About the velocity flow, 7 - 33 cm / sec is low velocity, (average 16 cm / s) is moderate velocity and the RI (resistive index) is low: 0.
Vận tốc thấp 7-33 c m/s, trung bình 16 c m/s, vận tốc tâm trương cao do dãn mạch nên RI thấp 0.