The Scan class

The Scan class defines the area of interest where to perform the beamforming. It can be either of a regular grid shape (GridScan) or with polar coordinates (PolarScan). You also can create your own (such as an irregular grid, with a zoom or so in a given ROI), as long as it inherits the Scan parent class. If you do so, keep in mind that some methods would need a specific attention. For example, the compute_envelope method on beamformed RFs is using the axial resolution to compute the beamformed sampling frequency, or FDMAS requires to downsample / upsample the data by default. Those standard methods won’t work on irregular grid.

It expects in any case:

• on_gpu, is_3d: General parameters defining if the scan is within the GPU memory or not, and if the grid must be 2D or 3D

• pixels: contains the coordinates of each of the points of the scan, of shape (2, nb_lateral, nb_axial) for 2D

• bounds: set the minimum values for each dimension

• nb_x, nb_y, nb_z: set the resolution of the x, y and z axes, by convention respectively the lateral, elevational and axial dimensions

The pixels are the coordinates used for beamforming.