Skull positioning

Question 1

Fronto-occipital central ray

Answer 1

Perpendicular to IR / 15-20° caudal

Question 2

Fronto-occipital baseline

Answer 2

Raised 15-20° to IR

Question 3

Fronto-occipital center point

Answer 3

Midline/MSP, nasion

Question 4

Fronto-occipital collimation

Answer 4

To include the entire cranial vault (anterior)

Question 5

Fronto-occipital evaluation criteria

Answer 5

Symmetry, lateral orbital margins equidistant, petrous pyramids in lower 1/3 of orbits

Question 6

Townes central ray

Answer 6

30° caudal

Question 7

Townes baseline

Answer 7

Perpendicular to IR

Question 8

Townes center point

Answer 8

MSP, 5 cm above nasion

Question 9

Townes collimation

Answer 9

To include the entire cranial vault (posterior)

Question 10

Townes evaluation criteria

Answer 10

Symmetry, dorsum sellae & medial foramen magnum equidistant, dorsum sellae projected through foramen magnum

Question 11

Lateral skull central ray

Answer 11

Perpendicular to IR

Question 12

Lateral skull center point

Answer 12

5 cm above EAM

Question 13

Lateral skull collimation

Answer 13

To include the entire cranial vault

Question 14

Lateral skull evaluation criteria

Answer 14

Superimposition of mandibular rami, TM joints, mastoid processes, orbital roofs

Question 15

Occipitomental central ray

Answer 15

Perpendicular to IR

Question 16

Occipitomental baseline

Answer 16

45-55° to IR

Question 17

Occipitomental center point

Answer 17

MSP, acanthion/root of nose

Question 18

Occipitomental collimation

Answer 18

Supra-orbital margins, zygomatic arches laterally

Question 19

Occipitomental evaluation criteria

Answer 19

Symmetry, petrous border below maxillary sinuses

Question 20

30° Occipitomental central ray

Answer 20

30° caudal

Question 21

30° Occipitomental baseline

Answer 21

45-55° to IR

Question 22

30° Occipitomental center point

Answer 22

MSP, base of the point of the chin

Question 23

30° Occipitomental collimation

Answer 23

All facial bones included

Question 24

30° Occipitomental evaluation criteria

Answer 24

Symmetry, orbital floor visible through maxillary sinuses

Question 25

Lateral facial bones central ray

Answer 25

Perpendicular to IR

Question 26

Lateral facial bones center point

Answer 26

Midway along radiographic baseline (Between outer canthus & EAM)

Question 27

Lateral facial bones collimation

Answer 27

All facial bones included (superimposed)

Question 28

Lateral facial bones evaluation criteria

Answer 28

Superimposition of mandibular rami, TM joints, orbital roofs, anterior cranial floor

Question 29

Occipito-frontal central ray

Answer 29

Perpendicular to IR

Question 30

Occipito-frontal baseline

Answer 30

25-30° to IR

Question 31

Occipito-frontal center point

Answer 31

MSP, level of mid-orbit

Question 32

Occipito-frontal collimation

Answer 32

All orbits & surrounding facial bones

Question 33

Occipito-frontal evaluation criteria

Answer 33

Symmetry, petrous ridge below inferior orbital margin

Question 34

Lateral orbit central ray

Answer 34

Perpendicular to IR

Question 35

Lateral orbit collimation

Answer 35

Entire orbit

Question 36

Lateral orbit evaluation criteria

Answer 36

Superimposition of orbital roofs

Question 37

Occipitomental sinuses central ray

Answer 37

Perpendicular to IR

Question 38

Occipitomental sinuses baseline

Answer 38

45-55° to IR

Question 39

Occipitomental sinuses center point

Answer 39

MSP, acanthion

Question 40

Occipitomental sinuses collimation

Answer 40

All sinuses included

Question 41

Occipitomental sinuses evaluation criteria

Answer 41

Symmetry, petrous border below maxillary sinuses, sphenoid sinuses seen through open mouth

Question 42

Occipito-frontal sinuses central ray

Answer 42

Perpendicular to IR

Question 43

Occipito-frontal sinuses baseline

Answer 43

20° to IR

Question 44

Occipito-frontal sinuses center point

Answer 44

MSP, level of mid-orbit

Question 45

Occipito-frontal sinuses collimation

Answer 45

All sinuses included

Question 46

Occipito-frontal sinuses evaluation criteria

Answer 46

Symmetry, petrous ridge below inferior orbital margin

Question 47

Lateral sinuses central ray

Answer 47

Perpendicular to IR

Question 48

Lateral sinuses baseline

Answer 48

Midway along radiographic baseline

Question 49

Lateral sinuses collimation

Answer 49

All sinuses included

Question 50

Lateral sinuses evaluation criteria

Answer 50

Symmetry

Question 51

PA mandible central ray

Answer 51

Perpendicular to IR

Question 52

PA mandible center point

Answer 52

Junction of lips, midline

Question 53

PA mandible collimation

Answer 53

Entire mandible & condyles

Question 54

PA mandible evaluation criteria

Answer 54

Symmetry, no rotation, entire mandible included

Question 55

Lateral oblique mandible central ray

Answer 55

10° cranial (some use straight ray)

Question 56

Lateral oblique mandible center point

Answer 56

Angle of mandible farthest from IR

Question 57

Lateral oblique mandible collimation

Answer 57

Entire mandible included

Question 58

Lateral oblique mandible evaluation criteria

Answer 58

Mandible clear of cervical spine, minimal superimposition on opposing side

Question 59

OM 55* paranasal sinus

Answer 59

Centre at root of nose Mouth is open just before exposure to demonstrate sphenoid sinuses Petrous ridge must sit below maxillary antra