The Patient Fiducials are spatial references of the patient body, used by the operator to measure distances from the Equipment Landmark to these references, thus allowing to locate the patient body in the Table Reference System. They are typically traverse planes through an anatomical reference point on the patient.

This is expressed in the RDSR TID 10002 by encoding the anatomical feature in (128772, DCM, "Reference Basis") and the nature of the plane in (128773, DCM, "Reference Geometry").

For a given Scope of Accumulation, multiple patient fiducials may be recorded, e.g., plane through the top of the head, and plane through the bottom of the feet.