The central ray is perpendicular to which line?

The central ray is perpendicular to which line?

• A. Infraorbital meatal line
• B. IOML
• C. Interorbital line
• D. Interpupillary line

Answer: (B)

The central ray is perpendicular to the infraorbital meatal line. This line runs from the infraorbital margin to the external auditory meatus and serves as a stable reference for positioning the beam. Directing the ray at a right angle to this line helps ensure a true, undistorted projection by aligning the beam with the skull’s base and sagittal plane, reducing tilt and shadowing of structures such as the orbital rims and temporal bones. Other lines exist as references for different views, but for this orientation the perpendicular relationship to the infraorbital meatal line provides the correct alignment.

The central ray is perpendicular to the infraorbital meatal line. This line runs from the infraorbital margin to the external auditory meatus and serves as a stable reference for positioning the beam. Directing the ray at a right angle to this line helps ensure a true, undistorted projection by aligning the beam with the skull’s base and sagittal plane, reducing tilt and shadowing of structures such as the orbital rims and temporal bones. Other lines exist as references for different views, but for this orientation the perpendicular relationship to the infraorbital meatal line provides the correct alignment.