1. ORBITAL IMAGING VI

3. Orbital pseudotumor:
 Orbital pseudo-tumor is one of the most
common causes of unilateral proptosis.
 It is generally a disease of middle age and
has an acute onset.
 A painful ophthalmoplegia and edema of
the eyelid or conjunctiva are present in
50% of the patients.
 Regression with steroid therapy is
considered a specific sign of the disease.
 Pseudoturnor may involve any or all intra-
orbital structures.

4. Orbital pseudotumor:
 Non-granulomatous orbital inflammatory
process.
 The second most common cause of
exophthalmos.
 Infiltrative or mass like soft tissue seen
invading any orbital structure.
 irregular margins and extends across multiple
compartments.
 May mimic neoplasm or aggressive infection.
 May extend intra-cranially.

5. Orbital pseudotumor:
 Categorized by areas of involvement:
A- Myositic pattern:
* Most common pattern.
* Involving any muscle and mutiple muscle on 50%.
* Involving tendinous insertion with tubular
configuration.
B- Lacrimal pattern:
* 2nd most common type.
* Diffuse oblong enlargement, particularly antero-
posterior dimension.

6. Orbital pseudotumor:
C- Anterior (eye and retrobulbar fat) pattern:
*3rd most common type.
* Variable involvement of retro-bulbar fat and nerve.
*Uveal-scleral form shows thickened sclera and shaggy
enhancement.
* Peri-neuritic form shows irregular nerve sheath
thickening and enhancement.
D- Diffuse (intra-conal- multi compartement) pattern:
*Overlap with anterior and other pattern.
*Frequently tume-factive and mass like appearance.

7. Orbital pseudotumor:
E- Apical (apex, intra cranial) pattern:
* Less common, involves orbital apex with posterior
extension through fissure.
* Tolosa-Hunt syndrome considered intra-cranial
variant with extension through cavernous sinus.

8. Orbital pseudotumor:
 CT imaging:
 Focal & infiltrative.
 Poorly circuscribed.
 Mass or thickening on
muscle, lacrimal and
orbital structures.
 Moderate diffuse
enhancement.
 Increase attenuation
on late enhancing
phase.

9. Orbital pseudotumor:

10. Orbital pseudotumor:
 MR imaging:
 Hypointense tonormal
muscle on TIWIs.
 Iso-intense to slighly
hyper-intense on
T2WIs and STIR.
 Due to high cellular
component and
fibrosis.
 Marked diffuse in-
homogenous
enhancement.

11. Orbital pseudotumor:

12. Orbital pseudotumor:

13. Orbital pseudotumor:

14. Graves ophthalmopathy:
 Is the most common cause of exophthalmos in
adults.
 Graves ophthalmopathy usually occurs 5 years
after the onset of thyroid disease.
 Autoimmune inflammation condition associated
with thyroid dys-function.
 Classically spindle-shaped enlargement of the
extra-ocular muscles is observed, with sparing of
the tendinous insertion.
 The inferior, medial, superior, and lateral rectus
muscles (listed in order of decreasing frequency of
involvement) may be involved.

15. Graves ophthalmopathy:
 These findings are usually bilateral (90%)and
symmetric (70%).
 Isolted muscle involvement on 5%, particularly
superior rectus.
 Additional imaging findings include increased
orbital fat, lacrimal gland enlargement, eyelid
edema, stretching of the optic nerve, and tenting of
the posterior globe.
 Treatment is primarily conservative, with radiation
therapy reserved for reduction of tension on the
optic nerve.

16. Graves ophthalmopathy:
 CT imaging:
 Iso-dense enlargement
of EOMs.
 Heterogeneous low
density area contents.
 Hypertrophied retro-
bulbar fat.
 Heterogeneous
increased
enhancement of
involved muscles.

17. Graves ophthalmopathy:

18. Graves ophthalmopathy:

19. Graves ophthalmopathy:
 MR imaging:
 Isointense
enlargement of EOMs
on T1WIs.
 Increase EOM signals
on acute phase and
decrease signal on
chronic phase on
T2WIs and STIR.
 Heterogeneous
enhancement of
involved muscles.

20. Graves ophthalmopathy:

21. Graves ophthalmopathy:

22. Optic Neuritis:
 Two type of acute ON :
A- MS associated ON.
B- Idiopathic isolated mono-symptomativ ON.
*Diffuse only enlargement of optic nerve with central or
peripheral enhancing pattern.
*Unilateral on 70%.
*segments of nerve involvement:
a- Anterior intra-orbital.45%.
b- Mid intra-orbital 60%.
c- Intra-canalicular 35%.
d- Pre-chiasmatic and chiasma 7%.

23. Optic Neuritis:
 CT imaging:
 Usually normal.
 May show minimal
optic nerve
enlargement.
 On post contrast
imaging, segmental
enhancing criteria.

24. Optic Neuritis:
 MR imaging:
 Mildly enlarged optic
nerve with ill defined
border on T1WIs.
 Enlarged optic nerve
with egmental bright
signal on T2WIs and
STIR.
 Central or peripheral
tram track enhancing
pattern on post
contrast imaging.

25. Optic Neuritis:

26. Optic Neuritis:

27. Optic Neuritis:

28. Lympho-proliferative lesions of
the orbit:
 LPLO spectrum including benign and malignant
tumors:
A- Lymphoidal hyperplasia 10-40%:
* Reactive or hyperplasia.
B- Lymphoma (NHL) 60-90%.
* Homogenus enhancing mass lesion any where on the
orbit.
* Lobulated well defined margins.
*May be have infiltrative presentation pattern or
associated inflammatory changes.

29. Lympho-proliferative lesions
of the orbit:
 Locations:
A-Anterior extra-conal orbital space, centered on
superior temporal quadrant.
B- Lacrimal gland.
C- Diffuse infiltrative pattern with intra-conal
component and peri-neural involvement.
D- Intra-cranial extension with predilection for
pituitary stalk.
* Bilateral presentation in 25%.
* Multifocal within orbital region in less than 5%.

30. Lympho-proliferative lesions
of the orbit:
 CT imaging:
 Iso dense to slightly
hyper-dense.
 Homogenous on
malignant lymphoma.
 In-homogenous on
hyperplasia.
 Rare calcification in
less than 5 %.

31. Lympho-proliferative lesions
of the orbit:
 Moderate diffuse
enhancement.
 Followed by decrease
enhancement on
delayed scan.

33. Lympho-proliferative lesions of
the orbit:
 MR imaging:
 Homogenous mildly
hyper-intense to
muscle on T1WIs.
 mildly hyper-intense
on T2WIs and STIR.
 Moderate to marked
homogenous
enhancement.

34. Lympho-proliferative lesions of
the orbit:

35. Lympho-proliferative lesions of
the orbit:

36. THANKS FOR YOU