Author:
Elizabeth Chorney
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NECT |
CECT |
MRI - T1 |
MRI - T2 |
MRI - T1 post-contrast |
MRI - Diffusion/ADC |
Additional comments |
Malignant Extraocular:
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Rhabdomyosarcoma |
Typically isodense to muscle with or without osseous destruction.
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Isointense to
extraocular muscle
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Variable, but usually hyperintense to extraocular muscle
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Enhancement
(axial)
Enhancement
(coronal) |
May
show restricted diffusion. High signal on diffusion
Low signal on corresponding ADC
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Most common extraocular malignancy in children, but still less
common than retinoblastoma |
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Lymphoma |
Variable. Typically homogeneous and isodense to slightly hyperdense relative to extraocular muscles. Image 1.
Image 2.
Note enlargement of infraorbital canal along infraorbital floor.
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Enhances (No image available.)
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Variable. Typically isointense to mildly hyperintense relative to extraocular muscles Image 1.
Image 2
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Variable. Typically mildly hyperintense relative to extraocular muscle. Image 1.
Image 2.
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Enhancement. Image 1.
Image 2.
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Restricted diffusion
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Optic
Glioma |
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Fusiform
enlargement with signal isointense to optic nerve
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Fusiform
enlargement with hyperintense signal relative to optic nerve. Axial.
Sagittal
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Enhancement of the enlarged portion of the optic nerve. Enhancement
may be diffuse or heterogenous. |
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Additional information on optic glioma via link below |
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Metastatic
Carcinoid |
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Variable. Here seen as round mass within the medial rectus muscle.
Image 2
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Variable. Here seen as slightly heterogenous and isointense to
extraocular muscle. |
Enhancement. Image 1
Image 2
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Can show radiotracer uptake on nuclear medicine Ocretotide scan
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Metastatic Breast
Cancer |
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Variable. Here seen as infiltration and enlargement of the medial rectus muscle, superior rectus muscle and lacrimal gland
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Variable. Here seen as heterogeneous hyperintense enlargement of the medial rectus muscle.
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Enhancement.. Image 1
Image 2
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Tumors that more commonly metastasize to orbit include, breast, prostate, lung, cutaneous melanoma, and kidney.
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Metastatic
Olfactory Neuroblastoma |
Variable. Here seen as large soft tissue mass in right ethmoid sinus with adjacent osseous destruction and direct extension into right orbit and maxillary sinus. Note associated proptosis.. Image
1.
Image
2.
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Variable. Here the soft tissue mass that is near isointense to extraocular muscle.
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Variable. Here the soft tissue mass is hyperintense to extraocular muscle.
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Enhancement. Also note
superior displacement of the globe.. Image 1
Image 2:
The lesion also involves the right temporalis muscle along the
lateral orbital wall
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Can show radiotracer uptake on on nuclear medicine FDG PET scan
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Basal Cell
Carcinoma |
Variable. Here seen predominantly as an ulcerated infiltrative mass
with local osseous erosion of the inferior and medial wall of the orbit. There
is soft tissue infiltration of the orbital fat and periorbital soft tissues. There is extension into the adjacent anterior ethmoid air cells. . Image 1.
Image 2.
Image 3
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Benign Extraocular:
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Hemangioma |
Well circumscribed and often ovoid or round (No image available.)
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Enhancing well circumscribed ovoid or round mass
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Isointense to
extraocular muscle
Image 2
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Hyperintense
to extraocular muscle
Image 2
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Post contrast
heterogenous enhancement (axial).
Post contrast
heterogenous enhancement (coronal)
Progressive enhancement
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Female predominance. Can progressively enlarge over time. Pregnancy can cause rapid growth.
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Plexiform
Neurofibroma |
Variable. Here seen as a soft tissue mass with ipsilateral sphenoid dysplasia and osseous defects in the posterior orbit.
Coronal view shows "egg shaped" expansion of the orbit
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Enhances (No image available.)
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Typically isointense to muscle. Here seen as infiltrating soft tissue mass extending into orbit
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Variable. Typically
hyperintense to extraocular muscle.
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Enhancement. Image 1.
Image 2
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Sphenoid dysplasia and infiltrative soft tissue mass is highly suggestive of plexiform neurofibroma.. Associated with NF1. Also look closely for optic nerve glioma in NF1 patients. A small percentage of plexiform neurofibromas will undergo sarcomatous degeneration.
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Meningioma |
Variable appearance. Here seen as
isodense to extraocular muscle
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Enhances (No image available)
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Can be isointense or slight hypointense
relative to extraocular muscle
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Isointense
to slightly hyperintense to extraocular muscle. May also see
heterogeneity or areas of T2 signal intensity due to calcification.
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Enhancement
on MR is typically peripheral or "tram track". Enhancement along
optic nerve sheath or in a eccentric mass off the sheath as in
this case.
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Female predominant. Association with neurofibromatosis type 2
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Dermoid |
Typically appear as well circumscribed encapsulated, unilocular
cystic mass. Here seen as oval cystic appearing lesion along the medial aspect of the right orbit. Image 1
Image 2
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No internal enhancement. Surrounding wall may show enhancement. (No image available.)
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Often T1 high signal intensity
relative to extraocular muscle, due to lipid content
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Variable. Typically high signal intensity
relative to extraocular muscle, not suppressed on FLAIR.
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No internal enhancement. Surrounding wall may show enhancement
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Can show restricted diffusion. (No image available)
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Congential benign lesion that arise from closed sacs lined by an ectodermal
epithelium. Probably the most common orbital lesion of childhood. The majority occur in the upper outer quadrant or the lacrimal fossa.
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Eosinophilic
Granuloma |
Soft tissue mass with adjacent beveled erosion of lateral wall of the orbit. Image 1.
Image 2
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Variable. Isointense to intermediate high signal intensity
relative to extraocular muscle.. Image 1
Image 2
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Variable. Typically hyperintense to extraocular muscle.
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Enhancement. Seen here as enhancing mass eroding the
superolateral orbital wall and extending up the frontal calvarium.
Note the beveled osseous defect. Image 1
Image 2
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Although LCH is fairly rare, among patients with LCH, orbital involvement is not uncommon.
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Intraocular neoplasms:
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Retinoblastoma |
Typically
hyperdense mass within the globe, usually with calcification
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Contrast enhancement is variable (No image available.)
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Slightly high signal intensity relative to vitreous (No image available.)
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Low signal intensity relative to vitreous. Internal calcification may make tumor appear heterogeneous
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Enhancement
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The most common intraocular tumor in children, typically seen before age 5. Retinoblastoma can be heritable or nonheritable. Can be bilateral approximately 20-34% of the time as reported by Chung et. al. In a patient with retinoblastoma and pineal or parasellar tumor, consider trilateral retinoblastoma syndrome.
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Melanoma |
Hyperdense (No image available.)
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Hyperdense and enhancement (No image available.)
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High signal intensity
relative to extraocular muscle
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Low signal intensity
relative to extraocular muscle.
Image 2
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Enhancement
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Second most common ocular malignancy and the most common primary ocular malignant neoplasm in adults.
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Medulloepithelioma |
Variable. Typically high density |
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Hyperintense relative to vitreous (No image available.)
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Hypointense relative to
vitreous (No image available.)
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Typically homogenous enhancement adjacent to ciliary body. Can have heterogeneous components
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Arises from the primitive medullary epithelium of the ciliary body. Can be seen in children and adults. In children consider differential of retinoblastoma, whereas in adults consider melanoma.
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Benign Intraocular:
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Choroidal
hemangioma |
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Variable. Seen here as hypointense relative to vitreous. |
Predominantly isointense
to mildly hyperintense relative to vitreous
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Strong early enhancement
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Can be sporadic or associated with Sturge Weber. Key differential should be distinguishing from ocular melanoma.
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Choroidal Osteoma |
Typically calcification in the posterior globe (No image available)
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Benign tumors, but excluding melanoma important in the workup. Typically present in young women.
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Tumor-like:
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Abscess |
Abnormal soft tissue density
medial to the right globe.
Coronal shows foci of air medial
to the right globe, as well as opacification of the ipsilateral maxillary sinus and ethomoid sinus.
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Peripheral enhancement (No image available)
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Low signal intensity along medial wall of right orbit with punctuate signal voids corresponding to air foci. Note associated mass effect on the globe
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High signal intensity and adjacent edema in surrounding
intraorbital soft tissues.. Inflammatory changes are also present in the right ethmoid sinus
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Low signal intensity centrally within the abscess and peripheral enhancement. Image 1
Image 2
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Restricted diffusion within the abscess
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Inflammatory
Orbital Pseudotumor |
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Variable. Typically isointense relative to extraocular muscle
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Variable
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Enhancement
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May show restricted diffusion
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Hematoma |
Nonspecific hyperdense area in right orbit consistent with acute blood product
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Slightly heterogeneous after contrast enhancement
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Variable appearance depending on age of blood products. Here seen as area of high T1 centrally with peripherally lower T1 signal intensity.
Two week follow up shows a significant decrease in size
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Variable appearance depending on age of blood products. Here seen as area of high T2 signal intensity.
Two week follow up shows a significant decrease in size
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Variable depending on the age of the hematoma. Here seen as area of restricted diffusion acutely
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Eyelid Hematoma |
Mild hyperdensity and soft tissue swelling
involving right eyelid and periorbital region. A right orbital floor fracture is also present.. Image 1
Image 2
Image 3
Image 4
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Graves
Opthalomopathy |
Variable. Note increased orbital fat, bilateral exopthalmos and enlargement of the extraocular muscles with sparing of tendinous junction
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Can have increased T2 high signal intensity due to edema if there is active inflammation (no image available)
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Helpful mneumonic "IM SLOW" describing the frequency of extraocular involvement in order of decreasing frequency corresponding to Inferior, Medial, Superior, and Lateral rectus muscles
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Sarcoid |
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Variable. Seen here as enlargement of the lacrimal glands, extraocular muscles (EOM) and enlargement at the (EOM) tendinous insertion
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Variable. Seen here as markedly low signal intensity within the extraocular muscles
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Variable, but typically enhances as seen here. |
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