The use of injected contrast agents in cadaveric computed tomography

The use of multi-detector computed tomography and magnetic resonance imaging in autopsy practice is increasing, and there is an international push towards minimally invasive autopsy. A significant obstacle to replacing conventional autopsy with standard imaging is failure to yield detailed information concerning the coronary arteries. A previously established technique to outline arteries is the Swiss-developed ‘whole body angiography’ technique using a heart lung machine and up to 3 litres of contrast agent. This project concerns the novel development of a quicker and cheaper targeted cardiac post-mortem computed tomography angiography (PMCTA) method to allow higher throughput. This thesis introduces the current knowledge of PMCTA, presents the development of the novel method, including a patented task-specific device, and then studies the accuracy of PMCTA ‘cause of death’ against autopsy in 24 cases referred from HM coroners. Cause of death was recorded by three groups of reviewers using a ‘view scan and grant protocol’ of clinical history, external examination and postmortem angiography findings. A further study was then performed related to obtaining informed consent by telephone from the next-of-kin for post mortem imaging in 200 cases. The data showed that using this protocol 82% of cases had a comparably worded cause of death to the autopsy. The ability of PMCTA to detect ischemic heart disease was assessed with a specificity of 88.9% and sensitivity of 100 % (PPV = 92.31 %, NPV =100%). Recruiting for a 200 case study of PMCTA we achieved a 96% consent rate with considerable support from the next-of-kin. These data suggest that a “View, scan and grant” protocol could be used to replace the routine autopsy in certain Coronial cases, leading to a larger 200 case study. The high consent rate helps dispel the notion that there is public objection to post-mortem research.