rtregistrationcalc

Calculates the 6DOF in IEC 61217 based on SRO, RTSS from in room imaging, and Plan

Requires Poetry 2.1+

Invocation

Command Line:

python compute_6dof_from_reg_rtss_plan.py <sro_filename> <rtss_filename> <rtionplan_filename>

GUI:

python gui.py

The algorithm for the Table Top Corrections calculation (for MOSAIQ) appears to be:

Apply the inverse rotation of the registration matrix to the difference of the planned isocenter (in reference CT coordinates) and the translation specified in the 4x4 registration matrix. Subtract that from the SetupIsocenter Convert from DICOM Patient coordinates to IEC 61217 Table Top Coordinates:

Code from compute_6dof_from_reg_rtss_plan.py:

rotation_inverse = rotation_matrix.transpose()  # nice feature of rotation matrices
reg_translation = four_by_four_matrix[0:3, 3]
delta_plan = plan_iso_dicom_patient - reg_translation
translate_dicom_patient = setup_iso_dicom_patient - rotation_inverse.dot(delta_plan)
translate_iec = convert_dicom_patient_to_iec(translate_dicom_patient, patient_position)

The order of decomposition is driven by the following code from the rotation_matrix_to_euler_angles() function:

_x = math.atan2(rotation_matrix[2, 1], rotation_matrix[2, 2])
_y = math.atan2(-rotation_matrix[2, 0], _sy)
_z = math.atan2(rotation_matrix[1, 0], rotation_matrix[0, 0])

To specify a different order of decomposition, one must generate the analytic representation (sin() and cos() for each rotation angle) and multiply in the desired order, then extract the original angles by determining which elements in combination represent the tangent of said Euler Angles.