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434 result(s) for "Tunica Media - diagnostic imaging"
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Computed Tomographic Distinction of Intimal and Medial Calcification in the Intracranial Internal Carotid Artery
Intracranial internal carotid artery (iICA) calcification is associated with stroke and is often seen as a proxy of atherosclerosis of the intima. However, it was recently shown that these calcifications are predominantly located in the tunica media and internal elastic lamina (medial calcification). Intimal and medial calcifications are thought to have a different pathogenesis and clinical consequences and can only be distinguished through ex vivo histological analysis. Therefore, our aim was to develop CT scoring method to distinguish intimal and medial iICA calcification in vivo. First, in both iICAs of 16 cerebral autopsy patients the intimal and/or medial calcification area was histologically assessed (142 slides). Brain CT images of these patients were matched to the corresponding histological slides to develop a CT score that determines intimal or medial calcification dominance. Second, performance of the CT score was assessed in these 16 patients. Third, reproducibility was tested in a separate cohort. First, CT features of the score were circularity (absent, dot(s), <90°, 90-270° or 270-360°), thickness (absent, ≥1.5mm, or <1.5mm), and morphology (indistinguishable, irregular/patchy or continuous). A high sum of features represented medial and a lower sum intimal calcifications. Second, in the 16 patients the concordance between the CT score and the dominant calcification type was reasonable. Third, the score showed good reproducibility (kappa: 0.72 proportion of agreement: 0.82) between the categories intimal, medial or absent/indistinguishable. The developed CT score shows good reproducibility and can differentiate reasonably well between intimal and medial calcification dominance in the iICA, allowing for further (epidemiological) studies on iICA calcification.
Simvastatin with or without Ezetimibe in Familial Hypercholesterolemia
In a 2-year clinical trial, the addition of ezetimibe to simvastatin had no effect on the progression of atherosclerosis, as measured by carotid-artery intima–media thickness, despite the additional lowering of levels of low-density lipoprotein cholesterol and C-reactive protein by ezetimibe when added to simvastatin. However, the study was not powered to assess clinical end points. The addition of ezetimibe to simvastatin had no effect on the progression of atherosclerosis, as measured by carotid-artery intima–media thickness, despite the additional lowering of levels of low-density lipoprotein cholesterol and C-reactive protein. A reduction in levels of low-density lipoprotein (LDL) cholesterol constitutes one of the cornerstones in the prevention of cardiovascular disease. In recent trials comparing various statins or the same statin at various doses, aggressive therapy to lower LDL cholesterol levels was associated with a reduction in rates of cardiovascular events. 1 – 4 However, administration of the highest approved statin dose offers only limited additional lowering of LDL cholesterol at the expense of an increased incidence of side effects. 5 Therefore, novel compounds that further reduce LDL cholesterol levels when added to statin therapy are of interest. A recently introduced compound, ezetimibe, selectively . . .
Tunica intima compensation for reduced stiffness of the tunica media in aging renal arteries as measured with scanning acoustic microscopy
Aging causes stiffness and decreased function of the renal artery (RA). Histological study with light microscopy can reveal microscopic structural remodeling but no functional changes. The present study aimed to clarify the association between structural and functional aging of the RA through the use of scanning acoustic microscopy. Formalin-fixed, paraffin-embedded cross-sections of renal arteries from 64 autopsy cases were examined. Speed-of-sound (SOS) values of three layers, which correspond to the stiffness, were compared among different age groups. SOS of the tunica media was examined in terms of blood pressure (BP) and SOS of the ascending aorta. Vulnerability to proteases was assessed by SOS reduction after collagenase treatment. The tunica intima presented inward hypertrophy with luminal narrowing, and the tunica media showed outward hypertrophic remodeling with aging. SOS of the tunica media and internal and external elastic laminae showed a reverse correlation with age. SOS of the tunica media was negatively correlated with BP and strongly associated with that of the aorta. The tunica media of young RAs were more sensitive to collagenase compared with the old ones. Scanning acoustic microscopy is useful for observing the aging process of the RA. This technique simultaneously shows structural and mechanical information from each portion of the RA. In the process of aging, the RA loses contractile function and elasticity as a result of protease digestion. The tunica media and the internal and external elastic laminae exhibit reduced stiffness, but the tunica intima stiffens with atherosclerosis. As a consequence, the RA's outer shape changes from round to oval with inward and outward hypertrophy. This indicates that the inner resistant intima supports the mechanical weakness of the tunica media to compensate for an increase in BP with aging.
Mannheim carotid intima-media thickness consensus (2004-2006). An update on behalf of the Advisory Board of the 3rd and 4th Watching the Risk Symposium, 13th and 15th European Stroke Conferences, Mannheim, Germany, 2004, and Brussels, Belgium, 2006
Intima-media thickness (IMT) is increasingly used as a surrogate end point of vascular outcomes in clinical trials aimed at determining the success of interventions that lower risk factors for atherosclerosis and associated diseases (stroke, myocardial infarction and peripheral artery diseases). The necessity to promote further criteria to distinguish early atherosclerotic plaque formation from thickening of IMT and to standardize IMT measurements is expressed through this updated consensus. Plaque is defined as a focal structure that encroaches into the arterial lumen of at least 0.5 mm or 50% of the surrounding IMT value or demonstrates a thickness >1.5 mm as measured from the media-adventitia interface to the intima-lumen interface. Standard use of IMT measurements is based on physics, technical and disease-related principles as well as agreements on how to perform, interpret and document study results. Harmonization of carotid image acquisition and analysis is needed for the comparison of the IMT results obtained from epidemiological and interventional studies around the world. The consensus concludes that there is no need to 'treat IMT values' nor to monitor IMT values in individual patients apart from exceptions named, which emphasize that inside randomized clinical trials should be performed. Although IMT has been suggested to represent an important risk marker, according to the current evidence it does not fulfill the characteristics of an accepted risk factor. Standardized methods recommended in this consensus statement will foster homogenous data collection and analysis. This will help to improve the power of randomized clinical trials incorporating IMT measurements and to facilitate the merging of large databases for meta-analyses.
Progression of Carotid Artery Intima-Media Thickness During 12 Years in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) Study
This study investigated the long-term effects of intensive diabetic treatment on the progression of atherosclerosis, measured as common carotid artery intima-media thickness (IMT). A total of 1,116 participants (52% men) in the Epidemiology of Diabetes Interventions and Complications (EDIC) trial, a long-term follow-up of the Diabetes Control and Complications Trial (DCCT), had carotid IMT measurements at EDIC years 1, 6, and 12. Mean age was 46 years, with diabetes duration of 24.5 years at EDIC year 12. Differences in IMT progression between DCCT intensive and conventional treatment groups were examined, controlling for clinical characteristics, IMT reader, and imaging device. Common carotid IMT progression from EDIC years 1 to 6 was 0.019 mm less in intensive than in conventional (P < 0.0001), and from years 1 to 12 was 0.014 mm less (P = 0.048); but change from years 6 to 12 was similar (intensive - conventional = 0.005 mm, P = 0.379). Mean A1C levels during DCCT and DCCT/EDIC were strongly associated with progression of IMT, explaining most of the differences in IMT progression between DCCT treatment groups. Albuminuria, older age, male sex, smoking, and higher systolic blood pressure were significant predictors of IMT progression. Intensive treatment slowed IMT progression for 6 years after the end of DCCT but did not affect IMT progression thereafter (6-12 years). A beneficial effect of prior intensive treatment was still evident 13 years after DCCT ended. These differences were attenuated but not negated after adjusting for blood pressure. These results support the early initiation and continued maintenance of intensive diabetes management in type 1 diabetes to retard atherosclerosis.
Ambient Air Pollution and Atherosclerosis in Los Angeles
Associations have been found between long-term exposure to ambient air pollution and cardiovascular morbidity and mortality. The contribution of air pollution to atherosclerosis that underlies many cardiovascular diseases has not been investigated. Animal data suggest that ambient particulate matter (PM) may contribute to atherogenesis. We used data on 798 participants from two clinical trials to investigate the association between atherosclerosis and long-term exposure to ambient PM up to 2.5 μm in aerodynamic diameter ( PM2.5). Baseline data included assessment of the carotid intima-media thickness (CIMT), a measure of subclinical atherosclerosis. We geocoded subjects' residential areas to assign annual mean concentrations of ambient PM2.5. Exposure values were assigned from a PM2.5surface derived from a geostatistical model. Individually assigned annual mean PM2.5concentrations ranged from 5.2 to 26.9 μ g/ m3(mean, 20.3). For a cross-sectional exposure contrast of 10 μ g/ m3PM2.5, CIMT increased by 5.9% (95% confidence interval, 1-11%). Adjustment for age reduced the coefficients, but further adjustment for covariates indicated robust estimates in the range of 3.9-4.3% (p-values, 0.05-0.1). Among older subjects (≥ 60 years of age), women, never smokers, and those reporting lipid-lowering treatment at baseline, the associations of PM2.5and CIMT were larger with the strongest associations in women ≥ 60 years of age (15.7%, 5.7-26.6%). These results represent the first epidemiologic evidence of an association between atherosclerosis and ambient air pollution. Given the leading role of cardiovascular disease as a cause of death and the large populations exposed to ambient PM2.5, these findings may be important and need further confirmation.
Relationship between leukoaraiosis, carotid intima-media thickness and intima-media thickness variability: Preliminary results
Objective To assess the relationship between the degree of leukoaraiosis (LA), carotid intima-media thickness (IMT) and intima-media thickness variability (IMTV). Materials and methods Sixty-one consecutive patients, who underwent a brain MRI examination and a carotid artery ultrasound, were included in this retrospective study, which conformed with the Declaration of Helsinki. Written informed consent was waived. In each patient, right/left carotid arteries and brain hemispheres were assessed using automated software for IMT, IMTV and LA volume. Results The mean hemispheric LA volume was 2,224 mm 3 (SD 2,702 mm 3 ) and there was no statistically significant difference in LA volume between the right and left hemispheres (p value = 0.628). The mean IMT and IMTV values were 0.866 mm (SD 0.170) and 0.143 mm (SD 0.100), respectively, without significant differences between the right and left sides (p values 0.733 and 0.098, respectively). The correlation coefficient between IMTV and LA volume was 0.41 (p value = 0.0001), and 0.246 (p value = 0.074) between IMT and LA volume. Conclusions IMTV significantly correlates with LA volume. Further studies are warranted to verify whether this parameter can be used clinically as a marker of cerebrovascular risk. Key Points • Intima-media thickness variability (IMTV) significantly correlates with leukoaraiosis volume. • IMTV could be used as a marker for cerebrovascular risk. • IMTV seems to be a better predictor of weighted mean difference than IMT.
Full-field optical coherence tomography for the diagnosis of giant cell arteritis
Histopathological examination of temporal artery biopsy (TAB) remains the gold standard for the diagnosis of giant cell arteritis (GCA) but is associated with essential limitations that emphasize the need for an upgraded pathological process. This study pioneered the use of full-field optical coherence tomography (FF-OCT) for rapid and automated on-site pathological diagnosis of GCA. Sixteen TABs (12 negative and 4 positive for GCA) were selected according to major histopathological criteria of GCA following hematoxylin-eosin-saffron-staining for subsequent acquisition with FF-OCT to compare structural modifications of the artery cell wall and thickness of each tunica. Gabor filtering of FF-OCT images was then used to compute TAB orientation maps and validate a potential automated analysis of TAB sections. FF-OCT allowed both qualitative and quantitative visualization of the main structures of the temporal artery wall, from the internal elastic lamina to the vasa vasorum and red blood cells, unveiling a significant correlation with conventional histology. FF-OCT imaging of GCA TABs revealed destruction of the media with distinct remodeling of the whole arterial wall into a denser reticular fibrous neo-intima, which is distinctive of GCA pathogenesis and accessible through automated Gabor filtering. Rapid on-site FF-OCT TAB acquisition makes it possible to identify some characteristic pathological lesions of GCA within a few minutes, paving the way for potential machine intelligence-based or even non-invasive diagnosis of GCA.
Intensive Diabetes Therapy and Carotid Intima–Media Thickness in Type 1 Diabetes Mellitus
Carotid intima–media thickness is considered to be a measure of atherosclerosis. This study examined intima–media thickness in participants in the Diabetes Control and Complications Trial. Six years after the trial ended, the progression of intima–media thickness was significantly less in patients who had received intensive as compared with conventional therapy. Diabetes mellitus is accompanied by a substantial increase in the risk of cardiovascular disease. 1 – 5 Most epidemiologic and clinical-trial data have derived from the study of type 2 diabetes, in which cardiovascular disease accounts for 70 percent of all deaths. 1 – 3 Much less is known about cardiovascular disease in type 1 diabetes. Although the absolute risk of cardiovascular disease is lower in patients with type 1 diabetes than in those with type 2 diabetes, owing in part to their younger age, the relative risk, as compared with that of nondiabetic persons of similar age, may be increased by a factor . . .
Intrauterine growth restriction is associated with persistent aortic wall thickening and glomerular proteinuria during infancy
Low birth weight, caused either by preterm birth or by intrauterine growth restriction, has recently been associated with increased rates of adult renal and cardiovascular disease. Since aortic intima–media thickening is a noninvasive marker of preclinical vascular disease, we compared abdominal aortic intima–media thickness among intrauterine growth restricted and equivalent gestational age fetuses in utero and at 18 months of age. The relationship between intrauterine growth restriction, fetal aortic thickening, and glomerular function during infancy was measured by enrolling 44 mothers with single-fetus pregnancies at 32 weeks gestation: 23 growth restricted and 21 of appropriate gestational age as controls. Abdominal aortic intima–media thickness was measured by ultrasound at enrollment and again at 18 months of age. Fetuses with intrauterine growth restriction had significantly higher abdominal aortic intima–media thickness compared with age controls when measured both in utero and at 18 months. At 18 months, the median urinary microalbumin and median albumin–creatinine ratio were significantly higher in those infants who experienced intrauterine growth restriction compared to the controls. Our results show that intrauterine growth restriction is associated with persistent aortic wall thickening and significantly higher microalbuminuria during infancy.