Flow, Motion and Parametric Imaging

The assessment of hemodynamic parameters of the cardiovascular system is of critical importance in the diagnosis and risk stratification of cardiac patients. MR imaging offers a range of methods to quantitatively map blood flow parameters and patterns throughout the circulatory system. Our work concerns the development and implementation of methods to probe flow properties, flow energetics and parameters of fluid-structure interactions. We employ multi-dimensional encoding strategies along with advanced image reconstruction approaches to permit data acquisition within clinically acceptable scan times.

Tissue perfusion is a critical parameter in the assessment of ischemic heart disease. MR contrast-enhanced perfusion imaging has been demonstrated to be highly diagnostic. To address the limited spatial resolution and coverage of conventional MR imaging techniques, we design and implement highly undersampled 3D imaging approaches allowing to dynamically map quantitative perfusion information of the entire heart. In close collaboration with clinical partners, these methods are applied on cardiac patients and their diagnostic and prognostic performance is validated relative to current reference methods.

Alterations of contraction and relaxation patterns of the heart are early and sensitive hallmarks of cardiac dysfunction. Using motion encoding principles based on MR tissue tagging, displacement encoding and tissue phase mapping in conjunction with reduced data acquisition concepts, we develop and apply methods to quantitatively assess motion patterns, tissue shear and strain rates. These data not only serve diagnostic purposes but also provide input and boundary conditions for advanced image-based biomechanical modeling to rationalize findings and predict changes of cardiac anatomy and function under various conditions.