Three-dimensional cardiac magnetic resonance imaging

Evaluation of time-varying cardiac structure and function is challenging because of the three-dimensional (3-D) anatomy and time-varying (4-D) behavior of the heart. Historically, contrast angiography has served as the cornerstone of cardiac diagnosis because of its excellent spatial and temporal resolution. However, magnetic resonance (MR) imaging is now increasingly applied because of the wide variety of available MR imaging and data acquisition techniques, including spin-echo, gradient-echo, wall motion techniques, 1H 31P spectroscopy, and, most recently, echo-planar imaging. Planar 2-D MR imaging is used to characterize many aspects of cardiac structure and function, including anatomic relationships, valvular heart disease, ischemic heart disease, and congenital abnormalities, among others. The development of imaging display and data postprocessing analysis techniques have paralleled the growth of these image and data acquisition schemes and, increasingly, an emphasis has been placed on defining structure and function in 3-D, or even 4-D. Three-dimensional reconstructions of the heart have commonly relied on conventional planar MR image acquisition techniques; a 3-D volume of data is then created from stacked 2-D images. Surface reconstruction and graphical rendering techniques are used to generate representations of the heart that depict 3-D and 4-D cardiac structure and function. These techniques have been used both clinically and experimentally in a variety of settings, including ischemic heart disease, MR coronary angiography, and congenital heart disease.