A PA skull projection shows the petrous pyramids filling the bony orbits. What positioning technique was likely used?

The correct answer indicates that the positioning technique involved utilizing the orbitomeatal line with the central ray perpendicular to the image receptor. This positioning is critical for obtaining a standard PA skull projection. When the orbitomeatal line is perpendicular to the image receptor, it ensures that the petrous pyramids are projected into the lower third of the orbits, leading to a clear and accurate representation of the skull.

In this technique, the patient's head is oriented correctly with the orbitomeatal line aligned and the central ray directed perpendicularly, which helps to minimize distortion and provide a true representation of the anatomy being examined.

When the petrous pyramids fill the bony orbits, it typically suggests a misalignment in the positioning technique, which can occur if the chin is not adequately tucked, or if there is an improper central ray angle. Therefore, the focus on correct alignment with the orbitomeatal line demonstrates the proper technique necessary for a PA skull projection in radiography.