Rad positioning III chapter 11 part 2 projection exam

16. Which cranial bone is best demonstrated with an AP axial (Towne method) projection of the skull?

Occipital

17. When using a 30-degree caudad angle for the AP axial (Towne method) projection of the skull, which positioning line should be perpendicular to the image receptor?

A. OML

B. IOML

C. GAL

D. AML

OML

18. A properly positioned AP axial (Towne method) projection should place the dorsum sellae into the middle aspect of the:

A. Orbits

B. Clivus

C. Foramen magnum

D. Anterior arch of C1

Foramen magnum

19. A lack of symmetry of the petrous ridges indicates which of the following problems with a radiograph of an AP axial projection?

A. Tilt

B. Central ray angle

C. Flexion or extension

D. Rotation

Rotation

20. If the patient cannot flex the head adequately for the AP axial (Towne method) projection, the technologist could place the __________________________ perpendicular to the image receptor and angle the central ray __________________________ degrees caudad.

IOML; 37

21. What evidence on an AP axial (Towne method) radiograph indicates whether the correct central ray angle and correct head flexion were used?

Dorsum sellae and posterior clinoids should be projected into the foramen magnum.

22. What central ray angle should be used for the PA axial (Haas method) projection for the cranium?

25 degrees cephalad

23. Where is the central ray centered for a lateral projection of the skull?

2 inches (5 cm) above the EAM

24. Which specific positioning error is present if the mandibular rami are not superimposed on a lateral skull radiograph?

A. Tilt

B. Rotation

C. Overflexion of head and neck

D. Incorrect central ray angle

Rotation

25. Where will the petrous ridges be projected with a 15-degree PA axial (Caldwell) projection of the cranium?

In the lower 1/3 of the orbits

26. Which specific positioning error is present if the petrous ridges are projected higher in the orbits than expected for a 15-degree PA axial projection?

Excessive flexion or insufficient central ray angle

27. Which projection of the cranium produces an image of the frontal bone with little or no distortion?

0 degrees posteroanterior (PA)

28. For a patient with possible trauma, what must be determined before performing the submentovertical (SMV) projection of the skull?

Rule out any possible cervical fractures or subluxation

29. What positioning error has been committed if the EAMs are not superimposed with one of them more superior than the other on a lateral projection of the cranium?

Tilt of the skull

30. Which skull positioning line is placed parallel to the plane of the IR for the SMV projection?

A. OML

B. IOML

C. AML

D. GML

IOML

31. Which of the following projections best demonstrates the sella turcica in profile?

A. AP axial

B. SMV

C. 15-degree PA axial

D. Lateral

Lateral

32. Which of the following projections best demonstrates the foramen rotundum?

A. SMV

B. 25 to 30-degree AP axial

C. 25 to 30-degree PA axial

D. Lateral

25 to 30-degree PA axial

33. Which of the following projections best demonstrates the clivus in profile?

A. AP axial

B. 15-degree PA

C. Lateral

D. SMV

Lateral

34. Where does the CR exit for a PA axial (Haas method) projection of the skull?

A. inches (4 cm) superior to the nasion

B. inch (2 cm) anterior to the EAM

C. inches (6.5 cm) above the glabella

D. Level of nasion

1 1/2 inches (4 cm) superior to the nasion

35. Which imaging modality is best to differentiate between an epidural and a subdural hemorrhage?

A. CT

B. MRI

C. Nuclear medicine

D. PET

CT

1. A radiograph of an AP axial (Towne method) projection of the cranium shows that the right petrous ridge is wider than the left side. Which specific positioning error is present on this radiograph?

Rotation of skull present; rotation of patient's face toward left

2. A radiograph of a 15-degree PA axial (Caldwell) projection of the cranium demonstrates that the petrous ridges are projected at the inferior orbital margin. Which positioning error(s) led to this radiographic outcome?

Excessive extension or excessive caudad central ray angle—projects the petrous ridges lower than expected (should be in the lower third of the orbit)

3. A radiograph of a 15-degree PA axial (Caldwell) projection demonstrates that the distance between the right midlateral orbital borders and lateral margin of the skull cortex is greater than the left side. Which positioning error led to this radiographic outcome?

Rotation of the patient's face (skull) to the left

4. A radiograph of an SMV projection of the skull shows that the mandibular condyles are within the petrous bone. Which specific positioning error led to this problem?

Insufficient extension of the skull, or central ray was not perpendicular to IOML

5. A radiograph of a lateral projection of the skull shows that the orbital plates are not superimposed. (One orbital plate is slightly superior to the other.) Which specific positioning error led to this radiographic outcome?

Skull tilt

6. A lateral skull radiograph demonstrates one mandibular ramus about 0.5 cm more anterior than the other. Which positioning error occurred?

Skull rotation

7. An AP axial (Towne method) radiograph for the cranium demonstrates the dorsum sellae projected above, or superior to, the foramen magnum. The foramen magnum is distorted. Which positioning error(s) occurred?

Central ray angled <37 degrees to the IOML, or <30 degrees to the OML (would be caused by 30-degree angle to IOML). This error can be addressed with more flexion of the neck as well.

8. Situation: A patient comes to the radiology department with a possible tumor of the pituitary gland. Which radiographic projection of the cranium best demonstrates any bony involvement of the sella turcica?

Collimated, lateral projection of the sella turcica

*9. Situation: A patient with a possible linear fracture of the right parietal bone enters the emergency room. Which single radiographic projection of the skull best demonstrates this fracture?

Right lateral projection of the skull

10. Situation: A patient comes to the radiology department for a skull series, but the patient cannot assume the correct position for either version of the AP axial (Towne method) projection because of a very short neck and severe spinal kyphosis. What can the technologist do to demonstrate the occipital bone?

Should perform the PA axial projection (Haas method)

*11. Situation: A patient with a possible basal skull fracture enters the emergency room. No CT scanner is available. Which specific position may provide radiographic evidence of this fracture?

Horizontal beam (dorsal decubitus) lateral position—will demonstrate a possible air-fluid level in the sphenoid sinus

12. Situation: A neonate has a clinical history of craniosynostosis. Because of the age of the patient, the physician does not order a radiographic procedure of the cranium. What other imaging modality can be performed to evaluate the patient for this condition?

Ultrasound (sonography)—a noninvasive means of evaluating the newborn's cranium

13. Situation: A patient with a clinical history of acoustic neuroma comes to the radiology department. Which imaging modality or modalities can be performed for this type of pathology?

Either MRI or CT can be performed

14. A radiograph of an AP axial (Towne method) projection for the cranium shows that the posterior arch of C1 is projected within the foramen magnum. The dorsum sellae is superimposed on the posterior arch as well. What is (are) the positioning error(s)?

Overangulation of the CR or excessive flexion of neck

15. A radiograph of an AP axial (Towne method) projection for the cranium shows that the mid- to lower mandible is cut off and not demonstrated. What should the technologist do?

No repeat exposure is required. Because of elongation of the facial mass with the AP axial projection for the skull, cutting off aspects of the mandible is acceptable

10. Where is the CR centered for a lateral position for the facial bones?

A. Outer canthus

B. Acanthion

C. Zygoma

D. Nasion

Zygoma

11. What is the proper method name for the parietoacanthial projection of the facial bones?

Waters method

12. Which facial bone structures are best seen with a parietoacanthial projection?

Orbits including infraorbital rims, bony nasal septum, maxillae, zygomatic bones, and arches

13. What CR angle must be used to project the petrous ridges just below the orbital floor with the PA axial (Caldwell method) projection?

A. None. CR is perpendicular.

B. 30 degrees

C. 20 degrees

D. 45 degrees

30 degrees

14. Which structures specifically are better visualized on the modified parietoacanthial (Waters) projection as compared with the basic Waters projection?

Orbital rims and orbital floors

15. Give two reasons why projections of the facial bones are performed PA rather than AP when possible.

A. Reduces OID of facial bones

B. Reduces exposure to anterior facial bones and neck structures such as thyroid glands

16. What are two differences between the lateral projection of the cranium and the lateral projection for the facial bones?

A. IR is placed in portrait orientation for facial bones but landscape for the cranium.

B. CR is centered to the zygoma for facial bones and 2 inches (5 cm) above the EAM for the cranium.

17. The parietoacanthial (Waters) projection for the facial bones has the __________________________ line perpendicular to the image receptor, which places the orbitomeatal line (OML) at a __________________________-degree angle to the tabletop and image receptor.

Mentomeatal; 37-degree

18. Where does the CR exit for a parietoacanthial (Waters) projection of the facial bones?

Acanthion

19. Where does the CR exit for a 15-degree PA axial (Caldwell) projection for the facial bones?

Nasion

20. The modified parietoacanthial (modified Waters) projection requires that the __________________________ line is perpendicular to the image receptor, which places the OML at a __________________________-degree angle to the tabletop and image receptor.

Lips-meatal; 55-degree

21. True/False: Lateral projections for nasal bones generally are taken bilaterally for comparison.

True

22. True/False: The oblique inferosuperior (tangential) tangential projection for a unilateral zygomatic arch requires that the skull be rotated and tilted 15 degrees away from the affected side.

False - toward the affected side

23. True/False: Both oblique inferosuperior (tangential) projections for the zygomatic arch are generally taken for comparison.

True

24. For a parietoacanthial (PA Waters) projection, the petrous ridges should be projected directly below the __________________________ and projected into the lower half of the maxillary sinuses or below the __________________________ for a modified Waters projection.

Maxillary sinuses; inferior orbital rims

25. For the superoinferior projection of the nasal bones, the image receptor is placed perpendicular to the __________________________ line. (Include the full term and abbreviation.)

Glabelloalveolar (GAL)

26. Which specific facial bone structures (other than the mandible) are best demonstrated with the submentovertical (SMV) projection if the correct exposure factors are used (soft tissue technique)?

Zygomatic arches

27. Where is the CR centered for an AP axial projection for the zygomatic arches?

1 inch (2.5 cm) superior to glabella to pass through midarches (at level of gonion)

28. List the proper method name and the common descriptive name for the parieto-orbital oblique projection for the optic foramen.

A. Rhese method

B. Three-point landing

29. The three aspects of the face that should be in contact with the head unit or tabletop when beginning positioning for the parieto-orbital oblique projection are the (A) ________________________, ________________________, and ________________________. The final angle between the midsagittal plane and the IR should be (B) ________________________, with the (C) ________________________ line perpendicular to the IR. This places the optic foramen in the (D) ________________________ quadrant of the orbit.

A. Cheek, nose, chin

B. 53 degrees

C. Acanthiomeatal

D. Lower outer

Best projection to demonstrate the Floor of orbits (blowout fractures)

Modified waters method

Best projection to demonstrate the optic foramen

Parieto-orbital oblique projection

Best projection to demonstrate the view of single zygomatic arch

Oblique inferosuperior projection

Best projection to demonstrate the profile image of nasal bones and septum

Lateral (nasal bones)

Best projection to demonstrate the bilateral zygomatic arches

Submentovertical (SMV) projection

Best projection to demonstrate the inferior orbital rim, maxillae, nasal septum, nasal spine, zygomatic bone, and arches

Parietoacanthial projection

1. True/False: The PA axial projection of the mandible produces an elongated view of the condyloid processes.

True

2. Which projection of the mandible projects the opposite half of the mandible away from the side of interest?

Axiolateral oblique

3. What must be done to prevent the ramus of the mandible from being superimposed over the cervical spine with an axiolateral oblique projection of the mandible?

Extend the chin

4. How much skull rotation (from the lateral skull position) toward the image receptor is required with an axiolateral oblique projection for demonstrating each of the following?

A. Body of the mandible: ________________________

B. Mentum region: ________________________

C. Ramus region: ________________________

D. General survey of the mandible: ________________________

E. What is the maximum CR angle needed for all of these projections?

A. 30 degrees

B. 45 degrees

C. 0 degrees, true lateral

D. 10 to 15 degrees

E. 25 degrees cephalad

5. What specific positioning error has been committed if both sides of the mandible are superimposed with an axiolateral oblique projection?

Insufficient cephalic CR angle or skull tilt

6. Where should the CR exit for a PA axial projection of the mandible?

Acanthion (at lips for PA projection)

7. Which cranial positioning line is placed perpendicular to the image receptor for a PA or PA axial projection of the mandible?

Orbitomeatal line (OML)

8. True/False: For a true PA projection of the mandibular body (if this is the area of interest), the AML should be perpendicular to the image receptor.

True

9. True/False: The CR should be angled 20 to 25 degrees caudad for the PA axial projection of the mandible.

False - cephalad

10. Which aspect of the mandible is best visualized with an AP axial projection?

Condyloid process

11. A. What CR angle is required for the AP axial projection of the mandible if the OML is placed perpendicular to the image receptor? B. If the infraorbitomeatal line (IOML) is perpendicular to IR, what CR angle is needed?

A. 35 degrees caudad

B. 42 degrees caudad

12. Where is the CR centered for an AP axial projection of the mandible?

Glabella

13. Which projection of the mandible demonstrates the entire mandible, including the coronoid and condyloid processes?

SMV projection

14. Which imaging system provides a single, frontal perspective of the entire mandible?

Orthopantomography (panoramic tomography)

15. What device provides inherent collimation during an orthopantomographic procedure?

Narrow, vertical slit diaphragm

16. Which cranial line is placed parallel to the floor for orthopantomography of the mandible?

Infraorbitomeatal line (IOML)

17. What type of image receptor must be used with analog orthopantomography?

Curved, nongrid cassette

18. True/False: The modified Law method provides a bilateral and functional study of the TMJ.

True

19. True/False: The mandibular condyles move anteriorly as the mouth is opened.

True

20. Which projection/method of the TMJ requires that the skull be kept in a true lateral position?

A. Modified Law

B. Schuller

C. Axiolateral oblique projection

D. Modified Towne

Schuller

21. The axiolateral (Schuller method) projection for the TMJ requires a CR angle of __________________________ degrees (caudad or cephalad).

25 to 30 degrees; caudad

22. The axiolateral oblique projection of the TMJ is commonly referred to as the (A) __________________________ method, which requires a (B) __________________________-degree head rotation from lateral and a (C) __________________________-degree caudad CR angle.

A. Modified Law

B. 15-degree

C. 15-degree

23. If the area of interest is the temporomandibular fossae, angle the CR __________________________ to the OML for the AP axial (modified Towne) projection to reduce superimposition of the TM fossae and mastoid portions of the temporal bone.

40 degrees caudad

24. Aligning the __________________________ plane perpendicular to the IR prevents rotation of either a PA or an AP axial mandible.

Midsagittal

1. What analog kV range should be used for sinus radiography? __________________________ Digital kV range? __________

70 to 85 kV (analog); 80 +/− 5 kV (digital systems)

2. To demonstrate any possible air or fluid levels within the sinuses, it is important to:

A. Perform positions erect when possible

B. Use horizontal x-ray beam

3. True/False: Ultrasound exams of the maxillary sinuses to rule out sinusitis are possible.

True

4. True/False: Magnetic resonance imaging is the preferred modality to study soft tissue changes and masses within the sinuses.

True

5. True/False: Secondary osteomyelitis is often caused by tumor invasion.

False

6. List the four most commonly performed routine projections for paranasal sinuses.

A. ___________

B. ___________

C. ___________

D. ___________

A. Lateral

B. PA Caldwell

C. Parietoacanthial (Waters method)

D. SMV

7. Which single projection for a paranasal sinus routine provides an image of all four sinus groups?

Lateral

8. If the patient cannot stand for the lateral projection of the paranasal sinuses, the projection should be taken with:

Horizontal x-ray beam

9. Which paranasal sinuses are best demonstrated with a PA (Caldwell) projection?

Frontal and anterior ethmoid

10. To avoid angling the CR for the erect PA (axial) Caldwell sinus projection, the head should be adjusted so that the OML is __________________________ degrees from horizontal.

15 degrees

11. A. Which group of paranasal sinuses is best demonstrated with a parietoacanthial (Waters) projection? ___________________________________________________

B. The OML forms a __________________________-degree angle with the image receptor with this projection.

A. Maxillary

B. 37-degree

12. Which positioning line is placed perpendicular to the image receptor for a parietoacanthial projection?

Mentomeatal line (MML)

13. Where are the petrous ridges located on a well-positioned parietoacanthial projection?

Just below the maxillary sinuses

14. Which paranasal sinuses are demonstrated with an SMV projection of the paranasal sinuses?

Sphenoid, ethmoid, and maxillary sinuses

15. Where should the CR exit for both the PA parietoacanthial (Waters) and the PA transoral (open-mouth Waters) projections?

Level of the acanthion