orbita radiography

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Radiography of the Orbits

Fall 2009

FINAL



Function of Orbits

1. Serve as bony sockets for the eyeballs

2. Openings for nerves and blood vessels



Division of the Orbits1. ________________

– Primarily composedof orbital plate of

frontal bone

2. ________________

– Zygoma (small

amount)

– Maxilla – Palatine

3. _______________

– Medial

• Lacrimal

– Lateral• Zygoma (large

amount)



Base of the OrbitThe circumference is

made of 3 bones:

1. _________________

2. _________________

3. _________________



Openings in Posterior Orbit

1. ______________ – Optic canal

– Sphenoid strut

2. ______________

3. ______________



ANGLE OF ORBITS

1. Each orbit projects

– 30 degrees superiorly

– 37 degrees toward MSP



Indications for Orbit and Eye

Radiography

1. Possible Fractures

1. Blowout2. Tripod

3. Lefort

2. Foreign body of the eye



Mechanisms producing

Orbital Fractures

1. Auto accidents

2. Assault

3. Falls, sports, and industrial accidents



Blowout Fracture



Blowout Fracture

1. Blow to the eye

2. Orbital floor is fractured

3. Soft tissue herniates

into maxillary sinuses

4. Often have ocular injury

Ponsell, 2003



Blowout Fracture



______________________



Tripod Fracture

1. Direct blow tozygoma

2. Visual concaveabnormalities

3. Usually orbits are

involved

4. Free floating zygoma

Ponsell, 2003



LeFort

Fractures

LeFort types II & IIIinvolve the orbits

Richardson, 2000



Lefort II and III



LeFort Fractures

1. Type II

1. Separation through: frontal processes

lacrimal bones

orbit floors,

zygomaticomaxillarysuture line

lateral wall of

maxillary sinuses

pterygoid

1. Complications

1. ____________

system obstruction

2. Infraorbital nerve

anesthesia

3. ____________

4. Malocclusion



Lefort 2



LeFort Fractures

1. Type III

1. Separation of mid third of

face at:

zygomaticotemporal naso-frontal sutures

and across orbital floors

1. Complications

1. _________________

2. Mal-union

3. _________________

4. Lenthening of mid face

5. _________________

system obstruction



LEFORT 3



Basic and Special Projections

1. Orbits

1. Basic• _________________

• _________________

2. Special• _________________

1. Eyes

1. Basic

• _______________

• _______________

• _______________

P i t thi l P j ti



Parietoacanthial Projection

Waters Method

1. Positioning

1. ____________

2. ____________

2. Lines and planes:

1. ____________

2. ____________

3. CR:

1. ___________

Ballinger & Frank, 1999, pg 317




Waters Method Radiograph

1. Distance from lateral

border of skull and

orbit equal on each

side

2. Petrous ridgesprojected

immediately below

maxillary sinuses

P i t thi l P j ti




Modified Waters

1. Positioning:

1. _____________

2. Lines and planes1. _____________

2. _____________

3. CR

1. ____________



Modified Waters Radiographs

1. Petrous ridges

projected

immediately below

the inferior border ofthe orbits

2. Equal distance from

lateral orbit to lateral

skull on both sides



Modified Parietoacanthial

Modified Waters method



Modified Waters

Radiograph & Diagram



Acanthioparietal Projection

Reverse Waters Method

1. Positioning

_______________

2. Lines and planes

_______________ _______________

3. CR

_______________




Reverse Waters Radiograph

1. Distance from lateral

border of skull and

orbit equal on each

side

2. Petrous ridgesprojected

immediately below

maxillary sinuses



Parietoorbital Projection (Rhese Method)

(PA) Optic Canal and Foramen Radiograph

1. Optic canal & foramen visibleat end of sphenoid ridge ininferior & lateral quadrant oforbit

2. Entire orbital rim

3. Supraorbital margins lying insame horizontal plane

4. Close beam restriction to theorbital region



Rhese Diagram and Radiograph

Rh M th d



Rhese Method

(AP) Optic Canal and Foramen1. Positioning:

1. _______________

2. _______________

2. Lines and planes:1. _______________

2. _______________

3. AP- CR:

1. _______________


Rhese Method



Rhese Method

(AP) Optic Canal and Foramen

Radiograph1. Optic canal & foramen visible

at end of sphenoid ridge ininferior & lateral quadrant oforbit

2. Entire orbital rim

3. Supraorbital margins lying insame horizontal plane

4. Close beam restriction topthe orbital region



Rhese Radiograph and Diagram



Foreign objects in the EYE



Lateral Eye for Foreign Body

1. Density & contrastpermitting optimalvisibility of orbit andforeign bodies

2. SI orbital roofs

3. Close beamrestriction



PA Axial (EYE)1. Positioning

1. Forehead & nose onIR.

2. Center IR ¾ “ distalto nasion

3. ________________

2. Lines and planes:1. ________________

3. CR:

1. Through center oforbits, 30 degreescaudal



PA Axial Eye Radiograph

1. Petrous pyramidslying below orbitalshadows

2. No rotation ofcranium

3. Close beamrestriction

Modified Waters



Modified Waters

(EYE)1. Positioning:

1. IR at level of orbits

2. Rest pt’s chin on IR

3. Instruct pt to close eyes

and hold eyes still

2. Lines and planes:

1. MSP perp

2. OML 50 degrees

3. CR:

1. Perp through mid-orbits



LETS REVIEW



Seven Bones of the Orbit

O i d S ti



Openings and Supporting

Structures of Openings of the Orbit

Parietoorbital Oblique Projection of



Parietoorbital Oblique Projection ofOrbits



References

Ballinger, P.W. & Frank, E.D. (1999).

Merrill’s atlas of radiographic positions and radiologicprocedures. V2. New York: Mosby

Ponsell, M.R. (2003). Assessing facial fractures in theemergency room. New Jersey

Richardson, M.L. (2000). Facial and mandibular fractures.

Retrieved May 5, 2007 from:http//www.rad.washington.edu/mskbook/facialfx.html

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