The study is a prospective-observational, explorative single-centre cohort study aimed to examine the influence of hemodynamic and geometric parameters on the progression of atherosclerotic alterations in peripheral vessels (carotids, femoral artery). Atherosclerotic alterations (IMT, plaque volume) will be measured with a ultrasound (IMT measurements and 3D quantitative plaque volumetry) and magnetic resonance imaging (MRI). Geometric parameters (e.g. carotid/femoral bifurcation angle, carotid/femoral bifurcation area) are assessed with magnetic resonance imaging (MRI) and also 3D ultrasonography.

A total of 100 patients with an asymmetrical plaque distribution in carotid and femoral arteries will be tested. Only patients who are already enrolled in the "Correlation of Artherosclerotic Plaque Volume and Intima Media Thickness With Soluble P-selectin" (NCT01895725) and who are tested prior for an asymmetrical plaque distribution will be included in this study. MRI will be performed once whereas ultrasound imaging will be be repeated once per year (up to five times) to assess changes in these parameters over time. Also plasma samples will be collected once yearly and tested for traditional and novel cardiovascular risk factors.

The primary endpoint of the planned study will be the correlation between geometrical and hemodynamic parameters as stated above and the progression of atherosclerosis as measured by plaque volume and IMT in the carotid and femoral arteries, respectively.

Secondary endpoints will include the correlation of geometrical and hemodynamic parameters with established (hypertension, smoking, diabetes, dyslipidemia) and novel risk factors (hsCRP, P-selectin, cholesteryl ester transfer protein (CETP), intercellular adhesion molecule-1 (ICAM-1), CETP TaqIb polymorphism), with cardiovascular event rate, plaque localization, plaque morphology and the additional predictive value of geometrical parameters compared to an established risk score (SCORE card).

Inclusion Criteria:

• asymmetrical (side difference) plaque distribution in carotids/femoral arteries which was tested in at least two prior 3D-ultrasound examinations (absolute side difference in carotid arteries ≥ 30 mm3 or in femoral arteries ≥50 mm3 and relative side difference in carotid arteries/femoral arteries ≥50% )

Exclusion Criteria:

• actual pregnancy, lactation period, chronic renal insufficiency (GFR<20ml/min)

Only patients who are already enrolled in the "Correlation of Artherosclerotic Plaque Volume and Intima Media Thickness With Soluble P-selectin" (NCT01895725) and who are tested prior for an asymmetrical plaque distribution will be included in this study.