Imaging three-dimensional cardiac function

The three-dimensional (3-D) nature of myocardial deformations is dependent on ventricular geometry, muscle fiber architecture, wall stresses, and myoc ardial-material properties. The imaging modalities of X-ray angiography, ec hocardiography, computed tomography, and magnetic resonance (MR) imaging (M RI) are described in the context of visualizing and quantifying cardiac mec hanical function. The quantification of ventricular anatomy and cavity volu mes is then reviewed, and surface reconstructions in three dimensions are d emonstrated. The imaging of myocardial wall motion is discussed, with an em phasis on current MRT and tissue Doppler imaging techniques and their poten tial clinical applications. Calculation of 3-D regional strains from motion maps is reviewed and illustrated with clinical MRI tagging results. We con clude by presenting a promising technique to assess myocardial-fiber archit ecture, and we outline its potential applications, in conjunction with quan tification of anatomy and regional strains, for the determination of myocar dial stress and work distributions. The quantification of multiple componen ts of 3-D cardiac function has potential for both fundamental-science and c linical applications.