Chapter 20 Positioning Flashcards


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1

Which of the following skull types is considered average in size and shape?

a. mesocephalic

b. brachycephalic

c. dolichocephalic

a. mesocephalic

2

Which skull type is narrow from side to side?

a. mesocephalic

b. dolichocephalic

c. brachycephalic

b. dolichocephalic

3

In a typically shaped head, the petrous pyramids project anteriorly and medially at what angle?

a. 37 degrees

b. 40 degrees

c. 47 degrees

d. 54 degrees

c. 47 degrees

4

Which plane of the head is placed parallel to the plane of the IR for a lateral projection of the skull?

a. sagittal

b. transverse

c. midsagittal

d. midcoronal

c. midsagittal

5

The central ray and center of the IR position for a lateral projection of the skull is:

a. 1 inch below the EAM

b. 2 inches below the EAM

c. 1 inch above the EAM

d. 2 inches above the EAM

d. 2 inches above the EAM

6

Which of the following is true regarding the lateral projection of the skull?

1.) the midsagittal plane of the head is parallel to the plane of the IR

2.) the interpupillary line is perpendicular to the IR

3.) the mentomeatal line is parallel with the bottom edge of the IR

a. 1 and 2

b. 1 and 3

c. 2 and 3

d. 1, 2, and 3

a. 1 and 2

7

Which of the following should be seen superimposed on a lateral projection of the skull?

1.) orbital roofs

2.) external acoustic meati

3.) temporomandibular joints

a. 1 and 2

b. 1 and 3

c. 2 and 3

d. 1, 2, and 3

d. 1, 2, and 3

8

Which method of examining the skull will demonstrate the petrous ridges in the orbits, the ethmoid and frontal sinuses, and the crista galli?

a. Towne

b. Caldwell

c. Schüller

d. Rhese

d. Caldwell

9

The central-ray angle for the PA axial (Caldwell) projection of the skull is:

a. 5 degrees cephalad

b. 10 degrees cephalad

c. 12 degrees caudad

d. 15 degrees caudad

d. 15 degrees caudad

10

Which of the following is perpendicular to the plane of the IR for a Caldwell projection of the skull?

a. glabellomeatal line

b. acanthiomeatal line

c. orbitomeatal line

d. mentomeatal line

c. orbitomeatal line

11

Often a patient cannot be turned into the prone position for a PA axial projection of the skull (Caldwell method). What central-ray angle could be used if the AP axial projection is used instead?

a. 10 degrees caudad

b. 15 degrees cephalad

c. 10 to 15 degrees caudad

d. 10 to 15 degrees cephalad

b. 15 degrees cephalad

12

Which of the following lines is placed perpendicular to the plane of the IR for the AP axial (Towne) projection?

a. orbitomeatal line

b. infraorbitomeatal line

c. glabellomeatal line

d. acanthiomeatal line

a. orbitomeatal line

13

If the patient cannot flex the neck to place the orbitomeatal line perpendicular to the IR for an AP axial (Towne) projection, which line should be placed perpendicular?

a. acanthiomeatal line

b. infraorbitomeatal line

c. glabellomeatal line

d. mentomeatal line

b. infraorbitomeatal line

14

Which of the following is true regarding the placement of the IR for an AP axial (Towne) projection of the skull?

1.) its upper margin is at the level of the top of the cranium

2.) its upper margin is 2 inches above the top of the cranium

3.) its upper margin is 2 inches below the top of the cranium

a. 1 only

b. 2 only

c. 3 only

d. 1, 2, and 3

a. 1 only

15

Which method of examining the skull is identified in the figure below?

a. Haas

b. Towne

c. Rhese

d. Caldwell

b. Towne

16

If the infraorbitomeatal line is placed perpendicular to the IR during an AP axial (Towne) projection of the skull, how much is the central ray angled?

a. 15 degrees caudad

b. 30 degrees caudad

c. 37 degrees caudad

d. 45 degrees caudad

c. 37 degrees caudad

17

Which of the following is clearly demonstrated within the foramen magnum during an AP axial (Towne) projection of the skull?

1.) dorsum sellae

2.) sella turcica

3.) posterior clinoid processes

a. 1 and 2

b. 1 and 3

c. 2 and 3

d. 1, 2, and 3

b. 1 and 3

18

What is the central-ray angulation for demonstration of the entire foramen magnum during an AP axial (Towne) projection?

a. 37 degrees caudad

b. 40 degrees caudad

c. 60 degrees caudad

d. 40 to 60 degrees caudad

d. 40 to 60 degrees caudad

19

Which of the following methods will clearly demonstrate the petrous ridges, foramen magnum, dorsum sellae, and posterior clinical processes?

1.) Haas (PA axial)

2.) Towne (AP axial)

3.) Schüller (SMV)

a. 1 and 2

b. 1 and 3

c. 2 and 3

d. 1, 2, and 3

a. 1 and 2

20

What is the average central-ray angulation for the PA axial (Haas) projection of the skull?

a. 25 degrees caudad

b. 25 degrees cephalad

c. 30 degrees caudad

d. 30 degrees cephalad

b. 25 degrees cephalad

21

Which line should be placed parallel to the plane of the IR for the SMV projection of the cranial base?

a. acanthiomeatal line

b. orbitomeatal line

c. infraorbitomeatal line

d. mentomeatal line

c. infraorbitomeatal line

22

Radiographic demonstration of the cranial base is performed by which method?

a. Haas

b. Rhese

c. Towne

d. Schüller

d. Schüller

23

What is the central-ray angulation for the SMV projection?

a. 0 degrees

b. 5 degrees caudad

c. 5 degrees cephalad

d. 5 to 7 degrees cephalad

a. 0 degrees

24

The x-ray projection demonstrated in the figure below is the:

a. SMV

b. VSM

c. AP axial

d. PA axial

b. VSM

25

For an SMV projection of the cranial base, the central ray should always be perpendicular to the:

a. mentomeatal line

b. orbitomeatal line

c. infraorbitomeatal line

d. acanthiomeatal line

c. infraorbitomeatal line

26

Which of the following are clearly demonstrated on an SMV projection of the cranial base?

1.) mastoid process

2.) sphenoid process

3.) carotid canals

a. 1 and 2

b. 1 and 3

c. 2 and 3

d. 1, 2, and 3

d. 1, 2, and 3

27

Which of the following methods will demonstrate the optic canal?

a. Rhese

b. Towne

c. Schüller

d. Caldwell

a. Rhese

28

Which line is placed perpendicular to the IR for the parietoorbital oblique (Rhese) projection of the optic canal?

a. mentomeatal line

b. acanthiomeatal line

c. orbitomeatal line

d. infraorbitomeatal line

b. acanthiomeatal line

29

How many degrees is the head rotated for the parietoorbital (Rhese) projection of the optic canal?

a. 30 degrees

b. 45 degrees

c. 53 degrees

d. 60 degrees

c. 53 degrees

30

The central-ray angulation for the parietoorbital (Rhese) projection of the optic canal is:

a. 0 degrees

b. 5 degrees

c. 10 degrees

d. 15 degrees

a. 0 degrees

31

Which of the following would be demonstrated in the projection shown in the figure below?

a. petrous ridge

b. sphenoid sinus

c. optic canal

d. zygomatic arch

c. optic canal

32

Which parts of the patient's face touch the table for a PA axial projection (Caldwell method)?

1.) forehead

2.) nose

3.) chin

a. 1 and 2

b. 1 and 3

c. 2 and 3

d. 1, 2, and 3

a.1 and 2

33

Which of the following are demonstrated on an AP axial (Towne method) projection of the skull?

1.) petrous pyramids

2.) occipital bone

3.) posterior portion of the foramen magnum

a. 1 and 2

b. 1 and 3

c. 2 and 3

d. 1, 2, and 3

d. 1, 2, and 3

34

For an optimal image of the mastoid process, which of the following must occur?

1.) use of a 0.6-mm focal spot or less

2.) use of a high-resolution screen/IR

3.) use of the smallest possible field size

a. 1 and 2

b. 1 and 3

c. 2 and 3

d. 1, 2, and 3

d. 1, 2, and 3

35

For an AP axial Towne Method projection, to what level of the patient should the upper boarder of the IR be aligned?

Highest point of the vertex (about 2.5 inches superior to the glabella)

36

What image characteristic indicates that a general survey image of the skull is an AP projection instead of a PA projection?

the orbits are considerably magnified

37

When performing either the AP or AP axial projection for general surveys of the skull, where on the skull should the central ray be directed?

the nasion

38

For the AP axial projection of the skull, how should the central ray be directed?

15 degrees cephalic

39

For the AP projection of the skull, how should the central ray be directed?

Perpendicularly

40

For AP and AP axial projections, how should the OML be positioned with reference to the plane of the IR?

Perpendicular

41

For AP and AP axial projections, how should the midsagittal plane be positioned with reference to the plane of the IR?

Perpendicular

42

For the PA projection with a perpendicular central ray, list 5 structures shown:

- the orbits filled by the margins of the petrous pyramids

- the posterior ethmoidal air cells

- crista galli

- frontal bone

- frontal sinuses

43

For PA and PA axial projections of the skull, which parts of the patient's facial area should be in contact with the table or vertical grid device?

Forehead and nose

44

For PA and PA axial projections of the skull, how should the OML be positioned with reference to the plane of the IR?

Perpendicular

45

For PA and PA axial projections of the skull, how should the midsagittal plane be positioned with reference to the plane of the IR?

Perpendicular

46

For a lateral projection of the skull, which positioning line of the head should be parallel with the plane of the IR?

the IOML

47

For a lateral skull projection, how should the interpupillary line be positioned with reference to the plane of the IR?

Perpendicular

48

For a lateral skull projection, how should the midsagittal plane be positioned with reference to the plane of the IR?

Parallel

49

List 5 common positioning errors of the skull:

- Rotation

- Tilt

- Excessive Flexion

- Excessive Extension

- Incorrect central ray

50

What is the most effective way to protect the patient from unnecessary radiation during an x-ray of the skull?

restricting the radiation beam by using proper collimation

51

The majority of repeat examinations is due to this:

uncomfortable body position resulting in rotation or other motion

52

In a dolichocephalic skull, the petrous pyramids lie at what angle with the midsagittal plane?

40 degrees

53

Whether the radiographer elects to perform the exam with the patient in the recumbent or upright position depends on these 4 variables:

- the equipment available

- the age & condition of the patient

- radiographer and or radiologist preference whether upright images would increase diagnostic value (ex: showing air-fluid levels in paranasal sinuses)

54

In a brachycephalic skull, the petrous pyramids lie at what angle with the midsagittal plane?

54 degrees

55

What is the exit point of the CR for the Caldwell Method?

the nasion at an angle of 15 degrees caudad

56

Where is the CR for the Towne Method?

2.5" above the glabella

57

What is the exit point of the CR for the Haas Method?

1.5" superior to the nasion

58

Where is the CR for the SMV method?

A point 3/4" anterior to the level of the EAM

59

Where is the CR for a lateral projection of the eye?

Perpendicular through the outer canthus

60

Where is the CR for a lateral skull?

Perpendicular entering 2" superior to the EAM

61

What is the CR for the lateral dorsal decubitus skull?

2" above EAM

62

What is the CR angulation for a lateral skull?

0 degrees

63

What is the CR angulation for a lateral dorsal decubitus skull?

0 degrees

64

What is the CR angulation for the Caldwell Method (Pa axial)?

15 degrees caudad

65

What is the CR angulation for an AP/AP axial projection of the skull?

0 or 15 degrees cephalad

66

What is the CR angulation for the Towne Method?

30 degrees caudad to the OML or 37 degrees to the IOML

67

What is the CR angulation for the Haas Method?

25 degrees cephalad

68

What is the CR angulation for the SMV?

0 degrees

69

What is seen on a lateral skull?

- Superimposed orbital roofs and greater wings of sphenoid
- Superimposed mastoid regions and EAM
- Sella turcica seen in profile
- Radiographic penetration of parietal region
- No overlap of cervical spine by mandible

70

What is seen on a lateral dorsal decubitus?

- Superimposed orbital roofs and greater wings of sphenoid
- Superimposed mastoid regions and EAM
- Sella turcica seen in profile
- Radiographic penetration of parietal region
- No overlap of cervical spine by mandible

71

What is seen on a Caldwell method (PA axial)?

- Entire cranial perimeter showing three distinct tables of squamous bone
- Equal distance from lateral border of skull to lateral border of orbit on both sides
- Symmetric petrous ridges
- Petrous pyramids lying in lower third of orbit with a caudal central ray angulation of 15 degrees and filling the orbits with a 0 degree CR angulation
- Penetration of frontal bone without excessive density at lateral borders of the skull

72

What is seen on an AP axial projection of the skull?

- Entire cranial perimeter showing three distinct tables of squamous bone
- Equal distance from lateral border of skull to lateral border of orbit on both sides
- Symmetric petrous ridges
- Petrous pyramids lying in lower third of orbit with a caudal central ray angulation of 15 degrees and filling the orbits with a 0 degree CR angulation
- Penetration of frontal bone without excessive density at lateral borders of the skull

73

What is seen on a Towne method(AP axial)?

- Equal distance from lateral border of skull to lateral margin of foramen magnum on both sides, indicating no rotation
- Symmetric petrous pyramids
- Dorsum sellae and posterior clinoid processes visible within foramen magnum
- Penetration of occipital bone without excessive density at lateral borders of skull

74

What is seen on a Haas method (PA axial)?

- Projection of dorsum sellae and posterior clinoid processes within foramen magnum
- Equal distance from lateral border of skull to lateral margin of foramen magnum on both sides, indicating no rotation
- Symmetric petrous pyramids
- Entire cranium

75

What is seen on an SMV(Schuller Method)?

- Clearly visible structures of the cranial base, indicated by adequate penetration
- Equal distance from lateral border of skull to mandibular condyles on both sides, indicating no tilt
- Superimposition of mental protuberance over anterior frontal bone, indicating full extension of the neck
- Mandibular condyles anterior to petrous pyramids
- Symmetric petrosae