Question 1

An acanthioparietal sinus projection (Waters method) can be distinguished from a parietoacanthial sinus projection because
1)it demonstrates the bony nasal septum in alignment with the collimated field's longitudinal axis.
2)it demonstrates greater orbital magnification.
3)it demonstrates less distance from the lateral orbital rims to the lateral cranial cortices.
4)the petrous ridges are demonstrated superior to the maxillary sinuses.

Accepted Answer

The acanthioparietal sinus projection (Waters method) demonstrates greater orbital magnification and less distance from the lateral orbital rims to the lateral cranial cortices compared to the parietoacanthial projection.

Question 2

A patient is unable to elevate the chin enough for a parietoacanthial facial bone projection (Waters method). How could the positioning setup be adjusted for an optimal projection to be obtained?

Accepted Answer

Aligning the central ray parallel with the mentomeatal line (MML) compensates for the inability to elevate the chin, allowing for an optimal Waters method projection.

Question 3

An optimal PA cranium projection demonstrates all of the following except

Accepted Answer

In an optimal PA cranium projection, the anterior clinoids and dorsum sellae should be seen superior to the ethmoid sinuses, not inferior.

Question 4

A patient is unable to hyperextend the neck enough for an SMV cranial projection (Schueller method). How should the positioning setup be adjusted for an optimal projection to be obtained?

Accepted Answer

Aligning the central ray perpendicular to the Infraorbitomeatal Line (IOML) is the correct adjustment when a patient cannot hyperextend the neck for an SMV projection. This alignment ensures that the central ray is parallel to the IOML, compensating for the lack of neck extension and allowing for an optimal projection.

Question 5

An SMV cranial projection (Schueller method) with accurate positioning demonstrates
1)the nasal fossae just anterior to the ethmoid sinuses.
2)the mandibular mentum slightly posterior to the ethmoid sinuses.
3)an equal distance from the mandibular ramus to the lateral cranial cortex on both sides.
4)the bony nasal septum aligned with the long axis of the exposure field.

Accepted Answer

The SMV cranial projection (Schueller method) is used to visualize the base of the skull and the facial bones. Accurate positioning in this projection demonstrates the following:

1) The nasal fossae just anterior to the ethmoid sinuses (to visualize the nasal bones and septum).
2) The mandibular mentum slightly posterior to the ethmoid sinuses (to visualize the lower jaw and the hyoid bone).
3) An equal distance from the mandibular ramus to the lateral cranial cortex on both sides (to ensure proper alignment and symmetry).
4) The bony nasal septum aligned with the long axis of the exposure field (to minimize distortion and ensure proper visualization of the nasal bones).

Therefore, choice C (1, 3 and 4 only) is the best answer as it correctly identifies the structures that can be visualized and their accurate positioning in the SMV cranial projection (Schueller method).

Question 6

Which of the following is true of an SMV cranial projection (Schueller method) obtained with the vertex of the patient's head tilted toward the right side?

Accepted Answer

The mandibular mentum will be turned toward the side opposite the vertex tilt.

Question 7

A parietoacanthial sinus projection (Waters method) with accurate positioning demonstrates
1)an equal distance from the lateral orbital margin to the lateral cranial cortex on both sides.
2)the bony nasal septum in alignment with the long axis of the exposure field.
3)the petrous ridges demonstrated inferior to the maxillary sinuses.
4)the ethmoid sinus through the mouth cavity in an open-mouth position.

Accepted Answer

The parietoacanthial sinus projection (Waters method) is designed to visualize the facial bones, particularly the orbits, maxillary sinuses, and nasal septum. Correct positioning results in equal distance from the lateral orbital margin to the lateral cranial cortex on both sides (1), the bony nasal septum aligned with the long axis of the exposure field (2), and the petrous ridges positioned below the maxillary sinuses (3). The ethmoid sinuses are not visualized through the mouth cavity in an open-mouth position in this projection; that description does not apply to the Waters method.

Question 8

A lateral cranial projection demonstrates the EAM and inferior cranial cortices without superimposition. One of each corresponding structure is demonstrated inferior to the other. How was the patient mispositioned for such a projection to be obtained?

Accepted Answer

The patient's head was tilted, which would cause one ear and the corresponding inferior cranial cortex to appear lower than the other on the image, leading to the described mispositioning.

Question 9

An AP axial cranium projection (Towne method) demonstrating the dorsum sellae superimposing the atlas's posterior arch

Accepted Answer

The central ray angle should be adjusted to form a 30-degree angle with the orbitomeatal line (OML) to correct the superimposition of the dorsum sellae on the atlas's posterior arch.

Question 10

A optimally positioned AP axial cranium projection (Towne method) demonstrates all of the following except

Accepted Answer

A optimally positioned AP axial cranium projection (Towne method) should demonstrate the inferior occipital bone at the center of the exposure field, symmetrical petrous ridges, and the dorsum sellae within the foramen magnum. The posterior clinoids are not typically visible on this projection.

Question 11

For a submentovertex (SMV) cranial projection (Schueller method), the
1)central ray is aligned perpendicular to the IR.
2)central ray is centered to the midsagittal plane at a level 0.75 inch (2 cm) anterior to the level of the EAM.
3)IOML is parallel with the IR.
4)midsagittal plane is perpendicular to the IR.

Accepted Answer

In a submentovertex (SMV) cranial projection (Schueller method), the central ray is indeed aligned perpendicular to the image receptor (IR) and centered to the midsagittal plane at a level 0.75 inch (2 cm) anterior to the level of the External Auditory Meatus (EAM). Additionally, the Infraorbitomeatal Line (IOML) is aligned parallel with the IR, and the midsagittal plane is perpendicular to the IR. These positioning criteria ensure proper visualization of the desired anatomical structures in the SMV projection.

Question 12

The distance from the posterior clinoid process to the lateral foramen magnum is less on the patient's left side than on the right side on an AP axial cranium projection (Towne method). To obtain an optimal projection,

Accepted Answer

By rotating the patient's face toward the right side until the midsagittal plane is perpendicular to the IR, it will place the left petrous ridge closer to the IR, which will increase the distance from the posterior clinoid process to the lateral foramen magnum on the left side, resulting in a more optimal projection.

Question 13

A poorly positioned parietoacanthial facial bone projection (Waters method) demonstrates the petrous ridges within the maxillary sinuses. How was the positioning setup mispositioned for such a projection to be obtained?
1)The MML was not aligned perpendicular to the IR.
2)The patient's head was rotated toward the left side.
3)The patient's chin was tucked more than needed.
4)The central ray was angled too cephalically.

Accepted Answer

1) If the MML is not aligned perpendicular to the IR, the resulting image will show elongation or foreshortening of the facial bones. This can cause the petrous ridges to be superimposed over the maxillary sinuses.
3) If the patient's chin is tucked more than needed, the angle between the MML and the IR will be decreased, resulting in a more horizontal beam angle. This can cause the petrous ridges to be superimposed over the maxillary sinuses.
4) If the central ray is angled too cephalically, the resulting image will show a greater degree of superimposition between the petrous ridges and the maxillary sinuses.

Question 14

A lateral cranial projection with poor positioning demonstrates the greater wings of the sphenoid and anterior cranial cortices without superimposition. One of each of the corresponding structures is demonstrated posterior to the other. How was the patient mispositioned for such a projection to be obtained?

Accepted Answer

A lateral cranial projection should demonstrate the greater wings of the sphenoid and anterior cranial cortices without superimposition in which the structures are positioned one anterior and one posterior to the other. If they are both visible without superimposition, it indicates that the patient's head was rotated.

Question 15

A poorly positioned SMV cranial projection (Schueller method) demonstrates the mandibular mentum too far anterior to the ethmoid sinuses. How was the positioning setup mispositioned for such a projection to be obtained?
1)The patient's neck was overextended.
2)The IOML was not aligned parallel with the IR.
3)The central ray was angled too caudally.
4)The patient's head was tilted toward the right side.

Accepted Answer

The mandibular mentum appearing too far anterior to the ethmoid sinuses in an SMV projection indicates that the patient's neck was overextended and the infraorbitomeatal line (IOML) was not aligned parallel with the image receptor (IR), leading to incorrect positioning.

Question 16

For a parietoacanthial sinus projection (Waters method), the
1)patient is positioned upright to demonstrate air-fluid levels within the maxillary sinuses.
2)MML is aligned perpendicular to the IR.
3)central ray is centered to the acanthion.
4)OML is at a 37-degree angle with the central ray.

Accepted Answer

All statements are correct for the Waters method: the patient is upright for air-fluid levels, MML is perpendicular to the IR, the central ray is centered to the acanthion, and OML is at a 37-degree angle with the central ray.

Question 17

An SMV cranial projection (Schueller method) with poor positioning demonstrates the mandibular mentum posterior to the ethmoid sinuses. How could the positioning setup be adjusted for an optimal projection to be obtained?
1)Tilt the patient's head toward the left side.
2)Angle the central ray cephalically.
3)Increase neck extension.
4)Align the IOML parallel with the IR.

Accepted Answer

Angling the central ray cephalically, increasing neck extension, and aligning the IOML parallel with the IR will all help to improve the positioning for an optimal SMV cranial projection.

Question 18

A PA cranium projection demonstrating the petrous ridges superior to the supraorbital margins

Accepted Answer

When the petrous ridges are seen superior to the supraorbital margins in a PA cranium projection, it indicates that the patient's chin was tucked more than necessary. The correct positioning would have the petrous ridges filling the orbits or just below the supraorbital margin, depending on the specific projection desired.

Question 19

An acanthioparietal facial bone projection (Waters method) with poor positioning demonstrates the petrous ridges too far inferior to the maxillary sinuses. How could the positioning setup be adjusted for an optimal projection to be obtained?
1)Depress the patient's chin.
2)Align the central ray parallel with the MML.
3)Align the MML perpendicular to the IR.
4)Adjust the central ray angulation caudally.

Accepted Answer

The answer of An acanthioparietal facial bone projection (Waters method)...

Question 20

A less than optimal PA axial cranium projection (Caldwell method) that requires the chin to be elevated to obtain optimal positioning will

Accepted Answer

DFor the Caldwell method, elevating the chin (thus not aligning the orbitomeatal line (OML) properly) will result in the petrous ridges being projected into the superior half of the orbits (C) instead of just below or clear of the inferior orbital margin. Additionally, the correct positioning requires the infraorbitomeatal line (IOML) to be perpendicular to the image receptor (IR) for an optimal PA axial cranium projection (D), not the OML as implied when the chin is elevated.

Quiz 11: Image Analysis of the Cranium

A patient is unable to elevate the chin enough for a parietoacanthial facial bone projection (Waters method) . How could the positioning setup be adjusted for an optimal projection to be obtained?