The imaging of the orbit

1. The Orbit
Thorsang R1
Neuroradiology topic
04.06.2014

2. Outline
• Orbit overview
• Imaging techniques
• Orbital anatomy
• Diseases of the orbit

3. Major anatomic components
• Globe
• Optic nerve &
sheath
• Conal-intraconal
area
• Extraconal area

4. Differential diagnoses

5. Imaging techniques
MRI
• Initial imaging sequence of
choice for the orbit and CN
II
– Intraaxial, sellar, parasellar
lesions
– More sensitive
CT
• An adjunctive tool:
calcifications
– Small meningioma
– Retinoblastoma with
calcification

6. Imaging techniques

7. Orbital anatomy
• Roof
• Floor
• Medial wall
• Lateral wall
• Superior orbital
fissure
• Inferior orbital
fissure
• Optic canal

8. Orbital roof
• Frontal bone
with frontal
sinus
• Anteriorly thin
• Fossa for
lacrimal gland

9. Orbital floor
• Orbital plate of
maxilla
– Thin
-> blowout fx*
• Orbital process
of palatine bone
• Orbital surface
of zygomatic
bone

10. Medial orbital wall
• Lacrimal groove
• Lamina
papyracea
– Medial blowout
fracture*
– Spontaneous
dehiscence of
orbital fat
• Into ethmoid
sinus
• Sphenoid bone

11. Lateral orbital wall
• Orbital surface
of zygomatic
bone

12. Superior orbital fissure
Location
• Between roof
and lateral wall
• Surrounded by
sphenoid
• Beneath optic
canal
• Optic strut

13. Superior orbital fissure
Content
• Superior
opthalmic vein
• CN III, IV, VI
• CN V1
>> Conduit
between orbital
apex-cavernous
sinus

14. Inferior orbital fissure
Location
• Between floor
and lateral wall
• PPF fossa-NSP
masticator space

15. Inferior orbital fissure
Content
• CN V2, V3
• N.
– from PP gg.
• V.
– inf. Opthalmic v.-
pterygoid plexus
>> Deep face
inflammatory and
neoplastic lesions

16. Optic canal
• Lesser wing of
sphenoid bone
• Optic nerve +
ophthalmic artery
(in dural shealth)
• From suprasellar
cistern

17. Conal-intraconal area

18. Intraconal space pathology
• Venous vascular malformation
• Capillary hemangioma
• Venous dilatation
– Carotid Cavernous Fistula
– Varices
• Optic nerve lesions
– Optic neuritis
• MS
• Devic's syndrome
• Neuritis due to infection
(e.g.herpes zoster)
• Autoimmune (e.g.Lupus)
• Drugs (e.g.chloramphenicol,
ethambutol)
– Optic nerve glioma
– Optic nerve meningioma
– Pseudotumor
• Other cranial nerves
– Schwannoma of 3rd, 4th and
6th cranial nerve

19. Conal space pathology
• Thyroid eye disease
– usually enlargement of the inferior and medial rectus
• Pseudotumor:
– idiopathic orbital inflammation
• Adjacent inflammation:
– sinusitis
• Uncommon causes of enlargement of the extra-
ocular muscles
– glycogen storage disease and lymphoma

20. Extraconal area
• Fat
• Lacrimal gland
– Lens-shape
– Anterior,
superolateral
– Lies on levator
palpabrae and
lateral rectus
• Bone

21. Extraconal pathology
• Abscess due to sinusitis
• Schwannoma of the V1 and V2
• Bone lesions:
– Fibrous dysplasia of the sphenoid wing
– Metastases
– Multiple myeloma
• Diseases of the orbital appendages

22. Orbital appendages
• Lacrimal gland
– superolaterally in the orbit
– granulomatous, epithelial/glandular, and
developmental
• lacrimal sac
• lacrimal duct
– -> inferior terbinate into the nose

23. Diseases of the orbit
• Globe
• Optic nerve &
sheath
• Conal-intraconal
area
• Extraconal area

24. The ocular space
• Anterior chamber:
cornea anteriorly and the lens and iris posteriorly
– Rupture of the globe
– Hemorrhage: also known as anterior hyphema
– Cataract
– Keratitis: inflammation of the cornea
– Periorbital cellulitis
• Posterior chamber:
posterior to the iris
– Glaucoma
– Uveitis
– Ciliary melanoma
The globe

25. The globe
Vitreous body
posterior to the lens
– Rupture
– Hemorrhage
– CMV infection: especially in HIV
– Persistent Hyperplastic Primary Vitreous (PHPV)

26. Persistent hyperplastic primary
vitreous
• Unilateral leukokoria in male infants
• Persistent hyaloid canal
• Persistence of the primary vascular vitreous
• Hyperplasia of the residual embryonic
connective tissue
• PHPV is the second most common cause of
leukocoria
• Also develops glaucoma and cataract

27. • Findings:
– Microphtalmic globe with enhancing increased
density in the vitreous humor.
– Unilateral/bilateral tissue density band from back
of the lens to the posterior inner globe (Persistent
Cloquet’s canal)
– Retinal detachment (occurs in 30-55%)
Persistent hyperplastic primary
vitreous

28. Persistent hyperplastic primary
vitreous

29. The globe

30. Retina
• Retinoblastoma:
– a common tumor in children
• Hemangioblastoma:
– most common retinal tumor in the adult
– von Hippel Lindau disease
• Detachment:
– most common retinal lesion
– diabetic retinopathy

31. Retinoblastoma
• Common tumor in the first year of life
• Child < 3 years of age (98%)
• Other presentations: leukokoria, strabismus,
decreased visual acuity, family hx, eye pain,
proptosis
• Believed to arise from neuroectodermal cells

32. • 75% unilateral; 25% bilateral
• All bilateral cases are hereditary (AD) >>
deficient tumor suppression gene on
chromosome 13
• 90% calcified
Retinoblastoma

33. Retinoblastoma
• The other tumors in this age group are
– Neuroblastoma
– Wilm's tumor
– Leukemia
– Teratoma.

34. Retinoblastoma
• Techniques
– CT is prefered to detect calcification
– MR serves an adjunctive role
• Findings:
– CT: an intraocular mass with calcification
in a child<3 yr -> should consider retinoblastoma
– Extraocular spreading along the optic nerve
– Together with pinealoma
-> trilateral retinoblastoma

35. Retinoblastoma

36. DDx in a child with leukokoria
• Toxocara endophthalmitis
• Persistent hyperplastic vitreous
• Retinopathy of prematurity
• Coat’s disease

37. Calcifications
• In adults
– most common at the annulus of Zinn
– at the optic nerve head within the eye -> optic
disc drusen
(asymptomatic, but pseudo-papilledema from PE)
• In children
– retinoblastoma until proven otherwise

38. Coat’s disease
• A rare eye disorder: congenital non-hereditary
vascular malformation of the retina
– multiple telangiectatic vessels -> exudate leakage ->
retinal detachment
• A 6-to-8-year-old boy with unilateral leukokoria
• Symptoms occurs when the retina detaches ->
central visual loss
• Findings:
– Increased density of the vitreous
– Normal globe size, lack of calcification

39. Coat’s disease

40. Choroid
• Melanoma:
– choroid contains the melanin cells
• Metastases:
– choroid is the most vascular structure in the eye
• Detachment:
– usually post-traumatic

41. Uveal melanoma
• The most common primary intraocular
malignancy in adult
• A 50-to-70-year old with unilateral ocular
complaint
• 85% from choroid, 9% from ciliary body, and
6% from iris
• Dx from PE + U/S
• CT/MR when opaque ocular media prevents a
clear view

42. Uveal melanoma
– Findings
• Soft tissue mass adjacent to outer layer of the globe
that bulges inward toward the vitreous
• Mushroom cloud appearance
• Hyperintense on T1 and hypointense on T2

43. Sclera
• Infection:
– Sinusitis
– Viral
• Pseudotumor
• Detachment

44. Scleritis
• granulomatous inflammatory disorder
• Erythema and chemosis
• Characteristics
– optic disk edema
– exudative retinal detachment
– Choroidal folds and scleral thickening >> elevated mass

45. • Findings:
– CT:
• thickened posterior sclera, may enhanced
• Thickening of extraocular muscles can also be seen
– Magnetic resonance imaging
• nodular elevation into the vitreous
• Iso-to-hyperintense to normal sclera on T1
• Hypointense on T2
• moderate to marked inhomogeneous enhancement with Gd
• A retinal detachment appears as a crescent-shaped area that is
hyperintense on both T1 and T2
Scleritis

46. T1 fs + C

47. • collapsed globe (flat tire appearance)
Globe Rupture

48. • presence of intra-ocular air or a foreign body
• thick posterior sclera
• hazy outline of the globe
• enlarged anterior chamber
Globe Rupture

49. Retinal and choroidal detachment
• Retinal epithelium ends at the ora serrata
– > retinal detachment will not go beneath it
• Retinal detachment with hemorrhage
– adults with DM and HTN
– shaken baby syndrome
• Choroidal detachment
– recent intraocular surgery
– trauma

50. Detachment
Retinal Choroidal

51. Retinal

52. Choroidal

53. Coloboma
• A congenital globe defect, usually at the optic
nerve insertion point
• Often there is microphtalmia and the eye
protrudes inferiorly.
• 10% also have other CNS anomalies.
• Findings:
– a small globe with a cystic outpouching of vitreous
at the optic nerve attachment site.
– Retroocular cyst

55. Coloboma
• Coloboma can be part of the CHARGE syndrome:
– Coloboma
– Heart anomalies
– choanal Atresia
– Retardation of growth and development
– Genital and Ear anomalies.
• Coloboma can also be part of the COACH syndrome:
– Cerebellar vermis hypoplasia,
– Oligophrenia (MR)
– congenital Ataxia
– Coloboma
– Hepatic fibrosis.

56. Diseases of the obit
• Globe
• Optic nerve &
sheath
• Conal-intraconal
area
• Extraconal area

57. Optic neuritis
• Presentations
– Visual loss over hours to days
– Pain on movement and tenderness when pressure
applied to globe
• Sporadic/multiple sclerosis
– If found, T2 whole brain should be done
• Less common causes
– pseudotumor, sarcoidosis, radiation, viral, TB,
syphilis neuritis

58. Optic neuritis

59. Multiple sclerosis

60. Devic's syndrome
• Neuromyelitis optica

62. Optic nerve/sheath tumor
• Optic nerve sheath meningioma
• Optic nerve glioma

63. Meningioma
• The most common optic nerve sheath tumor
• ischemic neuropathy due to venous obstruction
• progressive visual loss, papilledema, optic atrophy, pale disc
• Strong association with NF-2
• Abnormal enhancement of the optic nerve sheath
• Calcifications 20-50%

64. Abnormal enhancement of
the optic nerve sheath

65. Optic nerve glioma
• Juvenile pilocytic astrocytomas WHO type 1
• Anywhere along the optic tract from the occipital
region to the chiasm and the optic nerve
• 50% of optic nerve glioma have NF1.
• Only 10% of NF1 have optic nerve glioma.
• Less commonly cystic in NF than in non-NF
• Age 4-5 years and only 20% of patients have
visual symptoms.

66. Neurofibromatosis type I
At least 2 of
• Six cafe au lait macules
• Two neurofibromas of any type or 1 plexiform neurofibroma
• Multiple freckles in the axillary or inguinal region
• Bone dysplasia
• Optic glioma
• Two or more iris hamartomas (Lisch nodules)
• A first-degree relative with NF1

67. Optic nerve glioma
T2 T1fs + Gd

68. Diseases of the obit
• Globe
• Optic nerve &
sheath
• Conal-intraconal
area
• Extraconal area

70. Thyroid opthalmopathy
• Compressive optic neuropathy
– Direct compression by the muscles
– Ischemic by compression of the vessels

71. Idiopathic inflammatory pseudotumor
• Idiopathic inflammation of the orbit
• Any part of the orbit: muscles, tendons, fat, optic
nerve, nerve sheet, lacrimal gland

72. Pseudotumor

73. Thyroid eye Pseudotumor

74. Diseases of the obit
• Globe
• Optic nerve &
sheath
• Conal-intraconal
area
• Extraconal area

75. Periorbital abscess

76. Periorbital abscess
• Complications
– Venous thrombosis of the superior and inferior
ophthalmic vein
– Cavernous sinus thrombosis and cavernous-
carotid fistula in certain fungal sinusitis
(e.g.aspergillosis)

77. Orbital and periorbital cellulitis
• A 'red hot eye' and proptosis
• Orbital VS periorbital cellulitis ->
>> the orbital septum <<
• Periorbital cellulitis
– The orbital septum and the superficial part
– OPD—PO ATB
• Orbital cellulitis
– the structures posterior to the septum are also involved.
– IPD--IV ATB

78. Orbital cellulitis

79. Proptosis with sphenoid wing lesion
Four sphenoid wing lesions that can cause proptosis:
• Fibrous dysplasia
• Paget's disease
• Meningioma with hyperostosis of the sphenoid wing

80. Orbital appendages
• Lacrimal gland
• lacrimal sac
• lacrimal duct

81. Lesions of the lacrimal gland
• Inflammation
– The most common lesions of the lacrimal gland
– i.e. Sjoegren's, TB, fungus, pseudotumor
– Do not cause masses
Children
– congenital obstructions of the valves in the
lacrimal duct -> dacryocystoceles
adults
– strictures from ethmoid sinusitis or stones ->
epiphera or increased tearing

82. Dacryocystocele

83. • Lacrimal gland mass
– Lymphoma
– Pleomorphic adenoma
– Epithelial tumors (adenoid cystic tumor)
Lesions of the lacrimal gland

84. Tumors
• Epidermoid and dermoid tumors
– Developmental
– Usually arises anteriorly between the globe and
orbital periosteum
– Well-circumscribed cystic masses containing
debris
– Dermoid may contain fat, teeth, and hair

85. Vascular malformation
• Carotid cavernous sinus fistula
• Cavernous hemangioma
• Capillary hemangioma
• Lymphangioma

86. Carotid cavernous sinus fistula
Cavernous carotid a.
—cavernous sinus

87. Capillary hemangioma
• 6-12 months of age
• Involutional at 5-7 years of age
• Mostly skin, but also in the extraconal of the eye
• PHACE-syndrome:
– Posterior fossa malformations,
– Hemangiomas
– Arterial anomalies
– Cardiac malformation
– Eye abnormalities such as coloboma, glaucoma
• CT—irregular margin

88. Capillary hemangioma

89. Venous vascular malformations
• The most common intraconal mass in an adult
• 45-year-old women with slow progressive
proptosis, diplopia, visual loss
• Most are unilocular
• CT
– Phleboliths
– sharply circumscribed, round, dense mass
– Spare apex
– Bony erosion

90. Venous vascular malformation

91. lymphatic malformation
• Lymphangioma
• Childhood onset (60% before 16 y/o)
• May abruptly hemorrhage resulting in fluid-fluid
levels
• May be extraconal or multicompartmental
• Association with intracranial malformations
– Turner's
– fetal alcohol syndrome
• Absence of contrast enhancement in pure
lymphatic lesions

92. lymphatic malformation

93. orbital varix
• Propulsion of the eye during straining
• During valsalva -> extreme dilation
Valsalva

94. Conclusion
• Orbital anatomy
• Disease approach
• Diseases of the orbit

95. Approach to diseases
• Globe
• Optic nerve &
sheath
• Conal-intraconal
area
• Extraconal area

96. The globe

97. Disease approach

98. Q & A

99. References
• Harnsberger, H. Ric., and H. Ric.
Harnsberger. Handbook of Head and Neck
Imaging. St. Louis: Mosby, 1995. Print.
• Grossman, Robert I., and David M.
Yousem. Neuroradiology. Philadelphia, PA:
Mosby Elsevier, 2010. Print.
• "Orbita - Pathology." The Radiology Assistant :.
N.p., n.d. Web. 20 May 2014

100. Thank You