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Radiography of the Orbits

Radiography of the Orbits. Ballinger & Frank, 1999, pg 291. Function of Orbits. Serve as bony sockets for the eyeballs Openings for nerves and blood vessels. Division of the Orbits. Roof Primarily composed of -orbital plate of frontal bone Floor Zygoma (small amount) Maxilla Palatine

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Radiography of the Orbits

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  1. Radiography of the Orbits Ballinger & Frank, 1999, pg 291

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

  3. Division of the Orbits • Roof • Primarily composed of -orbital plate of frontal bone • Floor • Zygoma (small amount) • Maxilla • Palatine • Two Walls • Medial • Lacrimal • Lateral • Zygoma (large amount)

  4. Bones of the Orbits - 7

  5. Base of the Orbit • The circumference • or circular base • Made of 3 bones • Frontal (cranial bone) • Orbital plate • Forms most of the roof • Maxilla ( facial bone) • Helps form the floor • Zygoma (facial bone) • Forms part of the lateral wall and some of the floor

  6. Openings in Posterior Orbit • Optic Foramen • Optic canal • Sphenoid strut • Superior Orbital Fissure • Inferior Orbital Fissure

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

  8. Indications for Orbit and Eye Radiography • Possible Fractures • Foreign body of the eye

  9. Mechanisms producing Orbital Fractures • Auto accidents • Assault • Falls, sports, and industrial accidents

  10. Blowout Fracture • Blow to the eye • Orbital floor is fractured • Soft tissue herniates into maxillary sinuses • Often have ocular injury Ponsell, 2003

  11. Tripod Fracture • Direct blow to zygoma • Visual concave abnormalities • Usually orbits are involved Ponsell, 2003

  12. LeFort Fractures LeFort types II and III involve the orbits Richardson, 2000

  13. Type 3 Separation of mid third of face at zygomaticotemporal, naso-frontal sutures, and across orbital floors Complications Non-union Mal-union Malocclusion Lenthening of mid face Lacrimal system obstruction LeFort Fractures

  14. Type II Separation through frontal processes, lacrimal bones, orbit floors, zygomaticomaxillary suture line, lateral wall of maxillary sinuses, and pterygoid Complications Lacrimal system obstruction Infraorbital nerve anesthesia Diplopia malocclusion LeFort Fractures

  15. Orbits Basic Parietoorbital (Rhese Method) Parietoacanthial (Waters method) Special Modified Parietoacanthial (Modified Waters method) Eyes Basic Lateral PA Axial Modified Parietoacanthial (Modified Waters method) Basic and Special Projections

  16. Parietoacanthial ProjectionWaters Method • Tip of extended chin on grid device • OML 37 degrees from plane of cassette • MSP perpendicular to cassette • MML perpendicular to cassette • CR exits acanthion Ballinger & Frank, 1999, pg 317

  17. Parietoacanthial ProjectionWaters Method Radiograph • Distance from lateral border of skull and orbit equal on each side • Petrous ridges projected immediately below maxillary sinuses

  18. Modified Parietoacanthial Projection Modified Waters • OML 55 degree angle from plane of IR • MSP perp • CR perpendicular and exits acanthion

  19. Modified Parietoacanthial Projection Modified Waters Radiographs • Petrous ridges projected immediately below the inferior border of the orbits • Equal distance from lateral orbit to lateral skull on both sides

  20. Modified Parietoacanthial Projection Modified Waters method

  21. Modified Waters Radiograph & Diagram

  22. Acanthioparietal ProjectionReverse Waters Method • Patients chin up and neck adjusted so the OML is 37 degrees from cassette • MML perpendicular to cassette • MSP perpendicular to cassette • CR enters acanthion Ballinger & Frank, 1999, pg 320

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

  24. Parietoorbital ProjectionRhese Method(PA) Optic Canal and Foramen • 3 point landing • Zygoma, nose, and chin • AML perpendicular to cassette • MSP forms a 53 degrees angle from cassette • PA- CR enters 1”superior and posterior to TEA • PA- CR exits through the affected orbit Ballinger & Frank, 1999, pg 290

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

  26. Rhese Method(AP) Optic Canal and Foramen • 3 point landing • Zygoma, nose, and chin • AML perpendicular to cassette • MSP forms a 53 degrees to cassette • AP- CR enters uppermost orbit at inferior lateral quadrant Ballinger & Frank, 1999, pg 292

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

  28. Rhese Radiograph and Diagram

  29. Foreign objects in the EYE

  30. Lateral Projection (EYE) • Use non-grid high resolution technique • Semiprone or seated upright • Affected eye closest to cassette • MSP parallel with plane of IR • Instruct pt to look straight ahead • IPL perpendicular to IR • CR: Perp through outer canthus

  31. Lateral Eye for Foreign Body • Density & contrast permitting optimal visibility of orb it and foreign bodies • SI orbital roofs • Close beam restriction

  32. PA Axial (EYE) • Non-grid high resolution technique • Forehead & nose on IR. • Center IR ¾ “ distal to nasion • MSP & OML perp • Eyes closed & held still • CR: Through center of orbits, 30 degrees caudal

  33. PA Axial Eye Radiograph • Petrous pyramids lying below orbital shadows • No rotation of cranium • Close beam restriction

  34. Modified Waters (EYE) • IR at level of orbits • Rest pt’s chin on IR • MSP perp and OML 50 degrees from IR • CR: Perp through mid-orbits • Instruct pt to close eyes and hold eyes still

  35. Modified Waters Radiograph • Petrous Pyramids lying well below orbital shadows • Symmetric visualization of orbits • Close beam restriction

  36. LETS REVIEW

  37. Seven Bones of the Orbit

  38. Seven Bones of the Orbit • A. Frontal bone- orbital plate • B. Sphenoid bone • C. Palatine bone • D. Zygomatic bone • E. Maxillary bone • F. Ethmoid bone • G. Lacrimal bone

  39. Openings and Supporting Structures of Openings of the Orbit

  40. Openings and Supporting Structures of Openings of the Orbit • A. Optic Foramen • B. Sphenoid Strut • C. Superior Orbital Fissure • D. Inferior Orbital Fissure

  41. Parietoorbital Oblique Projection of Orbits

  42. A. Frontal bone- orbital plate B.Sphenoid bone C. Optic foramen & canal D. Superior orbital fissure E. Inferior orbital fissure F. Sphenoid strut G. Lateral orbital margin H. Superior orbital margin Parietoorbital Oblique Projection of Orbits

  43. Orbital anatomy Review • http://www.uth.tmc.edu/radiology/test/er_primer/face/images/wtrs02.html

  44. References Ballinger, P.W. & Frank, E.D. (1999). Merrill’s atlas of radiographic positions and radiologic procedures. V2. 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

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