![]() This method was applied in 1160 participants of the multi-ethnic study of atherosclerosis (MESA) in subjects aged 45–84 years. However, PWV can also be measured using 2D phase-contrast MRI offering the possibility to exclusively study stiffness of the thoracic aorta. PWV was a strong and independent predictor of cardiovascular events and all-cause mortality in a large meta-analysis including 16,000 patients examined by Doppler flow or tonometry and followed over 8 years 11. Aortic wall thickness increased by 0.03 mm/year in 423 subjects of a population study using two-dimensional (2D) MRI in the descending aorta and during 10-year-follow-up 10. Annual progression was 0.1 mm per year and comparable to other population studies (growth rates = 0.1–0.2 mm/year) while an increase of 0.5 mm/year was considered the upper limit of normal 9. 2000 subjects between 50 and 70 years of age of the Danish population. Growth of the diameter of the ascending and descending aorta was studied using CT-angiography in ca. Therefore, quantification of helicity is of high interest especially in patients with diseases of the aortic valve or the aorta 6, 7, 8. Physiological helicity seems to be atheroprotective while abnormal helicity has been associated with aortic dilation and aneurysms. Helicity is another promising hemodynamic parameter representing the rotational component of blood flow. Consequently, PWV has been recommended as an independent parameter for individual risk assessment 4, 5. Measuring PWV offers the chance to monitor vascular ageing, identify subjects at risk for cardiovascular events and intervene timely through lifestyle modifications and medication 3. Aortic pulse wave velocity (PWV) reflects stiffness and is a strong predictor of future cardiovascular events and all-cause mortality 2. Progressive atherosclerosis of the aorta leads to an increase of aortic diameter, wall thickness and stiffness 1. Aortic aging determined by 3D multi-parametric MRI is now available for future comparisons in patients with diseases of the aortic valve or aorta. 3D MRI was able to characterize changes in aortic diameter, plaque thickness, PWV and helicity during six years in our population. By contrast, helicity increased significantly in the DAo in both genders (0.28 to 0.29 and 0.29 to 0.30, respectively). Local normalized helicity volumes (LNHV) decreased significantly in the AAo and AA (0.33 to 0.31 and 0.34 to 0.32 in females and 0.34 to 0.32 and 0.32 to 0.28 in males). Mean diameter of the ascending aorta (AAo) decreased and plaque thickness increased significantly in the aortic arch (AA) and descending aorta (DAo) in females. All underwent 3 T MRI of the thoracic aorta including 3D T1 weighted MRI (spatial resolution 1 mm 3) for measuring aortic diameter and plaque thickness and 4D flow MRI (spatial/temporal resolution = 2 mm 3/20 ms) for calculating global and regional aortic pulse wave velocity (PWV) and helicity of aortic blood flow. We followed 80 of 126 subjects of a population study (20 to 80 years of age at baseline) using the identical methodology 6.0 ± 0.5 years later. We comprehensively studied morphological and functional aortic aging in a population study using modern three-dimensional MR imaging to allow future comparison in patients with diseases of the aortic valve or aorta.
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