Author: Elizabeth Chorney
NECT CECT MRI - T1 MRI - T2 MRI - T1 post-contrast MRI - Diffusion/ADC Additional comments
Malignant Extraocular:  
Rhabdomyosarcoma Typically isodense to muscle with or without osseous destruction. Isointense to extraocular muscle Variable, but usually hyperintense to extraocular muscle Enhancement (axial)

 

Enhancement (coronal)

May show restricted diffusion. High signal on diffusion

 

Low signal on corresponding ADC

Most common extraocular malignancy in children, but still less common than retinoblastoma
 
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.

Enhances (No image available.) Variable. Typically isointense to mildly hyperintense relative to extraocular muscles Image 1.

 

Image 2

Variable. Typically mildly hyperintense relative to extraocular muscle. Image 1.

 

Image 2.

Enhancement. Image 1.

 

Image 2.

Restricted diffusion
 
Optic Glioma   Fusiform enlargement with signal isointense to optic nerve Fusiform enlargement with hyperintense signal relative to optic nerve. Axial.

 

Sagittal

Enhancement of the enlarged portion of the optic nerve. Enhancement may be diffuse or heterogenous.     Additional information on optic glioma via link below
     
Metastatic Carcinoid   Variable. Here seen as round mass within the medial rectus muscle.

 

Image 2

Variable. Here seen as slightly heterogenous and isointense to extraocular muscle.   Enhancement. Image 1

 

Image 2

  Can show radiotracer uptake on nuclear medicine Ocretotide scan
     
Metastatic Breast Cancer   Variable. Here seen as infiltration and enlargement of the medial rectus muscle, superior rectus muscle and lacrimal gland Variable. Here seen as heterogeneous hyperintense enlargement of the medial rectus muscle. Enhancement.. Image 1

 

Image 2

Tumors that more commonly metastasize to orbit include, breast, prostate, lung, cutaneous melanoma, and kidney.
     
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.

Variable. Here the soft tissue mass that is near isointense to extraocular muscle. Variable. Here the soft tissue mass is hyperintense to extraocular muscle. 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

Can show radiotracer uptake on on nuclear medicine FDG PET scan
   
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

   
         
Benign Extraocular:  
Hemangioma Well circumscribed and often ovoid or round (No image available.)   Enhancing well circumscribed ovoid or round mass Isointense to extraocular muscle

 

Image 2

Hyperintense to extraocular muscle

 

Image 2

Post contrast heterogenous enhancement (axial).

 

Post contrast heterogenous enhancement (coronal)

Progressive enhancement

Female predominance. Can progressively enlarge over time. Pregnancy can cause rapid growth.
   
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

Enhances (No image available.) Typically isointense to muscle. Here seen as infiltrating soft tissue mass extending into orbit Variable. Typically hyperintense to extraocular muscle. Enhancement. Image 1.

 

Image 2

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.  
   
Meningioma Variable appearance. Here seen as isodense to extraocular muscle Enhances (No image available)   Can be isointense or slight hypointense relative to extraocular muscle Isointense to slightly hyperintense to extraocular muscle. May also see heterogeneity or areas of T2 signal intensity due to calcification. 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. Female predominant. Association with neurofibromatosis type 2
   
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

No internal enhancement. Surrounding wall may show enhancement. (No image available.)   Often T1 high signal intensity relative to extraocular muscle, due to lipid content Variable. Typically high signal intensity relative to extraocular muscle, not suppressed on FLAIR. No internal enhancement. Surrounding wall may show enhancement Can show restricted diffusion. (No image available)   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.
   
Eosinophilic Granuloma Soft tissue mass with adjacent beveled erosion of lateral wall of the orbit. Image 1.

 

Image 2

  Variable. Isointense to  intermediate high signal intensity relative to extraocular muscle.. Image 1

 

Image 2

Variable. Typically hyperintense to extraocular muscle.  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

Although LCH is fairly rare, among patients with LCH, orbital involvement is not uncommon.
   
Intraocular neoplasms:  
Retinoblastoma Typically hyperdense mass within the globe, usually with calcification Contrast enhancement is variable (No image available.)   Slightly high signal intensity relative to vitreous (No image available.) Low signal intensity relative to vitreous. Internal calcification may make tumor appear heterogeneous Enhancement 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.
     
Melanoma Hyperdense (No image available.)   Hyperdense and enhancement (No image available.)   High signal intensity relative to extraocular muscle Low signal intensity relative to extraocular muscle.

 

Image 2

Enhancement Second most common ocular malignancy and the most common primary ocular malignant neoplasm in adults.  
     
Medulloepithelioma Variable. Typically high density     Hyperintense relative to vitreous (No image available.)   Hypointense relative to vitreous (No image available.) Typically homogenous enhancement adjacent to ciliary body. Can have heterogeneous components 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.
       
Benign Intraocular:  
Choroidal hemangioma     Variable. Seen here as hypointense relative to vitreous.   Predominantly isointense to mildly hyperintense relative to vitreous Strong early enhancement Can be sporadic or associated with Sturge Weber. Key differential should be distinguishing from ocular melanoma.
     
Choroidal Osteoma Typically calcification in the posterior globe (No image available)       Benign tumors, but excluding melanoma important in the workup. Typically present in young women.
           
Tumor-like:  
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.

Peripheral enhancement (No image available) Low signal intensity along medial wall of right orbit with punctuate signal voids corresponding to air foci. Note associated mass effect on the globe High signal intensity and adjacent edema in surrounding intraorbital soft tissues.. Inflammatory changes are also present in the right ethmoid sinus Low signal intensity centrally within the abscess and peripheral enhancement. Image 1

 

Image 2

Restricted diffusion within the abscess
 
Inflammatory Orbital Pseudotumor   Variable. Typically isointense relative to extraocular muscle Variable Enhancement May show restricted diffusion
     
Hematoma Nonspecific hyperdense area in right orbit consistent with acute blood product Slightly heterogeneous after contrast enhancement 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

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

Variable depending on the age of the hematoma. Here seen as area of restricted diffusion acutely
 
Eyelid Hematoma Mild hyperdensity and soft tissue swelling involving right eyelid and periorbital region. A right orbital floor fracture is also present.. Image 1

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Graves Opthalomopathy Variable. Note increased orbital fat, bilateral exopthalmos and enlargement of the extraocular muscles with sparing of tendinous junction Can have increased T2 high signal intensity due to edema if there is active inflammation (no image available)   Helpful mneumonic "IM SLOW" describing the frequency of extraocular involvement in order of decreasing frequency corresponding to Inferior, Medial, Superior, and Lateral rectus muscles
         
Sarcoid   Variable. Seen here as enlargement of the lacrimal glands, extraocular muscles (EOM) and enlargement at the (EOM) tendinous insertion Variable. Seen here as markedly low signal intensity within the extraocular muscles Variable, but typically enhances as seen here.