fig54

Figure 54. Echo-Doppler study in the parasternal short-axis projection illustrating how to measure the minimal ductal diameter. The color flow signal of the patent ductus arteriosus (PDA) as shown in (B) is removed and the 2-dimensional (2D) minimal diameter is measured in (A). Descending aorta (DAo), pulmonary artery (PA), and right ventricular outflow tract (RVOT) are labeled. Reproduced from Ref.^[36].