The artefacts of death: CT post-mortem findings.

Post-mortem CT is an increasingly used tool for investigating cause of death. While sharing many similarities with pre-mortem imaging, a number of unique artefacts occur at post-mortem CT, and these have the potential to mask underlying disease processes. It is vital that the artefacts associated with the process of dying and decompositional changes are recognised to avoid misdiagnosis. The following pictorial review discusses and illustrates the important and common post-mortem changes.

The effect of post-mortem computed tomography angiography (PMCTA) using water-soluble, iodine-based radiographic contrast on histological analysis of the liver, kidneys and left ventricle of the heart.

The purpose of this study was to investigate the impact of post-mortem computed-tomography angiography (PMCTA) on the histology of the liver, kidneys and heart. Multiple tissue cores were collected from the liver, left and right kidneys and left ventricle utilizing CT-guided biopsy. Subsequent whole body PMCTA was performed using a solution of polyethylene glycol and iodinated radiographic contrast, and an embalming pump. Corresponding biopsy cores were collected at autopsy, and blinded histology analysis assessing for PMCTA-induced histology artefact was performed. The blinded analysis of pre-PMCTA and post-PMCTA biopsy samples demonstrated that whole body PMCTA had no effect on the histological analyses of the liver (0%, CI = 0-13.7%), left ventricle of the heart (0%, CI = 0-36.9%) and right kidney (0%, CI = 13.2%), however likely caused increased Bowman's capsule spaces in the left kidney of one case (4%, CI = 0.01-20.4%). Other artefactual histological changes identified included eosinophilic material in the liver, whiter interstitium and dilated tubules in kidney samples, and autolysis-related changes, however these could not be categorically attributed to the PMCTA procedure. PMCTA causes zero or minimal effect to the histological examination of the liver, left kidney, right kidney and left ventricle, and as such performing PMCTA prior to autopsy is unlikely to impact autopsy histological results in these organs.

Platelet function as a risk factor for venous thromboembolism in the Framingham Heart Study.

INTRODUCTION: The relationship of venous thromboembolism (VTE) with platelet reactivity is unclear. Platelet function plays a key role in arterial thrombosis. Evidence suggests antiplatelet agents also effects in reducing VTE. Our aim is to describe the role of baseline platelet function in development of VTE in the community-based Framingham Heart Study (FHS) cohort. MATERIALS AND METHODS: Participants in the Framingham Offspring cohort fifth examination and Omni cohort first examination were eligible. We used light transmission aggregometry to measure platelet aggregation in response to collagen and a range of ADP and epinephrine doses. The study population consisted of 2831 participants [average age 54.3years; 57% female]. RESULTS AND CONCLUSIONS: During a median follow-up of 20.4years, we observed 138 incident VTE events. In age-, sex- and cohort-adjusted analysis an increase in collagen lag time was associated with increased risk for incident VTE (HR 1.01 [1.00-1.02]; p=0.049). Increased maximal aggregation to low dose epinephrine (1.0µM) was associated with lower VTE risk (HR 0.84 [0.71-0.99]; p=0.042]). However, additional multivariable analyses attenuated the collagen-VTE and epinephrine-VTE associations to trends, primarily due to adjustment for baseline body mass index (BMI), a VTE risk factor and potential modifier of platelet function. Secondary analyses considering varying follow-up periods, cancer incidence and interim aspirin use did not dramatically affect the collagen and epinephrine trends observed. Baseline platelet aggregability was only weakly associated with incident VTE, and in a paradoxical direction, in a community-based population. Other markers of platelet function and hemostasis could prove to be more useful predictors.

Death from pulmonary embolism of cyanoacrylate glue following gastric varix endoscopic injection.

We present the case of a 25 year old woman with a complex past medical history including Crigler-Najjar syndrome (Type 1) with a liver transplant in 1993 and subsequent development of cirrhosis with portal hypertension in the transplanted liver. The deceased presented to hospital with hematemesis and investigations showed a large gastric varix. The varix was injected with cyanoacrylate glue. Within 30 min of injection the patient became acutely hypoxic. Urgent chest X-ray demonstrated radio opaque glue within the pulmonary arteries. It was evident that future treatment was futile and supportive treatment was withdrawn. The deceased was referred for medico legal post mortem examination. The post mortem CT scan performed prior to autopsy showed widespread radio-opaque material within the pulmonary arteries. At autopsy, rubbery grey/tan "clot" occluded the major proximal and segmental pulmonary arteries. Microscopic examination of the "clot" showed clumps of erythrocytes surrounded by foreign material. We discuss this relatively uncommon but well recognized complication of variceal injection with cyanoacrylate glue.

Lethal hemorrhage from a ureteric-arterial-enteric fistula diagnosed by postmortem CT angiography.

Fistula formation following pelvic surgery and radiotherapy, including ureteric-arterial fistulas (UAF), is well documented, however, ureteric-arterial-enteric fistula is extremely rare. Conventional autopsy is usually required for the definitive diagnosis of pelvic vascular fistulas although an accurate diagnosis can still be complicated and challenging. The role of post-mortem computed tomography (PMCT) as an adjunct to conventional autopsy is well documented in the literature. One of the limitations of PMCT is the diagnosis of vascular conditions. Post-mortem computed tomography angiography (PMCTA) is a recently introduced technique that can assist in detecting such pathology. We present a case of post-radiotherapy ureteric-arterial-enteric fistula presenting as massive rectal and vaginal bleeding diagnosed prior to autopsy on PMCTA. The role of PMCTA in the diagnosis of such a UAF has not previously been reported in the literature.

Demonstration of liver metastases on postmortem whole body CT angiography following inadvertent systemic venous infusion of the contrast medium.

An 86-year-old woman was hospitalized for breathlessness and a large right-sided pleural effusion. Approximately 1 h after thoracentesis, she developed a hemothorax resulting in hypotension and death. Routine postmortem CT scanning showed a large volume right hemothorax and a markedly enlarged liver. In an attempt to determine the origin of bleeding prior to autopsy, a postmortem CT angiogram was performed. Following inadvertent cannulation of the left long saphenous vein and infusion of ∼1,700 mL of a polyethylene glycol 200 and iodine-based radiographic contrast solution into systemic veins using a mechanical pump, CT scanning revealed a dense hepatic "parenchogram" containing multiple large, filling defects indicative of metastases. These were confirmed at autopsy. Microscopic evaluation of the liver using hematoxylin and eosin staining showed marked histological artifact characterized by centrilobular sinusoidal expansion although histology of the adenocarcinoma metastases was typical and apparently unaffected by the contrast solution. Postmortem CT angiography using an aqueous radiographic contrast agent in the so-called venous phase seems to be useful for the identification of hepatic parenchymal metastatic disease although it does cause histological artifact.

Spontaneous acute subdural hematoma complicating arachnoid cyst.

The overwhelming majority of cases of acute subdural hematoma in the forensic setting occur as a result of head trauma. We report a case of sudden unexpected death in a middle-aged woman with a history of arachnoid cyst who had sudden spontaneous onset of severe headache that was rapidly followed by collapse and death. A postmortem multiple-slice computed tomographic scan showed a large acute subdural hematoma associated with hemorrhage into an arachnoid cyst. Subdural hemorrhage is an uncommon but well-described complication of an arachnoid cyst.

Body composition and resting energy expenditure in clinically stable, non-weight-losing patients with severe emphysema.

STUDY OBJECTIVES: To characterize the metabolic status of weight-stable and clinically stable individuals with advanced emphysema. PATIENTS: Seventy-nine patients with severe emphysema (FEV(1), 29 +/- 13% of predicted [mean +/- SD]) evaluated for enrollment in the National Emphysema Treatment Trial and 20 age-matched healthy subjects were studied. SETTING: Pulmonary function laboratory of university-affiliated teaching hospital. INTERVENTIONS: Data collection. MEASUREMENTS AND RESULTS: We measured lung function, body composition, serum leptin levels, serum tumor necrosis factor receptors (sTNF-Rs), resting oxygen consumption (RVO(2)) normalized to weight in kilograms (RVO(2)/kg), and RVO(2) normalized to fat-free mass (FFM) [RVO(2)/FFM]. The patient group and healthy group had similar age, body mass index (BMI), and body composition. RVO(2)/kg, RVO(2)/FFM, and sTNF-R levels were higher in patients compared to healthy subjects. There were no differences in serum leptin levels between emphysematous and healthy subjects, and there was no correlation between leptin and sTNF-R and RVO(2)/kg. Furthermore, both groups had similar gender-related differences in FFM, percentage of body fat, and serum leptin levels. Patients with lower BMI showed the greatest differences from control subjects in RVO(2)/kg. CONCLUSION: In weight-stable subjects with advanced emphysema, RVO(2)/kg and RVO(2)/FFM were higher compared to healthy subjects, especially in those with BMI in the lower end of the normal range. RVO(2)/kg and RVO(2)/FFM did not correlate with leptin or sTNF-R levels. These data show that a higher metabolic rate is found in patients with emphysema who are clinically and weight stable. Thus, hypermetabolism is a feature of the disease and not sufficient to lead to weight loss.