faisceau Doppler

CONT: Les systèmes Doppler actuels sont toujours couplés; une même sonde sert à l’imagerie et à l’émission du faisceau Doppler. L’image Doppler couleur se superpose en temps réel sur la coupe échographique.

CONT: When the Doppler beam is pointing towards the direction of blood flow a positive Doppler shifted signal is observed, but once the Doppler beam is pointed away from the direction of blood flow a negative Doppler shifted signal is seen. The smaller the angle between the Doppler beam and blood vessel, the larger the Doppler shifted signal. Very small signals are produced as the Doppler beam angle approaches a 90° angle.