Echocardiographic functional images based on tissue velocity information

Abstract

Tissue velocity information (TVI) is acquired by sampling of tissue Doppler velocity values at discrete points. The information is stored in an interfoiled format with gray scale imaging during one or several cardiac cycle at a high temporal resolution, > 60 Hz, giving signals that tolerate mathematical processing as derivation, integration and Fourier analysis of velocity profiles without distortions. The software enables the possibility to analyze multiple velocity profiles from any localization within the acquired scanned sector. The myocardial tissue velocity direction and color-coded numerical value can be computed along any chosen curve form (C-line) and be presented as a spatial function of velocities against time (C-mode). The velocity curves can also be presented in several new functional modes as color-coded running cineloops: phase imaging, time delay imaging, amplitude imaging, acceleration imaging, instantaneous phase imaging, wrapped phase imaging. The software also allows color or C-mode presentation of tissue contraction and expansion. This facilitates the differentiation between active and passive myocardial tissue movements, thus improving the ability to differentiate between healthy and diseased myocardial tissue. This article presents several applications of the software in normals and in cardiac patients.