Background. The state of the aorta is a key factor in the prognosis of the patient’s life, since the distension of the ascending aorta in systole determines the blood supply to the myocardium in diastole. Paramagnetic contrast-enhanced MRI provides a reliable assessment of pathological neoangiogenesis, however, in fact, studies of the aorta are performed descriptively, without calculating mechanical strength and extensibility. Objective. To develop and clinically test on the patients with atherosclerotic lesions and myocarditis a method for quantitative assessment of extensibility and mechanical elasticity of the aortic wall.Design and methods. Were examined 12 patients with acute myocardial infarction with ST segment elevation, as a control group 11 patients without clinical and instrumental signs of atherosclerosis of large arteries and aorta. All underwent MRI of the chest and heart with paramagnetic contrast enhancement (PMCE) and ECG synchronization. The indices of aortic distensibility, distensibility normalized to pulse BP, Young’s modulus of the aortic wall, systolic distension of the ascending aorta (mL), index of strengthening of the aortic wall in PMCE were calculated.Results. Ascending aortic distensibility decreased in patients with myocarditis and acute infarction. Young’s modulus and distensibility of the ascending aorta significantly correlated with the value of the aortic wall enhancement index in PMCE. Myocardial damage in acute infarction and myocarditis was noted with a decrease in systolic expansion of the ascending aorta below 10 ml due to its reduced elasticity.Conclusion. There is a relationship between pathological accumulation of a paramagnet in the wall of the ascending aorta, a decrease in its elasticity, a decrease in the volume of systolic aortic dilation, and the development of hypoperfusion myocardial damage. Magnetic resonance elastometry of the aortic wall makes it possible to assess violations of aortic distensibility and predict the development of ischemic damage in the myocardium of the left ventricle.

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The distinct growth of cardiovascular diseases (CVD) and aortic diseases in the world requires accurate diagnostic methods for their early prediction. In modern research, more and more attention is paid to biomechanics and numerical models of accurate quantitative calculations. The assessment of aortic pathology using magnetic resonance imaging (MRI) acquires great clinical significance, since it makes it possible to simultaneously assess the anatomical topography and physical properties of the aorta. A broad study of changing biomechanical processes will complement the existing ideas about the basics of aneurysm formation and aortic dissection. MRI is a modern non-invasive method that provides the necessary data to as-sess the physical properties of the wall and directional flows in the aorta.

Background. Vascular stiffness is an important predictor of cardiovascular disease. The vascular wall biomechanical parameters change not only in patients with genetic disorders of the connective tissue. This means that, regardless of etiology, the early detection of a progressive loss of aortic elasticity is of great clinical importance in preventing the development of severe complications. Assessment of aortic biomechanical parameters using magnetic resonance imaging (MRI) is a new level of visualization for aortic diseases allowing to improve surgical tactics and prevent complications. A number of biomechanical parameters determined by aortic MRI demonstrates the process of its wall remodeling, so their analysis will allow to develope an algorithm for the early diagnosis of aneurysms and the threat of acute aortic syndrome.Objective: using aortic MRI data, to evaluate the aortic biomechanical parameters and hemodynamics at pre- and postoperative stages and their impact on the occurrence of complications and relapses in the long-term period.Material and methods. Between 2020 and 2023, in Petrovsky Russian Scientific Center of Surgery, aortic MRI was performed prospectively before and after surgery in 107 patients with diagnoses of ascending aortic aneurysm (55 patients: 48 (87%) males and 7 (13%) females, mean age 79.4±14.91 years) and DeBakey type I and III aortic dissection, chronic stage (52 patients: 44 (85%) males and 8 (15%) females, mean age 54.32±10.41 years).Results. The quantitative data analysis in the postoperative period showed a decrease in the aortic wall elastic properties in the form of extensibility (0.4 [0.34; 0.54] %/mm Hg in the aneurysm group; 0.5 [0.25; 0.55] %/mmHg in the dissection group) and an increase in stiffness in the form of Young’s modulus (0.6 [0.38; 0.68] MPa in the aneurysm group; 0.5 [0.39; 0.83] MPa in the dissection group). Hemodynamic changes in the dissection group after surgery demonstrated a significant increase in values of maximum velocity in the descending aorta (78.6 [66.24; 130.78] cm/sec) and pressure gradient at the celiac trunk level (2.10 [1.76; 6.84] mm Hg). When assessing the pulse wave velocity parameter in both groups, high values were noted with a tendency to increase after surgery (in the aneurysm group, 7.7 [5.7; 20.3] cm/s before surgery versus 8.7 [6.5; 10.65] cm/s after surgery; in the dissection group, 9.7 [6.8; 12.9] versus 12.7 [7.7; 15.7] cm/s, respectively).Conclusion. Monitoring general hemodynamics and blood flow patterns together with an assessment of the aortic wall elasticity will make it possible to identify patients with borderline aortic dilatation. At the same time, studies of the aortic prosthetic segment are of particular interest. The obtained data on hemodynamic changes occuring at the border of the prosthetic and native segments of the operated aorta can confirm and justify the development of a complication in the form of distal stent graft-induced new entry (dSINE).