The document provides information on imaging of the orbit. It discusses orbital anatomy including the bony orbit and passages. It then covers various imaging modalities used for the orbit such as radiography, ultrasound, CT, MRI, angiography and their applications. Finally, it discusses common orbital lesions that can be imaged such as inflammatory lesions, tumors, vascular lesions, and infections. Imaging plays an important role in evaluating the numerous pathologies that can affect the confined space of the orbit.

1. IMAGING OF THEIMAGING OF THE
ORBITORBIT
DR NAVNI GARGDR NAVNI GARG
MBBS, DNBMBBS, DNB
MEDANTA-THE MEDICITYMEDANTA-THE MEDICITY

2. IntroductionIntroduction
The orbit, a confined space of 30 cc withThe orbit, a confined space of 30 cc with
four walls (roof, lateral wall, medial wallfour walls (roof, lateral wall, medial wall
and floor), is bordered by the brain onand floor), is bordered by the brain on
one side and sinuses on two of the other,one side and sinuses on two of the other,
and can be the host to numerous diseaseand can be the host to numerous disease
processes including tumors, inflammationsprocesses including tumors, inflammations
and infections.and infections.

3. Orbital AnatomyOrbital Anatomy
 Bony orbit refers to the shell of bone whichBony orbit refers to the shell of bone which
surrounds and protects the eye.surrounds and protects the eye.
 Bony orbit is a pyramidal cavity with anBony orbit is a pyramidal cavity with an
elliptical base presenting anteriorly and theelliptical base presenting anteriorly and the
apex posteriorly at 22 degrees lateral from theapex posteriorly at 22 degrees lateral from the
visual axis.visual axis.

4. FLOOR OF ORBITFLOOR OF ORBIT

5. FLOORFLOOR
 The inferior wall or floor is composed of theThe inferior wall or floor is composed of the
orbital plate of the maxilla, the zygomatic boneorbital plate of the maxilla, the zygomatic bone
anterolaterally and the orbital plate of theanterolaterally and the orbital plate of the
palatine bone posteriorly. The inferior orbitalpalatine bone posteriorly. The inferior orbital
fissure provides passage for the maxillaryfissure provides passage for the maxillary
division of CNV, the infraorbital artery,division of CNV, the infraorbital artery,
branches of the sphenopalatine ganglion, andbranches of the sphenopalatine ganglion, and
branches of the inferior ophthalmic vein to thebranches of the inferior ophthalmic vein to the
pterygoid plexus.pterygoid plexus.

6. LATERAL WALLLATERAL WALL

7. LATERAL WALLLATERAL WALL
 The lateral wall is made up from the frontalThe lateral wall is made up from the frontal
process of the zygoma and the greater wingprocess of the zygoma and the greater wing
lateral to the optic foramen. Mention Whitnall’slateral to the optic foramen. Mention Whitnall’s
tubercle – lateral canthal ligament attaches. Thetubercle – lateral canthal ligament attaches. The
superior orbital fissure demarcates it from thesuperior orbital fissure demarcates it from the
orbital roof.orbital roof.

8. SUPERIOR WALLSUPERIOR WALL

9. MEDIAL WALLMEDIAL WALL

10. MEDIAL WALLMEDIAL WALL
 The medial wall is composed of the frontalThe medial wall is composed of the frontal
process of the maxilla, the lacrimal bone, theprocess of the maxilla, the lacrimal bone, the
lamina papyracea, and some of the lesser wing.lamina papyracea, and some of the lesser wing.
Posteriorly the optic foramen is related to thePosteriorly the optic foramen is related to the
posterior ethmoid air cells.posterior ethmoid air cells.

11. Anatomy – FascialAnatomy – Fascial
CompartmentsCompartments

12. Fascial CompartmentsFascial Compartments

13. EyelidEyelid

14. EyelidEyelid

15. Anatomy – Lacrimal SystemAnatomy – Lacrimal System

16. Passages of the Bony OrbitPassages of the Bony Orbit
1.Superior orbital fissure1.Superior orbital fissure
-Lesser and greater wings of the sphenoid.-Lesser and greater wings of the sphenoid.
-3,4,6&terminal branches of ophthalmic n.-3,4,6&terminal branches of ophthalmic n.
opth.veins,lacrimal .n,opth.veins,lacrimal .n,
frontal.n,nasociliary.n,orbital br of middlefrontal.n,nasociliary.n,orbital br of middle
meningel artery,lacrimal arterymeningel artery,lacrimal artery
2.Inferior orbital fissure2.Inferior orbital fissure
- Greater wing of the sphenoid, maxilla, and- Greater wing of the sphenoid, maxilla, and
palatine bones of the orbit,laterally bypalatine bones of the orbit,laterally by
zygomatic bonezygomatic bone
-Max. n,zygomatic.n,infraorbital vessels,inferior-Max. n,zygomatic.n,infraorbital vessels,inferior
ophth.v,parasympathetic to lacrimal glandophth.v,parasympathetic to lacrimal gland
3.Optic canal3.Optic canal
-Lies within the sphenoid bone,where lesser-Lies within the sphenoid bone,where lesser
wing attached to body of sphenoidwing attached to body of sphenoid
-Optic n.,opth.v,central retinal vein-Optic n.,opth.v,central retinal vein

17. Extraocular musclesExtraocular muscles

18. IMAGING MODALITIESIMAGING MODALITIES
RADIOGRAPHRADIOGRAPH
 Limited roleLimited role
 Various viewsVarious views
 Used to detect problems resulting from injury or trauma to theUsed to detect problems resulting from injury or trauma to the
eye, foreign bodieseye, foreign bodies

19. PA VIEW
LATERAL VIEW
Orbitoparietal oblique projection
RHESE METHOD-OPTIC CANAL

20. ULTRASOUNDULTRASOUND
 High frequency –Eye ball with 7.5 MHz/10MHzHigh frequency –Eye ball with 7.5 MHz/10MHz
Orbit proper is scanned with 5MHz/7.5MHzOrbit proper is scanned with 5MHz/7.5MHz
 Color Doppler imaging – central retinal artery and veinColor Doppler imaging – central retinal artery and vein
occlusions, cranial arteritis, nonarteritic ischemic opticocclusions, cranial arteritis, nonarteritic ischemic optic
neuropathy, and carotid disease.neuropathy, and carotid disease.

21. Computed tomography (CT)Computed tomography (CT)
 Thin sections with multiplanar scanning (axial, coronal andThin sections with multiplanar scanning (axial, coronal and
sagittal planes) and the possibility of three-dimensionalsagittal planes) and the possibility of three-dimensional
reconstructionreconstruction
 Contiguous thin section(2-3mm),thicker section(4-5mm)Contiguous thin section(2-3mm),thicker section(4-5mm)
coronal planes,displayed in both soft tissue and bone windowscoronal planes,displayed in both soft tissue and bone windows
 Plane-axial imaging parellel to infra-orbitomeatal linePlane-axial imaging parellel to infra-orbitomeatal line

22. CT ANATOMYCT ANATOMY
SUPERIOR ORBITAL FISSURE
INFERIOR ORBITAL FISSUREOPTIC CANAL

23. MRIMRI
 Better than CT for soft tissue differencesBetter than CT for soft tissue differences
 SEQUENCES: spin echo T1 and T2 weighted thin section (3SEQUENCES: spin echo T1 and T2 weighted thin section (3
mm) contiguous (or with small interslice gap) images aremm) contiguous (or with small interslice gap) images are
acquired in axial, coronal and possibly oblique planes.acquired in axial, coronal and possibly oblique planes.
 Fat suppression combined with post-contrast imagingFat suppression combined with post-contrast imaging
significantly improve visualisation of subtle masses and opticsignificantly improve visualisation of subtle masses and optic
nerve lesions.nerve lesions.
 FLAIR sequence - used to suppress the CSF hyperintensityFLAIR sequence - used to suppress the CSF hyperintensity
for the evaluation of optic nerve sheath complex.for the evaluation of optic nerve sheath complex.

24. MR ANATOMYMR ANATOMY

25. CAROTID ARTERIOGRAPHYCAROTID ARTERIOGRAPHY
 To confirm presence of arteriovenous malformation andTo confirm presence of arteriovenous malformation and
diurnal shunts, as well as certain tumors such as meningiomasdiurnal shunts, as well as certain tumors such as meningiomas
to localize feeding vessels.to localize feeding vessels.
 For balloon occlusion in patientsFor balloon occlusion in patients
with carotidocavernous fistula.with carotidocavernous fistula.

26.  Inflammatory lesionsInflammatory lesions
 Orbital traumaOrbital trauma
 TumorsTumors
 Cystic lesionsCystic lesions
 Vascular lesionsVascular lesions
 Ocular lesionsOcular lesions
 Congenital lesionsCongenital lesions
ORBITAL LESIONSORBITAL LESIONS

27. APPROACHAPPROACH
 Central orbital spaceCentral orbital space : Cavernous hemangioma,optic: Cavernous hemangioma,optic
nerve tumorsnerve tumors
 Tenon’s spaceTenon’s space : Inflammatory lesions-: Inflammatory lesions-
PseudotumorsPseudotumors
 Peripheral orbital spacePeripheral orbital space : Capillary hemangioma,lacrimal: Capillary hemangioma,lacrimal
gland tumors,dermoid cystgland tumors,dermoid cyst
lymphangiomalymphangioma
 Subperiosteal spaceSubperiosteal space : Subperiosteal: Subperiosteal
hematoma,inflammatoryhematoma,inflammatory
& neoplastic lesions of PNS& neoplastic lesions of PNS

28. Intraconal lesionsIntraconal lesions
 Cavernous hemangiomaCavernous hemangioma
 Optic N.Optic N.
meningioma,glioma,neuritismeningioma,glioma,neuritis
 LymphomaLymphoma
 PseudotumorPseudotumor
 LymphangiomaLymphangioma
 VarixVarix
 CCFCCF
 MetsMets
 Orbital cellulitisOrbital cellulitis
Extraconal lesionsExtraconal lesions
 Capillary hemangiomaCapillary hemangioma
 Dermoids & epidermoidDermoids & epidermoid
 Lacrimal gland lesionsLacrimal gland lesions
 SarcoidosisSarcoidosis
 RhabdomyosarcomaRhabdomyosarcoma
 LymphangiomaLymphangioma
 PseudotumorPseudotumor

29. INFLAMMATIONINFLAMMATION
CellulitisCellulitis
 Acute bacterial infection -Acute bacterial infection -
extension of an infection fromextension of an infection from
the paranasal sinuses or eyelidthe paranasal sinuses or eyelid
 CT -increased density area ,CT -increased density area ,
swelling of the anterior orbitalswelling of the anterior orbital
tissues ,obliteration of the fattissues ,obliteration of the fat
planesplanes
 Confined to the extraconalConfined to the extraconal
space - if left untreated, it canspace - if left untreated, it can
enter the muscle cone andenter the muscle cone and
intraconal space.intraconal space.
 MRI- hypointense on T1- andMRI- hypointense on T1- and
hyperintense on T2hyperintense on T2

30.  Most common cause of bilateralMost common cause of bilateral
proptosis -4:1 Femalesproptosis -4:1 Females
 Symmetrical swelling of theSymmetrical swelling of the
extraocular muscles.extraocular muscles.
 Medial and inferior rectus muscles -Medial and inferior rectus muscles -
most involved.most involved.
 Muscle enlargementMuscle enlargement
characteristically involves the bodycharacteristically involves the body
of the muscle, sparing the tendinousof the muscle, sparing the tendinous
attachment to the globe.attachment to the globe.
Grave’s diseaseGrave’s disease

31. PseudotumorPseudotumor
 Non-specific inflammationNon-specific inflammation
 Unilateral , 25% unilateral exophthalmosUnilateral , 25% unilateral exophthalmos
 Involves - extraconal and intraconal spacesInvolves - extraconal and intraconal spaces
 EOM enlargement: one muscle, inferior rectusEOM enlargement: one muscle, inferior rectus
most commonmost common
 Lacrimal gland enlargementLacrimal gland enlargement
 Optic nerve enlargement + irregularityOptic nerve enlargement + irregularity

32.  Scleral enhancement (50%)Scleral enhancement (50%)
 Streaky intraconal fatStreaky intraconal fat
 Orbital mass (intra- or extraconal,Orbital mass (intra- or extraconal,
discrete or irregular)discrete or irregular)
 CT scan - areas of soft tissue densityCT scan - areas of soft tissue density
with poorly defined margins.with poorly defined margins.
 Earliest changes of pseudotumor -Earliest changes of pseudotumor -
subtle edema of the retrobulbar fat.subtle edema of the retrobulbar fat.
 MR-hypointense to fat-T1,MR-hypointense to fat-T1,
isointense on T2isointense on T2

33.  Graves’ diseaseGraves’ disease
 PseudotumorPseudotumor
 Orbital cellulitisOrbital cellulitis
 A-V MalformationA-V Malformation
 Carotid-cavernous fisulaCarotid-cavernous fisula
 Infiltration by tumorInfiltration by tumor
 Spontaneous or traumatic hematomaSpontaneous or traumatic hematoma
Enlarged Extraocular musclesEnlarged Extraocular muscles

34. SarcoidosisSarcoidosis
 Rarely involves the orbit.Rarely involves the orbit.
 Affects the retrobulbar tissuesAffects the retrobulbar tissues
 Extend along the optic nerveExtend along the optic nerve
posteriorly through the optic canal toposteriorly through the optic canal to
involve the chiasm , suprasellarinvolve the chiasm , suprasellar
cisterns.cisterns.

35. Optic neuritisOptic neuritis
 Multiple sclerosis,infections,Multiple sclerosis,infections,
autoimmune disease,radiationautoimmune disease,radiation
optic neuropathyoptic neuropathy
 CT and MR- may be normal.CT and MR- may be normal.
 Enlargement of opticEnlargement of optic
nerve,some degree ofnerve,some degree of
enhancementenhancement
 MR-Optic nerve thickened,MR-Optic nerve thickened,
hyperintense on T2hyperintense on T2
 Post contrast fat suppressed,T1Post contrast fat suppressed,T1
MR –Best technique-localisedMR –Best technique-localised
or diffuse areas of enhancementor diffuse areas of enhancement

36. MucormycosisMucormycosis
 Poorly controlled diabetes,Poorly controlled diabetes,
immunocompromised patientimmunocompromised patient
 Starts in the nasal cavity orStarts in the nasal cavity or
paranasal sinuses - secondarilyparanasal sinuses - secondarily
involves the orbit.involves the orbit.
 The clinical picture and imagingThe clinical picture and imaging
features are oftenfeatures are often
indistinguishable from any otherindistinguishable from any other
orbital cellulitis.orbital cellulitis.

37. Langerhans’ Cell HistiocytosisLangerhans’ Cell Histiocytosis
 Children-1-4yrsChildren-1-4yrs
 Orbit-20%Orbit-20%
 Proptosis,edema and erythema ofProptosis,edema and erythema of
eyelid,optic nerve atrophy,papilloedemaeyelid,optic nerve atrophy,papilloedema
 Frontal bone-most involvedFrontal bone-most involved
 Erosions,marked destruction of roof, lateralErosions,marked destruction of roof, lateral
wall of orbit,greater wing of sphenoidwall of orbit,greater wing of sphenoid
 CT-Abnormal soft tissue thickening inCT-Abnormal soft tissue thickening in
orbit,proptosisorbit,proptosis

38. ORBITAL TRAUMAORBITAL TRAUMA
 4 Major locations: intraocular, intraorbital, intracanalicular,4 Major locations: intraocular, intraorbital, intracanalicular,
and intracranialand intracranial
 Blow-out or blow-in fractures, with peripheral considerationBlow-out or blow-in fractures, with peripheral consideration
of Tripod and Le Fort fractures.of Tripod and Le Fort fractures.
 RadiographRadiograph
 Displaced bone fragmentDisplaced bone fragment
 Asymmetric hemorrhage-related opacification of a paranasalAsymmetric hemorrhage-related opacification of a paranasal
sinussinus
 Unilateral opacification of the ethmoid air cellsUnilateral opacification of the ethmoid air cells
 Orbital emphysema.Orbital emphysema.
 Tear drop sign-Tear drop sign-
herniated orbital contents, periorbital fat and inferior rectusherniated orbital contents, periorbital fat and inferior rectus
muscle.muscle.

39. Blowout FracturesBlowout Fractures
 Originally defined as orbital floorOriginally defined as orbital floor
fractures without fracture orbital rim,fractures without fracture orbital rim,
but with entrapment one or more softbut with entrapment one or more soft
tissue structurestissue structures
 Medial wall is most often damagedMedial wall is most often damaged
with orbital rim being intactwith orbital rim being intact
 ““Pure” blowout fractures – trap doorPure” blowout fractures – trap door
rotation to bone fragments involvingrotation to bone fragments involving
central area of bone.central area of bone.
 ““Impure” fracture – fracture lineImpure” fracture – fracture line
extends to orbital rimextends to orbital rim

40. Injuries associated with blow outInjuries associated with blow out
fracturesfractures
 Ruptured globeRuptured globe
 Retroorbital hemorrhageRetroorbital hemorrhage
 Vitreous hemorrhageVitreous hemorrhage
 HyphemaHyphema
 Anterior chamber angle recessionAnterior chamber angle recession
 Dislocated lensDislocated lens
 Secondary glaucomaSecondary glaucoma
 Retinal detachmentRetinal detachment

41. Globe RuptureGlobe Rupture
 Penetrating or blunt traumaPenetrating or blunt trauma
 Blunt trauma-anterior-posteriorBlunt trauma-anterior-posterior
compression of the globe increasescompression of the globe increases
intraocular pressure - sclera tearsintraocular pressure - sclera tears
-uveoscleral infolding with-uveoscleral infolding with
hypotony of eyehypotony of eye
 Sharp objects or those traveling atSharp objects or those traveling at
high velocity - perforate the globehigh velocity - perforate the globe
directlydirectly

42. Penetrating TraumaPenetrating Trauma
 Foreign bodies may beForeign bodies may be
glass, wood, metal, or otherglass, wood, metal, or other
 Look for entrance and exitLook for entrance and exit
sitessites

43. Foreign BodyForeign Body
 Plain radiograph –initial modalityPlain radiograph –initial modality
 CT scanCT scan
• Delineating a foreign body which isDelineating a foreign body which is
close to the coats of the eyeballclose to the coats of the eyeball
• Localising foreign bodies adjacentLocalising foreign bodies adjacent
to the lensto the lens
• Presence of other foreign bodies inPresence of other foreign bodies in
the orbit, brain and fractures if any,the orbit, brain and fractures if any,
can also be detectedcan also be detected

44. ORBITALTUMORSORBITALTUMORS
Optic Nerve LesionsOptic Nerve Lesions
Optic gliomasOptic gliomas
 Occur in children ; associationOccur in children ; association
with neurofibromatosis .with neurofibromatosis .
 Benign optic glioma in children ,Benign optic glioma in children ,
aggressive glioma in adultsaggressive glioma in adults
 Slow-growing, nonaggressiveSlow-growing, nonaggressive
 CT- fusiform,tortuosCT- fusiform,tortuos
enlargement of the optic nerve.enlargement of the optic nerve.
They can extend posteriorlyThey can extend posteriorly
through the optic canal tothrough the optic canal to
involve the optic chiasm.involve the optic chiasm.
 Contrast enhancement lessContrast enhancement less
compared to meningioma.compared to meningioma.
T1
Post-gad T1 fat sat

45. MENINGIOMAMENINGIOMA
Type 1. Sphenoid wingType 1. Sphenoid wing
meningiomasmeningiomas
 Lie behind the eyesLie behind the eyes
 CT - well defined smooth outlinedCT - well defined smooth outlined
mass showing marked contrastmass showing marked contrast
enhancement,contiguity withenhancement,contiguity with
adjacent dura and hyperostosis ofadjacent dura and hyperostosis of
adjacent bones.adjacent bones.
 Bone destruction mimic metastatic orBone destruction mimic metastatic or
other malignant tumorsother malignant tumors

46. Type 2. Optic nerve sheathType 2. Optic nerve sheath
meningiomasmeningiomas
 Middle-aged femalesMiddle-aged females
 Tubular appearanceTubular appearance
 Enhance more than gliomas , "railroadEnhance more than gliomas , "railroad
track" appearance -characteristictrack" appearance -characteristic
 CalcificationCalcification
 Hyperostosis around the optic canalHyperostosis around the optic canal

47. Type 3.Meningiomas arising de novo from arachnoid cellsType 3.Meningiomas arising de novo from arachnoid cells
inside orbitinside orbit
 Grow around the eye socketsGrow around the eye sockets
 Cause pressure in the eyes - bulging appearanceCause pressure in the eyes - bulging appearance

48. SchwannomasSchwannomas
 Benign, non-invasive peripheral nerveBenign, non-invasive peripheral nerve
tumor, from any nerve in orbittumor, from any nerve in orbit
 Rare, 20 -70 yearsRare, 20 -70 years
 CT/MR - well circumscribed ovoidCT/MR - well circumscribed ovoid
massmass
 Most commonly intraconal, may beMost commonly intraconal, may be
extraconal (trochlear, supraorbitalextraconal (trochlear, supraorbital
nerves)nerves)

49. Intraconal/Extraconal TumorsIntraconal/Extraconal Tumors
Cavernous hemangiomasCavernous hemangiomas
 Benign, well-encapsulated lesionsBenign, well-encapsulated lesions
with wide vascular spaceswith wide vascular spaces
 Intraconal space, lateral to the opticIntraconal space, lateral to the optic
nervenerve
 CT—Well demarcated soft tissueCT—Well demarcated soft tissue
mass ,variable contrast enhancementmass ,variable contrast enhancement
 MR –iso-hyperintense T1,MR –iso-hyperintense T1,
moderately hyperintense,flowmoderately hyperintense,flow
voids on T2.voids on T2.

50. LymphangiomasLymphangiomas
 Children ,young adultsChildren ,young adults
 Unencapsulated,extraconalUnencapsulated,extraconal
 Poorly defined margins, showPoorly defined margins, show
little or no contrast enhancementlittle or no contrast enhancement
 May involve conjunctiva, eyelidsMay involve conjunctiva, eyelids
or deep orbitor deep orbit
 CT/MRI shows multi-CT/MRI shows multi-
compartmental naturecompartmental nature
 cystic components with multiplecystic components with multiple
fluid levels of varying signalfluid levels of varying signal
intensityintensity

51. LymphomaLymphoma
 Relatively uncommonRelatively uncommon
 Conjunctiva and lacrimal glandConjunctiva and lacrimal gland
 Homogeneous lesions withHomogeneous lesions with
relatively well-defined margins.relatively well-defined margins.
 MR-When there is dense packing-MR-When there is dense packing-
low on T1,T2low on T1,T2
When packing less dense-High onWhen packing less dense-High on
T2T2
 Can invade adjacent sinusCan invade adjacent sinus
compartmentscompartments

52. Soft tissue tumorsSoft tissue tumors
RhabdomyosarcomaRhabdomyosarcoma
 Most common primary malignantMost common primary malignant
orbital tumor of childhood.orbital tumor of childhood.
 Very aggressive tumor - showsVery aggressive tumor - shows
extensive destruction.extensive destruction.
 MR-low to intermediate onMR-low to intermediate on
T1,bright on T2T1,bright on T2

53. Fibrous Histiocytoma (Solitary Fibrous Tumour)Fibrous Histiocytoma (Solitary Fibrous Tumour)
 Arises from the connective tissues cells of the orbit.Arises from the connective tissues cells of the orbit.
 These are usually moderately large, rounded well-definedThese are usually moderately large, rounded well-defined
tumours in the socket.tumours in the socket.
TeratomasTeratomas
 RareRare
 Characterized by areas of calcification and fat density.Characterized by areas of calcification and fat density.

54. Tumors of the Eyelid and PreseptalTumors of the Eyelid and Preseptal
SpaceSpace
 Tumors of the anterior compartmentTumors of the anterior compartment
- extend posteriorly into the- extend posteriorly into the
extraconal space.extraconal space.
 Basal cell carcinoma - 80%Basal cell carcinoma - 80%
 Other - squamous cell and sebaceousOther - squamous cell and sebaceous
cell carcinomas and adenocarcinoma.cell carcinomas and adenocarcinoma.

55. Lacrimal Gland TumorsLacrimal Gland Tumors
 Enlargement of lacrimal fossa -Enlargement of lacrimal fossa -
displacement of globe , nodisplacement of globe , no
inflammatory signsinflammatory signs
 50% epithelial, 50%50% epithelial, 50%
lymphoproliferativelymphoproliferative
 CT scan – lymphoid show smoothCT scan – lymphoid show smooth
enlargement of gland, epithelial areenlargement of gland, epithelial are
irregular ;homogeneous characterirregular ;homogeneous character
and moderate contrast enhancement.and moderate contrast enhancement.
 Poorly defined margins with bonePoorly defined margins with bone
destruction - malignancy, but evendestruction - malignancy, but even
the malignant lesions can bethe malignant lesions can be
relatively well-defined.relatively well-defined.

56. Dermoid CystDermoid Cyst
 Most common congenital lesionMost common congenital lesion
 1/3rd childhood orbital tumors.1/3rd childhood orbital tumors.
 Location -Superior temporal quadrant atLocation -Superior temporal quadrant at
the frontozygomatic suture, nasal aspectthe frontozygomatic suture, nasal aspect
of upper orbit at the frontoethmoidalof upper orbit at the frontoethmoidal
suturesuture
 May have cystic or solid components.May have cystic or solid components.
 On CT scan the lesion is seen as a lowOn CT scan the lesion is seen as a low
density, extraconal, nonenhancing massdensity, extraconal, nonenhancing mass
with smooth margins. Fat fluid levelwith smooth margins. Fat fluid level
may be present.may be present.
 These may show fat, fluid or soft tissueThese may show fat, fluid or soft tissue
signal , show calcificationsignal , show calcification

57. Colobomatous CystsColobomatous Cysts
 Coloboma - congenital or acquired notch,Coloboma - congenital or acquired notch,
gap or fissure in which a portion of normalgap or fissure in which a portion of normal
tissue is absenttissue is absent
 Cleft appears in the inferonasal quadrant ofCleft appears in the inferonasal quadrant of
the globe.the globe.
 > 60% - bilateral> 60% - bilateral
 Affected eye - normal sized orAffected eye - normal sized or
microphthalmic . A cleft in the globe may bemicrophthalmic . A cleft in the globe may be
visualized . Tunnel-like connection betweenvisualized . Tunnel-like connection between
the eye and the cyst is often very thin andthe eye and the cyst is often very thin and
difficult to image.difficult to image.
 CT - anatomic relationship of the cyst to theCT - anatomic relationship of the cyst to the
globe prior to surgical intervention , anyglobe prior to surgical intervention , any
associated developmental anomalies of theassociated developmental anomalies of the
brain.brain.

58. ACQUIRED CYSTSACQUIRED CYSTS
Lacrimal Gland CystsLacrimal Gland Cysts
 Occur due to blockage of the excretoryOccur due to blockage of the excretory
ducts and may be located in the orbitalducts and may be located in the orbital
or palpebral lobes of the main glandor palpebral lobes of the main gland
 These cysts appear as low-density,These cysts appear as low-density,
nonenhancing lesions on CT .nonenhancing lesions on CT .

59. Hematic CystsHematic Cysts
 Deeply placed, incompletely resorbedDeeply placed, incompletely resorbed
hematomas which may remainhematomas which may remain
unchanged for long periods of time .unchanged for long periods of time .
 Orbital roof - most common siteOrbital roof - most common site
 CT - well defined, extraconal, nonCT - well defined, extraconal, non
enhancing mass in the subperiosteal,enhancing mass in the subperiosteal,
medullary or diploic spaces.medullary or diploic spaces.
 Shows high CT attenuation value- dueShows high CT attenuation value- due
to hemosiderin deposition and protein-to hemosiderin deposition and protein-
rich fluid.rich fluid.
 Commonly associated with erosion andCommonly associated with erosion and
expansion of the adjacent bonesexpansion of the adjacent bones

60. Parasitic CystsParasitic Cysts
Cellulosae CystsCellulosae Cysts
 Most common intra-orbital parasiticMost common intra-orbital parasitic
infestation.infestation.
 May be intraocular or extraocularMay be intraocular or extraocular
 Extraocular muscles - commonestExtraocular muscles - commonest
 CT- cysts may be seen as a small round,CT- cysts may be seen as a small round,
welldefined, nonenhancing area of lowwelldefined, nonenhancing area of low
attenuation. The scolex, may or may not beattenuation. The scolex, may or may not be
visualized.visualized.
 Contrast enhanced CT scans-pericysticContrast enhanced CT scans-pericystic
inflammation – thick, irregular enhancing cystinflammation – thick, irregular enhancing cyst
walls, thickening of involved muscle andwalls, thickening of involved muscle and
streaky soft tissue densities in the orbital fat.streaky soft tissue densities in the orbital fat.

61. Hydatid CystsHydatid Cysts
 Seen in patients from endemicSeen in patients from endemic
regions.regions.
 Larval form of EchinococcusLarval form of Echinococcus
granulosusgranulosus
 On CT scan, these cysts may appearOn CT scan, these cysts may appear
as well defined, uni-locular or multi-as well defined, uni-locular or multi-
locular large cysts, with or withoutlocular large cysts, with or without
globe displacement .globe displacement .

62. Adjacent Structure CystsAdjacent Structure Cysts
CephalocoelesCephalocoeles
 RareRare
 Meninges, CSF and brain herniateMeninges, CSF and brain herniate
through a bone defect or through athrough a bone defect or through a
natural anatomic opening.natural anatomic opening.
 < 1% orbital masses.< 1% orbital masses.
 CT - bony defect , herniated massCT - bony defect , herniated mass
 MR -study of choiceMR -study of choice
Encephalocele
Menigocele

63. MucoceleMucocele
 Expanding cystic lesions covered by aExpanding cystic lesions covered by a
mucous membrane.mucous membrane.
 Obstruction of ostium in a sinusObstruction of ostium in a sinus
 2/3 -frontal sinuses2/3 -frontal sinuses
 CT - Homogeneous, low density,CT - Homogeneous, low density,
nonenhancing soft tissue masses,nonenhancing soft tissue masses,
expansion of the involved sinus andexpansion of the involved sinus and
erosion of the adjacent orbital wallserosion of the adjacent orbital walls

64. Orbital MetastasisOrbital Metastasis
 Relatively rareRelatively rare
 Simultaneous brain metastasis - in two thirds of patientsSimultaneous brain metastasis - in two thirds of patients
with orbital metastasis.with orbital metastasis.
 Adults - Breast, lung, prostate, stomach, etc.Adults - Breast, lung, prostate, stomach, etc.
 Children, - Neuroblastoma, Ewing's sarcoma and leukemia.Children, - Neuroblastoma, Ewing's sarcoma and leukemia.
 Morphological pattern is variable- may be infiltrative andMorphological pattern is variable- may be infiltrative and
poorly defined or produce a well defined masspoorly defined or produce a well defined mass

65. NEUROBLASTOMA METASTASISNEUROBLASTOMA METASTASIS

66. VASCULAR LESIONSVASCULAR LESIONS
Orbital varixOrbital varix
 Congenital venous vascularCongenital venous vascular
malformations in which afferent andmalformations in which afferent and
efferent vessels are veinsefferent vessels are veins
 Spontaneous thrombus is common.Spontaneous thrombus is common.
Calcified phleboliths may be seenCalcified phleboliths may be seen
 Orbital phlebogaraphy-demonstrateOrbital phlebogaraphy-demonstrate
afferent &efferent veinsafferent &efferent veins
 CT - fusiform or globular densities ,CT - fusiform or globular densities ,
enhance brightly.enhance brightly.
 MR -A mixture of flow void and flowMR -A mixture of flow void and flow
enhancement.enhancement.
 Valsalva maneuver- increase in sizeValsalva maneuver- increase in size

67. Arterio venous malformationsArterio venous malformations
 RareRare
 Associated with intracranial AVMAssociated with intracranial AVM
 MR -Serpiginous areas of flow-voidMR -Serpiginous areas of flow-void

68. Carotid Cavernous FistulaCarotid Cavernous Fistula
 Abnormal communicationAbnormal communication
between the carotid artery andbetween the carotid artery and
the cavernous sinus.the cavernous sinus.
 Traumatic or spontaneous, highTraumatic or spontaneous, high
flow or low flow, direct or dural.flow or low flow, direct or dural.
 ‘‘Hockey stick' sign of anHockey stick' sign of an
engorged superior ophthalmicengorged superior ophthalmic
veinvein
 Gold standard-selectiveGold standard-selective
arteriographyarteriography

69. Osseous LesionsOsseous Lesions
 Dysplasias, primary and metastaticDysplasias, primary and metastatic
bonebone
 TumoursTumours
 Fibrous dysplasia - diffusely dense,Fibrous dysplasia - diffusely dense,
having a ground glass appearance buthaving a ground glass appearance but
may be heterogenous.may be heterogenous.

70. OCULAR LESIONSOCULAR LESIONS
Vitreous HemorrhageVitreous Hemorrhage
 Vitreous -normally clear and echo free onVitreous -normally clear and echo free on
US.US.
 Patients with diabetic retinoathy andPatients with diabetic retinoathy and
trauma.trauma.
 US - scattered, low amplitude echoes,US - scattered, low amplitude echoes,
which subsequently becomes highlywhich subsequently becomes highly
echogenic.echogenic.
 Estimation of the extent of vitreousEstimation of the extent of vitreous
haemorrhage is important to know thehaemorrhage is important to know the
prognosis for spontaneousprognosis for spontaneous
clearing and planning for vitrectomyclearing and planning for vitrectomy
 Normal vitreous of low attenuation onNormal vitreous of low attenuation on
CT scan but in vitreous haemorrhage itCT scan but in vitreous haemorrhage it
becomes diffusely hazy.becomes diffusely hazy.

71. Ocular detachmentsOcular detachments

72. Retinal DetachmentRetinal Detachment
 Separation of the inner layers of the retinaSeparation of the inner layers of the retina
from retinal pigment epithelium (RPE,from retinal pigment epithelium (RPE,
choroids)choroids)
 US- thin echogenic membrane attached toUS- thin echogenic membrane attached to
optic nerve head posteriorly and ora serrataoptic nerve head posteriorly and ora serrata
anteriorly, often assuming V or Y shapedanteriorly, often assuming V or Y shaped
appearance.Moves with eye ball with no orappearance.Moves with eye ball with no or
few after movementsfew after movements
 CT - mild or focal retinal detachmentCT - mild or focal retinal detachment
cannot be detected. Significant retinalcannot be detected. Significant retinal
detachment may be seen on contrastdetachment may be seen on contrast
enhancementenhancement
 CT as V or Y shaped appearance due toCT as V or Y shaped appearance due to
lifted up retinal leaves and subretinal fluidlifted up retinal leaves and subretinal fluid
or exudative collection.or exudative collection.

73. Vitreous detachmentVitreous detachment
 Later middle age ,Short sightedLater middle age ,Short sighted
peoplepeople
 Injury to the eye or headInjury to the eye or head
 US- Detachment - smooth, dome-US- Detachment - smooth, dome-
shaped, and thick.shaped, and thick.
 Extensive- multiple dome-shapedExtensive- multiple dome-shaped
detachments, which may "kiss" in thedetachments, which may "kiss" in the
central vitreous cavity. Hemorrhagiccentral vitreous cavity. Hemorrhagic
- subchoroidal space is filled with a- subchoroidal space is filled with a
multitude of dotsmultitude of dots

74. Choroidal detachmentChoroidal detachment
 Seen as homogenous domeSeen as homogenous dome
shaped membrane notshaped membrane not
attached to the optic discattached to the optic disc
 Moves with eye ballMoves with eye ball
 Suprachoidal space may beSuprachoidal space may be
clear in serous,echogenicclear in serous,echogenic
in hemorrhagic choroidalin hemorrhagic choroidal
detachmentdetachment

75. RetinoblastomaRetinoblastoma
 Most common intraocular malignant tumor of childhood.Most common intraocular malignant tumor of childhood.
 First 2 years of life.First 2 years of life.
 10% - autosomal dominant trait; rest - sporadic mutations of10% - autosomal dominant trait; rest - sporadic mutations of
chromosome 13.chromosome 13.
 30% - bilateral.30% - bilateral.
 US -distinguish retinoblastomas from non-neoplasticUS -distinguish retinoblastomas from non-neoplastic
conditions, detecting calcificationsconditions, detecting calcifications
 CT- detect intraocular calcification and shows intraocularCT- detect intraocular calcification and shows intraocular
extent of the tumorextent of the tumor
 MRI - useful in identifying any associated hemorrhagic orMRI - useful in identifying any associated hemorrhagic or
exudative retinal detachment .exudative retinal detachment .
Hyperintense comapred to vitreous on T1and proton density,Hyperintense comapred to vitreous on T1and proton density,
low signal –T2low signal –T2

76. RETINOBLASTOMARETINOBLASTOMA

77. D/D RETINOBLASTOMAD/D RETINOBLASTOMA
 PHPVPHPV
 Coats diseaseCoats disease
 Retinopathy of prematurityRetinopathy of prematurity
 ToxocoriasisToxocoriasis
 Retinal detachmentRetinal detachment
 EndophthalmitisEndophthalmitis
 Congenital cataract,glaucomaCongenital cataract,glaucoma
 Vitreous hemorhageVitreous hemorhage
 Choroidal osteoma,hemangiomaChoroidal osteoma,hemangioma

78. Metastatic Tumours of the EyeballMetastatic Tumours of the Eyeball
 Second most common intraocular tumours of the adult .Second most common intraocular tumours of the adult .
 Usually metastasize to the choroid ,rarely to the iris.Usually metastasize to the choroid ,rarely to the iris.
 Most common sites of origin - breast, lung,gastrointestinalMost common sites of origin - breast, lung,gastrointestinal
cancer.cancer.

79. Choroid MelanomaChoroid Melanoma
 6-7th decades6-7th decades
 Single ,unilocular, arise fromSingle ,unilocular, arise from
preexisting nevi in the choroid.preexisting nevi in the choroid.
 Aggressive tumorsAggressive tumors
 CT- high density and do not calcify.CT- high density and do not calcify.
 MR-Compared to the vitreous, theyMR-Compared to the vitreous, they
are high signal on T1-weightedare high signal on T1-weighted
images and low signal on T2-images and low signal on T2-
weighted images.weighted images.
 Subretinal effusion - common.Subretinal effusion - common.

80. Paranasal Sinus MassesParanasal Sinus Masses
 Potentially can spread to involve the orbitPotentially can spread to involve the orbit
 Most common: mucoceleMost common: mucocele
 Neoplasms of this area are uncommon, but frequently involveNeoplasms of this area are uncommon, but frequently involve
orbitorbit
 Benign tumors push periorbita, malignant invadeBenign tumors push periorbita, malignant invade

81. Neoplasms of Paranasal SinusNeoplasms of Paranasal Sinus
 UncommonUncommon
 Most common – SCCaMost common – SCCa
 Orbital invasion in 2/3 of patients with SCCaOrbital invasion in 2/3 of patients with SCCa
 Orbital extension - poor prognosisOrbital extension - poor prognosis

82. Congenital LesionsCongenital Lesions
Persistent hyperplastic primary vitreousPersistent hyperplastic primary vitreous
(PHPV)(PHPV)
 Unilateral ,may be present at birth.Unilateral ,may be present at birth.
 D/D- retinoblastoma.D/D- retinoblastoma.
 US- a triangular retrolental band of softUS- a triangular retrolental band of soft
tissuetissue
 CT- layering of fluid with highCT- layering of fluid with high
attenuation. microophthalmos.attenuation. microophthalmos.
 MRI –fibrovascular retrolental massMRI –fibrovascular retrolental mass
-hypointense on both T1 and T2W-hypointense on both T1 and T2W
images.images.

83. Coats' diseaseCoats' disease
 Exudative retinopathy fillingExudative retinopathy filling
subretinal space with asubretinal space with a
lipoproteinaceous fluid.lipoproteinaceous fluid.
 Characterised by talengectasisCharacterised by talengectasis
 Unilateral,6-8 yrUnilateral,6-8 yr
boys.Calcification is uncommonboys.Calcification is uncommon
 MR-homogenous hyperintensityMR-homogenous hyperintensity
of subretinal fluid-of subretinal fluid-
T1,T2.Detached V shapedT1,T2.Detached V shaped
retina-low signal on T1,T2retina-low signal on T1,T2

84. AnophthalmosAnophthalmos
 Failure of development of theFailure of development of the
optic vesicleoptic vesicle
 Often bilateral and may beOften bilateral and may be
associated with an optic vesicleassociated with an optic vesicle
cyst.cyst.
 Other conditions-micro-Other conditions-micro-
opthlmos,opthlmos,
macro-ophtalmosmacro-ophtalmos

85. CONGENITAL CYSTIC EYECONGENITAL CYSTIC EYE
 Failure of optic vesicle to invaginateFailure of optic vesicle to invaginate
 Complex cyst in orbit without any vestigeComplex cyst in orbit without any vestige
of globeof globe
 CT-Enlarged orbit containingCT-Enlarged orbit containing
ovoid,septated cystovoid,septated cyst
Superior orbital fissure widenedSuperior orbital fissure widened
 MR-Signal intensity is not equal to vitreosMR-Signal intensity is not equal to vitreos
as it is filled with serum.rudimentaryas it is filled with serum.rudimentary
connection to thinned optic nerve mayconnection to thinned optic nerve may
be seenbe seen

86. Benign LesionsBenign Lesions
Optic nerve drusenOptic nerve drusen
 Represents cellular accretions of hyaline-likeRepresents cellular accretions of hyaline-like
material in the optic disk.material in the optic disk.
 Bilateral -73% and frequently calcify.Bilateral -73% and frequently calcify.
 Many are asymptomatic, but arcuate visualMany are asymptomatic, but arcuate visual
field defects may be present.field defects may be present.
 CT - Discrete rounded high densitiesCT - Discrete rounded high densities
confined to the optic disk surface.confined to the optic disk surface.
Choroidal OsteomasChoroidal Osteomas
 Idiopathic or may develop within aIdiopathic or may develop within a
degenerated choroidal hemangioma or andegenerated choroidal hemangioma or an
inflammatory scar.inflammatory scar.
 Located near the optic disk.Located near the optic disk.

87. ConclusionsConclusions
 Orbital anatomy complex with closeOrbital anatomy complex with close
association to sinuses and cranial vaultassociation to sinuses and cranial vault
 Broad range of diseases and tumorsBroad range of diseases and tumors
 Often need multi-specialty cooperationOften need multi-specialty cooperation
 Plain radiograph- limited rolePlain radiograph- limited role
 US-Intraocular lesionsUS-Intraocular lesions
 CT&MRI-Preferred modality of choiceCT&MRI-Preferred modality of choice

88. THANK TOUTHANK TOU
THANK YOU