Fig 4. A, Graphs show correlations between sonographic and MR phase-contrast volume measurement values for vertebral arteries. Most of volume measurements are near the line of equality indicating that BFI provides similar blood volume estimates with MR phase-contrast quantification.

B, Correlation between measurements of vertebral arteries obtained with CDI versus MR phase-contrast imaging is shown as scatter plot.

C, Correlation between flow volume measurements of vertebral arteries obtained with PDI versus MR phase-contrast imaging is shown as scatter plot.