Imaging of adult ocular abnormali es.
Sangha B, Agovida B, Forster BB, and Andrews G
University of Bri sh Columbia, Department of Radiology Vancouver, Bri sh Columbia, Canada
Canadian Associa on of Radiologists mee ng, 76th Annual Learning Objec ves Review the anatomy of the globe
Describe the features of trauma c globe injuries.
Describe the imaging features of non-trauma c globe abnormali es such as detachments and provide a differen al for globe calcifica on.
Provide an approach to evalua ng ocular neoplasms.
Review the common post-surgical changes of the globe.
Anatomy
1 - Globe has 3 layers : Anterior Chamber 1. Fibrous coat Ciliary Cornea - formed by cornea anteriorly Body Lens and sclera posteriorly Vitreous Chamber 2. Uvea Re na – formed by choroid, ciliary Sclera Choroid body and the iris
3. Re na – neural layer, converts light Axial T1w, contrast enhanced into neural signals fat saturated image
Globe Rupture – Findings2-5
- Loss of volume or contour abnormality - Discon nuity of the fibrous coat (sclera or cornea) - Intra-ocular foreign body - Intra-ocular gas Axial CT – contour abnormality - Collapsed globe (‘Flat re’ of globe with increased density sign) within posterior chamber in keeping with vitreous hemorrhage and globe rupture Globe Rupture - Pi alls
Axial CT – scleral buckle Axial CT – contour and intra-ocular gas abnormality of the used in treatment of posterior globe in keeping re nal detachment with a staphyloma Anterior Chamber Injuries - Hyphema or hemorrhage in anterior chamber is o en clinically evident (assess for increased density) - Imaged to rule-out corneal rupture or other injuries - Corneal tear or rupture – decreased volume of anterior 2 chamber is sugges ve
Axial CT – subtle fla ening and Axial CT – increased density volume loss of le anterior within anterior chamber making chamber compared to right – the lens look large in pa ent surgically proven corneal tear with clinical hyphema Lens Injuries3 - Include lens disloca on and subluxa on - Can be trauma c or non-trauma c - If non-trauma c, suggest work-up for connec ve ssue disorders such as Marfan’s or Ehlers-Danlos syndrome
Axial CT – lted appearance to Axial CT – lens dislocated and this dislocated lens. Note the si ng within posterior chamber intra-ocular gas in keeping with globe rupture. Posterior Chamber Injuries - Vitreous hemorrhage is common - Re nal detachment – assess for funnel shaped density or 6 signal along re nal layer
Serial CT’s in the same pa ent Axial CT – Increased density along imaged on Day 1, 4, and 12 posterior globe (arrows) is in keeping show progression of posterior with re nal detachment. Loss of chamber hemorrhage globe volume and gas are in keeping with trauma c globe rupture. Re nal Detachment
- Re na is firmly a ached at op c nerve and oro-serrata (point at which choroid and ciliary body fibers converge) 6-7 - Fluid tracking between layers leads to ‘funnel’ shape density
Axial CT – Increased funnel-shaped Axial T2w (le ) and T1w contrast density along posterior globe (arrows) is enhanced (right) images from in keeping with re nal detachment. the same pa ent – arrows demonstrate a re nal detachment.
Choroidal Detachment - Fluid accumulates between choroid and sclera - Fluid tracks in a circumferen al pa ern along the lateral 6 walls of the globe
Axial CT – Increased density along Axial T2w (le ) and T1w (right) lateral globe (arrows) is in keeping images– arrows demonstrate with hemorrhagic choroidal choroidal detachment. detachment in this trauma pa ent. Globe Calcifica on - Wide differen al that ranges from benign to malignant - Most common en es include drusen, dystrophic calcifica on and phthisis bulbi
Axial CT demonstrates an Axial CT demonstrates likely atrophic, collapsed, calcified dystrophic calcifica on of the globe in keeping with phthisis choroid in this pa ent who had bulbi. undergone previous radia on for an op c glioma. Globe Calcifica on
Axial non-contrast CT demonstrates calcifica on at the op c discs bilaterally in keeping with drusen.
Axial contrast-enhanced CT demonstrates an enhancing mass within the le eye associated with calcifica on in this pa ent with primary breast cancer .
Ophthalmi s - Inflamma on of the globe can be due to extrinsic process such as orbital celluli s7 - Can be due to primary intraocular inflamma on (endo-ophthalmi s) from an infec ous e ology or from extrinsic delivery of infec ous agents via surgery or trauma
CT - stranding around globe with subtle CT – thickening of the globe with choroidal increased density along lateral margins detachment in this case of endo-ophthalmi s (arrows) sugges ve of choroidal detachment or effusion in this case of orbital celluli s. Coat’s disease - Exuda ve re ni s - Predominantly occurs in young males around age 10, but can present in adult males8
Axial CT shows increased density of exudate between layers of re na (arrow) with associated calcifica on in this 20 year old male with Coat’s disease. Ocular Neoplasms
- O en present with vision changes, but can be asymptoma c
- Metastases are most common malignant neoplasm presen ng within the globe in adults
- Uveal melanoma is most common primary malignant neoplasm in adults
- Intraocular schwannoma is a benign neoplasm which can mimic an uveal melanoma
Metastases - Breast and lung cancers tend to be most frequent primary site of metastases presen ng within the globe - Look for addi onal lesions on rest of images
Axial contrast-enhanced CT demonstrates an enhancing Axial contrast-enhanced CT shows a mass within the le mass within the le eye associated with calcifica on in mandible that was at the inferior most aspect of the orbital exam this pa ent with primary breast cancer . in the same pa ent.
Uveal Melanoma - Account for the majority of melanomas whose primary site is not the skin9
- Most commonly present in pa ents in their 50’s
Axial T2w, axial T1w and axial T1w contrast- enhanced images – demonstrate a low T2 signal, high T1 signal, enhancing mass in posterior chamber that was pathologically an uveal melanoma with re nal detachment. Intra-ocular Schwannoma - Mimic uveal melanomas on imaging - Tend to be located in cilio-choroidal region10
- O en diagnosed on pathology a er surgical removal
Axial T1w, fat-saturated, Axial T2w and Axial T1 contrast-enhanced images – demonstrate a high T1 signal, low T2 signal, enhancing mass in the region of the ciliary body that was pathologically a schwannoma. Post-surgical appearance - Post surgical appearances are commonly mistaken for pathology11
Axial CT demonstrates intra- Axial CT demonstrates a normal ocular silicone implant used to bilateral post-cataract treat a re nal detachment. appearance (arrow on le )
Post-surgical appearance - Varying procedures used to treat re nal detachments
Axial CT shows a scleral buckle Axial CT demonstrates a scleral around the right globe. buckle with air inside the globe.
Post-surgical appearance
- Prostheses can have varying appearances
A B
Axial CT demonstrates an A. Axial CT demonstrates a prosthesis within the le orbit ocular prosthesis within B. Sagi al CT with bone algorithm demonstrates the same the right orbit. prosthesis.
Summary - Trauma c injuries to the globe include: globe rupture, anterior and posterior chamber hemorrhage, lens subluxa on/disloca on, and detachments - Re nal detachments have a funnel shape towards the op c disc while choroidal detachments are more lateral and circumferen al - Globe calcifica on can be of benign or malignant e ology. - Most common malignant globe masses in adults are metastases and uveal melanoma. - Post-surgical changes of the globe can have varying appearance.
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