Postmortem CT and MRI findings of massive fat embolism

• Published in: International journal of legal medicine Vol. 134; no. 2; pp. 669 - 678
• Main Authors: Makino, Yohsuke, Kojima, Masatoshi, Yoshida, Maiko, Motomura, Ayumi, Inokuchi, Go, Chiba, Fumiko, Torimitsu, Suguru, Hoshioka, Yumi, Yamaguchi, Rutsuko, Saito, Naoki, Urabe, Shumari, Tsuneya, Shigeki, Horikoshi, Takuro, Yajima, Daisuke, Iwase, Hirotaro
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.03.2020; Springer Nature B.V
• Subjects: Autopsies; Computed tomography; Embolisms; Evaluation; Forensic Medicine; Forensic pathology; Histology; Magnetic resonance imaging; Medical imaging; Medical Law; Medicine; Medicine & Public Health; Original Article; Sequences; Staining; Postmortem MRI; Forensic radiology; Forensic pathology; Fat embolism; Postmortem CT
• ISSN: 0937-9827; 1437-1596; 1437-1596
• DOI: 10.1007/s00414-019-02128-8

Objective To elucidate postmortem computed tomography (PMCT) and postmortem magnetic resonance (PMMR) imaging findings suggesting massive fat embolism. Materials and methods Consecutive forensic cases with PMCT and PMMR scans of subjects prior to autopsy were assessed. For PMCT, 16- or 64-row multidetector CT scans were used; for PMMR, a 1.5 T system was used. MRI sequences of the chest area included T2- and T1-weighted fast spin-echo imaging, T2*-weighted imaging, T1-weighted 3-dimensional gradient-echo imaging with or without a fat-suppression pulse, short tau inversion recovery, and in-phase/opposed-phase imaging. At autopsy, forensic pathologists checked for pulmonary fat embolism with fat staining; Falzi’s grading system was used for classification. Results Of 31 subjects, four were excluded because fat staining for histopathological examination of the lung tissue could not be performed. In three of the remaining 27 subjects, histology revealed massive fat embolism (Falzi grade III) and the cause of death was considered to be associated with fat embolism. CT detected a “fat-fluid level” in the right heart or intraluminal fat in the pulmonary arterial branches in two subjects. MRI detected these findings more clearly in both subjects. In one subject, CT and MRI were both negative. There were no positive findings in the 24 subjects that were fat embolism–negative by histology. Discussion and conclusion In some subjects, a massive fat embolism can be suggested by postmortem imaging with a “fat-fluid level” in the right heart or intraluminal fat in the pulmonary arterial branches. PMMR potentially suggests fat embolism more clearly than PMCT.