Coordinate system - cerr/CERR GitHub Wiki

Non-oblique scans

CERR’s coordinate system is based on the RTOG specifications. The physical units are cm. The RTOG specification states that the +x is towards the right of the gantry when viewed from the couch. This results in the following for various patient positions:

• Head First Supine (HFS): patient’s right is displayed on the left side of the viewer.
• Head First Prone (HFP): patient’s right is displayed on the right side of the viewer.
• Feat First Supine (FFS): patient’s right is displayed on the right side of the viewer.
• Feat First Prone (FFP): patient’s right is displayed on the left side of the viewer.

Oblique scans

The coordinate system is aligned with the image. The structure and dose distributions are mapped to the image coordinates.