Beamforming grid

The beamforming grid defines the set of points from which the participants will have to reconstruct their envelope image (image before log compression). The dimensions of this grid are defined by the physical properties of the probe. The width is computed as

$$ \text{width} = \left(\text{number of elements}-1\right) \cdot \text{pitch} = 38.1 \text{ mm.} $$

We fix the maximum depth to 50 mm. The resolution of the grid is dimensioned according to the probe settings. The axial space between two consecutive nodes of the grid is set to λ/4 which corresponds to 0.074 mm with a total of 609 lines. In order to be sufficiently accurate during the evaluation procedures, the lateral scan is set to λ/3 (compared to the λ/2 value used in [1]) which corresponds to 0.098 mm with a total of 387 columns.

[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.