| A | B |
|---|
| What is the PA skull (Caldwell) projection primarily used to evaluate? | Frontal bone, frontal sinuses, and superior orbital margins. |
| What CR angle is used for the Caldwell (PA axial) skull projection? | 15° caudad, exiting at the nasion. |
| What structures are best seen in the AP axial (Towne) projection? | Occipital bone, dorsum sellae, and foramen magnum. |
| What is the CR angle for the Towne projection? | 30° caudad to OML (or 37° caudad to IOML), entering 2.5 inches above glabella. |
| What anatomy is demonstrated in the lateral skull projection? | Entire cranium, sella turcica, clivus, and cranial walls superimposed. |
| For the lateral skull projection, where is the CR centered? | 2 inches superior to the EAM. |
| What is the main purpose of the SMV (Schüller) projection of the skull? | To visualize the base of the skull, sphenoid sinus, and foramen ovale/spinosum |
| For the SMV projection, how is the CR directed? | Perpendicular to IOML, entering midway between gonions. |
| Which skull projection is best for demonstrating the facial bones and orbits? | Waters (Parietoacanthial) projection. |
| What is the CR exit point for the Waters projection? | Acanthion |
| What baseline is used for the Caldwell projection? | OML (orbitomeatal line) perpendicular to the IR |
| In the Towne projection, what error occurs if the dorsum sellae is seen superior to the foramen magnum? | CR underangulation or OML not perpendicular. |
| What error occurs in the Towne projection if the dorsum sellae is projected into the foramen magnum? | CR overangulation. |
| For the lateral skull projection, what line is placed perpendicular to the IR? | Interpupillary line (IPL). |
| In the SMV projection, what baseline should be parallel to the IR? | IOML (infraorbitomeatal line). |
| What positioning line is used for the Waters projection? | MML (mentomeatal line) perpendicular to IR. |
| What is demonstrated in the reverse Waters projection? | Facial bones and orbits in trauma patients who cannot be placed prone. |
| What projection best demonstrates the zygomatic arches? | SMV for zygomatic arches. |
| In the PA skull projection (no angle), where should the petrous ridges be projected? | Fill the orbits |
| In the Caldwell skull projection (15° caudad), where should the petrous ridges be located? | In the lower third of the orbits. |
