Comparative imaging techniques and models.

Abstract

In vitro modeling remains an effective method of assessing the effect of hemodynamic variables and instrumentation settings on the display characteristics of imaging modalities. Most emphasis has been placed on the quantitative estimation of mitral regurgitation using the zone of flow convergence proximal to the regurgitant orifice on color Doppler flow mapping. Comparative studies of cardiac ultrasound imaging and flow-related magnetic resonance imaging have led to an improved understanding of the appearance of flow voids on cine magnetic resonance imaging and the shape of flow velocity fields on color Doppler flow mapping. We review recent advances in the above areas and introduce some of the more innovative recent research in the area of cardiac imaging. The results of evaluating imaging techniques using in vitro and animal models provide useful insights into the basic display characteristics of these often quite different modalities and supply a valuable basis for the interpretation of these images in the clinical setting. Comparative clinical observations of a variety of cardiac imaging techniques such as transesophageal and transthoracic echocardiography, magnetic resonance imaging, and computed tomography scanning can often highlight and explain differences in their individual characteristics and clinical utility.