IR Size: 10x12 CW
SID: 40""
• Side of interest: closest to IR
• Oblique: shoulders
• _|_ 2"" superior to EAM
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•
• Entire cranium w/ NR or tilt
• NR by sella turcica in profile
• SI orbital roofs, greater wings of sphenoid, EAMs, TMJs
IR Size: 10x12 LW
SID: 40""
• Pt prone or seated/upright in PA position:
• Pt forehead & nose: rest on bucky
• AP/AP axial may also be performed-Cephalad angles entering nasion (Orbits will be magnified ^ OID):
• CR exits Nasion.
• General study 15° caudad; if frontal bone of interest CR _|_; if superior orbital fissures of interest CR 20°-25° caudad; if rotundum foramina of interest CR 25°-30° caudad.
•
• MSP centered to IR & OML _|_ to IR, Nasion to crosshairs
• NR by Lat. Borders of skull equidistant to orbits
• Symmetric petrous ridges
• For Gen study- petrous ridges in lower 1/3 of orbits or for PA 0° filling orbits
IR Size: 10x12 LW
SID: 40""
• Pt supine or seated
• If pt Can flex neck use: OML _|_ to CR, if not use IOML _|_ to CR
• If pt Can flex neck (use OML _|_) CR 30° caudad, if pt Can't (use IOML _|_) CR 37° caudad
•
•
• NR by Lat. Borders of skull equidistant to foramen magnum
• Symmetric petrous ridges
• Dorsum sellae & post. Clinoid processes within foramen magnum
IR Size: 10x12 LW
SID: 40""
• Pt supine or seated
• Extend neck to rest: vertex of head on grid
• CR _|_ to IOML 3/4"" anterior (towards ceiling) to level of EAM midway between mandibular angles
•
•
• NR by Lat. Borders of skull equidistant to mandibular condyles
• Mandibular Condyles should be anterior to petrous ridges
• Dens within foramen magnum
• Clearly visible structures of cranial base
• Symmetric petrous ridges
