not an easily treatable disease, poor prognosis
No requirement for full autopsy  family's wishes respected without compromise of information

53. How will PMCT affect you?

54. Evidential Issues?
Are there evidential issues with performing PMCT prior to autopsy in homicides? No
Protocols have been developed to account for this
Body bag remains sealed at all times from scene to mortuary to CT to theatre
OC Body accompanies the body from scene, into CT room, to theatre
Body bag is not opened and body is not manipulated in performing the CT
Body movement is limited to lifting on and off CT table

55. Presenting the Evidence
Forensic pathologists are well aware that their evidence is difficult for some to hear
We are exquisitely aware of how confronting autopsy photos may be, even the “nice” ones
We are trying to find better ways to educate the jury, without alienating them or losing the accuracy of information
Computer 3D modelling programmes available but aren’t perfect and are generic, not specific
PMCT 3D images may be the way to get accuracy, sanitisation and understandable evidence all in one

56. Computer model
Injury indicative only
Not specific to the deceased
PMCT 3D image
Actual injuries
Specific to the deceased

57. Computer model
Injuries indicative only
Not specific to the deceased
PMCT 3D image
Actual injuries
Specific to the deceased

58. Whose evidence is it?
PMCT is very much a collaborative effort in practise
Forensic Pathologists
Experts at diagnosing disease and injury
Anatomical and pathological knowledge
See a greater severity of injury, a greater extreme of natural disease
Understand post-mortem change and decomposition and the artefacts this generates
Clinical Radiologists
Experts at CT interpretation and disease diagnosis
But what they see in live patients may differ to that seen in the deceased
Forensic radiologists
Understand the imaging of the deceased far better than clinical radiologists and are an extraordinarily valuable resource
But…

59. Whose evidence is it?
If you want images to act as a pictorial representation of the injuries in lieu of photos, to supplement a verbal explanation or as an illustration:
A forensic pathologist can do this, just like we would talk to diagrams or photos
If the radiology interpretation and images require specialist interpretation and discussion of radiology-related issues:
A forensic radiologist or clinical radiologist with forensic expertise will be needed
Do not expect a clinical radiologist without post-mortem experience to be an expert in PMCT
There are artefacts in PMCT that can mimic significant disease processes but are a post-mortem phenomenon, not “real” disease or injury9 9

60. What do the Courts think?
The literature is scant in this regard
Premise of the Jeffrey paper10:
It is not always clear at the start of a coronial autopsy whether what appears to be a natural death, may turn out to be a covert homicide or whether future criminal or civil court proceedings may occur
Would the use of PMCT alone affect any potential judicial proceedings?
Survey of Judge, Barrister, Solicitor, Coroner and Police
“Non-invasive autopsy report” 10

61. Findings of note: Issues:
CT was excellent for demonstrating trauma and COD was same in the majority of cases and differences were only minor
Manner of death unchanged in all cases
But it’s not just about cause and manner of death!
The judge was the one most accepting of the non-invasive reports
Issues:
PMCT as a viable alternative?
Autopsy is Gold Standard so anything less has reduced credibility
Loss of ability to perform histology
No internal neck dissection in neck compression
Concern regarding false positive or negative findings
Uncertainty or speculation in evidence is unhelpful
A less than full examination means there is uncertainty and pathologist may not be able to exclude possibilities
There may be uncertainty after a full PM, but at least one may be “certainly uncertain” with a full dataset of information
Accepted that non-invasive PM has financial benefits and is more acceptable to families
It was felt the use of CT imagery would enhance the presentation of findings in Court

62. The future? What will tomorrow be like?

63. Will I be out of a job? Thankfully not!
Forensic pathologists continue to drive this revolution and are becoming skilled forensic radiologists
The Royal College of Pathologists of Australasia is forming a Forensic Radiology Special Interest Group
Potential for a Diploma in Forensic Radiology

64. PMCT and Evidence
The VIFM, led by Dr Soren Blau (anthropologist) and Dr Chris O’Donnell (forensic radiologist)
Pilot study examining use of 3D printing of PMCT images as evidence in Court
3D print of a skull fracture vs verbal evidence vs photo vs image of CT
3D image has excellent level of clarity as perceived by jurors and with good levels of acceptability

65. In Practise
PMCT continues to revolutionise how medicolegal death investigation will occur
But for the Courts, I think that full autopsies will remain the Gold Standard for some time yet
Angiography will play an increasing role
What level of proof will you require for me to tell you an injury exists?
The more we do, the more we will know our limits
Whatever happens, it’s a fun ride ahead!