Analysis of Ventricular Wall Motion Using Color-Coded Tissue Doppler Imaging System

We developed a new color Doppler system by which Doppler signals associated with tissue motion can be determined, and called it the tissue Doppler imaging (TDI) system. Using high-speed scanning, the frame rate was 26–38 F/s, and the pulse repetition frequency was 4.5–6.0 kHz. Under these conditions, the lowest measurable velocity was improved to 2 mm/s. Wall motion toward the transducer was coded as red, and that away from the transducer, as blue. To examine the accuracy and validity of the measured velocity of ventricular wall motion, we performed in vitro and in vivo studies. The results demonstrate that the present TDI system accurately represents the tissue velocity, and is applicable for creating two-dimensional images of the ventricular wall motion in real time, facilitating the visual assessment of abnormal ventricular wall motion.