The effect on cadaver blood DNA identification by the use of targeted and whole body post-mortem computed tomography angiography

Application of contrast media in post-mortem imaging (CT and MRI)

The application of contrast media in post-mortem radiology differs from clinical approaches in living patients. Post-mortem changes in the vascular system and the absence of blood flow lead to specific problems that have to be considered for the performance of post-mortem angiography. In addition, interpreting the images is challenging due to technique-related and post-mortem artefacts that have to be known and that are specific for each applied technique. Although the idea of injecting contrast media is old, classic methods are not simply transferable to modern radiological techniques in forensic medicine, as they are mostly dedicated to single-organ studies or applicable only shortly after death. With the introduction of modern imaging techniques, such as post-mortem computed tomography (PMCT) and post-mortem magnetic resonance (PMMR), to forensic death investigations, intensive research started to explore their advantages and limitations compared to conventional autopsy. PMCT has already become a routine investigation in several centres, and different techniques have been developed to better visualise the vascular system and organ parenchyma in PMCT. In contrast, the use of PMMR is still limited due to practical issues, and research is now starting in the field of PMMR angiography. This article gives an overview of the problems in post-mortem contrast media application, the various classic and modern techniques, and the issues to consider by using different media.

Adult post-mortem imaging in traumatic and cardiorespiratory death and its relation to clinical radiological imaging

The use of post-mortem imaging is expanding throughout the world with increasing use of advanced imaging techniques, such as contrast-enhanced CT and MRI. The questions asked of post-mortem imaging are complex and can be very different, for example for natural sudden death investigation will focus on the cause, whereas for trauma the cause of death is often clear, but injury patterns may be very revealing in investigating the background to the incident. Post-mortem imaging is different to clinical imaging regarding both the appearance of pathology and the information required, but there is much to learn from many years of clinical research in the use of these techniques. Furthermore, it is possible that post-mortem imaging research could be used not only for investigating the cause of death but also as a model to conduct clinically relevant research. This article reviews challenges to the development of post-mortem imaging for trauma, identification and cardiorespiratory death, and how they may be influenced by current clinical thinking and practice.

Tissue microscopic changes and artifacts in multi-phase post-mortem computed tomography angiography in a hospital setting: a fatal case of systemic vasculitis

A 27-year-old man suddenly died in hospital of acute respiratory distress syndrome secondary to severe systemic vasculitis. Multi-phase post-mortem computed tomography angiography followed by scientific autopsy of the thoracic and abdominal cavity and histology was performed, illustrating the advantages and drawbacks of such techniques. Imaging enabled us to examine the cranium, as the family refused cerebral dissection. MPMCTA revealed absence of opacification of the left middle cerebral artery. But parenchymal findings of thoracic and abdominal organs were still difficult to interpret after both imaging and macroscopic examination during the autopsy. Microscopic examination provided the definitive diagnosis of cause of death. Analysis revealed systemic vasculitis of the lung complicated by diffuse alveolar, mediastinal, splenic and retroperitoneal lesions. We were unable to determine the type of vasculitis, whether polyarteritis nodosa or microscopic polyangiitis, because of artifactual glomerular collapse. We observed some structural changes in tissue secondary to contrast agent injection, affecting the vascular system and renal parenchyma in particular. Such artifacts must be known in order to avoid misinterpreting them as pathological findings. MPMCTA and conventional autopsy are two complementary techniques showing both their specific advantages and limits which have to be known in order to choose the appropriate technique. One limit of both techniques is the detection of microscopic findings which can only be obtained by additional histological examination. This case report underlines this fact and demonstrates that caution is required in some cases if microscopic analyses are carried out after contrast agent injection.