What anatomical structure should be included in the collimation for APOM imaging?

In an Anterior-Posterior Open Mouth (APOM) imaging procedure, the appropriate anatomical structures that should be included in the collimation are critical for ensuring that the area of interest—primarily the cervical spine and specifically the first and second cervical vertebrae (the atlas and axis)—is well visualized. The mastoid process, which is situated just behind the ear and serves as an important landmark for proper anatomical orientation, should indeed be included in the collimation.

Incorporating the mastoid process ensures that the resulting image captures the necessary anatomical relationships and allows for an accurate diagnosis. Proper collimation helps in minimizing patient exposure to radiation while also enhancing the image quality by reducing scatter.

The other options, while they may be significant anatomical structures, do not directly pertain to the requirements of the APOM view. For example, the orbit of the eye is not a focus area in this imaging technique, nor is the chin a crucial landmark for this specific view. The shoulder blade, being part of the thoracic structure, is also outside the primary focus of the cervical spine examination in an APOM view. Therefore, including the mastoid process is essential for achieving a comprehensive and diagnostic image in this particular X-ray procedure