Cranial Bones Review Flashcards
Patient position for AP axial townes of the cranial bones:
- Pt upright AP
- Posterior head against IR
- Tuck the chin to bring OML perpendicular to IR
- Adjust MSP straight no tilt or rotation
IR for ap axial townes:
Medium LW
CR for AP axial townes:
30 degrees caudad if OML
37 if OML
Entering 2.5” above glabella and exiting foramen magnum
Colliamtion for AP axial townes:
Include skull vertex and occipital bone and lateral skull margins
Image critique for AP axial townes:
- Equal distance from lat borders of skull to lat margins of foramen magnum (rotation)
- Symmetric petrous pyramids (tilt)
- Dorsum sellae and posterior clinoid visible WITHIN the foramen magnum
If the dorsum sella is above the foramen magnum, what needs to change?
Increase caudal angle
OR
Tuck patients chin down so OML is perpendicular to IR
If the anterior arch of C1 is seen in the foramen magnum what needs to change?
Decrease caudal angle
OR
Extend patient’s neck so OML is perpendicular to IR
Patient position for Lateral Cranial Bones:
- seated upright
- L or R lateral
- IPL perpendicular
- MSP parallel
- IOML perpendicular to front edge of IR (chin lifted slightly)
IR for lateral
Medium CROSSWISE
CR for Lateral
Perpendicular to IR, entering 2” superior to EAM
Collimation for Lateral:
Include vertex of skull to base of skull lengthwise and frontal and occipital bone crosswise (1” past skin line)
How to check for rotation on lateral cranial bones:
- Orbital roofs and G. Wings of sphenoid should be SI
- Mastoid regions and EAM also SI
- TMJs SI
- Sella turcica in profile
(anterior posterior alignment)
How to check tilt on lateral cranial bones;
superior/inferior alignment of orbital roofs, G. wings, mastoid and EAM, TMJs and sella turcica in profile
If IOML is perpendicular to front edge of IR, there should be no overlap of what?
Mandible and C-spine
