Exam 1 Roentgenometrics Flashcards
Martins Basilar Angle
Detects Platybasia
Should be 137-152 degrees
Nasion to the center of the sella turcica to the basion
Chamberlain’s Line
Hard palate to the opisthion
Odontoid should not extend more than 7mm above this line.
Detects basilar invagination (acquired) or basilar impression (congenital)
McGregor’s Line
Hard palate to the inferior occiput
Odontoid should not extend above this line 8-10mm
George’s Line
Line along the posterior vertebral bodies
Used to detect antero/retrolisthesis/spondylolisthesis
ADI Measurement
3mm in adults
5mm in children
Atlanto-axial “overhang” sign
Lateral masses of C1 appearing more lateral than the superior articular processes of C2.
This indicates a C1 fracture (Jefferson’s fracture)
Cervical lordosis angles
> 45 = hyper
Cervical Lordosis Depth Method
Tip of odontoid to posterior surface of C7
Measure the depth at C4
Average = 8-12mm
Harrison Posterior Tangent Method
Line drawn on the posterior surfaces of C2 and C7 and this angle is measured
Average is 34
Ruth Jackson Stress Lines
Line extending and intersecting from the posterior aspects of C2 and C7
Cervical Gravitational Line
From odontoid tip down vertically
Should traverse the anterior-superior aspect of C7
Indicates anterior head carriage
Sagittal Canal Measurement
Normal >16mm
Stenosis
Retropharyngeal Space
Retrotracheal Space
Spondylolisthesis grades
Grade 1 100%
Detected by George’s Line
Ulmann’s Line
If L5 crosses the perpendicular line created by the top of sacrum then spondylo
Tear drop distance
9-11mm or greater than 2mm from side to side
Kline’s Line
Drawn along the outer border of the femoral neck
Indicates a slipped femoral capital epiphysis
Shenton Line
Curved line from inferior pubic ramus to the medial femoral neck
Should be a normal smooth arc
Abnormal in hip dislocation, femur fx and SCFE
Kohler’s Line
From medial pelvic brim to the external margin of the obturator foramen
Acetabulum should not extend beyond this line
Indicates acetabular protrusion (otto’s pelvis)
Boehler’s Angle
28-40 degrees is normal
Acromiohumeral space
Average is about 10mm
Any less indicates supraspinatus tendinopathy
Epiphysis
Gives length to bone
Apophysis
Attachment site for ligaments and tendons
