Orbits/Nasal Bones (6/12/2024)

What is Aurora’s orbit routine?

30^o Caldwell, Waters, affected lateral

Why is PA not done for orbits?

petrous ridges will be in the way

Explain patient and CR positioning for an orbit Caldwell

patient

• erect or prone

• nose and forehead against IR

• OML perpendicular

CR

• angle 30^o caudal (to knock petrous ridges far enough below orbital floor)

• exit at nasion

What is demonstrated on a Caldwell for orbits?

• petrous ridges below the orbital floor

• superior orbital fissures

• marker anywhere

• sent as if person was standing in front of you

• can cone down all the way to just the orbits!

Explain patient and CR positioning for the parietoacanthial (Waters) orbit image

patient

• erect or prone

• rest head on extended chin to place MML perpendicular to IR

• (OML forms 37^o angle to IR)

CR

• perpendicular to IR

• exiting at acanthion

What is demonstrated on a parietoacanthial orbit image?

• petrous ridges below maxillary sinuses

• entire orbits (floor will be distorted)

• marker anywhere

• collimate down to orbits

Explain patient and CR positioning for lateral orbits

patient

• erect, supine, or prone

• affected side against IR

• IP line perpendicular to IR

CR

• perpendicular to IR

• entering at outer canthus

What is demonstrated on a lateral orbit image?

• lateral view of bony orbit AND soft tissue

• marker anterior

• collimate down to orbits

What is Aurora’s routine for pre-MRI orbits?

Waters and lateral

When are pre-MRI orbits done?

for people with a history of working with metal or having metal in eyes

Explain where the optic foramen is in relation to the MSP and OML

37^o to MSP

30^o to OML

Explain the patient and CR positioning for the orbits parieto-orbital (Rhese view) image

patient

• erect or prone

• rest head on cheek, chin, and nose (3 point landing)

• MSP forms 53^o angle to IR

• AML is perpendicular to IR

  • if overextended: optic canal is too low

  • if underextended: optic canal is too high

CR

• perpendicular to IR

• entering 1” superior and 1” posterior to upside TEA

What is demonstrated on the orbits parieto-orbital (Rhese) image?

• cross-sectional view of optic canal lying in lower outer quadrant of downside orbit

• both sides done for comparison

What is Aurora’s nasal bones routine?

PA, Waters, both laterals

Explain patient and CR positioning for nasal bones PA

patient

• erect or prone

• rest head on nose and forehead

• OML perpendicular to IR

CR

• perpendicular to IR

• exiting at nasion

What is demonstrated on a nasal bones PA image?

• petrous ridges entirely filling orbits, frontal bone, crista galli, nasal bones, nasal septum, posterior ethmoids, frontal sinuses

• marker placed anywhere

• collimated down (usually 4 × 6 light field)

Explain patient and CR positioning for nasal bones parietoacanthial (Waters) image

patient

• erect or prone

• rest head on chin to put MML perpendicular

• OML forms 37^o angle to IR

CR

• perpendicular to IR

• exiting at acanthion

What is demonstrated on a nasal bone parietoacanthial (Waters) image?

• petrous ridges below maxillary sinuses

• orbits, zygomas, and maxillary sinuses

• potential deviated nasal septum

Explain patient and CR positioning for nasal bones lateral images

patient

• erect or semi-prone

• patient obliqued

• IP line perpendicular to IR

CR

• perpendicular to IR

• entering ½” inferior to nasion

• NON-GRID

What is demonstrated on a nasal bones lateral image?

• lateral view of nasal bones AND soft tissue

• both sides done for comparison

• mark side down anteriorly

• collimate way down

  • include where nasal bone articulates with frontal bone

  • include all nasal spine

What technique is used for lateral nasal bones?

60 kVp @ 0.8 mAs

What technique is used for nasal bones and orbits?

same as facial bones