BACKGROUND AND PURPOSE:SWI is a high-resolution 3D, fully velocity-compensated gradient-echo sequence that uses both magnitude and phase data. The purpose of this study was to investigate the phase behavior of the capsule of pyogenic brain abscesses with noncontrast SWI.
An obese 52-year-old woman underwent mitral valve replacement. On the first day after the operation, she had left-sided weakness. Brain CT showed right side middle cerebral artery infarction, and a hypodense filling defect was noted in the right distal internal carotid artery (figure, A). Region of interest measurement of CT density of the hypodense lesion was -83 Hounsfield units (figure, B), indicating a macroscopic fat embolus. The patient died 2 days later. Cerebral fat macroembolism is a rare cause in thromboembolic stroke. Perioperative cerebral fat embo-lism of cardiac surgery can be caused by aortic cannulation during cardiopulmonary bypass, aortic clamping, median sternotomy, and dislodgement of pericardial or epicardial fat. 1,2
CE-SWI shows the multilayer appearance of the capsule in pyogenic brain abscesses, which may arise from postprocessing procedures originally designed to enhance susceptibility contrast. Although SWI may provide additional information valuable in the diagnosis of pyogenic brain abscesses, image interpretation should be exercised with caution, particularly for CE-SWI.
Abstract-Objective:To examine the associations between postmortem Alzheimer disease (AD) neuropathology and autopsy-verified cardiovascular disease. Methods: The authors examined 99 subjects (mean age at death ϭ 87.6; SD ϭ 8.7) from the Mount Sinai School of Medicine Department of Psychiatry Brain Bank who were devoid of cerebrovascular disease-associated lesions or of non-AD-related neuropathology. Density of neuritic plaques (NPs) and neurofibrillary tangles (NFTs) as well as coronary artery and aortic atherosclerosis, left ventricular wall thickness, and heart weight were measured. Partial correlations were used to assess the associations of the four cardiovascular variables with NPs and NFTs in the hippocampus, entorhinal cortex, and multiple regions of the cerebral cortex after controlling for age at death, sex, dementia severity, body mass index, and ApoE genotype. These analyses were also repeated separately for ApoE4 carriers and noncarriers. Results: The extent of coronary artery disease and to a lesser extent atherosclerosis were significantly associated with the density of cardinal neuropathologic lesions of AD in this autopsy sample (significant correlations between 0.22 and 0.29). These associations were more pronounced for the ApoE4 allele carriers (n ϭ 42; significant correlations between 0.34 and 0.47). Conclusions: The degree of coronary artery disease is independently associated with the cardinal neuropathological lesions of Alzheimer disease. These associations are primarily attributable to individuals with the ApoE4 allele. NEUROLOGY 2006;66:1399-1404 The prevalence of dementia rises steeply with age, doubling every 4 to 5 years from age 60 years, so that more than one-third of individuals older than 80 years are likely to have a dementia.1 Alzheimer disease (AD) remains the most common cause of dementia in the elderly.2 Postmortem studies suggest that the hippocampus and entorhinal cortex are the first brain areas to be affected, with cortical association areas being increasingly involved as the disease progresses. 3,4 Cardiovascular risk factors including diabetes, hypertension, hyperlipidemia, and homocystinemia are associated with vascular dementia, but recent studies have suggested that they are also independently associated with AD.5 However, few studies have examined the specific association of cardiovascular damage with the cardinal neuropathologic lesions of AD directly. The Rotterdam study examined wall thickness and plaques of the carotid arteries, assessed by ultrasonography, and found that both clinically diagnosed probable AD and vascular dementia were associated with atherosclerosis. 6 An interaction between apolipoprotein E genotype (ApoE) and atherosclerosis in the etiology of AD (specifically, an augmented risk of AD in subjects with both a high atherosclerosis score and an ApoE4 allele) was also found in that study. Other investigators have reported that ApoE4 but not cardiovascular disease (measured postmortem) was associated with the extent of AD neuropathology.
7The curr...
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