DICOM PS3.3 2021e - Information Object Definitions
A.34.17.4.4 Channel Source

Channel Source Sequence (003A,0208) in each Channel Definition Sequence Item DCID 3034 “Body Position Channels”.

The Channel Source Code for a channel encoding the patient's position as fixed values is (130410, DCM, "Patient position").

The Channel Source Code for a channel encoding the patient's rotation around the body's longitudinal axis (head-feet axis) is (130411, DCM, "Patient rotation longitudinal").

The Channel Source Code for a channel encoding the elevation of the patient against horizontal is (130412, DCM, "Patient elevation").

DICOM PS3.3 2021e - Information Object Definitions