The Caldwell (occipitofrontal) PNS view: patient upright facing the image receptor with forehead and nose touching so the orbitomeatal line (OML) is perpendicular to the receptor. The central X‑ray beam is angled 15° caudad to the OML, directed to the nasion. This projects the frontal and ethmoid sinuses and places the petrous ridges in the lower third of the orbits.

The Caldwell view is a PA axial skull radiograph (patient faces the film) with the central ray angled about 15° caudad; it best demonstrates the frontal and ethmoid sinuses and superior orbital rims. The Waters view (occipitomental) uses neck extension with the OML angled ≈37° to the film and projects the CR through the acanthion, optimally showing maxillary sinuses and the orbital floor.

The Caldwell view is a PA axial skull radiograph taken with the central X-ray beam angled caudally (about 15°). It projects the frontal and anterior ethmoid sinuses, orbital rims and nasal bones with petrous ridges positioned low in the orbits. It’s commonly used to assess frontal and ethmoid sinus disease, orbital or facial fractures, and anterior skull base pathology.

A PA (posteroanterior) view directs the X-ray from back to front with the patient’s anterior surface against the image receptor, producing a true frontal projection. The Caldwell view is a PA axial projection for skull/paranasal sinus imaging: the forehead and nose touch the receptor while the beam is angled about 15° caudally to depress the petrous ridges into the lower orbits and better show frontal/ethmoid regions.

Position the patient PA with forehead and nose against the image receptor so the orbitomeatal line (OML) is perpendicular. Center the central ray at the nasion and angle it 15° caudally. Ensure no head rotation, immobilize, instruct the patient to suspend respiration, and use appropriate shielding. This projects the petrous ridges into the lower third of the orbits for frontal sinus/skull assessment.

PNS (paranasal sinuses) on an X-ray denotes radiographic imaging of the air-filled sinuses around the nose (maxillary, frontal, ethmoid, sphenoid). PNS X-rays help detect sinusitis (fluid levels, mucosal thickening), bone fractures, or foreign bodies. Common views include Waters, Caldwell and lateral. CT is more sensitive and often preferred for complex disease or facial trauma.