Background and Aims. Pulmonary fat embolism can be a cause of death in cases with trauma, during orthopedic surgery and also in non-traumatic conditions, such as burns, pancreatitis, fatty liver or sickle cell disease. As postmortem CT angiography(PMCTA) becomes more widespread, it is important to determine how it affects the diagnosis of pulmonary fat embolism. The aims of this study were to determine if the oily contrast liquid used in PMCTA induces artefactual pulmonary fat embolism, if such artefacts differ from non-artefactual (original) pulmonary fat embolism and if pulmonary fat embolism can be detected and graded before PMCTA.
Materials and Methods. Data acquisition for this prospective study was performed between November 2013 and December 2014. Consecutive cases of adults who received PMCTA followed by autopsy were included in this study. Cases were excluded if the state of alteration was too advanced. Pulmonary biopsies of each lung were taken before and after the PMCTA as were fragments of each lung with a twin-edged knife (TEK) during the autopsy. The samples were examined under the microscope without fixation or staining and after an Oil-Red 0 staining. Pulmonary fat embolism was graded according to Falci et al.
Results. Fifty-four (54) cases were included. Original pulmonary fat embolism was diagnosed in 20 cases out of54 on biopsies performed before PMCTA, almost all having presented traumatic events before death and/or rib fractures due to resuscitation attempts. As expected, structures with the aspect of pulmonary fat embolism were present in almost all cases (44 cases out 'at 54 on biopsies I 51 cases out of 54 on TEK samples) after PMCTA. The microscopic aspect of original and PMCT A-induced pulmonary fat embolism was identical. Grading of the pulmonary fat embolism according to Falci et al. depended on the quality of the biopsies.
Conclusions. PMCTA with oily contrast liquid induces artefactual pulmonary fat embolism that cannot be visually differentiated from original pulmonary fat embolism. However, original pulmonary fat embolism can be diagnosed with biopsies performed before PMCT A. In order to assure the diagnosis and correct grading of pulmonary fat embolism, the quality of the biopsy should be checked before PMCT A with oily contrast is performed. If it is impossible to obtain biopsies of good quality, the indication of a PMCTA must be discussed in cases where pulmonary fat embolism is suspected, particularly if it is a potential cause of death.