ANALYSIS OF VENTRICULAR WALL-MOTION USING COLOR-CODED TISSUE DOPPLER IMAGING-SYSTEM

We developed a new color Doppler system by which Doppler signals assoc iated with tissue motion can be determined, and called it the tissue D oppler 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. Un der these conditions, the lowest measurable velocity was improved to 2 mm/s. Wall motion toward the transducer was coded as red, and that aw ay from the transducer as blue. To examine the accuracy and validity o f the measured velocity of ventricular wall motion, we performed in vi tro and in vivo studies. The results demonstrate that the present TDI system accurately in real time, facilitating the visual assessment of abnormal ventricular wall motion.