Figure 3
From: Pulmonary artery stiffness assessed by velocity-encoding MRI: comparison of techniques
The Flow-Area method for measuring PWV. A succession of cross-sectional images showing the main pulmonary artery distending during early systole. The vessel cross-sectional area and flow are semi-automatically measured for each frame during early systole. The plotting shows the measured areas versus flow. A line is fitted to the data, where PWV is determined as the line slope (flow change over area change).