radiography of the orbits

Radiography of the OrbitsRadiography of the Orbits

Ballinger & Frank, 1999, pg 291

Function of OrbitsFunction of Orbits

Serve as bony sockets for the Serve as bony sockets for the eyeballseyeballs

Openings for nerves and blood Openings for nerves and blood vesselsvessels

Division of the OrbitsDivision of the Orbits RoofRoof

Primarily composed of -orbital plate of frontal Primarily composed of -orbital plate of frontal bonebone

FloorFloor Zygoma (small amount)Zygoma (small amount) MaxillaMaxilla PalatinePalatine

Two WallsTwo Walls Medial Medial

LacrimalLacrimal

LateralLateral Zygoma (large amount)Zygoma (large amount)

Bones of the Orbits - 7Bones of the Orbits - 7

Base of the OrbitBase of the Orbit The circumferenceThe circumference

or circular baseor circular base

Made of 3 bonesMade of 3 bones Frontal (cranial bone)Frontal (cranial bone)

Orbital plateOrbital plate Forms most of the roofForms most of the roof

Maxilla ( facial bone)Maxilla ( facial bone) Helps form the floorHelps form the floor

Zygoma (facial bone)Zygoma (facial bone) Forms part of the lateral Forms part of the lateral

wall and some of the wall and some of the floorfloor

Openings in Posterior OrbitOpenings in Posterior Orbit

Optic ForamenOptic Foramen Optic canalOptic canal Sphenoid strutSphenoid strut

Superior Orbital Superior Orbital FissureFissure

Inferior Orbital Inferior Orbital FissureFissure

ANGLE OF ORBITSANGLE OF ORBITS Each orbit projects Each orbit projects

30 degrees superiorly30 degrees superiorly 37 degrees toward MSP37 degrees toward MSP

Indications for Orbit and Eye Indications for Orbit and Eye RadiographyRadiography

Possible FracturesPossible Fractures

Foreign body of the eyeForeign body of the eye

Mechanisms producingMechanisms producing Orbital Fractures Orbital Fractures

Auto accidentsAuto accidents

AssaultAssault

Falls, sports, and industrial accidentsFalls, sports, and industrial accidents

Blowout FractureBlowout Fracture

Blow to the eyeBlow to the eye

Orbital floor is Orbital floor is fracturedfractured

Soft tissue Soft tissue herniates into herniates into maxillary sinusesmaxillary sinuses

Often have ocular Often have ocular injuryinjury

Ponsell, 2003

Tripod FractureTripod Fracture

Direct blow to Direct blow to zygomazygoma

Visual concave Visual concave abnormalitiesabnormalities

Usually orbits are Usually orbits are involvedinvolved

Ponsell, 2003

LeFort FracturesLeFort Fractures

LeFort types II and III involve the orbitsLeFort types II and III involve the orbits

Richardson, 2000


Type 3Type 3

Separation of mid third Separation of mid third of face at of face at zygomaticotemporal, zygomaticotemporal, naso-frontal sutures, naso-frontal sutures, and across orbital floorsand across orbital floors

ComplicationsComplications Non-unionNon-union

Mal-unionMal-union

MalocclusionMalocclusion

Lenthening of mid faceLenthening of mid face

Lacrimal system Lacrimal system obstructionobstruction


Type IIType II

Separation through Separation through frontal processes, frontal processes, lacrimal bones, lacrimal bones, orbit floors, orbit floors, zygomaticomaxillarzygomaticomaxillary suture line, lateral y suture line, lateral wall of maxillary wall of maxillary sinuses, and sinuses, and pterygoidpterygoid

ComplicationsComplications Lacrimal system Lacrimal system

obstructionobstruction

Infraorbital nerve Infraorbital nerve anesthesiaanesthesia

DiplopiaDiplopia

malocclusionmalocclusion

Basic and Special Basic and Special ProjectionsProjections

OrbitsOrbits

BasicBasic Parietoorbital Parietoorbital

(Rhese Method)(Rhese Method) Parietoacanthial Parietoacanthial

(Waters method)(Waters method)

SpecialSpecial Modified Modified

Parietoacanthial Parietoacanthial (Modified Waters (Modified Waters method)method)

EyesEyes

Basic Basic LateralLateral

PA AxialPA Axial

Modified Modified Parietoacanthial Parietoacanthial (Modified Waters (Modified Waters method)method)

Parietoacanthial ProjectionParietoacanthial ProjectionWaters MethodWaters Method

Tip of extended chin Tip of extended chin on grid deviceon grid device

OML 37 degrees from OML 37 degrees from plane of cassetteplane of cassette

MSP perpendicular to MSP perpendicular to cassettecassette

MML perpendicular to MML perpendicular to cassettecassette

CR exits acanthionCR exits acanthionBallinger & Frank, 1999, pg 317

Parietoacanthial ProjectionParietoacanthial ProjectionWaters Method RadiographWaters Method Radiograph

Distance from lateral Distance from lateral border of skull and border of skull and orbit equal on each orbit equal on each sideside

Petrous ridges Petrous ridges projected projected immediately below immediately below maxillary sinusesmaxillary sinuses

Modified Parietoacanthial Modified Parietoacanthial Projection Modified Waters Projection Modified Waters

OML 55 degree OML 55 degree angle from plane of angle from plane of IRIR

MSP perpMSP perp

CR perpendicular CR perpendicular and exits acanthionand exits acanthion


RadiographsRadiographs Petrous ridges Petrous ridges

projected projected immediately below immediately below the inferior border of the inferior border of the orbitsthe orbits

Equal distance from Equal distance from lateral orbit to lateral orbit to lateral skull on both lateral skull on both sidessides


methodmethod

Modified Waters Modified Waters Radiograph & DiagramRadiograph & Diagram

Acanthioparietal ProjectionAcanthioparietal ProjectionReverse Waters MethodReverse Waters Method

Patients chin up and Patients chin up and neck adjusted so the neck adjusted so the OML is 37 degrees OML is 37 degrees from cassettefrom cassette

MML perpendicular to MML perpendicular to cassettecassette

MSP perpendicular to MSP perpendicular to cassettecassette

CR enters acanthionCR enters acanthionBallinger & Frank, 1999, pg 320

Reverse Waters RadiographReverse Waters Radiograph

Distance from lateral Distance from lateral border of skull and border of skull and orbit equal on each orbit equal on each sideside

Petrous ridges Petrous ridges projected projected immediately below immediately below maxillary sinusesmaxillary sinuses

Parietoorbital ProjectionParietoorbital ProjectionRhese MethodRhese Method

(PA) Optic Canal and Foramen(PA) Optic Canal and Foramen 3 point landing3 point landing

Zygoma, nose, and chinZygoma, nose, and chin

AML perpendicular to AML perpendicular to cassettecassette

MSP forms a 53 degrees MSP forms a 53 degrees angle from cassetteangle from cassette

PA- CR enters 1”superior PA- CR enters 1”superior and posterior to TEAand posterior to TEA

PA- CR exits through the PA- CR exits through the affected orbitaffected orbit


Parietoorbital ProjectionParietoorbital ProjectionRhese MethodRhese Method

(PA) Optic Canal and Foramen (PA) Optic Canal and Foramen RadiographRadiograph

Optic canal & foramen Optic canal & foramen visible at end of visible at end of sphenoid ridge in sphenoid ridge in inferior & lateral inferior & lateral quadrant of orbitquadrant of orbit

Entire orbital rimEntire orbital rim

Supraorbital margins Supraorbital margins lying in same lying in same horizontal planehorizontal plane

Close beam restriction Close beam restriction to the orbital regionto the orbital region

Rhese MethodRhese Method(AP) Optic Canal and (AP) Optic Canal and

ForamenForamen 3 point landing3 point landing

Zygoma, nose, and chinZygoma, nose, and chin

AML perpendicular to AML perpendicular to cassettecassette

MSP forms a 53 MSP forms a 53 degrees to cassettedegrees to cassette

AP- CR enters AP- CR enters uppermost orbit at uppermost orbit at inferior lateral inferior lateral quadrantquadrant


Rhese MethodRhese Method(AP) Optic Canal and Foramen (AP) Optic Canal and Foramen

RadiographRadiograph Optic canal & foramen Optic canal & foramen

visible at end of visible at end of sphenoid ridge in sphenoid ridge in inferior & lateral inferior & lateral quadrant of orbitquadrant of orbit

Entire orbital rimEntire orbital rim

Supraorbital margins Supraorbital margins lying in same lying in same horizontal planehorizontal plane

Close beam restriction Close beam restriction top the orbital regiontop the orbital region

Rhese Radiograph and Rhese Radiograph and DiagramDiagram

Foreign objects in the EYEForeign objects in the EYE

Lateral Projection (EYE)Lateral Projection (EYE) Use non-grid high Use non-grid high

resolution techniqueresolution technique

Semiprone or seated Semiprone or seated uprightupright

Affected eye closest to Affected eye closest to cassettecassette

MSP parallel with plane of MSP parallel with plane of IRIR

Instruct pt to look straight Instruct pt to look straight aheadahead

IPL perpendicular to IRIPL perpendicular to IR

CR: Perp through outer CR: Perp through outer canthuscanthus

Lateral Eye for Foreign BodyLateral Eye for Foreign Body

Density & contrast Density & contrast permitting optimal permitting optimal visibility of orb it visibility of orb it and foreign bodiesand foreign bodies

SI orbital roofsSI orbital roofs

Close beam Close beam restrictionrestriction

PA Axial (EYE)PA Axial (EYE) Non-grid high Non-grid high resolution resolution techniquetechnique

Forehead & nose Forehead & nose on IR.on IR.

Center IR ¾ “ distal Center IR ¾ “ distal to nasionto nasion

MSP & OML perpMSP & OML perp Eyes closed & held Eyes closed & held

stillstill CR: Through center CR: Through center

of orbits, 30 of orbits, 30 degrees caudaldegrees caudal

PA Axial Eye RadiographPA Axial Eye Radiograph

Petrous pyramids Petrous pyramids lying below orbital lying below orbital shadowsshadows

No rotation of No rotation of craniumcranium


Modified Waters (EYE)Modified Waters (EYE) IR at level of orbitsIR at level of orbits

Rest pt’s chin on IRRest pt’s chin on IR

MSP perp and OML 50 MSP perp and OML 50 degrees from IRdegrees from IR

CR: Perp through mid-CR: Perp through mid-orbitsorbits

Instruct pt to close Instruct pt to close eyes and hold eyes stilleyes and hold eyes still

Modified Waters RadiographModified Waters Radiograph

Petrous Pyramids Petrous Pyramids lying well below lying well below orbital shadowsorbital shadows

Symmetric Symmetric visualization of orbitsvisualization of orbits


LETS REVIEWLETS REVIEW

Seven Bones of the OrbitSeven Bones of the Orbit

Seven Bones of the OrbitSeven Bones of the Orbit

A. Frontal bone- A. Frontal bone- orbital plateorbital plate

B. Sphenoid boneB. Sphenoid bone C. Palatine boneC. Palatine bone D. Zygomatic boneD. Zygomatic bone E. Maxillary boneE. Maxillary bone F. Ethmoid boneF. Ethmoid bone G. Lacrimal boneG. Lacrimal bone

Openings and Supporting Openings and Supporting Structures of Openings of the Structures of Openings of the

OrbitOrbit

Openings and Supporting Openings and Supporting Structures of Openings of the Structures of Openings of the

OrbitOrbit A. Optic ForamenA. Optic Foramen

B. Sphenoid StrutB. Sphenoid Strut

C. Superior Orbital C. Superior Orbital FissureFissure

D. Inferior Orbital D. Inferior Orbital FissureFissure

Parietoorbital Oblique Parietoorbital Oblique Projection of OrbitsProjection of Orbits

Parietoorbital Oblique Projection of Parietoorbital Oblique Projection of OrbitsOrbits

A. Frontal bone- orbital A. Frontal bone- orbital plateplate

B.Sphenoid boneB.Sphenoid bone C. Optic foramen & canalC. Optic foramen & canal D. Superior orbital fissureD. Superior orbital fissure

E. Inferior orbital fissureE. Inferior orbital fissure F. Sphenoid strutF. Sphenoid strut G. Lateral orbital marginG. Lateral orbital margin H. Superior orbital marginH. Superior orbital margin

Orbital anatomy ReviewOrbital anatomy Review

http://www.uth.tmc.edu/radiology/http://www.uth.tmc.edu/radiology/test/er_primer/face/images/test/er_primer/face/images/wtrs02.htmlwtrs02.html

ReferencesReferences

Ballinger, P.W. & Frank, E.D. (1999).Ballinger, P.W. & Frank, E.D. (1999).Merrill’s atlas of radiographic positions and Merrill’s atlas of radiographic positions and radiologic procedures. V2. New York: Mosbyradiologic procedures. V2. New York: Mosby

Ponsell, M.R. (2003). Assessing facial fractures in Ponsell, M.R. (2003). Assessing facial fractures in the emergency room. New Jerseythe emergency room. New Jersey

Richardson, M.L. (2000). Facial and mandibular Richardson, M.L. (2000). Facial and mandibular fractures. Retrieved May 5, 2007 from: fractures. Retrieved May 5, 2007 from: http//www.rad.washington.edu/mskbook/facialfx.hhttp//www.rad.washington.edu/mskbook/facialfx.htmltml

radiography of the orbits

Documents

lateral orbit

waters oml

lateral skull

lateral border of skull

cassettemml perpendicular

orbit floors

degrees superiorly37

maxillary sinusesoften