Orbital Lesions by Anatomic Compartment: A Practical Differential
A practical radiology review of Orbital Lesions by Anatomic Compartment: A Practical Differential, focused on imaging findings, differential diagnosis, reporting points, and...
A practical radiology review of Orbital Lesions by Anatomic Compartment: A Practical Differential, focused on imaging findings, differential diagnosis, reporting points, and high-yield teaching pearls.
- MS neuritis = T2 bright + enhance
- ION = sudden painless + restricted DWI
- Glioma (NF1) = tortuous nerve
- Meningioma (NF2) = “tram-track”
Intraconal
- CVM = slow, delayed fill ⏳
- Varix = grows w/ Valsalva
- LM = cystic + fluid-fluid
Conal (EOMs)
- TED = “I’M SLOw” Coca-Cola bottle
- Myositis = tendon involved
- IgG4 = lat rectus nerves
- Lymphoma = restricted DWI
Extraconal
- Cellulitis = pre vs post septum
- IH (infant) = flow voids
- Rhabdo = kids + restricted DWI
- Schwannoma = hetero, NF2
- Neurofibroma = “target sign”
Lacrimal
- Pleomorphic adenoma = painless
- Adenoid cystic = painful, PN spread
- Lacrimal lymphoma = restricted DWI
Globe
- Retinoblastoma = calc + DWI
- Melanoma = T1 bright T2 dark mushroom
- Ret detachment = V-shape
- Choroid detachment = tennis ball
Rules of thumb
- Diffusion restricted? → lymphoma/rhabdo/ION
- Progressive delayed enh.? → CVM ⏳
- Tendon spared? → TED | Tendon hit? → myositis
Systematic review and reporting
Confirm the epicentre before narrowing the differential: globe, optic nerve–sheath complex, intraconal space, extraocular muscle cone, extraconal space, lacrimal gland, orbital apex, or adjacent sinonasal compartment. Describe laterality, margins, T1 and T2 signal, diffusion, enhancement, hemorrhage or calcification, and any flow-related features. Then document mass effect on the globe and optic nerve, proptosis, apical crowding, bony remodeling or destruction, perineural spread, and intracranial or sinonasal extension. CT is particularly useful for bone and calcification; MRI better characterizes the optic pathway, orbital apex, cavernous sinus, and soft-tissue spread.
Compartment and imaging pattern refine—but do not by themselves establish—the diagnosis. Age, tempo, pain, visual symptoms, immune status, and prior malignancy should shape the final differential and urgency.
Pearls
- Always think compartment-based differential!
- Enhancement pattern & diffusion are in narrowing dx
- NF1 → gliomas/neurofibromas | NF2 → meningiomas/schwannomas
- Use “tram-track”, “target sign”, “Coca-Cola bottle” mnemonics
Clinical use note
This content is educational and is not patient-specific medical advice. Every phrase, template, classification result, and recommendation must be verified and adapted by a physician using the complete examination, clinical context, current guidelines, and institutional protocol.
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