The ct struct

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:

ct.cube

The cube is a N_x × N_y × N_z -matrix (N_x,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.

ct.resolution

The resolution specifies the size of each voxel in x-, y-, and z-direction in [mm].

ct.cubeDim

Number of voxels in x-, y- and z-direction (N_x, N_y and N_z).

ct.numOfCtScen

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.