Measurements in Skeletal Radiology

Question 1

Sella Turcica AKA

Answer 1

Pituitary Fossa Size

Question 2

Sella Turcica

Answer 2

Greatest AP max 16mm

greatest vertical max 12

Question 3

Sella Turcica larger than Max (16 by 12)

May indicate:

Answer 3

pituitary neoplasm
extra pituitary neoplasm
aneurysm
or could be normal

Question 4

Basilar Angle AKA

Answer 4

Welcomer’s
Martin’s
Sphenobasilar Angle

Question 5

Basilar Angle

Answer 5

nation to center of sella Turcica to basin
Normal 123 to 152 degrees
average 157

Question 6

Basilar Angle of Platybasia

Answer 6

> 152 degrees

Congenital or aquired

Question 7

McGregor’s Line AKA

Answer 7

Basal Line

Question 8

McGregor’s Line

Answer 8

hard palate to the inferior surface of occiput, relationship to dens apex

Question 9

McGregor’s Line Indicates

Answer 9

Basilar impression - platybasia
occipitalization
bone softening
rheumatoid

Question 10

Chamberlain’s Line AKA

Answer 10

palato-ocipital Line

Question 11

Chamberlain’s Line

Answer 11

hard palate to opisthion - odontoid apex

Question 12

MaCrae’s Line AKA

Answer 12

Formen Magnum Line

Question 13

Foramen Magnum Line

Answer 13

basion to opisthion and relationship of occiput and adenoid
inferior margin of occiput should lie at or below th line
perpendicular though odontoid apex shot intersect anteriorly 1/4

Question 14

Foramen Magnum Line AKA MaCrae’s Line Indicates

Answer 14

Platybasia
atlanto-occipital joint dislocation
odontoid fracture

Question 15

ADI AKA

Answer 15

prudential interspace

Atlas-dens interval

Question 16

ADI

Answer 16

poster margin of anterior tubercle and anterior comical surface of odontoid at the mid portion of the joint
May have a V configuration in flexion
Inverted V in Extension
Trauma, occipitalization, Trisomy 21, Paryngeal infections (Grisel’s Disease), seronegative arthropathies

Question 17

ADI Adults

Answer 17

1-3mm

Question 18

ADI Children before puberty

Answer 18

1-5mm

Question 19

Contour Lines

Answer 19

Four Bony
One soft
anterior body
Poster body (George's line)
spinolaminar (most reliable)
posterior spinous (least reliable)

Question 20

Contour Lines

Answer 20

Must all break in the same direction unless loss of intrasegmental structural osseous integrity

Question 21

Canal Size *

Answer 21

C1 = Minimum of 16mm
C2 = Minimum of 14mm
C3-C7 = >13mm

Question 22

Pre vertebral Space:
Retro Pharyngeal
laryngeal
tracheal

Answer 22

C2-C4 max 7

C5-7 max 22 mm