Post-Mortem Imaging as an Alternative to Autopsy: Development of Techniques for Improving Diagnostic Accuracy
ISD Roberts, R Benamore, EW Benbow, J Harris, A Jackson, S Lee, T Patankar, Z Traill. John Radcliffe Hospital, Oxford, United Kingdom; Churchill Hospital, Oxford, United Kingdom; Manchester Royal Infirmary, Manchester, United Kingdom; Hope Hospital, Salford, United Kingdom; The University of Manchester, Manchester, United Kingdom; Leeds General Infirmary, Leeds, United Kingdom
Background: Increasing public objection to autopsy has led to a search for minimally-invasive alternatives. In the first large validation study of post-mortem imaging in non-forensic autopsies, we identify specific strengths and weaknesses of imaging and, on the basis of this data, refine radiological techniques in order to improve diagnostic accuracy.
Design: Adult deaths reported to the Coroner (n=120) were investigated using whole body CT and MRI, followed by full autopsy. The first 10 cases were used to familiarise radiologists with post-mortem changes, the final 10 for coronary angiography. For the remaining 100 cases, radiologists were blinded to autopsy results. Following reporting, radiology and autopsy findings were reviewed and discrepancies discussed. This was performed in 6 batches of 15-20 cases, in order to increase radiologists' experience.
Results: There was a major discrepancy between radiological and autopsy cause of death in 30% of cases. Radiologists were asked to indicate their level of confidence in the cause of death and whether autopsy would be required if this was a routine service. Confidence levels were definite 45%, probable 27%, possible 18% and unascertained cause 9% of cases. In 46% of cases, the radiologists indicated that autopsy was not required. For this group, the major discrepancy rate was 13%. The commonest source of error on imaging was missed coronary heart disease (CHD). As this is also the most frequent cause of death at Coronial autopsy, improved sensitivity for CHD is required before post-mortem imaging can be recommended for routine practice. In order to improve detection of myocardial lesions, additional oblique MRI sequences were introduced, providing short axis sections of the heart which revealed myocardial infarcts not previously detected on imaging. In order to identify coronary artery lesions that could not be demonstrated on cross-sectional imaging, we developed a novel method of post-mortem CT coronary angiography, validated in the final 10 cases.
Conclusions: Common causes of sudden death are frequently missed on CT and MRI. Defining the specific weaknesses of cross-sectional radiology facilitates the development of imaging techniques that may improve diagnostic accuracy.
Monday, March 22, 2010 2:15 PM
Platform Session: Section G, Monday Afternoon