Radiopaedia (AP view)
Radiopaedia (PA view)
Observation of skull fractures, dislocations, tumorous lesions, and Paget’s disease. AP imaging is useful for patients who cannot be imaged in the PA direction.
Considering the increased radiation exposure to the lens, we are considering imaging in the PA direction instead of the AP direction. Confirm the purpose of the examination. Remove any obstacles (hairpins, eyeglasses, earrings, necklaces, dentures, etc.).
Prone position (PA) or supine position (AP) (standing or sitting is also acceptable).
Align the mid-sagittal plane with the long axis of the film.
From the head side, ensure that the distance between both external auditory canals and the film is equal.
Place a marker (R or L) without fail.
Retract the chin and make the OML (Orbitomeatal Line) perpendicular to the film.
→ Prolonged chin retraction can cause discomfort for the patient, so adjust the angle at the end. Alternatively, use a positioning block to elevate the head end by placing it under the pillow.
CR, distance, field size
CR : Direct the X-ray beam perpendicular to the intersection of the mid-sagittal plane and the OML (Orbitomeatal Line). If chin retraction is difficult, angle the beam according to the angle of the OML.
Distance : 100cm
Field size : Include the entire head, including the soft tissues.
75kV / 16mAs
grid ( + )
Is the suture line projected symmetrically on both sides?
Is the distance from the orbital rim to the outer edge of the skull equal and depicted symmetrically?
Both the outer and inner plates should be observable.
The conical process should be projected in the upper 1/3 of the orbit.
Ensure that the following anatomical structures are observed under appropriate imaging conditions (frontal bone, crista galli, internal auditory canal, frontal sinus, ethmoid sinuses, conical process, and sella turcica).
If imaged in the AP direction, structures such as the orbit will be magnified in projection.
AP view 2:39~
PA view 4:40~