| A | B |
|---|
| line from hard palate to base of occiput (>8 mm in males, & >10 in females indicates basilar impression) | mcgregor's line |
| hard palate to opisthion/poster foramen magnum (>7 mm = basilar impression) | chamberlain's line |
| line from nasion to center of sella turcica (>152 indcates platybasia/basilar impression) | basilar angle (martin's basilar angle) |
| anterior foramen magnum to posterior foramen magnum (basilar impression) | macrae's line (foramen magnum line) |
| C1 anterior tubercle to the odontoid (>3mm in adults, >5mm in kids) | ADI |
| posterior body margins are checked for alignement (antero/retrolisthesis) | george's line |
| lines drawn at C2 and C7 posterior bodies (flexion intersects at C5/C6, extension intersects C4/C5) | stress line of cervical spine (jackson's) |
| anterior vertebral bodies to soft tissue (retropharyngeal C4 >7mm, retrotracheal C6 >20mm) | prevertebral soft tissues |
| line drawn parallel and through sacral base, perpendicular line drawn from sacral promontory | ullmann's line |
| line drawn parallel and through the inferior end plate | macnab's line |
| line drawn along the pelvic inlet to the outer aspect of obturator foramen; measurement for protrusio acetabuli | kohler's line |
| smooth curvilinear line is drawn along the inferior femoral neck to the superior aspect of the obturator foramen (slipped capital epiphysis) | shenton's line |
| line drawn through and parallel to the femoral shaft, perpendicular lineis drawn tangential to the tip of greater trochanter | skinner's line |
| line drawn along the outer margins of the femoral neck (slipped femoral capital epiphysis) | klein's line |
| three highest point on the superior aspect of the calcaneus are connected with two lines (>28 degrees is a problem) | boehler's angle |
