Which of the following angles are not considered part of beam geometry?

Which of the following angles are not considered part of beam geometry?

• A. x-ray tube angle
• B. object angle
• C. rotor angle
• D. image receptor (IR) angle

Answer: (C)

Beam geometry describes how the X‑ray beam is directed and projected from the source through the object to the image receptor. This involves the relative angles of the X‑ray tube, the object (or patient), and the image receptor. The tube angle changes the projection direction, the object angle tilts the anatomy so it’s aligned with the beam, and the image receptor angle adjusts how the detector sits in relation to the beam to control distortion and magnification. The rotor angle, however, is not part of this projection geometry. The rotor is a mechanism that spins the anode to distribute heat and prepare the focal spot for exposure; its orientation does not define how the beam travels through the patient or onto the receptor. So rotor angle does not belong to beam geometry.

Beam geometry describes how the X‑ray beam is directed and projected from the source through the object to the image receptor. This involves the relative angles of the X‑ray tube, the object (or patient), and the image receptor. The tube angle changes the projection direction, the object angle tilts the anatomy so it’s aligned with the beam, and the image receptor angle adjusts how the detector sits in relation to the beam to control distortion and magnification. The rotor angle, however, is not part of this projection geometry. The rotor is a mechanism that spins the anode to distribute heat and prepare the focal spot for exposure; its orientation does not define how the beam travels through the patient or onto the receptor. So rotor angle does not belong to beam geometry.