What is the recommended positioning of the patient's head for a SMV projection of the sinuses, with a horizontal beam?

What is the recommended positioning of the patient's head for a SMV projection of the sinuses, with a horizontal beam?

• A. Hyperextended
• B. Hyperflexed
• C. Neutral
• D. Slightly rotated

Answer: (A)

Hyperextension is used because you want the infraorbitomeatal line (IOML) to be parallel to the imaging plane. When the neck is extended, the skull base sits correctly relative to the beam, allowing a true SMV projection of the sinuses with the central ray horizontal and perpendicular to the IOML. This brings the frontal, ethmoid, sphenoid, and maxillary sinuses into view from vertex to mandible without the petrous ridges obscuring them. If the head isn’t extended, the IOML isn’t aligned, leading to distortion or superimposition by the petrous pyramids or surrounding structures, and the sinuses won’t be demonstrated properly. A neutral or flexed position or any rotation would shift the anatomy and degrade the image, whereas hyperextension preserves the proper alignment for an optimal view.

Hyperextension is used because you want the infraorbitomeatal line (IOML) to be parallel to the imaging plane. When the neck is extended, the skull base sits correctly relative to the beam, allowing a true SMV projection of the sinuses with the central ray horizontal and perpendicular to the IOML. This brings the frontal, ethmoid, sphenoid, and maxillary sinuses into view from vertex to mandible without the petrous ridges obscuring them. If the head isn’t extended, the IOML isn’t aligned, leading to distortion or superimposition by the petrous pyramids or surrounding structures, and the sinuses won’t be demonstrated properly. A neutral or flexed position or any rotation would shift the anatomy and degrade the image, whereas hyperextension preserves the proper alignment for an optimal view.