What is the recommended patient position for a SMV projection of the sinuses with a horizontal beam?

• A. Supine
• B. Standing or sitting
• C. Prone
• D. Recumbent

Answer: (B)

With a horizontal beam, the SMV projection of the sinuses is best done with the patient upright (standing or sitting) to allow full neck extension and proper alignment of the IOML with the image receptor. Having the head extended so the IOML is parallel to the IR enables the horizontal central ray to pass through the submental region perpendicularly, giving a clear view of the frontal and sphenoid sinuses without superimposition from the zygomatic arches or mandible. Lying down can limit how far the neck can extend, increase motion, and allow the tongue and mandible to intrude into the field, degrading image quality.