ARRT Head and Neck Procedures 2 — Questions and Answers
Question 1: Which projection of the skull best demonstrates the petrous ridges in the lower third of the orbits?
- PA Caldwell (15°) (Correct answer)
- AP axial Towne
- Submentovertex (SMV)
- Lateral skull
Correct answer: PA Caldwell (15°)
The PA Caldwell projection with 15° caudal angulation projects the petrous ridges into the lower third of the orbits.
Question 2: For a parietoacanthial (Waters) projection, the OML forms what angle with the image receptor?
- 37° (Correct answer)
- 45°
- 55°
- 25°
Correct answer: 37°
In the Waters projection, the OML is angled 37° from the plane of the image receptor to project the petrous ridges below the maxillary sinuses.
Question 3: The SMV (submentovertex) projection is primarily used to demonstrate which structures?
- Zygomatic arches and base of skull (Correct answer)
- Frontal sinuses and orbits
- Cervical vertebrae and trachea
- Mastoid air cells and petrous pyramids only
Correct answer: Zygomatic arches and base of skull
The SMV projection demonstrates the zygomatic arches, base of skull, sphenoid sinuses, and mandibular condyles.
Question 4: On a lateral cervical spine radiograph, which landmark is used to ensure the image includes C7?
- Visualization of the C7-T1 interspace (Correct answer)
- The hyoid bone at C3
- The epiglottis at C4
- The thyroid cartilage at C5
Correct answer: Visualization of the C7-T1 interspace
The C7-T1 interspace must be visualized on a lateral cervical spine image to ensure complete coverage of all cervical vertebrae.
Question 5: Which sinus is best demonstrated on the PA Caldwell projection?
- Frontal sinus (Correct answer)
- Maxillary sinus
- Sphenoid sinus
- Ethmoid sinus
Correct answer: Frontal sinus
The PA Caldwell projection with 15° caudal tilt best demonstrates the frontal sinuses and anterior ethmoid air cells.
Question 6: For an AP axial (Towne) projection of the skull, the central ray is directed at what angle caudally when using the OML?
- 30° (Correct answer)
- 15°
- 45°
- 25°
Correct answer: 30°
For the Towne projection using the OML, the central ray is angled 30° caudally to demonstrate the occipital bone and dorsum sellae.
Question 7: A radiograph of the nasal bones is taken in which standard projection?
- Lateral (Correct answer)
- PA axial
- AP axial
- Submentovertex
Correct answer: Lateral
Nasal bones are routinely imaged in the lateral projection to demonstrate fractures of the nasal bones in profile.
ARRT Head and Neck Procedures 2
Which projection of the skull best demonstrates the petrous ridges in the lower third of the orbits?