Question 1

Which sinuses are best demonstrated with a parietoacanthial projection?

Accepted Answer

The parietoacanthial projection, also known as the Waters view, is primarily used to best demonstrate the maxillary sinuses.

Question 2

Which sinus is projected through the oral cavity with a parietoacanthial transoral projection?

Accepted Answer

The sphenoid sinus is projected through the oral cavity with a parietoacanthial transoral projection. This projection allows for a direct view of the sphenoid sinus by aiming the X-ray beam through the open mouth, bypassing the dense bones of the skull that could obscure the sinus in other views.

Question 3

A radiograph of a parieto-orbital oblique projection for the optic foramen reveals that the optic foramen is projected into the maxillary sinus.Which of the following modifications is necessary to produce a more diagnostic image?

Accepted Answer

The answer of A radiograph of a parieto-orbital oblique projection...

Question 4

Which plane or perspective is most often produced for a CT scan of the sinuses?

Accepted Answer

The coronal plane is most often used for CT scans of the sinuses as it provides a clear view of the frontal, ethmoid, maxillary, and sphenoid sinuses in one view. This is the most commonly produced plane for imaging the sinuses. The sagittal and transverse planes may also be used but they are not as effective as the coronal plane for imaging of the sinuses. The axial oblique plane is not typically used for CT scans of the sinuses.

Question 5

What is the position of the skull for an axiolateral projection (Schuller method) of the TMJ?

Accepted Answer

The Schuller method requires the skull to be in a true lateral position for the axiolateral projection of the TMJ.

Question 6

A patient enters the ED with a possible nasal bone fracture.The physician is concerned about a possible bony nasal septum deviation and fractured nasal bones.Which of the following routines would best diagnose these injuries?

Accepted Answer

The parietoacanthial (Waters view) provides a good view of the nasal septum and the lateral nasal bone projection allows for assessment of the nasal bones. The superoinferior (axial) projection is useful for evaluating the nasal bone for fractures from a superior view, making this combination of projections most suitable for diagnosing nasal bone fractures and bony nasal septum deviation.

Question 7

Which sinuses are best demonstrated with the PA projection?

Accepted Answer

The PA (posteroanterior) projection best demonstrates the frontal and ethmoid sinuses, as it allows for a direct view of these structures without the overlying density of the skull obscuring them.

Question 8

The recommended digital systems kV range for the superoinferior tangential (axial) projection of the nasal bones is:

Accepted Answer

The recommended digital systems kV range for the superoinferior tangential (axial) projection of the nasal bones is 70 to 80. This range provides optimal image quality and contrast for this projection. Choice A and B are too low and may result in poor image quality, while choice D is too high and may result in excessive radiation exposure to the patient.

Question 9

A radiograph of an axiolateral oblique projection of the mandible reveals that the mandibular body is greatly foreshortened.Which of the following modifications is necessary to produce a more diagnostic image?

Accepted Answer

Increasing the rotation of the skull toward the image receptor will help elongate the mandibular body, reducing foreshortening and producing a more diagnostic image.

Question 10

A patient enters the ED with a possible fracture of the proximal ramus of the mandible.Which of the following routines would best diagnose this fracture?

Accepted Answer

The PA axial mandible projection, axiolateral projection with no skull rotation, and a 35° AP axial projection are best suited for diagnosing a fracture of the proximal ramus of the mandible, as they provide clear views of the ramus without distortion.

Question 11

A patient enters the ED with a possible fracture of the right zygomatic arch.Which of the following routines would best diagnose a possible fracture of this structure?

Accepted Answer

The answer of A patient enters the ED with a...

Question 12

A patient enters the ED with facial bone injuries.The physician is concerned about a possible blow-out fracture of the left orbit.Which one of the following projections would best diagnose this injury?

Accepted Answer

The modified parietoacanthial (modified Waters) projection is the best projection for diagnosing a blow-out fracture of the left orbit as it allows for visualization of the entire orbit, including the medial and lateral walls. The other projections listed may provide some information but are not as specific for this type of injury.

Question 13

Along with the use of erect positions, what other technical factor is important to demonstrate air/fluid levels in paranasal sinuses?

Accepted Answer

A horizontal x-ray beam is important to demonstrate air/fluid levels in paranasal sinuses as it allows the air/fluid levels to separate and become visible on the radiograph. Vertically oriented x-ray beams can make it difficult to distinguish between air and fluid levels.

Question 14

Where is the CR centered for a lateral projection of the sinuses?

Accepted Answer

For a lateral projection of the sinuses, the central ray (CR) is centered midway between the outer canthus and the external auditory meatus (EAM) to properly visualize the sinus structures.

Question 15

Where should the optic foramen be located with a well-positioned parieto-orbital oblique projection of the optic foramina?

Accepted Answer

The answer of Where should the optic foramen be located...

Question 16

A radiograph of a PA Caldwell (15° caudad) projection for cranium reveals that the petrous ridges are projected into the lower one-third of the orbits.Which of the following modifications should be made during the repeat exposure to produce a more diagnostic image?

Accepted Answer

The petrous ridges are correctly positioned in the lower one-third of the orbits for a PA Caldwell projection with a 15° caudad angle, so no modification is needed.

Question 17

How much skull rotation, from a lateral position, is recommended to best demonstrate the body of the mandible for an axiolateral/axiolateral oblique projection?

Accepted Answer

A 30° rotation toward the IR is recommended to best demonstrate the body of the mandible in an axiolateral/axiolateral oblique projection.

Question 18

A radiograph of a lateral projection of the facial bones reveals that the mandibular rami are not superimposed.What specific positioning error is present on this radiograph?

Accepted Answer

When the mandibular rami are not superimposed, it suggests a rotation error. This can occur when the patient's head is not aligned properly or if the head is turned to one side.

Question 19

A radiograph of a parietoacanthial (Waters method) projection reveals that the petrous ridges are superimposed over the lower 30% of the maxillary sinuses.What specific positioning error (if any) led to this radiographic finding?

Accepted Answer

Insufficient extension of the skull and neck causes the petrous ridges to project too low, overlapping the maxillary sinuses more than desired in a Waters projection.

Question 20

What CR angle is required for the axiolateral (Schuller method) projection of the TMJs?

Accepted Answer

For the axiolateral (Schuller method) projection of the TMJs, the CR should be angled 25° to 30° caudad from a perpendicular position to the film.

Quiz 11: Cranium, Facial Bones, and Paranasal Sinuses