This study demonstrates that, in the case of diagnostic image quality, contrast-enhanced MDCT permits an accurate identification of coronary plaques and that computed tomography density values measured within plaques reflect echogenity and plaque composition.

We conclude that 64-slice CT reveals encouraging results to noninvasively detect different types of coronary plaques located in the proximal coronary system. The ability to determine plaque burden currently is hampered by mainly an insufficient reproducibility.

Objectives-Pericardial fat as a visceral fat depot may be involved in the pathogenesis of coronary atherosclerosis. To gain evidence for that concept we sought to investigate the relation of pericardial fat volumes to risk factors, serum adiponectin levels, inflammatory biomarkers, and the quantity and morphology of coronary atherosclerosis. PϾ0.001). No association was found between BMI and coronary atherosclerosis. PAT volumes Ͼ300 cm 3 were the strongest independent risk factor for coronary atherosclerosis (odds ratio 4.1; CI 3.63 to 4.33) also significantly stronger compared to the Framingham score. We furthermore demonstrated that elevated PAT volumes are significantly associated with low adiponectin levels, low HDL levels, elevated TNF-␣ levels, and hsCRP. Conclusion-In the present study we demonstrated that elevated PAT volumes are associated with coronary atherosclerosis, hypoadiponectinemia, and inflammation and represent the strongest risk factor for the presence of atherosclerosis and may be important for risk stratification and monitoring. Key Words: cardiac CT Ⅲ pericardial fat Ⅲ obesity Ⅲ adiponectin Ⅲ plaque imaging T here is growing evidence that regional visceral fat distribution may contribute to an unfavorable metabolic and cardiovascular risk profile. 1,2 In patients with obesity, insulin resistance, diabetes, and hyperlipidemia visceral fat hypertrophies and transforms into a multifunctional organ that produces and secretes multiple endocrine and paracrine factors promoting inflammation, neovascularization, and oxidative stress, features that also characterize atherosclerosis. 3 Pericardial fat as a local visceral fat depot with close proximity to coronary arteries may serve as a source of inflammatory cytokines and cells that may locally enhance systemic proatherogenic effects via outside to inside signaling. 4,5 Thus it may be a specific parameter indicating an unfavorable cardio-metabolic state and may be used for risk stratification. To date, however, only little attention has focused on this regional fat depot located around the heart and its relation to cardiovascular risk factors, and the quantity and composition of coronary atherosclerosis is not well studied yet. Methods and Results-UsingMulti-slice CT is a noninvasive tool that allows to reliably assess both obstructive and nonobstructive subclinical coronary artery disease in an earlier stage than invasive angiography. 6 -9 Based on density measurements, plaques can be further characterized in noncalcified, mixed, and calcified plaques. 7 By using the same scan data this tool furthermore allows to quantify the exact pericardial fat volume. 9 We thus sought to assess the relation of pericardial fat volume to cardiovascular risk factors, levels of inflammatory cytokines, adiponectin, and to the extent and the phenotype of coronary atherosclerosis.

Objectives: Chemerin is a recently discovered adipokine that regulates adipocyte differentiation and modulates chemotaxis and activation of dendritic cells and macrophages. Given the convergence of adipocyte and macrophage function, chemerin may provide an interesting link between obesity, inflammation and atherosclerosis in humans. We sought to examine the relationship of i) chemerin and markers of inflammation, ii) chemerin and components of the metabolic syndrome, and iii) chemerin and coronary atherosclerotic plaque burden and morphology. Design: Serum chemerin levels were determined in 303 patients with stable typical or atypical chest pain who underwent dual-source multi-slice CT-angiography to exclude coronary artery stenosis. Atherosclerotic plaques were classified as calcified, mixed, or non-calcified. Results: Chemerin levels were highly correlated with high sensitivity C-reactive protein (rZ0.44, P!0.0001), interleukin-6 (rZ0.18, PZ0.002), tumor necrosis factor-a (rZ0.24, P!0.0001), resistin (rZ0.28, P!0.0001), and leptin (rZ0.36, P!0.0001) concentrations. Furthermore, chemerin was associated with components of the metabolic syndrome including body mass index (rZ0.23, PZ0.0002), triglycerides (rZ0.29, P!0.0001), HDL-cholesterol (rZK0.18, PZ0.003), and hypertension (P!0.0001). In bivariate analysis, chemerin levels were weakly correlated with coronary plaque burden (rZ0.16, PZ0.006) and the number of non-calcified plaques (rZ0.14, PZ0.02). These associations, however, were lost after adjusting for established cardiovascular risk factors (odds ratio, OR 1.17, 95% confidence interval (CI) 0.97-1.41, PZ0.11 for coronary plaque burden; OR 1.06, 95% CI 0.96-1.17, PZ0.22 for non-calcified plaques). Conclusions: Chemerin is strongly associated with markers of inflammation and components of the metabolic syndrome. However, chemerin does not predict coronary atherosclerosis.

The relation of heart rate and image quality in the depiction of coronary arteries, heart valves and myocardium was assessed on a dual-source computed tomography system (DSCT). Coronary CT angiography was performed on a DSCT (Somatom Definition, Siemens) with high concentration contrast media (Iopromide, Ultravist 370, Schering) in 24 patients with heart rates between 44 and 92 beats per minute. Images were reconstructed over the whole cardiac cycle in 10% steps. Two readers independently assessed the image quality with regard to the diagnostic evaluation of right and left coronary artery, heart valves and left ventricular myocardium for the assessment of vessel wall changes, coronary stenoses, valve morphology and function and ventricular function on a three point grading scale. The image quality ratings at the optimal reconstruction interval were 1.24+/-0.42 for the right and 1.09+/-0.27 for the left coronary artery. A reconstruction of diagnostic systolic and diastolic images is possible for a wide range of heart rates, allowing also a functional evaluation of valves and myocardium. Dual-source CT offers very robust diagnostic image quality in a wide range of heart rates. The high temporal resolution now also makes a functional evaluation of the heart valves and myocardium possible.