Skull Positioning Flashcards
Degree difference between orbitomeatal and infraorbitomeatal?
7-8 degrees
Five most common positioning errors made during skull radiography.
Rotation, tilt, excessive flexion, excessive extension, incorrect CR angle
When using a 30 degree caudad angle for the AP Axial projection of the skull, which positioning line should be perpendicular to the IR?
OML
A properly positioned AP Axial should place the dorsum sellae into the middle aspect of the ….
Foramen Magnum
A lack of symmetry of the petrous ridges on a AP Axial suggest what positioning error?
Rotation
If the patient cannot flex the head adequately for the AP Axial how can the technician adjust the CR and patient position?
Place IOML perpendicular to the IR and angle the CR 37 degrees caudad.
What evidence on a AP Axial radiograph indicates the correct CR angle and head flexion?
Dorsum Sellae & posterior clinoids are projected into foramen magnum.
Where is the CR centered for a lateral skull?
2 “ above EAM
Where will the petrous ridges be projected with a 15 degree PA Axial of cranium?
lower 1/3 of orbits
Which specific positioning error is present if the mandibular rami are not superimposed on a lateral skull?
Rotation
Which specific positioning error is present if the petrous ridges are projected higher in the orbits than expected for a 15 degree PA Axial?
Excessive flexion or incorrect CR angle
Which projection of the cranium produces an image of the frontal bone with no distortion?
0 degree PA
What positioning error has been committed if the EAMs are not superimposed and one is more superior than the other in lateral skull?
Tilt
Petrous Ridge location on 0 degree PA?
Petrous ridges superimpose superior orbital ridges
Where does the CR exit for PA 0 degree?
the glabella
