Pseudolesion in the right parafissural liver parenchyma on CT: The base is found in embryology and collagen content.

BACKGROUND: Computed tomography (CT) images of livers may show a hypo-attenuated structure alongside the falciform ligament, which can be a focal fatty pseudolesion and can mimic a malignancy. The preferred location is on the right parafissural site, ventral in segment IVa/b. The etiology is not clear, nor is it known how the histology of this location develops. These are evaluated in this study. METHODS: 40 adult cadavers with autopsy and / or postmortem CT in a university hospital and a forensic center were included. Liver biopsies were taken at the left side of the falciform ligament as control, and at the right side as the possible precursor of a pseudolesion; these were examined for collagen and fat content. Cadavers with steatotic (>5% fat) or fibrotic (>2% collagen) control samples were excluded. RESULTS: Significantly more collagen was present in the right parafissural liver parenchyma: median 0.68% (IQR: 0.32-1.17%), compared to the left side 0.48% (IQR: 0.21-0.75%) (p 0.008), with equal fat content and CT attenuation values. The etiophysiology goes back to the demise of the umbilical venes in the early embryonic and neonatal period. CONCLUSIONS: The right parafissural area contains more collagen and an equal amount of fat compared to the control left side. This supports the hypothesis of delayed, 'third' inflow: the postnatal change in blood supply from umbilical to portal leaves the downstream parafissural area hypoperfused leading to hypoxia which in turn results in collagen accumulation and the persistence of paraumbilical veins of Sappey.

Comparing thoracoabdominal injuries of manual versus load-distributing band cardiopulmonary resuscitation.

OBJECTIVE: To identify and compare manual and load-distributing band (LDB) cardiopulmonary resuscitation (CPR)-related injuries. METHODS: Retrospective observational cohort study. Adult, nontraumatic deaths with a postmortem computed tomography scan (PMCT) performed were classified into two groups: deceased after LDB CPR or after manual CPR. PMCT scans were reviewed for thoracoabdominal injuries such as fractures, pneumothorax and hemorrhage. The injuries between groups were compared. RESULTS: LDB CPR (n = 43) showed increased incidences of posterior rib fractures (53 vs 18%, P = 0.006), pneumothorax (23 vs 4%, P = 0.04) and more pericardial fluid (median 12 vs 6 mm, P = 0.002) compared with manual CPR (n = 29). Multivariable regression analysis revealed that LDB CPR was significantly associated with posterior rib fractures [odds ratio (OR) 5.37, 95% confidence interval (CI): 1.44-20.09, P = 0.01). Pneumothorax (OR 6.80, 95% CI: 0.73-62.99, P = 0.09) and the amount of pericardial fluid (OR 3.40, 95% CI: 0.20-56.32) were not significantly associated with LDB CPR. No significant difference was found for anterolateral rib fractures, sternal fractures, vertebral fractures, pleural fluid, hemothorax, hemopericardium, pneumoperitoneum, perihepatic, perisplenic and perirenal hemorrhage. CONCLUSION: Rib fractures, sternal fractures, hemothorax and hemopericardium are common CPR-related injuries. LDB CPR is significantly associated with more posterior rib fractures and a trend toward more pneumothoraces is observed when compared with manual CPR. This knowledge is important for caretakers in the case of ongoing CPR, as a pneumothorax may attribute to not achieving persistent return of spontaneous circulation, and to improve postresuscitation care of survivors.

Can virtual autopsy with postmortem CT improve clinical diagnosis of cause of death? A retrospective observational cohort study in a Dutch tertiary referral centre.

OBJECTIVE: To investigate whether virtual autopsy with postmortem CT (PMCT) improves clinical diagnosis of the immediate cause of death. DESIGN: Retrospective observational cohort study. INCLUSION CRITERIA: inhospital and out-of-hospital deaths over the age of 1 year in whom virtual autopsy with PMCT and conventional autopsy were performed. EXCLUSION CRITERIA: forensic cases, postmortal organ donors and cases with incomplete scanning procedures. Cadavers were examined by virtual autopsy with PMCT prior to conventional autopsy. The clinically determined cause of death was recorded before virtual autopsy and was then adjusted with the findings of virtual autopsy. Using conventional autopsy as reference standard, we investigated the increase in sensitivity for immediate cause of death, type of pathology and anatomical system involved before and after virtual autopsy. SETTING: Tertiary referral centre. PARTICIPANTS: 86 cadavers that underwent conventional and virtual autopsy between July 2012 and June 2016. INTERVENTION: PMCT consisted of brain, cervical spine and chest-abdomen-pelvis imaging. Conventional autopsy consisted of thoracoabdominal examination with/without brain autopsy. PRIMARY AND SECONDARY OUTCOME MEASURES: Increase in sensitivity for the immediate cause of death, type of pathology (infection, haemorrhage, perfusion disorder, other or not assigned) and anatomical system (pulmonary, cardiovascular, gastrointestinal, other or not assigned) involved, before and after virtual autopsy. RESULTS: Using PMCT, the sensitivity for immediate cause of death increased with 12% (95% CI 2% to 22%) from 53% (41% to 64%) to 64% (53% to 75%), with 18% (9% to 27%) from 65% (54% to 76%) to 83% (73% to 91%) for type of pathology and with 19% (9% to 30%) from 65% (54% to 76%) to 85% (75% to 92%) for anatomical system. CONCLUSION: While unenhanced PMCT is an insufficient substitute for conventional autopsy, it can improve diagnosis of cause of death over clinical diagnosis alone and should therefore be considered whenever autopsy is not performed.

Correlation Between Liver Volumetric Computed Tomography Results and Measured Liver Weight: A Tool for Preoperative Planning of Liver Transplant.

OBJECTIVES: Before liver transplant, it is necessary to know the size of the organ in advance of the procedure. We studied the correlation between liver volumetric computed tomography results and liver weight. MATERIALS AND METHODS: Postmortem volumetric computed tomography was conducted on cadavers before autopsy, and 3-dimensional liver volume was estimated with semiautomated software. Liver weight was then determined at autopsy. Linear regression and univariate analysis of variance results were used to determine the accuracy of volumetric 3-dimensional computed tomography in estimating liver weight. We also used 2-dimensional liver sizes to design a 2-dimensional formula to estimate liver volume. RESULTS: We found that 3-dimensional volumetric computed tomography was able to accurately estimate liver weight (standard error = 157 g) with a liver density of 0.99 g/mL. Intraobserver and interobserver variabilities were small. The 2-dimensional formula estimated liver weight slightly less accurately (standard error = 212 g). CONCLUSIONS: We conclude that liver weight can be estimated accurately with 3-dimensional volumetric computed tomography; estimates were more precise than with the 2-dimensional formula-based liver volume estimation. Volumetric computed tomography can be an important tool during preoperative workup before transplant surgery.

Liver parenchyma at the site of hypodense parafissural pseudolesion contains increased collagen.

PURPOSE: To identify a histological substrate explaining the hypodense pseudolesion in the liver at the right side of the falciform ligament and the correlation with CT radiodensity. MATERIALS AND METHODS: Tissue specimens were obtained from the right (pseudolesion) and left (control) side of the falciform ligament at the level of the left portal vein, in deceased adults during autopsy. Radiodensity was measured at the same locations at CT. Digital image analysis determined the amount of collagen and fat in histological sections, and the number of portal triads and central veins were counted. Glycogen content was visually assessed by the area percentage of the histological section. RESULTS: Specimens from 17 patients showed a 39% increase in collagen for the site of the pseudolesion compared to the contralateral side (p = 0.08). No significant differences were found for the amount of fat, glycogen, portal triads, or central veins. In one patient a pseudolesion was visible on CT, and this contained 52% more collagen than the control side. CONCLUSION: The pseudolesion at the right parafissural side in the liver contains more collagen compared to the control left side, while there is no difference in fat or glycogen content or number of portal and hepatic veins. Collagen may be the cause of the pseudolesion.