diagnostic imaging of orbital lesions
TRANSCRIPT
![Page 1: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/1.jpg)
Head & Neck
Orbit
![Page 2: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/2.jpg)
Mohamed Zaitoun
Assistant Lecturer-Diagnostic Radiology Department , Zagazig University Hospitals
EgyptFINR (Fellowship of Interventional
Neuroradiology)[email protected]
![Page 3: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/3.jpg)
![Page 4: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/4.jpg)
![Page 5: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/5.jpg)
Knowing as much as possible about your enemy precedes successful battle
and learning about the disease process precedes successful management
![Page 6: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/6.jpg)
Orbit1-Anatomy of the Orbit2-Orbital Mass Lesions3-Orbital Trauma
![Page 7: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/7.jpg)
1-Anatomy of the Orbit :-The orbit is a pyramidal space that is formed by seven
bones-The globe lies in the anterior orbit; the globe and its
contents are contained by three layers :1-The sclera and cornea form the fibrous outermost
layer2-The vascular uveal tract, including the ciliary body
anteriorly and the choroid posteriorly, forms the middle layer
3-The retina forms the innermost sensory layer
![Page 8: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/8.jpg)
Photomicrograph (original magnification, × 80; hematoxylineosin stain) shows the three layers of the globe
![Page 9: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/9.jpg)
-The lens is connected to the sclera by radially oriented zonular fibers
-The lens divides the globe into an anterior segment, which contains the aqueous humor, and the posterior segment, which contains the more viscous vitreous humor
-The iris further subdivides the anterior segment into the anterior chamber and the posterior chamber
-Posterior to the globe, the six extraocular muscles and their intermuscular fascial membranes form an intraorbital conical structure
-Veins and lymphatics lie within the orbital fat of the muscle cone-Centrally, the optic nerve sheath passes from the posterior globe
to the brain-The optic nerve sheath is an extension of the dura mater and
contains the ophthalmic artery, the optic nerve, and small veins
![Page 10: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/10.jpg)
Unenhanced axial CT scan of a healthy 32-year-old man. AC = anterior chamber, L = lens, ON= optic nerve, PS = posterior segment (vitreous humor)
![Page 11: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/11.jpg)
-Orbital Structures :1-Globe (lens , anterior chamber , posterior
chamber , vitreous , sclerouveal coat)2-Intraconal , extraconal fat
3-Optic nerve and sheath4-Ophthalmic artery and vein
5-Rectus muscles
![Page 12: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/12.jpg)
Normal orbital anatomy, axial CT image (left) with color overlays shows the orbit divided into intraocular and extraocular spaces by the muscle cone and their relationships to the globe, coronal CT images (right) with color overlays show the configuration of the extraocular muscles, vascular structures, and lacrimal gland
![Page 13: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/13.jpg)
![Page 14: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/14.jpg)
Orbital Spaces: -Intraconal space:
space inside the rectus muscle pyramid
-Extraconal space: space outside the rectus muscle pyramid
-Preseptal space-Postseptal space
-Lacrimal fossa
![Page 15: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/15.jpg)
![Page 16: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/16.jpg)
![Page 17: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/17.jpg)
The intraconal space is located within the muscle cone It contains the optic nerve , vessels and cranial nerves III , IV and VI
![Page 18: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/18.jpg)
Extraconal space
![Page 19: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/19.jpg)
![Page 20: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/20.jpg)
![Page 21: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/21.jpg)
Orbital Septum :-Represents condensed orbital rim periosteum-Attaches to outer margins of bony orbit and
deep tissues of lids- Separates all the structures in the orbit from
soft tissues in the face (preseptal versus postseptal)
![Page 22: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/22.jpg)
![Page 23: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/23.jpg)
2-Orbital Mass Lesionsa) Within or involving the globeb) Within the muscle cone (Intraconal)c) Arising from the muscle cone (conal)d) Outside the muscle cone (Extrconal)e) Arising from the orbital wall
![Page 24: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/24.jpg)
a) Within or involving the Globe :1-Retinoblastoma2-Melanoma3-Detachment and Choroidal Effusion
![Page 25: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/25.jpg)
![Page 26: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/26.jpg)
1-Retinoblastoma :a) Incidenceb) Typesc) Clinical Pictured) Radiographic Featurese) Differential Diagnosis
![Page 27: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/27.jpg)
a) Incidence :-The most important ocular tumor of childhood-20-40% of patients have bilateral tumors and this is most
often the AD type-5-10% of patients have a family history of
retinoblastoma -Children with the hereditary form are at risk of
developing second non-ocular malignancies either within or out of the radiation field , osteosarcoma is the commonest tumor
![Page 28: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/28.jpg)
b) Types :-Four types have been recognized :1-Those that are non-inheritable2-Those that are inherited as an AD trait 3-Those that are associated with a partial
deletion of chromosome 134-Bilateral retinoblastoma and pineal tumor
(trilateral retinoblastoma)
![Page 29: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/29.jpg)
Trilateral retinoblastoma
![Page 30: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/30.jpg)
c) Clinical Picture :-Most children present with leukokoria or white pupillary reflex
![Page 31: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/31.jpg)
d) Radiographic Features :1-CT :-Intraocular high density (calcification , hemorrhage)
mass-Over 90% of tumors show calcification on CT which may
be small , large , single or multiple-Diffuse infiltrating tumors are less likely to show
calcification-Intraocular calcification in children under 3 years of age
is highly suggestive of retinoblastoma
![Page 32: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/32.jpg)
-In absence of calcification in retinoblastoma , suspect other mass lesions :
1-Persistent Hyperplastic Primary Vitreous (PHPV) :
-Congenital persistence of remnants of hyaloid vessels
-Small globe with a shadow of retrolental mass-Unilateral
![Page 33: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/33.jpg)
PFV in a 3-year-old boy, (a) Axial CT image shows uniform high attenuation of the vitreous. (b) Axial T2 shows the hyaloid canal (arrow), a characteristic finding of PFV. (c) T1+C shows enhancement of the retrolental primary vitreous (arrow)
![Page 34: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/34.jpg)
PHPV
![Page 35: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/35.jpg)
PHVV with microphthalmia
![Page 36: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/36.jpg)
2-Coat’s Disease :-Rare-Not a congenital lesion-Age : 6-8 years , more in males-No retrolental mass-Unilateral retinal telangiectasia >> massive subretinal
exudate >> Retinal Detachment3-Retinopathy of Prematurity (Retrolental
Fibropalsia):-Bilateral-History of prematurity & oxygen therapy
![Page 37: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/37.jpg)
Coat’s disease, (a, b) Axial unenhanced (a) and contrast-enhanced (b) CT images of the right orbit show an intraocular high-attenuation lesion, no calcification or enhancement is seen
![Page 38: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/38.jpg)
Coat’s disease, (a, b) Axial unenhanced (a) and contrast-enhanced fat-saturated (b) T1 show the intraocular lesion, which is homogeneous with intermediate signal intensity, no enhancement is seen after administration of contrast material
![Page 39: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/39.jpg)
-The non-calcified component of the tumor is moderately dense on CT , enhances poorly or not at all and may be difficult to differentiate from the associated retinal detachment and subretinal effusion
-The presence of enhancement excludes subretinal exudate and haemorrhage while marked enhancement suggests persistent hyperplastic primary vitreous (PHPV)
![Page 40: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/40.jpg)
![Page 41: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/41.jpg)
![Page 42: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/42.jpg)
![Page 43: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/43.jpg)
![Page 44: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/44.jpg)
2-MRI :*T1 : The tumor is slightly/moderately
hyperintense*T2 : Moderately low intensity *T1+C : The tumor enhances
![Page 45: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/45.jpg)
T1
![Page 46: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/46.jpg)
T2
![Page 47: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/47.jpg)
T1+C
![Page 48: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/48.jpg)
e) Differential Diagnosis :1-Persistent Hyperplastic Primary Vitrous2-Coat’s Disease3-Retinopathy of prematurity4-Toxocariasis (close contact with dogs)5-Chronic Retinal Detachment6-Retinal Astrocytoma (T.S.) 7-Retinal Dysplasia
![Page 49: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/49.jpg)
-N.B. : Differential Diagnosis of Intraorbital Calcification :a) Retina :1-Drusen 1% population at optic disc (benign)2-Retinoblastoma3-Retinocytoma4-Tuberous sclerosis (TS): "giant drusen", astrocytic
hamartomas5-Epiretinal membranes6-Retrolental fibroplasia (retinopathy of prematurity),
rare calcification 7-Coats disease
![Page 50: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/50.jpg)
Drusen Retinoblastoma
![Page 51: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/51.jpg)
Retinal astrocytic hamartoma in a patient with tuberous sclerosis, axial unenhanced CT image shows a high-attenuation focal intraocular mass (arrowhead) in the right globe
![Page 52: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/52.jpg)
b) Retinochoroidal :-Chorioretinitis : most commonly
following Toxoplasmosis
c) Choroidal :1-Choroidal osteoma : more common in patients
with tuberous sclerosis2-Choroidal angioma : occasionally calcify
![Page 53: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/53.jpg)
Chorioretinitis Choroidal osteoma
![Page 54: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/54.jpg)
d) Sclerochoroidal :1-Metastatic calcification :-Abnormal calcium and phosphate metabolisma) Hyperparathyroidismb) Pseudohypoparathyroidismc) Renal tubular acidosis2-Dystrophic calcification :-Abnormal tissues become calcified, despite normal
calcium and phosphate metabolism-Seen occasionally in elderly caucasians, most
frequently men3-Phthisis bulbi :-Is the end result of major injury to the eye (trauma,
infection) with a shrunken calcified 'lump' remaining4-Scleral calcific plaques (senile)
![Page 55: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/55.jpg)
Phthisis bulbi Senile scleral calcific plaque
![Page 56: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/56.jpg)
2-Melanoma :a) Incidenceb) Radiographic Featuresc) Prognosis
![Page 57: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/57.jpg)
a) Incidence :-Most common (75%) ocular malignancy in
adults-Arises from pigmented choroidal layer , retinal
detachment is common
![Page 58: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/58.jpg)
Diagram illustrates how a melanotic lesion causes retinal detachment, as melanoma breaks through the choroid, it separates the retina from the choroid
![Page 59: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/59.jpg)
b) Radiographic Features :1-CT :-Thickening or irregularity of choroid (localized, polypoid,
or flat)-Exophytic , biconvex mass lesion related to choroid-Usually unilateral, posterior location-Retinal detachment, common-Contrast enhancement2-MRI :-T1 hyperintense , T2 hypointense
![Page 60: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/60.jpg)
Unenhanced, axial CT image of the right orbit showing a choroidal melanoma
![Page 61: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/61.jpg)
Choroidal melanoma discovered at fundoscopy in a 55-year-old woman, axial CT+C shows a subtle enhancing nodule at the level of the optic disk (arrow)
![Page 62: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/62.jpg)
(a) T1 shows that the mass (*) is mildly hyperintense, (b) T2 shows that the tumor (*) is hypointense, (c) T1+C shows that the tumor (*) enhances moderately, these findings are compatible with a typical malignant melanoma of the choroid
![Page 63: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/63.jpg)
Choroidal melanoma (a) T1 shows a rounded hyperintense mass (arrow) in the right posterior globe, (b) T2 , the lesion appears hypointense
![Page 64: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/64.jpg)
c) Prognosis :-Poor prognostic indicators : 1-Large tumor size2-Heavy pigmentation3-Infiltration of the angles , optic nerve , sclera
and ciliary body
![Page 65: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/65.jpg)
3-Detachment and Choroidal Effusion :-May mimic melanoma-Retinal detachment with hemorrhage is seen
mostly in adults with diabetes mellitus and hypertension
-In young infants it can be seen as part of a shaken baby syndrome
-In choroidal detachment recent intraocular surgery is the most common association followed by trauma
![Page 66: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/66.jpg)
![Page 67: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/67.jpg)
![Page 68: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/68.jpg)
**N.B. : Other globe lesions1-Drusen2-Globe-shape Abnormalities3-Leukokoria
![Page 69: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/69.jpg)
1-Drusen :-Focal calcification in hyaline bodies in the optic
nerve head-Usually bilateral and asymptomatic-Blurred disk margins may be mistaken for
papilledema
![Page 70: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/70.jpg)
![Page 71: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/71.jpg)
![Page 72: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/72.jpg)
![Page 73: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/73.jpg)
2-Globe-shape Abnormalities :a) Coloboma :-Focal outpouching involving retina, choroid, iris-Caused by deficient closure of fetal optic fissure-Located in region of optic disc-Associated with :Morning glory anomalyMicrophthalmos with cyst
![Page 74: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/74.jpg)
-Coloboma can be part of the CHARGE syndrome :ColobomaHeart anomaliesChoanal AtresiaRetardation of growth and developmentGenital and Ear anomalies
-Coloboma can also be part of the COACH syndrome:Cerebellar vermis hypoplasiaOligophrenia (MR)Congenital AtaxiaColobomaHepatic fibrosis
![Page 75: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/75.jpg)
![Page 76: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/76.jpg)
![Page 77: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/77.jpg)
![Page 78: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/78.jpg)
b) Staphyloma :-Acquired defect of globe wall with protrusion of choroid or
sclera-As opposed to coloboma, staphyloma defect is located off-
center
c) Axial Myopia :-AP elongation but no protrusion
d) Buphthalmos :-Congenital glaucoma; anterior ocular chamber drainage
problem
![Page 79: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/79.jpg)
Staphyloma
![Page 80: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/80.jpg)
3-Leukokoria :-Leukokoria refers to a white pupil-Clinical, not a radiologic finding-Underlying causes : 1-Retinoblastoma2-PHPV3-Congenital cataract4-Toxocariasis5-Other :-Sclerosing endophthalmitis-Coats' disease-Retrolental fibroplasia-Trauma-Chronic retinal detachment
![Page 81: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/81.jpg)
![Page 82: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/82.jpg)
b) Within the Muscle Cone (Intraconal) :1-Optic nerve Glioma 2-Optic nerve Meningioma 3-Hemangioma (mostly cavernous) and Orbital
varices4-Inflammatory Orbital Pseudotumor5-Lymphoma and Metastases6-Hematoma7-Neurofibroma
![Page 83: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/83.jpg)
The intraconal space is located within the muscle cone It contains the optic nerve , vessels and cranial nerves III , IV and VI
![Page 84: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/84.jpg)
1-Optic nerve Glioma :a) Incidenceb) Clinical Picturec) Radiographic Featuresd) Differential Diagnosis
![Page 85: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/85.jpg)
a) Incidence :-Most common cause of diffuse optic nerve
enlargement especially in childhood ( 1st decade of life )
-In neurofibromatosis (NF1) the disease may be bilateral
b) Clinical Picture :-Visual loss and painless with preservation of eye
movements because the lesion is intraconal
![Page 86: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/86.jpg)
c) Radiographic Features :1-CT :-The optic nerve is variably enlarged and the mass may
either be fusiform or exophytic in appearance , additionally the nerve may be elongated with kinking or buckling
-Enlargement of optical canal ; >1 mm difference between left and right is abnormal
-Lower CT density than meningioma-Contrast enhancement variable-Calcifications rare (but common in meningioma)
![Page 87: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/87.jpg)
![Page 88: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/88.jpg)
![Page 89: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/89.jpg)
2-MRI :*T1 : Enlargement, often iso to hypointense
compared to the contralateral side *T2 : Hyperintense centrally , low signal at the
periphery representing the dura*T1+C : Enhancement is variable
-Tumor extension best detected by MRI: chiasm → optic tracts → lateral geniculate body →
optic radiation
![Page 90: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/90.jpg)
Optic nerve glioma in a 6-year-old girl with proptosis. (a) Axial short inversion time inversion-recovery MR image shows an expansile mass that involves the right optic nerve, the hyperintense rim at the tumor periphery (arrowheads) reflects leptomeningeal infiltration. (b) Axial T1+C fat-suppressed image shows minimal enhancement in the mass (arrow), the nerve itself cannot be separated from the tumor
![Page 91: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/91.jpg)
Bilateral optic nerve gliomas in a 25-year-old man with NF-1., axial T1 shows the tortuous and kinked appearance of the bilateral optic nerves (arrows)
![Page 92: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/92.jpg)
Coronal T1 reveals circumscribed enlargement of the optic nerve with an isointense signal
![Page 93: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/93.jpg)
T1 reveals bilateral , fusiform enlargement of the optic nerves (arrows) in a 14-year-old patient with neurofibromatosis type 1 , consistent with bilateral optic nerve gliomas
![Page 94: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/94.jpg)
T1 in a 46-year-old man demonstrates enlargement of both optic tracts (arrowheads) and the optic chiasm (arrow)
![Page 95: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/95.jpg)
T2 reveals hyperintense signaling of the mass that is contained within the dura of the optic nerve
![Page 96: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/96.jpg)
T2 demonstrates bilateral optic nerve gliomas in the setting of NF1
![Page 97: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/97.jpg)
FLAIR , the fusiform image of the optic nerve tumor is seen , also here evident are several enhancing lesions in the midbrain and cerebellum, consistent with the classic hamartomatous CNS neurofibromas of NF1
![Page 98: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/98.jpg)
T2 in a 46-year-old man demonstrates a mass in the lateral geniculate nucleus of the thalamus resulting from contiguous extension of the patient's known optic nerve glioma
![Page 99: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/99.jpg)
T1+C shows enhancement of the fusiform , kinked shaped optic nerve tumor
![Page 100: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/100.jpg)
T1+C with fat saturation reveals diffuse intense enhancement of the intraorbital mass , the lesion is confined to the orbit
![Page 101: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/101.jpg)
T1+C with fat saturation in a 6-year-old girl demonstrates enhancement of the intracranial optic nerve (arrow) which is slightly expanded
![Page 102: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/102.jpg)
d) Differential Diagnosis :-From optic nerve meningioma1-Age :-Glioma , 50 % < 5 years-Meningioma , middle aged women2-Laterality :-Glioma , +/- bilateral -Meningioma , unilateral3-Hyperostosis :-In meningioma
![Page 103: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/103.jpg)
4-Optic canal :-Widened in 90 % in glioma and in 10 % in meningioma5-Calcification :-Glioma : rare without prior radiotherapy-Meningioma : Calcification6-Contrast :-Glioma : variable contrast with mottled lucencies due
to mucinous degeneration-Meningioma : diffuse homogenous enhancement
![Page 104: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/104.jpg)
2-Optic nerve sheath Meningioma :a) Incidenceb) Clinical Featuresc) Radiographic Featuresd) Differential Diagnosis
![Page 105: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/105.jpg)
a) Incidence :-Optic nerve sheath meningiomas arise from
arachnoid rests in meninges covering the optic nerve
-Age: 4th decade (80% female) ; younger patients typically have NF
-These lesions are almost always unilateral with the exception of NF2 patients which may be unlucky enough to have bilateral tumours
![Page 106: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/106.jpg)
b) Clinical Features :1-Visual loss (95 % of cases)2-Proptosis
![Page 107: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/107.jpg)
c) Radiographic Features :1-CT :a) Mass b) Enhancementc) Others
![Page 108: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/108.jpg)
a) Mass :-Tubular , 60%-Fusiform , surrounding the optic nerve , 25%-Eccentric , 15%-Calcification (common)
![Page 109: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/109.jpg)
Calcification
![Page 110: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/110.jpg)
b) Enhancement :-Intense contrast enhancement-Linear bands of enhancement (nerve within tumor)
: tram track sign (enhancing mass around the optic nerve , the optic nerve itself is not enlarged and is nonenhancing ; mass, such as a arising from the optic nerve sheath
c) Others :Sphenoid bone and / or optical canal hyperostosis
![Page 111: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/111.jpg)
Optic nerve sheath meningioma incidentally found in a 50-year-old woman, axial CT+C shows the tram-track configuration of an enhancing tumor (arrows) surrounding the optic nerve, the mass extends to the orbital apex, the optic nerve itself can be separated from the tumor
![Page 112: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/112.jpg)
Optic nerve tram-track sign, T1+C (A) shows an enhancing mass (thick small arrows) around the left optic nerve , the optic nerve (thin long arrow) itself is not enlarged and is nonenhancing, this is suggestive of a mass ; meningioma arising from the optic nerve sheath, T2 in a different patient (B) shows fusiform enlargement of the left optic nerve itself (arrows) , in a case of optic nerve glioma
![Page 113: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/113.jpg)
CT + C
![Page 114: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/114.jpg)
![Page 115: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/115.jpg)
Tram track sign
![Page 116: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/116.jpg)
*MRI :-T1 : Isointense to somewhat hypointense
compared to the optic nerve-T2 - Isointense to somewhat hyperintense
compared to the optic nerve-T1+C : Homogeneous enhancementd) Differential Diagnosis :-See before
![Page 117: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/117.jpg)
Optic nerve sheath meningioma in a 62-year-old patient who presented with blurry vision of the right eye, axial T1+C fat-suppressed shows an avidly enhancing tumor along both sides of the right optic nerve, the intraoptic and intracanalicular portions of the optic nerve are involved (arrows), as well as the prechiasmatic portion of the intracranial optic nerve (arrowhead). * = normal left intracranial optic nerve
![Page 118: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/118.jpg)
-N.B. Differential Diagnosis of Orbital Hyperostosis :1-Meningioma2-Sclerotic metastases3-FD4-Paget’s Disease5-Osteopetrosis6-Chronic Osteomyelitis7-Lacrimal Gland Tumor8-LCH9-Postradiotherapy
![Page 119: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/119.jpg)
-N.B. Optic Neuritisa) Causesb) Clinical Picturec) Radiographic Findings
![Page 120: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/120.jpg)
a) Causes :1-Multiple sclerosis (most common cause;
occurs in 80% of MS patients)Devic's syndrome: optic neuritis (bilateral) with
transverse myelitis (MS or ADEM may be the cause)
2-Ischemia3-Vasculitis
![Page 121: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/121.jpg)
b) Clinical Picture :1-Visual loss2-Pain on eye movement3-Afferent papillary defects
![Page 122: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/122.jpg)
c) Radiographic Findings :-Fat-suppressed T2 or post gadolinium with fat
suppression best for diagnosis-T2 : Typically findings are most easily identified in the
retrobulbar intra-orbital segment of the optic nerve, which appears swollen, with high T2 signal, high T2 signal persists and may be permanent; chronically the nerve will appear atrophied rather than swollen
-Enhancement of the optic nerve
![Page 123: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/123.jpg)
T2
![Page 124: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/124.jpg)
T2
![Page 125: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/125.jpg)
T2-weighted fat-saturated coronal image shows high signal in the left optic nerve, consistent with optic neuritis
![Page 126: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/126.jpg)
T1+C fat suppression shows edema and enhancement of the optic nerve (arrow)
![Page 127: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/127.jpg)
3-Hemangioma (usually cavernous) and Orbital varices :
Cavernous Hemangioma (adults): a) Incidenceb) Radiographic Features
![Page 128: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/128.jpg)
a) Incidence: -True capsule , benign
-Common benign tumor of the intraconal space most commonly in the lateral aspect
-Large , dilated venous channels with fibrous capsule
![Page 129: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/129.jpg)
b) Radiographic Features: 1-CT:
-Well circumscribed , somewhat hypoattenuating compared to muscle , which gradually fills in following administration of contrast
![Page 130: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/130.jpg)
Cavernous malformation in a 46-year-old man with right-sided headache, sagittal unenhanced CT image demonstrates a round, well-circumscribed intraconal mass that causes superior displacement of the optic nerve (*)
![Page 131: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/131.jpg)
Cavernous malformation in a 39-year-old woman with painless progressive proptosis, CT+C shows an enhancing intraconal mass (dot) immediately adjacent to the lateral rectus muscle (black arrows), the mass is causing medial deviation of the optic nerve (white arrow)
![Page 132: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/132.jpg)
![Page 133: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/133.jpg)
![Page 134: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/134.jpg)
![Page 135: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/135.jpg)
![Page 136: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/136.jpg)
2-MRI :*T1 :Isointense If areas of thrombosis are present, then hyperintense regions
may be visible *T2 :HyperintenseMay have low intensity septationPseudocapsule is of low intensity*T1+C :Low gradual irregular enhancement with delayed wash out
![Page 137: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/137.jpg)
Large cavernous malformation in a 43-year-old woman with painless proptosis of the right eye. (a) T1 shows a well-circumscribed, hypointense intraconal lesion causing orbital expansion (arrows), (b) T1+C fat-suppressed MR image, obtained immediately after the intravenous administration of a gadolinium-based contrast material, shows inhomogeneous enhancement predominantly in the center of the lesion (dot). (c) T1+C fat-suppressed MR image, obtained 1 hour later, shows the characteristic complete enhancement of the lesion
![Page 138: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/138.jpg)
T1
![Page 139: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/139.jpg)
T1
![Page 140: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/140.jpg)
T2
![Page 141: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/141.jpg)
`
T1 + C
![Page 142: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/142.jpg)
N.B. :Capillary Hemangioma (children ; strawberry nevus) : no capsule
a) Incidence: -Represents 10% of all pediatric orbital tumors
( Most common orbital tumor in infancy)-Infiltrates conal and extraconal spaces
-Grows for <1 year and then typically involutes-90% are associated with cutaneous angioma
-Can be part of the PHACE-syndrome: Posterior fossa malformations, Hemangiomas, Arterial anomalies, Cardiac malformation and Eye abnormalities such as coloboma, glaucoma
![Page 143: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/143.jpg)
b) Radiographic Features:1-CT :-The CT appearance is that of a strongly enhancing
lobulated mass , the enhancement is typically homogeneous
-On imaging alone , it is difficult to differentiate these lesions from other vascular lesions of the orbit thus relying on patients age and clinical appearance
![Page 144: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/144.jpg)
Capillary hemangioma in a 4-month-old boy with proptosis of the left eye, inferior displacement of the globe, and a bluish discoloration under the skin, CT+C depicts an intensely enhancing, irregularly marginated lesion with intraconal (dots) and extraconal (arrows) components
![Page 145: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/145.jpg)
2-MRI :*T1 : Hypointense*T2 : Iso- to hyperintense on with multiple
serpiginous flow voids*T1+C : Enhancement is homogenous with
gadolinium with marked enhancement of intra-tumoral vessels
-Its lobulated appearance with thin septa is characteristic
![Page 146: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/146.jpg)
Typical capillary hemangioma in a 41/2-month-old girl with proptosis of the right eye and cutaneous hemangioma. (a) T1 demonstrates an extraconal, lobulated, irregularly marginated lesion with hypointense signal and small serpentine flow voids (arrow), (b) T2 fat-suppressed image shows the same lesion with slight signal hyperintensity, characteristic fine internal septa, and flow voids (arrow), (c) T1+C fat-suppressed image demonstrates homogeneous intense enhancement of the lesion and provides improved delineation of the flow voids (arrow)
![Page 147: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/147.jpg)
Orbital Varices :a) Incidenceb) Radiographic Features
![Page 148: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/148.jpg)
a) Incidence :-Varices are the most common cause of spontaneous
orbital hemorrhage, however, these lesions are uncommon overall
-They typically manifest in the 2nd or 3rd decade of life, and they affect males and females equally
-The lesions result from a presumably congenital weakness in the postcapillary venous wall, a condition that leads to the proliferation of venous elements and massive dilatation of the valveless orbital veins
-Most varices have a large communication with the venous system and distend during maneuvers that increase venous pressure
-Patients with orbital varices usually manifest stress proptosis, which is characterized by a dramatic protrusion of the eye
![Page 149: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/149.jpg)
Conjunctival orbital varix in a 56-year-old man whose right eyelid bulges when straining, (a) Photograph obtained with the patient at rest shows a relatively normal appearance of the upper eyelid, (b) Photograph obtained during the Valsalva maneuver shows abnormal fullness of the upper eyelid, which appears bluish. (c) Photograph obtained with the upper eyelid elevated shows the varix
![Page 150: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/150.jpg)
b) Radiographic Features :1-CT :-Axial CT images obtained with the patient in the supine position
usually show a normal appearance or only mild enlargement of the involved veins
-A maneuver that increases venous pressure (scanning in the prone position, jugular vein compression with a tourniquet, or the Valsalva maneuver) is required to demonstrate lesion dispensability
-Varices may be smooth contoured, clublike, triangular, or segmentally dilated, or they may appear as a tangled mass of vessels
2-MRI :*T1 : Varices have hypo- to hyperintense*T2 : Hyperintense*T1+C : Usually enhance intensely after the administration of
contrast material
![Page 151: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/151.jpg)
Bilateral orbital varices in a 27-year-old woman with a sensation of eye pressure when stooping to pick up her child. (a) CT+C obtained with the patient at rest shows enhanced and slightly elongated soft-tissue lesions (arrows). (b) CTC+C obtained during the Valsalva maneuver shows the marked distention typical of orbital varices (arrows)
![Page 152: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/152.jpg)
Orbital varix in a 33-year-old woman with proptosis when straining. (a) T1 obtained with the patient supine shows a well-circumscribed, triangular, homogeneous, hypointense, retrobulbar lesion (dot), (b, c) T1+C fat-suppressed images obtained with the patient supine (b) and prone (c) show homogeneous intense enhancement of the lesion in b and enlargement and distention of the lesion in c, features that help confirm the diagnosis of an inferior ophthalmic venous varix
![Page 153: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/153.jpg)
4-Inflammatory Orbital Pseudotumor :-An enhancing soft tissue mass which may involve the muscle
cone or optic nerve (See later)
5-Lymphoma and Metastases :-See later
6-Hematoma :-Most are intraconal
7-Neurofibroma :-Rare
![Page 154: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/154.jpg)
c) Arising from the Muscle Cone :1-Inflammatory Orbital Pseudotumor2-Dysthyroid Ophthalmopathy 3-Rhabdomyosarcoma
![Page 155: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/155.jpg)
![Page 156: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/156.jpg)
1-Inflammatory Orbital Pseudotumor :a) Definitionb) Clinical Findingsc) Causesd) Radiographic Findingse) Differential Diagnosis
![Page 157: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/157.jpg)
a) Definition :-Inflammation of orbital soft tissues of unknown
origin
b) Clinical Findings :-Painful proptosis-Unilateral-Steroid responsive
c) Causes :-Idiopathic-Systemic disease: sarcoid , endocrine-Unrecognized focal infections , foreign bodies
![Page 158: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/158.jpg)
d) Radiographic Findings :-Infiltrating intraconal or extraconal inflammation presenting
as ill-defined infiltrations or less commonly as a mass-Typical features : 1-Unilateral2-Unlike thyroid ophthalmopathy , pesudotumors involve
tendons of muscles (because it is inflammatory disease)3-Muscle enlargement-Stranding of orbital fat (inflammation)-Enlarged lacrimal gland-May involve orbital apex including superior orbital fissure
(Tolosa-Hunt syndrome)-MRI : *T1 : affected region typically iso to hypointense
*T2 : affected region typically hypointense
![Page 159: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/159.jpg)
![Page 160: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/160.jpg)
![Page 161: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/161.jpg)
![Page 162: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/162.jpg)
T1
![Page 163: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/163.jpg)
T2
![Page 164: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/164.jpg)
e) Differential Diagnosis :Pseudotumor Thyroid
ophthalmopathyInvolvement Unilateral , 85% Bilateral , 85%
Tendon Involved Normal
Muscle Enlargement Enlargement: I > M > S > L
Fat Inflammation Increased amount of fat
Lacrimal gland Enlarged
Steroids Good response Minimal response
![Page 165: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/165.jpg)
2-Dysthyroid Ophthalmopathy :a) Definitionb) Clinical Featuresc) Gradesd) Radiographic Features
![Page 166: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/166.jpg)
a) Definition :-Orbital pathology (deposition of glycoproteins
and mucopolysaccharides in the orbit) caused by long-acting thyroid-stimulating factor (LATS) in Graves' disease
b) Clinical Features :-Painless proptosis , patients may be euthyroid ,
hypothyroid or hyperthyroid
![Page 167: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/167.jpg)
c) Grades :-Grade 1: Lid retraction , stare, lid lag (spasm of upper lid
due to thyrotoxicosis)-Grade 2: Soft tissue involvement-Grade 3: Proptosis as determined by exophthalmometer
measurement-Grade 4: Extraocular muscle involvement ; affects muscles
at midpoint-Grade 5: Corneal involvement-Grade 6: Optic nerve involvement: vision loss
![Page 168: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/168.jpg)
![Page 169: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/169.jpg)
d) Radiographic Features :1-Exophthalmos2-Muscle involvement :-Mnemonic for involvement: “I'M SLow”: Inferior (most common)
MedialSuperiorLateral
-Enlargement is maximal in the middle of the muscle and tapers toward the end (infiltrative, not inflammatory disease)
-Spares tendon insertions-Often bilateral, symmetrical3-Other :-Optic nerve thickening-Expansion of orbital fat
![Page 170: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/170.jpg)
![Page 171: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/171.jpg)
![Page 172: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/172.jpg)
![Page 173: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/173.jpg)
![Page 174: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/174.jpg)
![Page 175: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/175.jpg)
3-Rhabdomyosarcoma :a) Incidence b) Clinical Featuresc) Radiographic Featuresd) Spread
![Page 176: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/176.jpg)
a) Incidence :-Most common malignant orbital tumor in
childhood-Mean age: 7 years
![Page 177: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/177.jpg)
b) Clinical Features :-Rapid onset of proptosis , usually with lateral
deviation of the eye , as anteromedial or superomedial points of origin are most common
-Vision is preserved
![Page 178: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/178.jpg)
c) Radiographic Features :-Large , aggressive soft tissue mass (intraconal or extraconal)-Metastases to lung and cervical nodes1-CT :-Are typically homogeneous soft tissue masses isodense to
normal muscle , the mass may extend into the eyelid or through bone into the paranasal sinuses (especially the ethmoid sinus) and superiorly into the anterior cranial fossa
-Following contrast administration, enhancement is usually present
![Page 179: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/179.jpg)
-18-year-old male presenting with right sided proptosis and history of choroid plexus papilloma and seizures-Axial CT soft tissue window shows a soft tissue mass centered in the right ethmoid sinus with bony destruction and invasion into the right orbit and left ethmoid sinus
![Page 180: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/180.jpg)
-Coronal CT image using bone windows clearly demonstrates the osseous destruction and invasion of the right medial orbital wall , bilateral ethmoid sinuses , right frontal sinus , both nasal cavities , turbinates , and nasal septum
![Page 181: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/181.jpg)
-MRI :*T1-Low to intermediate intensity , iso intense to
adjacent muscle*T2-Usually hyperintense*T1+C-Shows considerable enhancement
![Page 182: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/182.jpg)
T1+C with fat saturation better demonstrate the enhancing soft tissue mass and its extension , the mass invades the medial orbit , displacing the right medial rectus laterally (black arrow) and causes proptosis (star) , on coronal , the mass is again seen invading the adjacent sinuses and obstructing the nasal passage ; however , unlike CT , abnormal enhancement is seen of the frontal dura (white arrows) , the dural thickening and enhancement are compatible with direct tumor invasion
![Page 183: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/183.jpg)
d) Spread :-The tumor is closely related to the paranasal sinuses and
though extension out of the orbit anteriorly and medially is not uncommon , most tumors lie preseptally or extraconally and extension backwards into the brain is not common
-It is important to differentiate between a primary orbital location and a parameningeal location (defined as a tumor close enough to the meninges to permit intracranial spread of tumor) because therapy differs
![Page 184: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/184.jpg)
d) Outside the Muscle Cone (Extrconal) :1-Orbital Cellulitis and Abscess 2-Lymphoma and Metastases3-Dermoid and Teratoma 4-Lymphangioma, Lymphohaemangioma 5-Spread from lacrimal gland tumors
![Page 185: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/185.jpg)
Extraconal space
![Page 186: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/186.jpg)
1-Orbital Cellulitis and Abscess :a) Etiologyb) Radiographic Features
![Page 187: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/187.jpg)
a) Etiology :-The orbital septum represents a barrier to
infectious spread from anterior to posterior structures
-Common causes of orbital infection include spread from infected sinus and trauma
![Page 188: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/188.jpg)
![Page 189: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/189.jpg)
b) Radiographic Features :-Periorbital cellulitis: soft tissue swelling-Postseptal infection (true orbital cellulitis) :*Subperiosteal infiltrate*Stranding of retrobulbar fat*Lateral displacement of enlarged medial rectus m.*Proptosis
![Page 190: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/190.jpg)
Preseptal Cellulitis : CT+C of the orbit shows soft tissue thickening of the right preseptal region (between arrows) , the retro-orbital fat is normal (arrowheads)
![Page 191: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/191.jpg)
Periorbital Abscess
![Page 192: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/192.jpg)
Opacification of left paranasal sinuses and left subperiosteal orbital abscesses of the orbital roof
![Page 193: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/193.jpg)
Orbital Cellulitis
![Page 194: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/194.jpg)
Orbital abscess
![Page 195: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/195.jpg)
Orbital abscess
![Page 196: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/196.jpg)
-Axial image from a CT scan of the orbits performed with contrast demonstrates sinusitis of the left ethmoid sinus and both sphenoid sinuses-There is left sided prespetal cellulitis anterior to the left orbit-Furthermore , there is a left sided subperiosteal abscess between the medial wall of the left orbit and the left medial rectus muscle
![Page 197: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/197.jpg)
2-Lymphoma and Metastases :-Lymphoma :a) Incidenceb) Clinical Featuresc) Radiographic Findings
![Page 198: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/198.jpg)
a) Incidence :-Orbital lymphomas account for only 2% of all
lymphomas but constitute 5-15% of all extranodal lymphomas and approximately 50% of all primary orbital malignancies in adults
-Typically patients are between 50 and 70 years of age
![Page 199: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/199.jpg)
b) Clinical Features :-Clinical presentation is variable as any part of the orbit can be
involved , in 25% of patients the conjunctiva is involved in which case patients demonstrate a (salmon red patch) of swollen conjunctiva
-The majority of patients who do not have conjunctival involvement (75% of cases) presentation is due to an orbital mass usually in the superior lateral quadrant in proximity to the lacrimal gland :
1-Palpable mass2-Exophthalmos3-Ptosis4-Diplopia and abnormal ocular movement-Generally the mass is painless , however a subset of patients
demonstrate inflammatory-like changes with pain , erythema and swelling, direct infiltration of the globe and / or optic nerve is rare and vision is usually preserved
![Page 200: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/200.jpg)
![Page 201: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/201.jpg)
c) Radiographic Findings :-Soft tissue mass either involving the conjunctiva or
elsewhere in the orbit , frequently in the upper outer quadrant , closely associated with the lacrimal gland
-Although the extraocular muscles may be surrounded or displaced by the mass , they can usually be identified as not being the origin of the tumor, helpful in distinguishing lymphomas from other orbital masses
-Invasion of the globe or optic nerve is rare
![Page 202: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/202.jpg)
a This graph represents the lymphoma distribution at the diagnosis, the superior (SUP) and lateral (LAT) quadrant is the most common, medial (MED) and inferior (INF) quadrants are less affected. b Coronal reconstruction of contrast CT shows bilateral orbital lymphoma: two homogeneous masses are circled in both superior and lateral quadrants
![Page 203: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/203.jpg)
-CT :*On non-contrast CT , the mass is usually
homogeneous in density either isodense or slightly hyperdense when compared to the extraocular muscles
-Following administration of contrast , only mild to moderate enhancement is seen similar again to the extraocular muscles and lacrimal gland
![Page 204: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/204.jpg)
CT+C obtained in two different patients show typical pattern of orbital involvement by lymphoma. a There is superior and lateral rectus muscle as well as lacrimal gland involvement in a coronal reconstruction of CT, it is highlighted the predominant superior lateral quadrant involved. b CT after contrast shows a slight enhancement lesion within the eyelid (red arrows)
![Page 205: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/205.jpg)
![Page 206: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/206.jpg)
-MRI :Similar to intracranial lymphoma , the densely cellular
nature of these tumors with high nucleus-to-cytoplasm ratio results in relatively specific appearances :
*T1 : Iso to hypointense to muscle*T2 : Iso to hyperintense to muscle*T1+C: Homogeneous enhancement*DWI : Increased signal intensity, i.e. restricted diffusion*ADC : Reduced values, i.e. restricted diffusion
![Page 207: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/207.jpg)
T1
![Page 208: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/208.jpg)
T2 FS
![Page 209: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/209.jpg)
T1+C
![Page 210: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/210.jpg)
-Metastases :*Children: Ewing's tumor , neuroblastoma &
leukemia*Adults: -Breast , lung , renal cell & prostate carcinoma-Direct extension of SCC from paranasal sinus
![Page 211: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/211.jpg)
Orbital soft tissue mass leading to bone erosion and intracranial invasion
![Page 212: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/212.jpg)
Breast cancer metastasis in a 56-year-old woman who presented with eye pain, axial T1+C fat-suppressed shows thickening of the left lateral rectus muscle (arrows), with involvement of the tendinous insertion, biopsy results revealed breast cancer, which was undiagnosed at presentation
![Page 213: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/213.jpg)
Metastatic scirrhous breast cancer in a 43-year-old woman with bilateral paradoxical enophthalmos. (a) Axial T1 shows abnormally hypointense and heterogeneous bilateral retrobulbar fat (arrows), (b) Axial T1+C fat-suppressed shows patchy enhancement of the retrobulbar fat (arrows), the left medial rectus is also thickened because of metastatic involvement (arrowhead)
![Page 214: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/214.jpg)
Melanoma metastatic to the extraocular muscle in a 37-year-old man who presented with decreased vision, Axial T1 shows a mass of the inferior rectus muscle that appears isointense (arrow), reflecting its amelanotic nature
![Page 215: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/215.jpg)
3-Dermoid and Teratoma :a) Incidenceb) Radiographic Features
![Page 216: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/216.jpg)
a) Incidence :-Common orbital tumor in childhood-Age: 1st decade
b) Radiographic Features :-Low CT attenuation and T1 hyperintensity (fat) are
diagnostic-Contiguous bone scalloping or sclerosis is common-May contain debris (inhomogeneous MRI signal)
![Page 217: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/217.jpg)
![Page 218: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/218.jpg)
![Page 219: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/219.jpg)
CT Ruptured Orbital dermoid cyst
![Page 220: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/220.jpg)
CT Ruptured Orbital dermoid cyst
![Page 221: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/221.jpg)
T1
![Page 222: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/222.jpg)
T2
![Page 223: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/223.jpg)
T1+C
![Page 224: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/224.jpg)
4-Lymphangioma & Lymphohaemangioma :a) Incidence b) Clinical Picturec) Radiographic Features
![Page 225: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/225.jpg)
a) Incidence :-2% of orbital childhood tumors-Known as venous lymphatic malformation -Age: 1st decade-Associated with other lymphangiomas in head
and neck-Lymphangiomas of the orbit do not involute
spontaneously
![Page 226: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/226.jpg)
b) Clinical Picture :-Although venous lymphatic malformations may
enlarge slowly, producing progressive proptosis, restriction of eye movements, or vertical globe displacement, many manifest abruptly because of hemorrhage
-Hemorrhages within these malformations often occur after minor trauma or infection and occasionally develop spontaneously
![Page 227: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/227.jpg)
Marked right proptosis and superior displacement of the globe, also note enlarged right orbit compared with left orbit
![Page 228: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/228.jpg)
c) Radiographic Features :1-CT :-Variable CT appearance because of different
histologic components (lymphangitic channels , vascular stroma)
-Multiloculated-Rim enhancement
![Page 229: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/229.jpg)
2-MRI :-MR imaging is the modality of choice for the evaluation of
lymphatic malformations because it best depicts the various components
-The signal intensity of the lesions depends on the type of fluid within the cystic components, whether hemorrhage has occurred, and the age of the hemorrhage
-T1 best depict lymphatic or proteinaceous fluid, and T1-weighted fat-suppressed images are best for detecting blood or blood products
-T2 fat-suppressed images provide improved visibility of components that contain nonhemorrhagic fluid
-T1+C : The use of contrast material does not typically provide significant additional information, but an absence of enhancement is indicative of a lymphatic component
-Fluid-fluid levels produced by hemorrhages of various ages within multiple cysts are almost pathognomonic
![Page 230: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/230.jpg)
Venous lymphatic malformation in an 11-year-old boy with progressive proptosis of the right eye and lateral displacement of the globe. (a) Axial unenhanced CT shows multiple fluid-fluid levels (arrows) within a lobulated, predominantly extraconal lesion, features typical of a lymphatic malformation with an intralesional hemorrhage. (b) Axial T2 fat-suppressed MR image shows multiple fluid-fluid levels within the lesion, which has both intra- and extraconal components
![Page 231: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/231.jpg)
Lymphatic malformation (lymphangioma), axial T2 shows a hyperintense, trans-spatial mass involving the intra- and extra-conal compartments. Hypointense septations (black arrows) are typical of this lesion. Layering blood products (white arrows) are variably present, and indicate recent intralesional bleeding
![Page 232: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/232.jpg)
5-Spread from Lacrimal Gland Tumors :a) Lymphoidb) Epithelial tumors
![Page 233: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/233.jpg)
a) Lymphoid , 50% :-Benign reactive lymphoid hyperplasia-Lymphomab) Epithelial tumors , 50% :-Benign mixed (pleomorphic) tumor (75% of
epithelial tumors)-Adenoid cystic carcinoma-Mucoepidermoid carcinoma- Malignant mixed tumor
![Page 234: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/234.jpg)
Lymphoma
![Page 235: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/235.jpg)
![Page 236: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/236.jpg)
![Page 237: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/237.jpg)
![Page 238: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/238.jpg)
Pleomorphic adenoma T1
![Page 239: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/239.jpg)
T2
![Page 240: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/240.jpg)
T1+C
![Page 241: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/241.jpg)
T1+C
![Page 242: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/242.jpg)
e) Arising from the Orbital Wall :1-Metastases and Lymphoma 2-Langerhans Cell Histiocytosis 3-Invasion by ethmoidal or maxillary antral
tumors 4-Ethmoidal Mucocoele
5-Spread of Ethmoidal or Antral infection
![Page 243: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/243.jpg)
Langerhans cell histiocytosis :-Occurs in children with peak incidence at age 1
and 4-Osteolytic mass like lesion located in the
superolateral orbit in pediatric patients with varibale degree of proptosis and inflammatory signs
-The diagnosis should be confirmed by histopathology and this will show the presence of langerhans cells
![Page 244: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/244.jpg)
![Page 245: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/245.jpg)
Coronal CT scan showing an osteolytic right superolateral orbit lesion
![Page 246: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/246.jpg)
![Page 247: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/247.jpg)
**N.B. : Erdeheim-Chester Disease :-Lipid granulomatosis with retroorbital
deposition, xanthelasma of eyelids, skeletal manifestations (medullary sclerosis, cortical thickening), and cardiopulmonary manifestations due to cholesterol emboli
-Rare
![Page 248: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/248.jpg)
**N.B. Ocular Manifestations of Phakomatosis:a) NF1 :1-Lisch nodules2-Sphenoid bone dysplasia3-Choroidal hamartoma4-Optic glioma5-Plexiform neurofibromab) NF2 :1-Meningioma2-Schwannoma
![Page 249: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/249.jpg)
c) Sturge-Weber :1-Choroidal angioma2-Buphthalmos3-Glaucomad) Tuberous sclerosis :-Retinal astrocytic hamartomae) Von Hippel-Lindau (VHL) :-Retinal angioma
![Page 250: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/250.jpg)
3-Orbital Trauma1-Anterior Chamber Injuries2-Injuries to the Lens3-Open-Globe Injuries4-Ocular Detachments5-Intraorbital Foreign Bodies6-Carotid Cavernous Fistula7-Optic Nerve Injuries
![Page 251: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/251.jpg)
Unenhanced axial CT scan of a healthy 32-year-old man. AC = anterior chamber, L = lens, ON= optic nerve, PS = posterior segment (vitreous humor)
![Page 252: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/252.jpg)
1-Anterior Chamber Injuries :-Posttraumatic bleeding into the anterior chamber, or
traumatic hyphema, is caused by the disruption of blood vessels in the iris or ciliary body
-The blood extravasates into the anterior chamber, where a blood-fluid level is usually readily appreciated at clinical examination
-CT images may show increased attenuation in the anterior chamber, but the primary role of imaging is to evaluate for other related injuries, corneal lacerations are usually associated with a penetrating trauma
![Page 253: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/253.jpg)
Photograph shows posttraumatic hyphema in a 25-year-old man
![Page 254: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/254.jpg)
-After a laceration, the iris may prolapse into the anterior chamber, thereby closing the defect
-On CT images, the key finding is decreased volume of the anterior chamber, which appears as a diminished anterior-posterior dimension compared to that of the normal globe
-Anterior subluxation of the lens is an important mimic of corneal laceration, to accurately diagnose a corneal laceration, the radiologist needs to not only assess the volume of the anterior chamber, but to also determine the position of the lens
![Page 255: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/255.jpg)
Corneal laceration in a 22-year-old man, unenhanced axial CT scan shows decreased volume of the anterior chamber, a finding that confirms the diagnosis
![Page 256: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/256.jpg)
2-Injuries to the Lens :-Blunt trauma to the eye results in deformation of the
globe and typically displaces the cornea and anterior sclera posteriorly
-Deformation of the globe causes the zonular attachments that hold the lens in position to stretch and potentially tear; tearing of the zonular attachments may be either partial or complete
-After a complete disruption, the lens may dislocate posteriorly or, less commonly, anteriorly
-Posterior dislocations are more common, in part because the iris impedes anterior subluxation of the lens
![Page 257: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/257.jpg)
-After complete posterior subluxation, the lens usually lies within the dependent portion of the vitreous humor
-If there is only partial disruption of the zonular fibers, the intact fibers retain one margin of the lens in its normal position just behind the iris while the remainder of the lens is angled posteriorly and projects into the vitreous humor
-Trauma is the most common cause of lens dislocation; it accounts for more than half of all cases
-An important pitfall for the radiologist to avoid is that of the spontaneous dislocated lens, nontraumatic lens dislocation may be associated with systemic connective tissue disorders, such as Marfan syndrome, Ehlers-Danlos syndrome, and homocystinuria
-If the dislocation is bilateral, the radiologist should suspect an underlying systemic condition
![Page 258: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/258.jpg)
Unenhanced axial CT scan of a 29-year-old man shows complete subluxation of the lens
![Page 259: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/259.jpg)
Unenhanced axial CT scan of a 49-year-old woman shows a partially dislocated lens
![Page 260: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/260.jpg)
3-Open-Globe Injuries :A ruptured globe or an open-globe injury must
be assessed in any patient who has suffered orbital trauma, because open-globe injuries are a major cause of blindness
-In blunt traumas, ruptures are most common at the insertions of the intraocular muscles where the sclera is thinnest
-If intraocular contents are visualized at clinical examination, a diagnosis of a ruptured globe can be obvious, otherwise, CT scanning is the test of choice
![Page 261: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/261.jpg)
-Blow-out fractures can occur through one or more of the walls of the orbit :
1-Inferior (floor), most common, orbital fat prolapses into the maxillary sinus and may be joined by prolapse of the inferior rectus muscle
2-Medial wall (lamina papyracea) , 2nd most common, occurring through the lamina papyracea, orbital fat and the medial rectus muscle may prolapse into the ethmoid air cells
3-Superior (roof)4-Lateral wall
![Page 262: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/262.jpg)
Inferior
![Page 263: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/263.jpg)
Medial
![Page 264: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/264.jpg)
-CT findings suggestive of an open-globe injury include a change in globe contour, an obvious loss of volume, the “flat tire” sign, scleral discontinuity, intraocular air, and intraocular foreign bodies
-Posterior movement of the lens enlarges or deepens the anterior chamber, a deep anterior chamber has been described as a clinical finding in patients with a ruptured globe and can also be a useful clue on CT image
-There are several non- traumatic causes for an altered globe contour that may mimic an open-globe injury, including congenital deformities at the optic nerve head (eg, coloboma) and acquired contour deformities, which may involve any portion of the globe (eg, staphyloma), a posttraumatic orbital hematoma may deform the globe, mimicking an open-globe injury
![Page 265: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/265.jpg)
75-year-old man with right globe rupture, axial unenhanced CT scan shows eyelid hematoma (thick straight arrow), lens dislocation (arrowhead), vitreous hemorrhage (thin straight arrow), and irregular scleral wall (curved arrow)
![Page 266: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/266.jpg)
80-year-old man with left eyeball rupture. Axial unenhanced CT scan shows gas (short arrow) and metallic foreign body (long arrow) in ruptured globe
![Page 267: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/267.jpg)
34-year-old man with left eyeball rupture, axial unenhanced CT scan shows shallow anterior chamber depth (ACD) of left globe (single arrow), ACD is evaluated at level of equator of globe from posterior surface of cornea to anterior surface of lens (parallel lines) and is measured along line perpendicular to long axis of lens (double arrows)
![Page 268: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/268.jpg)
Ruptured globe in a 43-year-old man. Unenhanced axial CT scan shows the flat tire sign, which indicates an open-globe injury
![Page 269: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/269.jpg)
Ruptured globe in a 35-year-old man. Unenhanced axial CT scan shows extrusion of the lens
![Page 270: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/270.jpg)
Open-globe injury in a 20-year-old man who presented with orbital trauma that may or may not have been an open-globe injury, unenhanced axial CT scan shows increased depth of the anterior chamber, which helps confirm the diagnosis of an open-globe injury
![Page 271: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/271.jpg)
Congenital coloboma in a 53-year-old man who presented with decreased visual acuity, unenhanced axial CT scan shows a deformity at the left optic nerve head
![Page 272: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/272.jpg)
Globe deformity in a 58-year-old man with facial fractures. (a) Unenhanced axial CT scan shows deformity of the globe, but it is unclear if there is an open-globe injury, after the facial fractures were internally fixed and the soft-tissue swelling decreased, the globe appeared normal, (b) Unenhanced axial CT scan shows no open-globe injury, a finding that suggests that the globe deformity was secondary to posttraumatic hematoma and soft-tissue swelling, which subsequently resolved
![Page 273: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/273.jpg)
4-Ocular Detachments :-The three layers of the globe can separate,
thereby creating potential spaces between the layers
-The retina is the inner, sensory layer of the globe
-The retina is very firmly attached along its anterior margin, called the ora serrata, and posteriorly at the optic disc
-The remainder of its surface is only loosely attached to the choroid
![Page 274: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/274.jpg)
-Retinal detachment occurs when the retina is separated from the choroid
- Common causes of retinal detachment include both inflammatory and neoplastic etiologies
-Retinal detachment may also occur secondary to trauma, particularly if there is a break in the retina, which can allow vitreous fluid to pass into the subretinal space
-Collections of subretinal fluid assume a characteristic V-shaped configuration, with the apex at the optic disk and the extremities at the ora serrata
![Page 275: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/275.jpg)
Photograph of a gross pathologic specimen (hematoxylineosin stain) shows a retinal detachment, note the characteristic V-shaped configuration caused by tethering of the retina near the optic nerve head (arrow), ON = optic nerve
![Page 276: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/276.jpg)
![Page 277: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/277.jpg)
Axial CT shows hemorrhagic subretinal fluid in another patient with retinal detachment (arrow)
![Page 278: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/278.jpg)
![Page 279: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/279.jpg)
-The choroid is part of the middle layer of the globe-It extends from the optic nerve head to the ora serrata
and is tethered to the sclera by arteries and veins, which supply this vascular layer
-Choroidal detachments are caused by an accumulation of fluid in the potential suprachoroidal space that lies between the choroid and the sclera
-Ocular hypotony is the underlying cause of choroidal detachment; hypotony may be the result of an inflammatory disease, accidental perforation, or surgery, decreased ocular pressure results in decreased pressure in the suprachoroidal space, transudate may accumulate in the suprachoroidal space, resulting in a serous choroidal detachment
![Page 280: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/280.jpg)
Unenhanced axial (a) and coronal (b) CT images of a 40-year-old woman show a right serous choroidal detachment secondary to ocular hypotony
![Page 281: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/281.jpg)
-If there is associated tearing of blood vessels, a hemorrhagic choroidal detachment may occur
-Suprachoroidal fluid collections usually assume a biconvex or lentiform configuration that extends from the level of the vortex veins to the ora serrata
-Posttraumatic bleeding can also occur within the vitreous humor, or it may occur in the layer between the vitreous and the retina
![Page 282: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/282.jpg)
Unenhanced axial CT scan of an 84-year-old woman shows a posttraumatic, hemorrhagic choroidal detachment
![Page 283: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/283.jpg)
Unenhanced CT scan of an 81-year-old woman receiving anticoagulation therapy, who presented after a trauma, shows an extensive vitreous hemorrhage
![Page 284: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/284.jpg)
5-Intraorbital Foreign Bodies :-The detection and localization of intraorbital foreign
bodies is an important task for the radiologist-CT is sensitive and is usually the first imaging test
performed-MR imaging may be of value, particularly for detecting
nonmetallic foreign bodies, however, a metallic foreign body must be definitively ruled out before MR imaging is performed, failure to detect a metallic foreign body before performing MR imaging may result in blindness
-Fortunately, CT is a very sensitive imaging modality that can demonstrate metal fragments less than 1 mm in size
![Page 285: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/285.jpg)
-CT is most sensitive in detection of glass objects-Unlike metallic and glass foreign bodies, wooden
foreign bodies usually appear hypoattenuating on CT images; because of their low attenuation, they can be mistaken for air, the radiologist should suspect a wood or organic foreign body if the low-attenuation collection seen on CT images displays a geometric margin
-MR imaging may demonstrate wooden foreign bodies in cases where CT results have been either negative or equivocal, T2 or T1+C performed with fat suppression can demonstrate an intraorbital foreign body by enhancing the inflammatory response seen surrounding that foreign body
![Page 286: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/286.jpg)
-Penetrating injury from a tree branch in a 7-year-old boy, the branch was removed, and unenhanced CT was performed to evaluate for any remaining foreign bodies
(a) CT scan shows only a low-attenuation defect; no definite foreign body is seen, three days later, the eye became infected, and contrast-enhanced CT was performed
(b) CT scan shows soft-tissue swelling and abnormal enhancement consistent with the infection, but no definite foreign body is seen
(c, d) Coronal unenhanced T2 inversion recovery (c) and coronal T1+C fat-saturated MR (d) show the infection surrounding a low-signal-intensity foreign body, the MR images were obtained on the same date as the CT images, during surgery, a small piece of wood was removed
![Page 287: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/287.jpg)
6-Carotid Cavernous Fistula :-The presence of posttraumatic diplopia
associated with proptosis and chemosis suggests a diagnosis of carotid cavernous fistula, objective pulsatile tinnitus may also be present
-A tear in the cavernous internal carotid artery allows arterial blood to enter the cavernous sinus, thereby increasing the sinus pressure and reversing the flow in the venous tributaries
![Page 288: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/288.jpg)
-On unenhanced CT scans of the orbit, a dilated superior ophthalmic vein is usually seen
-Isolated dilatation of the superior ophthalmic vein is a potential diagnostic pitfall; this finding has been reported in multiple other conditions, including cavernous sinus thrombosis, venous varix, Graves disease, and as a normal venous variant
-The diagnosis of carotid cavernous fistula can be confirmed with CT angiography, or more definitively with conventional angiography
![Page 289: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/289.jpg)
Carotid cavernous fistula in a 16-year-old boy who presented with exophthalmos and objective pulsatile tinnitus after trauma, (a) Axial CTA shows dilatation of the periorbital veins and the left superior ophthalmic vein and a dilated left cavernous sinus, (b) Sagittal CTA shows an apparent communication between the cavernous segment of the ICA and the cavernous sinus (arrow), (c) Lateral view from left internal carotid angiography shows the carotid cavernous fistula
![Page 290: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/290.jpg)
7-Optic Nerve Injuries :-Optic nerve injuries can result from either direct or
indirect trauma-Rarely, a blunt orbital injury may fracture the optic
canal and lacerate the optic nerve-More commonly, a definitive fracture is not found, in
these cases, the optic nerve or its vascular supply is torn, thrombosed, or compressed
-In patients with a rapid posttraumatic decrease in visual acuity, high-resolution CT of the orbital apex should be performed to evaluate for possible fracture and to guide surgical intervention, if there are no contraindications to MR imaging, T2 prolongation may be visualized as increased signal intensity in the injured optic nerve
![Page 291: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/291.jpg)
Optic nerve injury in a 33-year-old man who presented with multiple facial fractures and decreasing vision in his right eye, axial unenhanced CT scan shows a right orbital apex fracture with a bone fragment impinging on the optic nerve
![Page 292: Diagnostic Imaging of Orbital Lesions](https://reader036.vdocument.in/reader036/viewer/2022062522/587c70571a28abd04e8b58bf/html5/thumbnails/292.jpg)