Along with the use of erect positions, what other technical factor is important to demonstrate air/fluid levels in paranasal sinuses?

Question

Quizplus · Accepted Answer

A horizontal x-ray beam is important to demonstrate air/fluid levels in paranasal sinuses as it allows the air/fluid levels to separate and become visible on the radiograph. Vertically oriented x-ray beams can make it difficult to distinguish between air and fluid levels.

Along with the Use of Erect Positions, What Other Technical