Plane wave sequence

We selected a f-number of 1.75 as in [1]. The corresponding angle span $\left[−\alpha_{max}, \alpha_{max}\right]$ covered by the plane-wave sequence is then given as [2]

$$ \alpha_{max}\approx\frac{1}{2F}= \frac{1}{2\cdot 1.75} \approx 16°. $$

The maximum number of plane-waves in the sequence is computed as [2]

$$ N= \frac{L}{F \lambda} = \frac{38.1}{1.75\cdot0.296} \approx 74, $$

In order to have an odd number of plane waves, we decided to transmit 75 steered plane waves regularly spaced between $-\alpha_{max}$ and $\alpha_{max}$ for the acquisition of each phantom, which corresponds to an angle increment of 0.43°.

[1] G. Montaldo, M. Tanter, J. Bercoff, N. Benech, N. and M. Fink, Coherent plane-wave compounding for very high frame rate ultrasonography and transient elastography, IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 56(3):489-506, 2009.

[2] B. Denarie, T.A. Tangen, I.K. Ekroll, N. Rolim, H. Torp, T. Bjastad, and L. Lovstakken, Coherent Plane Wave Compounding for Very High Frame Rate Ultrasonography of Rapidly Moving Targets, IEEE Transactions on Medical Imaging, 32(7):1265-1276, 2013.