DICOM PS3.17 2025b - Explanatory Information

Z.2 Positioner Coordinate System Transformations

Any point of the Positioner coordinate system (PXp, PYp, PZp) can be expressed in the Isocenter coordinate system (PX, PY, PZ) by applying the following transformation:

Equation Z.2-1. 

(PX, PY, PZ)T = (R2 .R1)T .(R3 T .(PXp, PYp, PZp)T)

And inversely, any point of the Isocenter coordinate system (P X , P Y , P Z ) can be expressed in the Positioner coordinate system (P Xp , P Yp , P Zp ) by applying the following transformation:

Equation Z.2-2. 

(PXp, PYp, PZp)T= R3 .((R2 .R1).(PX, PY, PZ)T)

Where R1, R2 and R3 are defined as follows:

Equation Z.2-3. 


Equation Z.2-4. 


Equation Z.2-5. 


DICOM PS3.17 2025b - Explanatory Information