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Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
Vascular Lesions Of The Orbit
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Vascular Lesions Of The Orbit

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Vascular Lesions Of The Orbit

Vascular Lesions Of The Orbit

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  • 1. Vascular Lesions of the Orbit More than Meets the Eye Smoker et al : From the Departments of Radiology (W.R.K.S., N.K.Y.) and Ophthalmology (J.A.N.), University of Iowa Hospitals and Clinics 2008; 28:185–204 Present by Ekkasit S. MD
  • 2. Introduction <ul><li>Vascular lesions of the orbit are uncommon. </li></ul><ul><li>Several possible classification schemes exist: </li></ul><ul><ul><li>Mulliken and Glowacki , lesions are classified on the basis of their natural history, including their growth pattern and histologic composition. </li></ul></ul><ul><ul><li>Orbital Society , is based on hemodynamic flow </li></ul></ul>
  • 3. Introduction <ul><li>Mulliken and Glowacki </li></ul><ul><li>Described the clinical and imaging features of these lesions in the following groups: </li></ul><ul><li>Capillary hemangiomas </li></ul><ul><li>Venous vascular malformations (cavernous malformations and orbital varices) </li></ul><ul><li>Venous lymphatic malformations (capillary, cavernous, and cystic lymphatic malformations), </li></ul><ul><li>Arterial and arteriovenous lesions (arteriovenous malformations, arteriovenous fistulas, and ophthalmic artery aneurysms) </li></ul><ul><li>Neoplasms (hemangioblastomas, hemangiopericytomas, choroidal hemangiomas, choroidal melanomas, and vascular metastases) </li></ul><ul><li>Miscellaneous (Coats disease) </li></ul>The term mixed lesions has been used to describe those that have characteristics of two or more different lesions.
  • 4. Capillary Hemangiomas
  • 5. Capillary Hemangiomas (Benign Hemangioendothelioma) <ul><li>The most common orbital vascular tumor in infants ( 5.6% ) </li></ul><ul><li>More common in females (female-to-male ratio, 3:2) </li></ul><ul><li>Lesions usually appear at or shortly after birth, rapidly increase in size for 6–12 months, and then gradually involute over the next 5–7 years. </li></ul>
  • 6. Capillary Hemangiomas (Benign Hemangioendothelioma) <ul><li>Superficial lesions appear red, whereas subcutaneous lesions appear blue. </li></ul><ul><li>Proptosis, globe displacement, amblyopia. </li></ul><ul><li>They may expand slightly during crying or straining. </li></ul>
  • 7. Capillary Hemangiomas (Benign Hemangioendothelioma) <ul><li>Most capillary hemangiomas are entirely extraconal in location or have a substantial extraconal component. </li></ul><ul><li>May extend intracranially through the optic canal or superior orbital fissure. </li></ul><ul><li>The extraocular muscles and lacrimal glands occasionally are involved. </li></ul><ul><li>Histologic analysis demonstrates capillary-sized vascular spaces surrounded by proliferating benign endothelial cells. </li></ul>
  • 8. Copyright ©Radiological Society of North America, 2008 Smoker, W. R. K. et al. Radiographics 2008;28:185-204 Hemangioma
  • 9. Capillary Hemangiomas (Benign Hemangioendothelioma) <ul><li>Complications are rare but may include profuse hemorrhage , thrombosis , optic nerve compression , bone remodeling , and calcification . </li></ul><ul><li>May be found in association with the rare neurocutaneous syndrome known as PHACE </li></ul><ul><li>P osterior fossa brain malformations </li></ul><ul><li>Large facial H emangiomas </li></ul><ul><li>A rterial anomalies </li></ul><ul><li>C ardiac anomalies and aortic Coarctation </li></ul><ul><li>E ye abnormalities </li></ul><ul><li>( colobomas, optic nerve hypoplasia, increased retinal vascularity, and glaucoma) </li></ul>
  • 10. Capillary Hemangiomas (Benign Hemangioendothelioma) Treatment options include observation and topical, oral, or intralesional corticosteroid therapy. Interferon therapy, laser therapy, and surgery typically are reserved for patients with potentially life-threatening complications .
  • 11. Capillary Hemangiomas (Benign Hemangioendothelioma) <ul><li>CT </li></ul><ul><li>The preferred modality for the initial imaging evaluation because it can be performed without sedation. </li></ul><ul><li>Lobulated, irregularly marginated, and heterogeneous. </li></ul><ul><li>Intense homogeneous enhancement after the administration of contrast material. </li></ul><ul><li>US </li></ul><ul><li>Compressible and appear hyperechoic. </li></ul>Location : entirely extraconal or substantial extraconal component.
  • 12. Copyright ©Radiological Society of North America, 2008 CECT Capillary hemangioma in a 4-month-old boy with proptosis of the left eye, inferior displacement of the globe, and a bluish discoloration under the skin
  • 13. Capillary Hemangiomas (Benign Hemangioendothelioma) <ul><li>MRI </li></ul><ul><li>Hypointense on T1WI, and iso- to hyperintense on T2WI. </li></ul><ul><li>They enhance intensely after the administration of contrast material . </li></ul><ul><li>Lobules with thin septa, combined with intralesional and perilesional flow voids, are characteristic features. </li></ul>
  • 14. Copyright ©Radiological Society of North America, 2008 Axial T1-weighted MR image Typical capillary hemangioma in a 41/2-month-old girl with proptosis of the right eye and cutaneous hemangioma
  • 15. Axial T2-weighted fat-suppressed image Typical capillary hemangioma in a 41/2-month-old girl with proptosis of the right eye and cutaneous hemangioma
  • 16. Copyright ©Radiological Society of North America, 2008 Axial contrast-enhanced T1-weighted fat-suppressed image Typical capillary hemangioma in a 41/2-month-old girl with proptosis of the right eye and cutaneous hemangioma
  • 17. Venous Vascular Malformations Cavernous Malformations / Orbital Varices
  • 18. Cavernous Malformations (cavernous hemangiomas) <ul><li>The most common vascular lesions in adults. </li></ul><ul><li>However, their incidence is low overall, with two or fewer cases diagnosed per year at major referral institutions. </li></ul><ul><li>Most often in women (60%–70%) between the ages of mean age, 43–48 years. </li></ul><ul><li>An observed association between cavernous malformations and abrupt proptosis during puberty or pregnancy is suggestive of a contribution by hormone- or cytokine-mediated angiogenic factors to lesion growth. </li></ul>
  • 19. Cavernous Malformations (cavernous hemangiomas) <ul><li>Common symptom : progressive, painless proptosis (discovered incidentally at imaging evaluations). </li></ul><ul><li>Less common symptoms : pain, lid swelling, diplopia, a palpable lump, and recurrent episodes of obscured vision. </li></ul><ul><li>Usually are solitary and most often occur in the lateral aspect of the retrobulbar intraconal space . Rarely involve intramuscular, orbital apex ( monocular vision loss due to the compression of blood vessels that supply the optic nerve. </li></ul><ul><li>Occasionally extend intracranially through the superior orbital fissure, remodeling and intralesional calcification </li></ul>
  • 20. Cavernous Malformations (cavernous hemangiomas) At histologic analysis, large dilated vascular channels lined by flattened or attenuated endothelial cells with an intervening fibrous interstitium are visible
  • 21. Cavernous Malformations (cavernous hemangiomas) <ul><li>Management </li></ul><ul><li>Usually conservatively . </li></ul><ul><li>Surgical excision is reserved for those that cause severe proptosis or optic nerve compression. </li></ul><ul><li>Because of the inaccessibility of the small feeding arteries and the multiple collateral pathways available for recanalization, embolization therapy is not often performed. </li></ul>
  • 22. Cavernous Malformations (cavernous hemangiomas) <ul><li>US </li></ul><ul><li>Well-defined borders due to the pseudocapsule, moderate acoustic attenuation from intravascular blood, and a honeycomb-like structure. </li></ul><ul><li>Color Doppler US is useful for detecting and quantifying blood flow and for mapping the vasculature for surgical planning. </li></ul>
  • 23. Cavernous Malformations (cavernous hemangiomas) <ul><li>CT </li></ul><ul><li>Typically : well circumscribed, round or ovoid, homogeneously, hyperattenuating, intraconal lesions. </li></ul><ul><li>Occasionally : microcalcifications(phleboliths) ,may produce expansion of the orbital walls, may displace adjacent structures but do not invade them. </li></ul><ul><li>At multiphase dynamic contrast material– enhanced CT, poor enhancement is noted in the early arterial phase because of the low-flow arterial supply; contrast material does not fill the central part of the lesion until the late venous phase . </li></ul>
  • 24. Copyright ©Radiological Society of North America, 2008 CECT Cavernous malformation in a 39-year-old woman with painless progressive proptosis
  • 25. Cavernous Malformations (cavernous hemangiomas) <ul><li>MRI </li></ul><ul><li>Isointense to that of muscle on T1WI </li></ul><ul><li>Hyperintense to that of muscle on T2WI. </li></ul><ul><li>Internal septa are visible within larger lesions. </li></ul><ul><li>Progressive accumulation of contrast material on late phase dynamic images and delayed images. </li></ul>
  • 26. Copyright ©Radiological Society of North America, 2008 Axial T1-weighted MR image Large cavernous malformation in a 43-year-old woman with painless proptosis of the right eye
  • 27. Copyright ©Radiological Society of North America, 2008 Axial contrast enhanced T1-weighted fat-suppressed, image, obtained immediately after the intravenous administration of a gadolinium-based contrast material Large cavernous malformation in a 43-year-old woman with painless proptosis of the right eye
  • 28. Copyright ©Radiological Society of North America, 2008 Axial contrastenhanced T1-weighted fat-suppressed MR image, obtained 1 hour later Large cavernous malformation in a 43-year-old woman with painless proptosis of the right eye
  • 29. Copyright ©Radiological Society of North America, 2008 Large cavernous malformation cavernous malformation in a 43-year-old woman with painless proptosis of the right eye
  • 30. &nbsp;
  • 31. Orbital Varices <ul><li>Most common cause of spontaneous orbital hemorrhage . </li></ul><ul><li>Typically manifest in the 2nd or 3rd decade of life, males and females equally. </li></ul><ul><li>Often occur in association with contiguous or noncontiguous intracranial venous anomalies. </li></ul><ul><li>Most varices have a large communication with the venous system and distend during maneuvers that increase venous pressure. ( Stress proptosis ) </li></ul><ul><li>However, some have only a small communication with the venous system and do not distend but, instead, manifest with thrombosis and hemorrhage, producing a more sustained proptosis . </li></ul>
  • 32. Copyright ©Radiological Society of North America, 2008 Photograph obtained with the patient at rest Conjunctival orbital varix in a 56-year-old man whose right eyelid bulges when straining Photograph obtained during the Valsalva maneuver
  • 33. Copyright ©Radiological Society of North America, 2008 Conjunctival orbital varix in a 56-year-old man whose right eyelid bulges when straining Photograph obtained with the upper eyelid elevated
  • 34. Orbital Varices <ul><li>US </li></ul><ul><li>The distensibility of varices during the Valsalva maneuver . </li></ul><ul><li>An intermittently anechoic retrobulbar lesion that exhibits intrinsic flow during the Valsalva maneuver is indicative of a varix. </li></ul><ul><li>Color Doppler imaging may demonstrate a reversal of flow toward the transducer during the Valsalva maneuver. </li></ul>
  • 35. Orbital Varices <ul><li>CT </li></ul><ul><li>In supine position usually normal appearance or only mild enlargement of the involved veins. </li></ul><ul><li>A maneuver that increases venous pressure (scanning in the prone position, jugular vein compression with a tourniquet, or the Valsalva maneuver) is required to demonstrate lesion distensibility. </li></ul><ul><li>Varices may be smooth contoured, clublike, triangular, or segmentally dilated, or they may appear as a tangled mass of vessels. </li></ul>
  • 36. Copyright ©Radiological Society of North America, 2008 CECT image obtained with the patient at rest Bilateral orbital varices in a 27-year-old woman with a sensation of eye pressure when stooping to pick up her child CECT image obtained with the patient at Valsalva maneuver
  • 37. Orbital Varices <ul><li>MRI </li></ul><ul><li>Hypo- to hyperintense signal on T1WI. </li></ul><ul><li>Hyperintense signal on T2WI. </li></ul><ul><li>Usually enhance intensely after the administration of contrast material. </li></ul>
  • 38. Copyright ©Radiological Society of North America, 2008 Axial T1-weighted MR image obtained with the patient supine Orbital varix in a 33-year-old woman with proptosis when straining prone supine CE T1-weighted fat-suppressed images
  • 39. Venous Lymphatic Malformations
  • 40. Venous Lymphatic malformations ( Lymphagioma ) <ul><li>Arise from the pluripotent venous anlage , which may develop into both venous and lymphatic structures. </li></ul><ul><li>The lesions are sometimes referred to as no-flow or low-flow vascular malformations. </li></ul><ul><li>They may be evident at birth, but they generally manifest in infancy or childhood (43% are diagnosed before the age of 6 years; 60%, before the age of 16 years). </li></ul><ul><li>Overall, males and females are affected with approximately equal frequency. </li></ul>
  • 41. Venous Lymphatic malformations ( Lymphagioma ) <ul><li>Although venous lymphatic malformations may enlarge slowly, producing progressive proptosis . </li></ul><ul><li>Hemorrhages within these malformations often occur after minor trauma or infection and occasionally develop spontaneously . </li></ul><ul><li>A spontaneous intralesional hemorrhage may pro-duce variable-sized chocolate-colored cysts that may cause acute proptosis , restriction of eye movements and, occasionally, optic nerve compression. </li></ul><ul><li>Worsening proptosis during viral infections suggests that the more superficial and the larger its lymphatic component. </li></ul>
  • 42. Copyright ©Radiological Society of North America, 2008 Smoker, W. R. K. et al. Radiographics 2008;28:185-204 Venous lymphatic malformation in a 47-year-old woman with acute proptosis and restricted movement of the left eye
  • 43. Copyright ©Radiological Society of North America, 2008 Venous lymphatic malformation in a 5-year-old girl during an upper respiratory tract viral infection. after the patient recovered from the viral infection
  • 44. Venous Lymphatic malformations ( Lymphagioma ) <ul><li>Lymphatic malformations are unencapsulated, diffuse, and multicompartmental. </li></ul><ul><li>Often including both intraconal and extraconal components . </li></ul><ul><li>Orbital venous lymphatic malformations are isolated from the normal orbital vasculature and, unlike varices, are not affected by postural changes. </li></ul><ul><li>However, they may be associated with intracranial vascular malformations , especially developmental venous anomalies. </li></ul>
  • 45. Venous Lymphatic malformations ( Lymphagioma ) Histologic analysis demonstrates delicate, bloodless, lymph-filled, endothelium-lined vascular channels of various luminal diameters. Intervening connective-tissue septa contain lymphocytes and fragile blood vessels (neovascular tufts) that are thought to be the sources of hemorrhage.
  • 46. Venous Lymphatic malformations ( Lymphagioma ) <ul><li>Treatment is controversial and problematic. </li></ul><ul><li>Depends on the growth, size, location, and morphology of the particular lesion. </li></ul><ul><li>Observation and conservative management, when possible, are recommended. </li></ul><ul><li>Surgery has been suggested for lesions that cause marked stretching or compression of the optic nerve or corneal compromise or impending amblyopia . </li></ul><ul><li>Various alternative therapies have proved successful or promising, including the intralesional injection of sclerosing agents , fractionated beta irradiation , carbon dioxide laser ablation , and intralesional injection of steroids . </li></ul>
  • 47. Venous Lymphatic malformations ( Lymphagioma ) <ul><li>Modality of choice : best depicts the various components. </li></ul><ul><li>Signal intensity of the lesions depends on the type of fluid within the cystic components. </li></ul><ul><li>T1WI best depict lymphatic or proteinaceous fluid . </li></ul><ul><li>T1W fat-suppressed images are best for detecting blood products . </li></ul><ul><li>T2W fat-suppressed images provide improved visibility of components that contain nonhemorrhagic fluid . </li></ul>MRI
  • 48. Venous Lymphatic malformations ( Lymphagioma ) <ul><li>Contrast material does not provide significant additional information, but an absence of enhancement is indicative of a lymphatic component . </li></ul><ul><li>Fluid-fluid levels produced by hemorrhages of various ages within multiple cysts are almost pathognomonic . </li></ul>MRI
  • 49. Copyright ©Radiological Society of North America, 2008 Axial T2-weighted fat-suppressed MR image Venous lymphatic malformation in an 11-year-old boy with progressive proptosis of the right eye and lateral displacement of the globe
  • 50. Venous Lymphatic malformations ( Lymphagioma ) Cystic components usually demonstrate low-level internal echoes, but an intracystic clot may be hyperechoic US CT <ul><li>Poorly circumscribed, multicompartmental, and heterogeneously hyperattenuating, and they enhance minimally after contrast material administration. </li></ul><ul><li>Phleboliths may be present. </li></ul>
  • 51. Copyright ©Radiological Society of North America, 2008 Axial unenhanced CT image Venous lymphatic malformation in an 11-year-old boy with progressive proptosis of the right eye and lateral displacement of the globe
  • 52. Arterial and Arteriovenous Lesions Arteriovenous Fistulas / Wyburn-Mason Syndrome / Carotid Cavernous Fistulas / Ophthalmic Artery Aneurysms
  • 53. Arteriovenous Fistulas <ul><li>Arteriovenous fistulas that involve the orbit are rare. </li></ul><ul><li>These lesions typically manifest with periorbital swelling , dilated retinal veins and epibulbar vessels, visible or palpable pulsations , an audible bruit , glaucoma and, occasionally, visual field defects due to ophthalmic artery steal syndrome . </li></ul><ul><li>The pulsation and bruit can usually be diminished by compression of the ipsilateral common carotid artery. </li></ul>
  • 54. Arteriovenous Fistulas <ul><li>US, CT with standard and angiographic protocols, and MR imaging with standard and angiographic protocols can help diagnose arteriovenous fistulas; </li></ul><ul><li>However, conventional catheter-based angiography typically is required for precise definition and treatment planning. </li></ul><ul><li>Treatment involves embolization and in some cases surgery . </li></ul>
  • 55. Copyright ©Radiological Society of North America, 2008 Lateral projection from catheter-based angiography demonstrates early filling of a dural arteriovenous fistula (black arrow) fed by a dilated right ophthalmic artery (arrowheads). Intracranial venous drainage is faintly visible (white arrow). (b) Lateral projection from a later phase of the same angiographic examination shows rapid filling of the large intracranial venous component of the malformation (arrows). Orbital arteriovenous malformation in a 33-year-old man with proptosis and visible pulsations of the globe
  • 56. Wyburn-Mason Syndrome (Bonnet-Dechaume-Blanc) <ul><li>The Wyburn-Mason syndrome is an exceedingly rare oculocerebrocutaneous syndrome that consists of unilateral arteriovenous malformations of the visual pathways and midbrain . </li></ul><ul><li>The syndrome is congenital, nonhereditary, and without race or sex predilection. </li></ul><ul><li>It may occur with associated facial vascular nevi or telangiectasias . </li></ul>
  • 57. Copyright ©Radiological Society of North America, 2008 Smoker, W. R. K. et al. Radiographics 2008;28:185-204 Wyburn-Mason syndrome in a 16-year-old boy
  • 58. Wyburn-Mason Syndrome (Bonnet-Dechaume-Blanc) <ul><li>Symptoms are highly variable and depend on the size of the malformations. </li></ul><ul><li>Patients may present with cosmetic facial deformity, headache , seizure , intracranial hemorrhage , optic atrophy , and, occasionally, pulsatile exophthalmos . </li></ul><ul><li>Overall prognosis is poor. </li></ul>
  • 59. Copyright ©Radiological Society of North America, 2008 Axial contrast-enhanced CT images Wyburn-Mason syndrome in a 16-year-old boy
  • 60. Carotid Cavernous Fistulas <ul><li>Result from abnormal communication between the cavernous sinus and one or more branches of the internal or external carotid artery . </li></ul><ul><li>Occur in middle to late adulthood and are more common in women . </li></ul><ul><li>May result from direct trauma, surgery, dural sinus thrombosis, or atherosclerosis or may occur spontaneously. </li></ul><ul><li>Spontaneous carotid cavernous fistulas have been reported in patients with Ehlers-Danlos syndrome , osteogenesis imperfecta , and pseudoxanthoma elasticum . </li></ul><ul><li>Often manifest with the classic triad of pulsatile exophthalmos , conjunctival chemosis , and an auscultatory bruit . </li></ul>
  • 61. Copyright ©Radiological Society of North America, 2008 Smoker, W. R. K. et al. Radiographics 2008;28:185-204 Right carotid cavernous fistula in a 67-year-old woman Photograph shows conjunctival injection and mild proptosis. The patient also had papilledema and a bruit over the eye.
  • 62. Carotid Cavernous Fistulas <ul><li>However, a gradual decrease in visual acuity , with or without palsy of cranial nerves III, IV, V, and VI , may be the only sign. </li></ul><ul><li>Secondary findings such as proptosis, congestive extraocular muscle enlargement, superior ophthalmic vein distention, and cavernous sinus dilatation are usually identified at CT or MR imaging </li></ul><ul><li>Conventional catheter angiography is usually required for lesion classification and treatment planning before embolization. </li></ul>
  • 63. Copyright ©Radiological Society of North America, 2008 Carotid cavernous fistula in a 52-year-old woman with proptosis, chemosis, and conjunctival injection Axial T2-weighted MR images Axial maximum intensity projection image from MR angiography
  • 64. Carotid Cavernous Fistulas <ul><li>Carotid cavernous fistulas may be classified on the basis of the source of their arterial supply into the following four subtypes: </li></ul><ul><li>main internal carotid artery </li></ul><ul><li>dural branch of the internal carotid artery </li></ul><ul><li>dural branch of the external carotid artery </li></ul><ul><li>dural branches of both the internal and the external carotid arteries. </li></ul>
  • 65. Ophthalmic Artery Aneurysms <ul><li>Intracanalicular ophthalmic artery aneurysms are extremely rare. </li></ul><ul><li>They arise at the origin of the ophthalmic artery from the supraclinoid internal carotid artery. </li></ul><ul><li>Although they most often extend intracranially above the sella, they may sometimes extend into or through the optic canal . </li></ul><ul><li>Lesions with a maximal diameter of 2–3 mm are usually asymptomatic , whereas those with a diameter of more than 3 mm may compress the artery or optic nerve or, if they rupture, cause intracranial subarachnoid hemorrhage . </li></ul>
  • 66. Copyright ©Radiological Society of North America, 2008 CECT Ophthalmic artery aneurysm in a 44-year-old woman with a subarachnoid hemorrhage
  • 67. Copyright ©Radiological Society of North America, 2008 CT angiography Ophthalmic artery aneurysm in a 44-year-old woman with a subarachnoid hemorrhage
  • 68. Tumors Hemangioblastomas / Hemangiopericytomas / Choroidal Hemangiomas / Choroidal Melanomas / Metastases
  • 69. Hemangioblastomas <ul><li>Benign vascular tumor. </li></ul><ul><li>Hemangioblastomas represent 1%–2% of all primary tumors of the central nervous system. </li></ul><ul><li>Most hemangioblastomas that occur within the orbit are located in the retina , although locations within the optic nerve have been reported. </li></ul><ul><li>Ocular abnormalities due to a retinal hemangioblastoma are the earliest manifestations of von Hippel-Lindau disease in about 50% of cases. </li></ul>
  • 70. Hemangioblastomas <ul><li>von Hippel-Lindau disease : an AD disorder that is localized to chromosome 3. It is characterized by both benign and malignant tumors). </li></ul><ul><li>Ptients with a sporadic nonhereditary hemangioblastoma should undergo further evaluation for evidence of von Hippel-Lindau disease. </li></ul>
  • 71. Hemangioblastomas <ul><li>Patients with a retinal hemangioblastoma are usually asymptomatic until the 3rd decade of life . </li></ul><ul><li>A retinal hemangioblastoma may be a predisposing factor for retinal detachment , macular edema , and glaucoma . </li></ul><ul><li>Early detection, followed by laser coagulation or cryotherapy, may prevent vision loss. </li></ul>
  • 72. Hemangiopericytomas <ul><li>Rare.slowgrowing, highly vascular tumors. </li></ul><ul><li>Relatively common in the musculoskeletal system (lower extremities), pelvis, and retroperitoneum. </li></ul><ul><li>Approximately 15% of these tumors arise in the extracranial part of the head and neck, usually in the nasal cavity or paranasal sinuses. </li></ul><ul><li>Origin within the orbit is rare . </li></ul><ul><li>The tumors may occur at any time, from infancy through late adult life, although the mean ages at diagnosis in two large patient series were 45 years and 42 years. </li></ul>
  • 73. Hemangiopericytomas <ul><li>More common in males . </li></ul><ul><li>Slowly progressive, sometimes painful proptosis and decreased visual acuity . Other symptoms include extraocular motility abnormalities, visual field deficits, and congestion of the retinal and choroidal vessels. </li></ul><ul><li>Histologic findings range from benign to malignant characteristics, with many tumors demonstrating both. </li></ul><ul><li>Although metastases are uncommon, they were reported in 15% of patients in one series, with the lung being the most common site. </li></ul>
  • 74. Hemangiopericytomas <ul><li>These mesenchymal tumors arise from the pericytes of Zimmerman , contractile cells that surround the outer aspect of small vessels and that are thought to regulate lumen size and produce collagen. </li></ul><ul><li>Tumors are classified as sinusoidal , solid, or mixed . </li></ul><ul><li>Histologic analysis demonstrates staghorn-like capillary spaces lined by plump, proliferating pericytes, with intervening fibrous septa. </li></ul><ul><li>The classic staghornlike vascular pattern is not unique to hemangiopericytomas; it is encountered in a variety of other neoplasms, including synovial sarcomas, fibrous histiocytomas, and malignant peripheral nerve sheath tumors. </li></ul>
  • 75. Copyright ©Radiological Society of North America, 2008 Smoker, W. R. K. et al. Radiographics 2008;28:185-204 Hemangiopericytoma
  • 76. Hemangiopericytomas <ul><li>Hemangiopericytomas are usually lobulated, encapsulated, and well circumscribed, but they may have infiltrative margins. </li></ul><ul><li>The typical location is extraconal; lesions commonly arise in the adjacent paranasal sinuses. </li></ul><ul><li>The standard treatment is wide surgical excision . </li></ul><ul><li>Postoperative irradiation is recommended for incompletely excised lesions. Local recurrence in approximately 30% of cases has been reported, and lesions may recur up to 30 years after initial treatment. </li></ul>
  • 77. Copyright ©Radiological Society of North America, 2008 Axial contrast-enhanced CT Hemangiopericytoma in a 47-year-old man with proptosis of the left eye
  • 78. Hemangiopericytomas Moderately hyperechoic, with high vascularity on color doppler images, a feature that permits their differentiation from cavernous hemangiomas. US CT <ul><li>Typically homogeneous and lobulated. </li></ul><ul><li>May be : well circumscribed , irregular margins, osseous erosion ,involve the central nervous system. </li></ul><ul><li>Hemangiopericytomas enhance intensely ( marked early arterial phase and early venous phase enhancement followed by rapid washout.) </li></ul>
  • 79. Copyright ©Radiological Society of North America, 2008 Smoker, W. R. K. et al. Radiographics 2008;28:185-204 Hemangiopericytoma in a 47-year-old man with proptosis of the left eye
  • 80. Hemangiopericytomas MRI <ul><li>The signal intensity is similar to that of gray matter on T1- and T2-weighted images. </li></ul><ul><li>Digital subtraction angiography demonstrates a prominent arterial supply with an early florid blush and persistent tumor staining. </li></ul>
  • 81. Choroidal Hemangiomas <ul><li>These congenital vascular hamartomas typically manifest in middle-aged or elderly people (mean age, 31 years; age range, 7–58 years). </li></ul><ul><li>The solitary or circumscribed choroidal hemangioma is a benign vascular neoplasm that is confined to the choroid , has distinct margins, and is typically located posterior to the equator of the globe . </li></ul>
  • 82. Choroidal Hemangiomas <ul><li>Asymptomatic circumscribed choroidal hemangiomas do not require treatment unless retinal detachment occurs . ( laser photocoagulation ) </li></ul><ul><li>The clinical appearance of the circumscribed choroidal hemangioma is that of a smoothly elevated, slightly dome-shaped, reddish-orange choroidal mass that blends with the surrounding choroid. </li></ul>
  • 83. Choroidal Hemangiomas <ul><li>CT is useful for diagnosis, but MR imaging is considered to provide depiction superior to that of CT. </li></ul><ul><li>At CT, circumscribed choroidal hemangiomas in the absence of retinal detachment appear as ill-defined masses that exhibit intense enhancement after the administration of contrast material. </li></ul><ul><li>At MR imaging, Most have a lenticular shape with a maximal diameter of 3–11 mm and signal that is hyperintense to that of vitreous on T1WI . On T2-weighted fast spin-echo images, the signal is hyperintense to that of vitreous. The lesions enhance intensely after the administration of contrast material. </li></ul>
  • 84. Copyright ©Radiological Society of North America, 2008 CECT Circumscribed choroidal hemangioma in an 8-year-old girl
  • 85. Copyright ©Radiological Society of North America, 2008 Circumscribed choroidal hemangioma in an 8-year-old girl Axial unenhanced T1WI Axial unenhanced T2WI contrast-enhanced T1-weighted fat-suppressed
  • 86. Choroidal Melanomas <ul><li>The most common primary intraocular tumors in adults </li></ul><ul><li>Melanomas may occur in any of the three subdivisions of the uvea: the iris, the ciliary body, and the choroid. </li></ul>
  • 87. Choroidal Melanomas <ul><li>Most common among people of northern European descent and are uncommon among African American. </li></ul><ul><li>65% of melanomas occur in those older than 50 years. </li></ul><ul><li>Patients may be asymptomatic and the lesion discovered during a routine ophthalmologic examination. </li></ul><ul><li>Symptomatic patients may experience a vision loss , photopsia , and visual field deficits . </li></ul>
  • 88. Choroidal Melanomas <ul><li>Primarily metastasize to the liver , and some metastases manifest before primary tumor detection. Other sites of metastasis, in order of decreasing frequency, are lung, bone, kidney, and brain. </li></ul><ul><li>Treatment selection depends on the site of origin (choroid, ciliary,body, or iris), size, and location of the primary lesion as well as whether extraocular extension, recurrence, or metastases are present. </li></ul>
  • 89. Choroidal Melanomas <ul><li>Large melanomas (10 mm thick) traditionally have been managed with enucleation. </li></ul><ul><li>For medium-sized lesions (3–10 mm thick), plaque brachytherapy and external-beam radiation therapy have been accepted as alternatives to enucleation. </li></ul><ul><li>Small tumors (3 mm thick) should be monitored every 3–6 months with US. </li></ul><ul><li>Transpupillary thermotherapy was shown to be effective for small lesions, with fewer complications than radiation therapy and without the need for incisional surgery. </li></ul>
  • 90. Choroidal Melanomas <ul><li>CT provides a valuable method by which to demonstrate these lesions. ( Typically assessed with an ophthalmologic examination, fluorescein angiography, or US) </li></ul><ul><li>Unenhanced CT : elevated, hyperattenuating, and sharply marginated. </li></ul><ul><li>Contrast-enhanced dynamic CT : distinguish uveal melanomas from other lesions, such as choroidal hemangiomas, by providing information about vascularity and perfusion. </li></ul><ul><li>Most choroidal melanomas appear as well-defined solid masses at MR imaging . </li></ul>
  • 91. Choroidal Melanomas <ul><li>Those that are hemorrhagic or necrotic have varied MR imaging appearances. </li></ul><ul><li>Because of the paramagnetic effects of melanin, intensely melanotic melanomas have shorter T1 and T2 relaxation times, producing increased signal intensity on T1-weighted images and mark-edly decreased signal intensity on T2-weighted images. </li></ul><ul><li>Among ocular tumors, only Teaching Point melanomas manifest these signal intensity characteristics. </li></ul><ul><li>Unfortunately, amelanotic and slightly melanotic melanomas do not show the same signal intensity characteristics. </li></ul>
  • 92. Choroidal Melanomas <ul><li>Instead, the signal in these lesions may appear isointense on T1-weighted images and only slightly hypointense on T2-weighted images, similar to that in choroidal metastases and other tumors of the globe. </li></ul><ul><li>Following the administration of contrast material, choroidal melanomas demonstrate moderate to strong enhancement . </li></ul><ul><li>Contrast-enhanced fat-suppressed MR imaging also may demonstrate scleral invasion, tumor extension to the optic disc, and extraocular invasion. </li></ul>
  • 93. Axial contrast-enhanced T1-weighted fat-suppressed image Axial T1-weighted MR image Choroidal melanotic melanoma in a 51-year-old man with decreasing vision in the left eye Coronal T2-weighted MR image
  • 94. Metastases <ul><li>Uveal metastases typically reach the globe via the posterior ciliary arteries and, therefore, commonly involve the posterior half of the globe . </li></ul><ul><li>The primary lesions that are the most common sources of uveal metastases are breast and lung carcinomas . (also may involve extraocular muscles) </li></ul><ul><li>MR imaging is superior to CT for distinguishing uveal metastases from uveal melanomas. </li></ul>
  • 95. Copyright ©Radiological Society of North America, 2008 Smoker, W. R. K. et al. Radiographics 2008;28:185-204 Choroidal metastasis from stomach carcinoma in a 55-year-old man Axial T1-weighted MR image Axial T2-weighted MR image Axial contrastenhanced T1-weighted fat-suppressed MR image
  • 96. Coats Disease <ul><li>An idiopathic primary vascular anomaly of the retina . </li></ul><ul><li>Characteritic : retinal telangiectasias and exudative retinal detachment </li></ul><ul><li>Caused by : an accumulation of lipoproteinaceous exudate in the retina and subretinal space. ( unknown pathogenesis ) </li></ul><ul><li>Because of retinal detachment, children often present with leukokoria , and the disease may be difficult to clinically differentiate from retinoblastoma . </li></ul><ul><li>Although the disease is present at birth, signs and symptoms are delayed until retinal detachment produces loss of vision , typically between the ages of 6 and 8 years . </li></ul><ul><li>Boys are affected approximately twice as often as girls. </li></ul>
  • 97. Coats Disease <ul><li>US : may demonstrate retinal detachment and particulate echoes from subretinal material, presumably cholesterol crystals. </li></ul><ul><li>CT : findings include a normal-sized globe with increased overall attenuation due to the density of the subretinal exudate. CT also may demonstrate the retinal detachment . </li></ul><ul><li>Important for the distinction of Coats disease from retinoblastoma is the fact that true calcifications are common in retinoblastomas but occur rarely, if ever, in association with Coats disease. </li></ul>
  • 98. Coats Disease <ul><li>MR imaging : the signal intensity of the globe in Coats disease is somewhat variable, depending on the proportions of proteins and lipids. </li></ul><ul><li>Most often , there is diffuse signal hyperintensity on both T1- and T2-weighted images. </li></ul><ul><li>After the administration of contrast material , enhancement is visible along the leaves of the detached retina and at the sites where the retina inserts. </li></ul><ul><li>The absence of an enhancing mass helps distinguish Coats disease from retinoblastoma, persistent hyperplastic primary vitreous, and toxocaral endophthalmitis. </li></ul>
  • 99. Coats Disease <ul><li>If the disease is detected in its early stages , photocoagulation or cryotherapy may be used to obliterate the telangiectases. </li></ul><ul><li>In later stages of the disease, neovascularity of the iris often causes neovascular glaucoma with resultant blindness or severe eye pain, necessitating enucleation . </li></ul>
  • 100. Summary <ul><li>Vascular lesions of the orbit are confusing entities with imaging features that may overlap. </li></ul><ul><li>Diagnosis requires an understanding of the classification of vascular lesions, integration of the individual patient’s history with epidemiologic data, and familiarity with the imaging features that are typical of specific lesions. </li></ul><ul><li>The use of appropriate imaging techniques (eg, delayed contrast-enhanced imaging for cavernous malformations, prone imaging for orbital varices ) and recognition of pathognomonic features (eg, multiple fluid-fluid levels in lymphatic malformations, progressive delayed enhancement in cavernous malformations) are often essential for precise diagnosis. </li></ul>
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