fig6

Figure 6. The composite figure shows three two-dimensional echo and color Doppler video frames to illustrate color Doppler imaging. (A) The antegrade blood flow from the right ventricle (RV) into the main pulmonary artery (MPA) is marked by blue flow (as per the inset on the right). (B) The blood flow from the right atrium (RA) to the RV is marked by red. Both these examples show the usual direction of blood flow in the heart chambers. (C) The blood flow direction is reversed secondary to tricuspid insufficiency (inset to the right). Hence, the coding by the color of the Doppler signal assists the sonographer in recognizing the direction of blood flow. It may be noted that the color flow is laminar (uniform) in frames A and B suggesting lack of any flow disturbance while some degree of turbulence is seen in frame C. Reproduced from Ref.^[19].