Detection of pulmonary thrombembolism and postmortem clotting on postmortem magnetic resonance imaging

The purpose of this study was to develop a feasible imaging protocol superior to postmortem computed tomography (PMCT) and to establish diagnostic parameters for diagnosing pulmonary thromboembolism (PE) on postmortem magnetic resonance imaging (PMMR). The study collective of 113 subjects was prospectively investigated by PMMR for the presence of PE and / or postmortem clotting (cruor). PE was detected in 20 cases; the remaining 93 cases were investigated for the morphology of cruor. Age grading was performed by PMMR, autopsy and histology. The postmortem sedimentation effect was used for the applied imaging protocol on PMMR (supine and prone position). Visual distension of the pulmonary arteries in PE was seen in all cases, but not in the controls. Re-positioning of the corpse from supine in prone position proved to be beneficial in 90 %. Postmortem motion artifacts are firstly described in 20.4 %. Hyperacute PE (grade 1) presented with a homogenous and hypointense signal on T2w images, acute PE (grade 2) with slightly heterogeneous, but still homogenous hypointense signal, subacute PE (grade 3) was with heterogeneous and slightly hyperintense signal and chronic PE (grade 4) with predominately homogenous with scarce portions of heterogeneous but hyperintense signal. PMMR allowed for the detection of PE and for in situ depiction of combined age grading.