Radiography of the Orbits Fall 2010 FINAL 1

Function of Orbits 1. Serve as bony sockets for the eyeballs 2. Openings for nerves and blood vessels 2

Bones of the Orbits - 7 A B C D E I F G H 3

Division of the Orbits 1. _______ __ – Primarily composed of orbital plate of frontal bone 3. ________ – Medial • – Lateral • 2. ________ _ – – – Lacrimal Zygoma (large amount) Zygoma (small amount) Maxilla Palatine 4

Base of the Orbit The circumference is made of 3 bones: 1. ________ __ 2. ________ _ 3. ________ _ 5

Openings in Posterior Orbit 1. _______ – Optic canal – Sphenoid strut 2. _______ 3. _______ 6

ANGLE OF ORBITS 1. Each orbit projects – 30 degrees superiorly – 37 degrees toward MSP 7

Indications for Orbit and Eye Radiography 1. Possible Fractures 1. Blowout 2. Tripod 3. Lefort 2. Foreign body of the eye 8

Mechanisms producing Orbital Fractures 1. Auto accidents 2. Assault 3. Falls, sports, and industrial accidents 9

Blowout Fracture 10

$Blowout Fracture 1. Blow to the eye 2. Orbital floor is fractured 3. Soft$

Blowout Fracture 1. Blow to the eye 2. Orbital floor is fractured 3. Soft tissue herniates into maxillary sinuses 4. Often have ocular injury 11 Ponsell, 2003

Blowout Fracture 13

Tripod Fracture 1. Direct blow to zygoma 2. Visual concave abnormalities 3. Usually orbits are involved 4. Free floating zygoma 15 Ponsell, 2003

Le. Fort Fractures Le. Fort types II & III involve the orbits 16 Richardson, 2000

Lefort II and III 17

Le. Fort Fractures 1. Type II 1. Separation through: n n frontal processes lacrimal bones orbit floors, zygomaticomaxillary suture line n lateral wall of maxillary sinuses n pterygoid 1. Complications 1. ______ system obstruction 2. Infraorbital nerve anesthesia 3. ______ 4. Malocclusion 18

Lefort 2 19

Le. Fort Fractures 1. Type III 1. Complications 1. _________ 1. Separation of mid third of face at: n zygomaticotemporal n naso-frontal sutures n and across orbital floors 2. Mal-union 3. _________ 4. Lenthening of mid face 5. _________ system obstruction 20

LEFORT 3 21

LEFORT 3 22

Basic and Special Projections 1. Orbits 1. Eyes 1. Basic • • _________________ 2. Special • • _________________ 23

Parietoacanthial Projection Waters Method 1. Positioning 1. ____________ 2. Lines and planes: 1. ______ 2. ______ 3. CR: 1. ______ 24 Ballinger & Frank, 1999, pg 317

Parietoacanthial Projection Waters Method Radiograph 1. Distance from lateral border of skull and orbit equal on each side 2. Petrous ridges projected immediately below maxillary sinuses 25

Parietoacanthial Projection Modified Waters 1. Positioning: 1. _______ 2. Lines and planes 1. _______ 2. _______ 3. CR 1. ______ 26

Modified Waters Radiographs 1. Petrous ridges projected immediately below the inferior border of the orbits 2. Equal distance from lateral orbit to lateral skull on both sides 27

Modified Parietoacanthial Modified Waters method 28

Modified Waters Radiograph & Diagram 29

Acanthioparietal Projection Reverse Waters Method 1. Positioning n ________ 2. Lines and planes n _______________ 3. CR n ________ 30 Ballinger & Frank, 1999, pg 320

Reverse Waters Radiograph 1. Distance from lateral border of skull and orbit equal on each side 2. Petrous ridges projected immediately below maxillary sinuses 31

Parietoorbital Projection (Rhese Method) (PA) Optic Canal and Foramen 1. Positioning 1. ______________ 2. Lines and planes: 1. _______ 2. _______ 3. PA- CR: 1. enters 1”superior and posterior to TEA 4. PA- CR: 1. exits through the affected orbit 32 Ballinger & Frank, 1999, pg 290

Parietoorbital Projection (Rhese Method) (PA) Optic Canal and Foramen Radiograph 1. Optic canal & foramen visible at end of sphenoid ridge in inferior & lateral quadrant of orbit 2. Entire orbital rim 3. Supraorbital margins lying in same horizontal plane 4. Close beam restriction to the orbital region 33

Rhese Diagram and Radiograph 34

Rhese Method (AP) Optic Canal and Foramen 1. Positioning: 1. _______________ 2. Lines and planes: 1. ________ 2. ________ 3. AP- CR: 1. ________ 35 Ballinger & Frank, 1999, pg 292

Rhese Method (AP) Optic Canal and Foramen Radiograph 1. Optic canal & foramen visible at end of sphenoid ridge in inferior & lateral quadrant of orbit 2. Entire orbital rim 3. Supraorbital margins lying in same horizontal plane 4. Close beam restriction top the orbital region 36

Rhese Radiograph and Diagram 37

Foreign objects in the EYE 38

Lateral Projection (EYE) 1. Positioning: 1. Semiprone or seated upright 2. Affected eye closest to cassette 3. __________ 2. Lines and planes: 1. MSP parallel 2. IPL perpendicular 3. CR: 1. __________ 39

Lateral Eye for Foreign Body 1. Density & contrast permitting optimal visibility of orbit and foreign bodies 2. SI orbital roofs 3. Close beam restriction 40

1. Positioning 1. Forehead & nose on IR. 2. Center IR ¾ “ distal to nasion 3. ________ PA Axial (EYE) 2. Lines and planes: 1. ________ _ 3. CR: 1. Through center of orbits, 30 degrees caudal 41

PA Axial Eye Radiograph 1. Petrous pyramids lying below orbital shadows 2. No rotation of cranium 3. Close beam restriction 42

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 Modified Waters (EYE) 2. Lines and planes: 1. MSP perp 2. OML 50 degrees 3. CR: 1. Perp through mid-orbits 43

Modified Waters Radiograph 1. Petrous Pyramids lying well below orbital shadows 2. Symmetric visualization of orbits 3. Close beam restriction 44

LETS REVIEW 45

Seven Bones of the Orbit 46

Openings and Supporting Structures of Openings of the Orbit 47

Parietoorbital Oblique Projection of Orbits 48

References Ballinger, P. W. & Frank, E. D. (1999). Merrill’s atlas of radiographic positions and radiologic procedures. V 2. New York: Mosby Ponsell, M. R. (2003). Assessing facial fractures in the emergency room. New Jersey Richardson, M. L. (2000). Facial and mandibular fractures. Retrieved May 5, 2007 from: http//www. rad. washington. edu/mskbook/facialfx. html 49