MRI-based hemodynamical analysis in patients with surgically treated aortic coarctations

In management of cardiovascular diseases, information about the patient-specific behavior of blood flow and pressure can be essential. In the human aorta, velocity-encoded magnetic resonance imaging (MRI) is the only method capable of measuring complete time-resolved three-dimensional vector fields of the blood flow velocities. Additionally, computations of relative blood pressure from this data source have been presented in recent years. Thus, velocityencoded MRI can be a valuable measurement technique for both blood flow and blood pressure values in diagnostics and therapy control of aortic diseases. In the last years, we have developed the software framework MEDIFRAME for cardiovascular diagnostics based on MRI acquisitions. In this article, we apply our in-house developed software framework for a MRI-based hemodynamic analysis in five patients with surgically treated aortic coarctations. We compared our results to a control group of five healthy volunteers. The study included the measurement of blood flow velocities by phase-contrast MRI and the subsequent computation of relative blood pressure values. We generated a set of suitable visualizations for flow and pressure and created centerline diagrams of the cross-sectional area, flow and mean relative blood pressure. Additionally, characteristic values were computed from the centerline diagrams for every subject. In the vast majority of the visualization and quantification techniques of our software framework, we observed significant effects of the treated aortic coarctations. Therefore, we draw the conclusion that this kind of MRI-based hemodynamic analysis can be a valuable tool for diagnostics and therapy control of aortic coarctations.