Radiographic Measurements Q1

Question 1

McGregor’s Line (is drawn between)

Answer 1

posterior hard palate–> inferior surface of the occipital bone

Question 2

Min/Max measurement McGregor’s line

Answer 2

Dens should not project more than 8mm in males, 10 mm in females

Question 3

ADI Atlantodental Interval (line from)

Answer 3

Midpt of posterior margin of anterior tubercle of C1 to nearest point on anterior margin of odontoid process

Question 4

Normal ranges of measurement for Atlantodental Interval (ADI)

Answer 4

less than or equal to 3 mm in an adult

less than or equal to 5 mm in a child

Question 5

What view is taken for McGregor’s line

Answer 5

lateral skull/cervical

Question 6

What view is taken for ADI

Answer 6

lateral cervical spine (neutral, flexion, extension)

Question 7

George’s Line: Posterior Body Margin Line (points of line)

Answer 7

Line drawn along the posterior aspect of the vertebral bodies, extrapolate across disc space. – Relationship of posteroinferior body corner to subajacent posterosuperior body corner

Question 8

What view is George’s line taken from?

Answer 8

Lateral Spine (Cx,Tx,Lx) (neutral, flexion, extension)

Question 9

Min/Max measurement George’s Line

Answer 9

greater than or equal to 4mm between two views may indicate stability

Question 10

Spinolaminar Junction Line: Posterior Cervical Line (pts)

Answer 10

The most anterior point of the spinolaminar junction is identified at each level. These points are connected.

Question 11

What view is the Spinolaminar Junction Line/ Posterior Cervical Line taken from?

Answer 11

Lateral spine (Cx,Tx,Lx) (neutral, flexion, extension)

Question 12

Sagittal Dimension of the Cervical Spinal Canal is measured between which points?

Answer 12

Posterior surface of midvertebral body to spinolaminar junction

Question 13

Minimums for Sagittal Dimension of the Cervical Spinal Canal?

Answer 13

C1:16mm
C2: 14mm
C3: 13mm
C4-C7: 12mm

Question 14

Which view is the Sagittal Dimension of the Cervical Spinal Canal taken from?

Answer 14

Lateral Cervical

Question 15

Atlantoaxial Allignment (what to look for/draw)

Answer 15

Lateral mass of atlas should not overhang lateral margin of C2 superior facet (>1mm)
Overhang may be normal in children 4 yrs of age or younger
“X” drawn with lines from one C0-C1 joint through opposite C1-C2 gives general idea of symmetry, rotation at C1-C2

Question 16

What view is Atlantoaxial Allignment determined from?

Answer 16

AP Open Mouth

APOM

Question 17

Coronal Dimensions of the Cervical Spine Interpediculate Distance measures:

Answer 17

Measures shortest distance between inner cortical margins of pedicals at a given segment; Vary by spinal level

Question 18

Cervical Gravity Line is measured using what view?

Answer 18

Lateral neutral cervical

Question 19

Cervical Gravity Line is from where to where

Answer 19

A vertical line is drawn through the apex of the odontoid process. Should pass through the seventh cervical vertebral body
(Gross assessment of where the gravitational stresses are acting at the C/T Junction)

Question 20

Angle of Cervical Curve is measured how?

Answer 20

Two lines are drawn, one through and parallel to the inferior endplate of the 7th cervical body, the other through the midpoints of the anterior and posterior tubercles of the atlas.
Construct perpendiculars and measure the angle (Normally 35-45 degrees)

Question 21

What view is the Angle of Cervical Curve measured from?

Answer 21

Lateral cervical

Question 22

Prevertebral Soft Tissue is measured using which view?

Answer 22

Lateral cervical

Question 23

Prevertebral Soft Tissue is measured how?

Answer 23

Space measured between the vertebral bodies and the air shadow of the pharynx, larynx, and trachea

Question 24

What are the normal Prevertebral Soft Tissue measurements?

Answer 24

Usually 10mm at C1
6mm at C2 (Retropharyngeal interspace)
20mm at C6 (retrotracheal interspace
Increased with an ST mass

Question 25

Functional Evaluation for Instability is measured how? Normal range?

Answer 25

Template is drawn over cervical vertebral bodies and SPs in neutral.
Greater than 4mm translation at posterior body margin line suggest instability

Question 26

Functional Evaluation for instability is conducted using which view?

Answer 26

Lateral Cervical in neutral, flexion and extension