Radiographic Measurements Q1 Flashcards
McGregor’s Line (is drawn between)
posterior hard palate–> inferior surface of the occipital bone
Min/Max measurement McGregor’s line
Dens should not project more than 8mm in males, 10 mm in females
ADI Atlantodental Interval (line from)
Midpt of posterior margin of anterior tubercle of C1 to nearest point on anterior margin of odontoid process
Normal ranges of measurement for Atlantodental Interval (ADI)
less than or equal to 3 mm in an adult
less than or equal to 5 mm in a child
What view is taken for McGregor’s line
lateral skull/cervical
What view is taken for ADI
lateral cervical spine (neutral, flexion, extension)
George’s Line: Posterior Body Margin Line (points of line)
Line drawn along the posterior aspect of the vertebral bodies, extrapolate across disc space. – Relationship of posteroinferior body corner to subajacent posterosuperior body corner
What view is George’s line taken from?
Lateral Spine (Cx,Tx,Lx) (neutral, flexion, extension)
Min/Max measurement George’s Line
greater than or equal to 4mm between two views may indicate stability
Spinolaminar Junction Line: Posterior Cervical Line (pts)
The most anterior point of the spinolaminar junction is identified at each level. These points are connected.
What view is the Spinolaminar Junction Line/ Posterior Cervical Line taken from?
Lateral spine (Cx,Tx,Lx) (neutral, flexion, extension)
Sagittal Dimension of the Cervical Spinal Canal is measured between which points?
Posterior surface of midvertebral body to spinolaminar junction
Minimums for Sagittal Dimension of the Cervical Spinal Canal?
C1:16mm
C2: 14mm
C3: 13mm
C4-C7: 12mm
Which view is the Sagittal Dimension of the Cervical Spinal Canal taken from?
Lateral Cervical
Atlantoaxial Allignment (what to look for/draw)
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
What view is Atlantoaxial Allignment determined from?
AP Open Mouth
APOM
Coronal Dimensions of the Cervical Spine Interpediculate Distance measures:
Measures shortest distance between inner cortical margins of pedicals at a given segment; Vary by spinal level
Cervical Gravity Line is measured using what view?
Lateral neutral cervical
Cervical Gravity Line is from where to where
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)
Angle of Cervical Curve is measured how?
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)
What view is the Angle of Cervical Curve measured from?
Lateral cervical
Prevertebral Soft Tissue is measured using which view?
Lateral cervical
Prevertebral Soft Tissue is measured how?
Space measured between the vertebral bodies and the air shadow of the pharynx, larynx, and trachea
What are the normal Prevertebral Soft Tissue measurements?
Usually 10mm at C1
6mm at C2 (Retropharyngeal interspace)
20mm at C6 (retrotracheal interspace
Increased with an ST mass
Functional Evaluation for Instability is measured how? Normal range?
Template is drawn over cervical vertebral bodies and SPs in neutral.
Greater than 4mm translation at posterior body margin line suggest instability
Functional Evaluation for instability is conducted using which view?
Lateral Cervical in neutral, flexion and extension
