The ct struct - e0404/matRad GitHub Wiki
The ct structure contains, among others, the 3D-CT-cube (cube), obtained from the planning-CT, and the voxel resolution (resolution).
Screenshot of the ct-struct:
The cube is a Nx × Ny × Nz -matrix (Nx,y,z = number of voxels in x-, y- and z-direction) containing the water equivalent thickness of each voxel. We already translate HU to water equivalent electron density according to a look up table upon patient data import. The cube(s) is/are stored within a cell array to support multiple CT phases for 4D data.
The resolution specifies the size of each voxel in x-, y-, and z-direction in [mm].
Number of voxels in x-, y- and z-direction (Nx, Ny and Nz).
The number of considered CT scenarios. Usually, this corresponds to one but in a special research mode, it is also possible to handle multiple CTs.