HEAD AND NECK IMAGINGEHAB ABOU ELFOTOUH. MD.

ORBITAL IMAGING IV

CHOROIDAL HEMANGIOMA:

congenital vascular hamartomas.

Manifested in middle-aged or elderly people.

Equal distribution in both sexes.

CHOROIDAL HEMANGIOMA:

solitary choroidal hemangioma as abenign vascular neoplasm that is confined to the choroid.

Has ill defined margins.

Posterior chamber of the globe.

Diffuse hemangiomas occur in Sturge-Weber syndrome.

CHOROIDAL HEMANGIOMA:

CT imaging: Solitary ill-defined

mass. Posterior chamber

of the globe. High CT

attenuation. Intense

enhancement. With or without

retinal detachement.

CHOROIDAL HEMANGIOMA:

At MR imaging: A lenticular shape

mass.

Ill defined margins.

Posterior chamber.

Hyperintense to vitreous on T1-weighted images.

CHOROIDAL HEMANGIOMA:

On T2WIs, signals typically hyperintense.

Usually isointense to vitreous.

enhanced intensely after the administration of contrast material.

CHOROIDAL MELANOMA:

most common primary intraocular tumors in adults.

Melanomas occur in any of three subdivisions of uveaL tract.

From preexisting melanocytic nevi.

56%of melanomas occur in those older than 50 years.

CHOROIDAL MELANOMA:

Tumors initially have a flat growth profile.

later become elevated.

Erupting through the Bruch membrane with characteristic mushroom shape.

CHOROIDAL MELANOMA:

Primarily metastasize to the liver.

Some metastases manifest before primary tumor detection.

In order of decreasing frequency of distal metastasis are lung, bone, kidney, and brain

CHOROIDAL MELANOMA:

Large melanomas (10 mm thick) managed with enucleation.

medium- sized lesions (3–10 mm

thick) external-beam radiationtherapy.

Small tumors (3 mm thick) follow up 3–6 months with US or transpupillary thermotherapy.

CHOROIDAL MELANOMA:

At unenhanced CT:

Elevated posterior chamber mass.

Hyper-attenuating.

Sharply marginated.

CHOROIDAL MELANOMA:

At enhanced CT: Moderate intense

enhancement.

With or without retinal detachment.

Orbital metastasis.

CHOROIDAL MELANOMA:

At MR imaging: Posterior chamber

well-defined solid mass.

Melanotic melanomas have shorter T1 and T2 relaxation times.

Increased signal intensity on T1WIs.

CHOROIDAL MELANOMA:

Markedly decreased signal intensity on T2WIs.

Among ocular tumors, only melanomas manifest these signal intensity character.

CHOROIDAL MELANOMA:

Choroidal melanomas demonstrate moderate to strong enhancement.

Contrast-enhanced fat-suppressed MR imaging demonstrate scleral

invasion, extension to optic disc, and extraocular invasion.

CHOROIDAL MELANOMA:

Amelanotic melanomas has:

Isointense with vitreous on T1WIs.

slightly hypointense on T2-weighted images.

UVEAL METASTASES:

Through posterior ciliary arteries.

Commonly involve the posterior half of the globe.

primary lesions common sources of uveal metastases are breast and lung carcinoma.

UVEAL METASTASES:

Both eyes are affected in about one-third of cases.

Also may involve extraocular muscles.

MR imaging is superior to CT.

Signals similar to Amelanotic melanomas.

UVEAL METASTASES:

Homogenous enhancing criteria.

THANKS.