[Doppler tissue imaging: current status and future prospects].

Abstract

Colour Doppler myocardial imaging is a new technique which allows the visualization in the colour Doppler of myocardial tissues, instead of blood pool imaging. To permit the acquisition of this information some modifications are essential in the machine. The gain has to be reduced so that, firstly, the echoes from ventricular walls were similar to those from the blood pool. Secondly the Doppler velocity range has to be reduced to correspond to the normal velocity of the ventricular wall. These modifications allow the tissue echoes to pass the clutter filter and to be displayed in colour on the video screen. This technique may be able to evaluate the velocity of myocardial tissue, the acceleration and the strength within the myocardial wall with these maps, obtained by modifications in the software, called Velocity Map, Acceleration Map, Energy Map. The clinical applications of this technique are: 1) in the area of myocardial functions e.g.: measurements, volumes, diastolic functions; 2) in the area of myocardial ischemia e.g.: wall motion abnormalities, viability studies, perfusion with contrast agents, stress echo, infarct identification; 3) in the area of myocardial depolarisation e.g.: arrhythmias evaluation, ablation monitoring. Doppler tissue imaging in spite of good results obtained, needs a large clinical studies.