American Registry of Radiologic Technologists (ARRT) Practice Exam

Which view best captures the sphenoid sinus?

1. Waters view

2. Open mouth waters

3. Lateral sinus view

4. Caldwell view

The correct answer is: Open mouth waters

The open mouth Waters view is specifically designed to visualize the paranasal sinuses, including the sphenoid sinus, more effectively than other projections. When the mouth is opened in this view, the X-ray beam passes through the oral cavity, allowing for an unobstructed view of the sphenoid sinus located behind the nasal cavity. This projection helps minimize superimposition from the maxillary sinuses and other surrounding structures, enhancing the clarity of the sphenoid sinus visualization on the radiograph. In contrast, while the Waters view can show the maxillary sinuses well, it is not as effective in demonstrating the sphenoid sinuses due to the positions of other sinuses that can obscure it. The Caldwell view emphasizes frontal sinuses and can provide some information about the sphenoid sinus, but not as clearly as the open mouth Waters view. The lateral sinus view is primarily used to evaluate the relationships and dimensions of the sinuses but does not specifically target the sphenoid sinus as effectively as the open mouth Waters view does. Thus, the open mouth Waters view stands out as the best option for capturing the sphenoid sinus.