L29: Forensic Imaging

Question 1

What are the ethical issues in forensic cases?

Answer 1

• consent – needed whether the patient is alive or dead
• diagnostic challenges
• growing duties
• liabilities
• higher risks
• more sources of diagnostic errors
• growing awareness of healthcare safety have dramatically raised legal claims – ‘defensive medicine’

Question 2

What may be seen in forensic imaging?

Answer 2

• assault – can determine whether injuries are accidental or non-accidental
• burns – can determine whether someone died due to burns, or was killed then burned
• gunshots – can determine where bullets entered/exited, characteristics of bullet/weapon, extent of the injuries from the bullet
• mass trauma – need to determine cause of death for every victim
• post-mortem studies – need for CT and MRI

Question 3

Why are post-mortem studies important?

Answer 3

• medical history is a prerequisite for death investigation and autopsy
• in forensic pathology casework, the history is often incomplete, inaccurate, or of poor relevancy
• PMCT and MRI can provide important ancillary info prior to autopsy, mitigating a lack of history

Question 4

What are the advantages of PMCT?

Answer 4

• ‘non-destructive” documentation – does not preclude other forensic investigation, can be used in cultures where religion or family members will not accept traditional autopsy
• safe examination of bodies contaminated by infection, toxic substances, radionuclides, or other biohazards – minimally-invasive method for screening prior to conventional autopsy in high-risk cases
• ideal bone visualization (ie. fracture pattern), lung parenchyma disease, calcifications (stones, atherosclerosis), acute hemorrhage, air/gas (ie. pneumothorax, pneumatosis intestinalis, free air)
• easy identification of foreign bodies and anatomical positions
• evaluation of body parts not explored in routine autopsy
• 2D and 3D post-processing helps visualize findings for interested parties not attending the examination (ie. in court, CT images are better tolerated than autopsy images)
• easily-retrievable digital archives permit re-evaluation of the images considering new data and teleconsultation opinion
• possibility of biopsy guidance
• good availability – CT is widespread throughout the world, faster than traditional autopsy

Question 5

Describe how documental / legal transparency is done.

Answer 5

• document both the presence 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

Question 6

What is post-mortem angiography?

Answer 6

• involves injecting a contrast agent into the vasculature of a deceased individual to visualize the blood vessels
• different techniques and contrast media can be used
• CT Angiography (CTA) aids in the evaluation of pathologies of the cardiovascular system, particularly parietal and luminal coronary changes (but it is not as effective for detecting myocardial ischemia and necrosis)