Which projection will demonstrate the sphenoid sinus?

The lateral projection is the correct choice for demonstrating the sphenoid sinus. This view allows the radiographer to visualize the sphenoid sinus clearly because it projects the sinus into the path of the X-ray beam, showing its size and location in relation to other cranial structures.

In the lateral projection, the position of the patient allows for a side view of the skull, which provides an unobstructed view of the sphenoid sinus, located just posterior to the nasal cavity and inferior to the sella turcica. This view is essential for assessing the sinus for any pathology, such as infections or neoplasms.

Other projections, while useful for different diagnostic purposes, do not provide the same clarity for the sphenoid sinus. For example, the parietoacanthial projection primarily visualizes the maxillary sinuses and facial bones, while the AP axial (often referred to as the Towne view) focuses on the occipital area and may not adequately depict the sphenoid sinus. The submentovertex projection is important for viewing the basilar skull and the zygomatic arches but also does not specifically highlight the sphenoid sinus as effectively as the lateral view.