1. Orbit and Visual Pathway imaging strategies
Jalal JalalShokouhi-M.D.

2. X-RAY US CT

3. Orbit
• Configuration of orbital cone •
Contents:
- Globe (positio; size, density,
wall thickness)
- Eye muscles (position, course, density, width)
- Optic nerve (course, width)
- Ophthalmic vein (course, width)

4. Checklist
Orbits
• Symmetrical •
Normal size •
Normal orbital cone
Orbital walls
• Smooth, sharp borders •
No bone destruction •
No circumscribed widening of bone or softtissue
components

5. Globe
• Position •
Symmetry •
Size •
Spherical

6. Ocular contents • Density
Ocular wall
• Borders (smooth and sharp) •
Uniform thickness
Optic nerve
• Normal caliber •
Course

7. Eye muscles
• Position •
Width •
Course
Retrobulbar fat • Clear •
No masses

8. Ophthalmic vein • Course •
Caliber
Lacrimal gland • Size •
Symmetry •
No unilateral or bilateral enlargement •
Position
No excavation or destruction of adjacent bone •
Homogeneous internal structure •
No hypodense areas •
Smooth borders

9. Neurocranium
• Temporal lobes •
Frontal lobes
Paranasal
• Maxillary sinuses
sinuses
• Ethmoid cells

13. MRI

14. Orbits
• Shape (orbital cone) •
Size •
Symmetry •
Orbital walls:
- Borders (smooth and sharp)
- No bone destruction
- No circumscribed expansion of bony or softtissue
components of the orbital wall

15. Globe
• Shape (spherical) •
Size
Position
Symmetry •
Ocular contents:
- Signal intensity (fluid-equivalent) •
Ocular wall:
- Borders (smooth and sharp)
- Thickness •
Retrobulbar fat (clear) •
No masses

16. Optic nerve
• Caliber
Course
Eye muscles
• Position •
Width Course
Ophthalmic vein • Course •
Caliber

17. Lacrimal gland
• Size •
Symmetry •
No unilateral or bilateral enlargement •
Position
No excavation or destruction of adjacent bone •
Homogeneous internal structure •
No hypointense or hyperintense changes •
Smooth borders

18. Neurocranium
• Temporal lobes •
Frontal lobes
Paranasal sinuses • Maxillary sinuses •
Ethmoid cells

25. Exophtalmus

26. Differential Diagnosis: Orbital Swelling
• Orbital infection (bacterial, viral, fungal)
• Orbital inflammation: orbital pseudotumor; granulomatous diseases (sarcoid,
Wegener's granulomatosis); vasculitides, connective tissue disorders
Diagnosis
Orbital cellulitis (serratia isolated on culture)

27. Differential Diagnosis: Lacrimal Gland Mass
• Lymphoid/Inflammatory: acute (viral, bacterial, orbital pseudotumor, lymphoma)
or chronic (sarcoid, Wegener's, thyroid opthmalopathy, Sjbgrens's syndrome,
Mickulicz syndrome)
• Epithelial neoplasms: pleomorphic adenoma or malignant tumors (adenoid cystic
carcinoma, mucoepidermoid carcinoma, adenocarcinoma)
Diagnosis
Lacrimal gland enlargement due to acute dacroadenitis

30. Differential Diagnosis: Enlargement of the
Extraocular Muscles
• Infection (bacterial, viral or fungal)
• Thyroid orbitopathy
• Inflammatory conditions: orbital pseudotumor, Sjogrens's syndrome, Mickulicz's
syndrome, granulomatous conditions (sarcoid, Wegener's granulomatosis), connective
tissue disorders (rheumatoid arthritis, lupus, scleroderma), retained foreign
bodies
• Vasculitides (PAN, giant cell arteritis)
• Tumors: hemangioma, rhabdomyoma, plasmacytoma, lymphoma, leukemia, rhabdomyosarcoma
• Amyloidosis
Diagnosis
Orbital pseudotumor

34. Differential Diagnosis: Extraocular Muscle Enlargement
• Endocrine
• Thyroid ophthalmopathy
• Acromegaly
• Inflammatory
• Pseudotumor
• Infection: bacterial, fungal, parasitic (cysticercosis, trichinosis)
• Plasma cell granuloma
• Sarcoid
• Neoplastic
• Benign: rhabdomyoma
• Malignant: lymphoma, rhabdomyosarcoma, metastatic disease
• Vascular
• Carotid cavernous fistula
• Extradural arteriovenous fistula
• Deposition diseases: amyloid
Diagnosis
Thyroid orbitopathy

39. Differential Diagnosis: Diffuse
Hyperintensity in the Extra- and Intraconal
Fat on FAT SAT TIWI
• Artifactual: artifact due to failure of fat suppression
• Pathologic: orbital pseudotumor, orbital cellulitis, orbital neoplasm
Diagnosis
Artifact due to asymmetric failure of fat-suppression

44. Differential Diagnosis: Optic Nerve
Enlargement and Enhancement
(Optic Neuritis)
• Demyelinating disease': multiple sclerosis
• Inflammatory: collagen vascular disease, orbital pseudotumor, sarcoid
• Infectious: HIV-related optic neuropathies, tuberculosis, fungal infection, toxoplasmosis,
syphilis
• Neoplastic': optic glioma, optic nerve meningioma, metastasis, leptomeningeal
carcinomatosis
• Vascular': ischemic neuropathy (severe hypertension, systemic vasculopathies)
• Others: radiation induced optic neuropathy, optic nerve trauma
Note: ' indicates that the process is usually unilateral.

45. Diagnosis
Radiation-induced optic neuropathy

50. Diagnosis Cavernous hemangioma Differential Diagnosis: Retrobulbar
Intraconal Mass
• Hemangioma
• Schwanoma
• Metastasis
• Pseudotumor
• Meningioma
• Hemangiopericytoma
• Lymphangioma
• Varix
• Hematic cyst
Diagnosis
Cavernous hemangioma

52. Differential Diagnosis: Enlargement of the
Optic Nerve or Sheath
• Tumors: optic nerve glioma, optic nerve meningioma, optic nerve neuroma, lymphoma,
leukemia (chloroma), metastasis (hematogeneous: breast and lung, direct invasion:
retinoblastoma, uveal melanoma), hemangioblastoma, hemangiopericytoma
• Inflammatory lesions: orbital pseudotumor, optic neuritis, sarcoidosis
• Others: pseudotumor cerebri
Diagnosis
Intraorbital meningioma

55. Differential Diagnosis: Choroidal Mass
• Melanoma
• Hemangioma
• Hemorrhage
• Retinal/choroidal detachment
• Choroidal metastasis
• Sarcoidosis
• Retinal cyst
• Retinoblastoma
• Retinal gliosis
• Nevi
• Leiomyoma
• Schwanoma
• Neurofibroma
Diagnosis
Choroidal (uveal) melanoma

59. Differential Diagnosis: Intraocular Mass
in a Child
• Neoplastic conditions: retinoblastoma and retinocytoma", uveal melanoma,
metastases (neuroblastoma, most common), pseudoglioma (retinal astrocytoma
or astrocytic hamartoma)
• Nonneoplastic conditions: persistent hyperplastic primary vitreous (PHPV),
retinopathy of prematurity or retinal dysplasia (ROP)", Coat's disease, toxocariasis
or larval granulomatosis", chronic retinal detachment", uveitis
Diagnosis
Retinoblastoma

60. Thank you