Postmortem Imaging MDCT Features of Postmortem Change and Decomposition
Multidetector computed tomography (MDCT) has emerged as an effective imaging technique to augment forensic autopsy. Postmortem change and decomposition are always present at autopsy and on postmortem MDCT because they begin to occur immediately upon death. Consequently, postmortem change and decomposition on postmortem MDCT should be recognized and not mistaken for a pathologic process or injury. Livor mortis increases the attenuation of vasculature and dependent tissues on MDCT. It may also produce a hematocrit effect with fluid levels in the large caliber blood vessels and cardiac chambers from dependent layering erythrocytes. Rigor mortis and algor mortis have no specific MDCT features. In contrast, decomposition through autolysis, putrefaction, and insect and animal predation produce dramatic alterations in the appearance of the body on MDCT. Autolysis alters the attenuation of organs. The most dramatic autolytic changes on MDCT are seen in the brain where cerebral sulci and ventricles are effaced and gray-white matter differentiation is lost almost immediately after death. Putrefaction produces a pattern of gas that begins with intravascular gas and proceeds to gaseous distension of all anatomic spaces, organs, and soft tissues. Knowledge of the spectrum of postmortem change and decomposition is an important component of postmortem MDCT interpretation.
Available from: Maïa Proisy
- "The cause of IVG remains unclear. Exogenous causes such as intravenous catheters or decompression disease  have been suggested in adults. Another theory is that intravascular gas is produced during CPR procedures as in Shiotani study IVG was observed in 163 (71%) of 228 patients who underwent CPR . "
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ABSTRACT: To provide an overview of non-specific modifications on whole-body post-mortem computed tomography (PMCT) images of infants and children. Materials and methods: 69 infants and children underwent a whole-body PMCT scan at our institution following sudden unexpected death. Two paediatric radiologists reviewed the PMCT images, specifically focusing on non-specific postmortem modifications unrelated to the presumed cause of death. Results: Iatrogenic post-mortem modifications included focal infiltration of the legs (n=15) and hemopericardium (n=2). Vascular postmortem modifications included hypostasis (density in the posterior sagittal sinus was correlated with density in the dependent portion of the heart (p<0.001)), portal vein thrombosis (n=56, 75.3%), hyperattenuating aortic wall and reduced abdominal aortic diameter (n=69, 100%). Intravascular gas was detected in 40 subjects (57.9%). Ligamentum arteriosum calcification was seen in 42 children and was not correlated with age (p=0.68). Umbilical artery calcification was found in 30 children and was correlated with age (p<0.005). Gaseous distension of the stomach (n=45, 65.2%) and bowels (n=44, 63.7%) was a frequent finding. Mean liver density was 49.6±7.5. HU and mean spleen density was 43.2±5.9. HU. Ground-glass opacity was observed in 63 cases (91.3%) and mild bilateral consolidation in 16 cases (23.1%). Conclusion: Non-specific post-mortem signs are rare and new to clinical paediatric radiologists. They should be aware of these signs when interpreting whole-body PMCT images in cases of sudden unexpected death in infancy or childhood in order to avoid pitfalls that may have a critical impact.
Available from: Wataru Gonoi
- "High-resolution imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) are beginning to gain a role in postmortem investigations as adjuncts to more traditional methods in forensic medicine [1–5]. The postmortem CT (PMCT) findings of organs such as the brain, lung, heart, and liver have been described [6–12]. To our knowledge, however, the features of cardiac hypertrophy on PMCT have not been reported. "
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ABSTRACT: To evaluate the postmortem changes of the heart wall on postmortem (PM) computed tomography (CT) in comparison with those on ante mortem CT (AMCT), and in comparison with the pathological findings, obtained in the same patients.
We studied 57 consecutive patients who had undergone AMCT, PMCT, and pathological autopsy in our tertiary care hospital between April 2009 and December 2010. PMCT was performed within 20 hours after death, followed by pathological autopsy. The cardiac chambers were measured at five sites on both AMCT and PMCT by two board-certified radiologists who were not provided with clinical information. The differences in heart wall thickness between AMCT with and without contrast medium, between AMCT and PMCT, and between PMCT and pathological anatomy were evaluated statistically. Confounding factors of postmortem change such as gender, presence of arteriosclerosis, the organ related to cause of death, age, and elapsed time since death were examined statistically.
No significant differences were observed on AMCT in comparison of contrasted and non-contrasted images. The heart wall was significantly thicker on PMCT than on AMCT (p < 0.0001) at all five measurement sites. The heart wall was significantly thicker on PMCT than on pathology specimens when measured in accordance with pathological standard mensuration. However, no significant difference was observed between PMCT measurements and those of pathology specimens at any site when the papillary muscles and epicardial fat were included. No significant association was found between postmortem change in heart wall thickness and gender, presence of arteriosclerosis, the organ related to cause of death, age, or elapsed time since death.
This is the first longitudinal study to confirm greater thickness of heart wall on postmortem images compared with ante mortem images, in the same patients. Furthermore, the postmortem changes on CT were supported by the pathological findings.
Available from: Michael Thali
- "were excluded due to significant thoracic trauma (trauma that altered the normal anatomic relationships of the intra-thoracic organs) and 11 were excluded due to moderate or advanced decomposition, as defined by Levy et al. . No further cases were excluded. "
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Cardiomegaly has important medical and forensic implications. Left ventricular circumferential area (LVCA) has been proposed as a simple and effective measure of heart weight. We determined if LVCA reflects actual heart weight, as measured at autopsy.Methods: Two blinded radiologist independently and retrospectively measured the LVCA, in postmortem computed tomography scans of 50 decedents (34 male, 16 female, mean age 53 years). Actual heart weight was obtained from the written autopsy record. Calculated heart weight was derived using a linear regression equation describing the relationship between mean measured heart weight and actual heart weight.
The mean actual heart weight was 416.6 g (median 395.0 g, range 250.0–770.0 g, SD 97.9). The mean measured LVCA was 3756.3 mm2 (range 2133.5–7083.0 mm2, SD 794.2). There was a significant and strong positive correlation between the mean measured LVCA and actual heart weight (p<0.0001, correlation coefficient 0.707). There was no significant inter-observer variability. There was no significant difference between calculated heart weight and autopsy heart weight.
LVCA and calculated heart weight reflect actual heart weight, as measured at autopsy. These results suggest that heart weight estimation can be performed on non-contrast postmortem CT, using a linear regression equation based on the LVCA.
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