Orbital lesions ii

ORBITAL IMAGING IIHEAD AND NECK IMAGING

EHAB ABOU ELFOTOUH. MD.

Enlargementof the ophthalmic veins, causes: Orbital Varices.

Increased antero-grade flow, can result from vascular malformations of the face and scalp.

Obstruction of distal venous drainage, as cavernous sinus thrombosis.

Ab-normal retro-grade flow, as carotid–cavernous fistula.

Increased intracranial pressure.

Normal variant.

Orbital Varices.

Most common cause of spontaneous orbital hemorrhage.

Lesions result from congenital weakness in post-capillary venous wall.

Have a large communication with the venous system and distend during maneuvers that increase venous pressure.

Orbital Varices.

Have only a small communication with the venous system and do not distend.

Patients with usually manifest stress or painful proptosis.

Orbital Varices.

CT images: Normal appearance,

axial on supine position.

Or mild enlargement of the involved veins.

Increases venous pressure is required to demonstrate lesion distensibility.

Orbital Varices.

Varices may be smooth club-like, triangular, or segmental dilatation of Opth. veins.

Orbital mass of vessels.

Orbital Varices.

Orbital Varices.

Orbital Varices.

At MR imaging:

Hypo- to hyper-intense signal on T1.

Hyper-intense signal on T2.

Intense enhancing pattern.

Arteriovenous Fistulas:

Fed by ophthalmic artery branches.

Consist of multiple congenital micro-vascular connections between arteries and veins.

Manifest with peri-orbital swelling, dilated retinal veins, visible or palpable pulsations, an audible bruit, glaucoma, and, visual field defects.

Wyburn-Mason Syndrome:

Oculocerebro-cutaneous syndrome.

Consists of unilateral AVM of the visual pathways and midbrain.

Facial vascular nevi or telangiectasias.

Patients present with intracranial hemorrhage, optic atrophy and pulsatile exophthalmos.

Carotid Cavernous Fistulas:

Abnormal communication between the cavernous sinus and one or more branches of the internal or external carotid artery.

Causes direct trauma, surgery, dural sinus thrombosis, or spontaneously.

Spontaneous with Ehlers-Danlos syndrome and osteogenesis imperfecta.

Carotid Cavernous Fistulas:

Manifest with the classic triad of pulsatile exophthalmos, conjunctival chemosis, and an auscultatory bruit.

Gradual decrease in visual acuity.

Palsy of cranial nerves III, IV, V, and VI.

Carotid Cavernous Fistulas:

CT or MR imaging: Proptosis.

Extraocular muscle enlargement.

Superior ophthalmic vein distention.

Cavernous sinus dilatation .

Cavernous Sinus Thrombosis:

Cavernous Sinus Thrombosis:

cavernous sinus thrombosis:

Ophthalmic Artery Aneurysms:

Intracanalicular ophthalmic artery aneurysms are extremely rare.

More common carotid-ophthalmic artery aneurysms.

Arise at origin of the ophthalmic artery. May extend intra-cranially above the sella and

sometimes extend into or through optic canal. Lesion withdiameter of 2–3 mm are usually

asymptomatic. More than 3 mm may compress the artery or

optic nerve or rupture.

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