Rigor mortis at the myocardium investigated by post-mortem magnetic resonance imaging.
BACKGROUND
Post-mortem cardiac MR exams present with different contraction appearances of the left ventricle in cardiac short axis images. It was hypothesized that the grade of post-mortem contraction may be related to the post-mortem interval (PMI) or cause of death and a phenomenon caused by internal rigor mortis that may give further insights in the circumstances of death.


METHODS
The cardiac contraction grade was investigated in 71 post-mortem cardiac MR exams (mean age at death 52 y, range 12-89 y; 48 males, 23 females). In cardiac short axis images the left ventricular lumen volume as well as the left ventricular myocardial volume were assessed by manual segmentation. The quotient of both (LVQ) represents the grade of myocardial contraction. LVQ was correlated to the PMI, sex, age, cardiac weight, body mass and height, cause of death and pericardial tamponade when present. In cardiac causes of death a separate correlation was investigated for acute myocardial infarction cases and arrhythmic deaths.


RESULTS
LVQ values ranged from 1.99 (maximum dilatation) to 42.91 (maximum contraction) with a mean of 15.13. LVQ decreased slightly with increasing PMI, however without significant correlation. Pericardial tamponade positively correlated with higher LVQ values. Variables such as sex, age, body mass and height, cardiac weight and cause of death did not correlate with LVQ values. There was no difference in LVQ values for myocardial infarction without tamponade and arrhythmic deaths.


CONCLUSIONS
Based on the observation in our investigated cases, the phenomenon of post-mortem myocardial contraction cannot be explained by the influence of the investigated variables, except for pericardial tamponade cases. Further research addressing post-mortem myocardial contraction has to focus on other, less obvious factors, which may influence the early post-mortem phase too.
Center for Forensic Imaging Bern, Institute of Forensic Medicine, University of Bern, Bühlstr. 20, CH-3012 Bern, Switzerland.
Jérôme
J
Bonzon
Center for Forensic Imaging Bern, Institute of Forensic Medicine, University of Bern, Bühlstr. 20, CH-3012 Bern, Switzerland.
Corinna A
CA
Schön
Center for Forensic Imaging Bern, Institute of Forensic Medicine, University of Bern, Bühlstr. 20, CH-3012 Bern, Switzerland.
Nicole
N
Schwendener
Center for Forensic Imaging Bern, Institute of Forensic Medicine, University of Bern, Bühlstr. 20, CH-3012 Bern, Switzerland.
Wolf-Dieter
WD
Zech
Triemli Hospital, Institute of Radiology and Nuclear Medicine, Birmensdorferstr. 497, CH-8063 Zürich, Switzerland.
Levent
L
Kara
CMIV, Linköpings universitet/US, SE-581 85 Linköping, Sweden.
Anders
A
Persson
Center for Forensic Imaging Bern, Institute of Forensic Medicine, University of Bern, Bühlstr. 20, CH-3012 Bern, Switzerland. Electronic address: christian.jackowski@irm.unibe.ch.
Christian
C
Jackowski
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000473:pathology; D002305:Cardiac Tamponade / Q000473:pathology; D002648:Child; D005260:Female; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000473:pathology; D009206:Myocardium / Q000473:pathology*; D012189:Retrospective Studies; D012298:Rigor Mortis; D055815:Young Adult
Forensic radiology; Heart contraction; Post-mortem imaging; Rigor mortis