Sella Turcica - correct answer-AP dimension: ranges from 5-16mm; average is 11mm (maximum is
16mm)
-Vertical dimension: ranges from 4-12mm; average 8mm (maximum is 12mm
pituitary neoplasm
McRae line - correct answer atlanto-occipital dislocation
basilar impression
Chamberlain's Line (Palato-occipital line) - correct answer• The odontoid should not cross this line. I may
up to 3 mm
•Measurement greater than or equal to 7mm is abnormal
Mc Gregors Line (Basal line) - correct answer• line >8mm in males and >10mm in females
Atlantoaxial Alignment-"Overhang" Sign - correct answer• alar ligament instability or rotatory
atlantoaxial subluxation
Jefferson's fracture, odontoid fracture, alar ligament instability
Atlantodental Interval - correct answer• Adult patient less than or equal to 3mm
•Children less than or equal to 5mm
or rupture of the transverse atlantal ligament.
George's Line - correct answer• May be a sign of ligamentous instability, fracture, dislocation or
degenerative joint disease
•anterolisthesis or retrolisthesis
, Spinolaminar Line - correct answer The cortical white line of the Spinolaminar junction at each level C1-
C7
the spinolaminar junction line in children should not be >2mm anterior to this line.
Sagittal Canal Dimension—Cervical Spine - correct answer•C1—16-31mm
•C2—14-27mm
•C3—13-23mm
•C4-C7—12-22mm
Torg-Pavlov Ratio - correct answer• A ratio less than 0.8 is an indicator of spinal stenosis
dimension/vertebral body width
Retropharyngeal Interspace - correct answer Upper limits of C2 of is 7mm
Upper limits of C6 is 20-22mm
Angle of the Cervical Curve - correct answer•35-45 degrees
Cervical Gravity Line - correct answer• The line should pass through the C7 body
•The line allows a gross assessment of where the gravitational stress are acting at the cervicothoracic
junction.
Thoracic Cage Dimension - correct answer• Male—11-18cm
•Females—9-15cm
Lumbar Lordosis - correct answer The average appears to be 50-60 degrees
Lumbosacral angle - correct answer• Upright film—26-57 degrees; average is 41 degrees
Lumbosacral Disc Angle - correct answer •Between 10-15 degrees