Comparison of conventional autopsy with post-mortem magnetic resonance, computed tomography in determining the cause of unexplained death

Conventional autopsy is the gold standard for identifying unexplained death but due to declines in referrals, there is an emerging role for post-mortem imaging. We evaluated whether post-mortem magnetic resonance (PMMR) and computed tomography (PMCT) are inferior to conventional autopsy. Deceased individuals ≥ 2 years old with unexplained death referred for coronial investigation between October 2014 to December 2016 underwent PMCT and PMMR prior to conventional autopsy. Images were reported separately and then compared to the autopsy findings by independent and blinded investigators. Outcomes included the accuracy of imaging modalities to identify an organ system cause of death and other significant abnormalities. Sixty-nine individuals underwent post-mortem scanning and autopsy (50 males; 73%) with a median age of 61 years (IQR 50-73) and median time from death to imaging of 2 days (IQR 2-3). With autopsy, 48 (70%) had an organ system cause of death and were included in assessing primary outcome while the remaining 21 (30%) were only included in assessing secondary outcome; 12 (17%) had a non-structural cause and 9 (13%) had no identifiable cause. PMMR and PMCT identified the cause of death in 58% (28/48) of cases; 50% (24/48) for PMMR and 35% (17/48) for PMCT. The sensitivity and specificity were 57% and 57% for PMMR and 38% and 73% for PMCT. Both PMMR and PMCT identified 61% (57/94) of other significant abnormalities. Post-mortem imaging is inferior to autopsy but when reported by experienced clinicians, PMMR provides important information for cardiac and neurological deaths while PMCT is beneficial for neurological, traumatic and gastrointestinal deaths.