Cavernous sinus síndrome. Diferencial diagnosis.

Transcription

1 Cavernous sinus síndrome. Diferencial diagnosis. Poster No.: C-1766 Congress: ECR 2014 Type: Educational Exhibit Authors: V. M. Vilela, H. C. Marques, L. L. Macedo, R. V. Leite, L. C Campos, B. L. Dutra ; Juiz de Fora, MG/BR, Juiz De Fora/BR Keywords: Neoplasia, Infection, Aneurysms, Biopsy, Abscess delineation, MR-Diffusion/Perfusion, MR, CT, Neuroradiology brain, Head and neck DOI: /ecr2014/C-1766 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 51

2 Learning objectives The cavernous sinus syndrome usually results in mass effect on the internal structures due to primary lesions or direct extension of parasellar lesions. We reviewed the literature on the subject and presented characteristic imaging findings of the main pathologies that cause this syndrome illustrated by cases from 4 institutions. Images for this section: Fig. 1: Coronal plane schematic drawing of the cavernous sinus and parasellar regions anatomy. Observe the cavernous sinus (blue), cranial nerves (yellow) and arteries (red). Page 2 of 51

3 Fig. 2: Cavernous sinus and parasellar regions anatomy. 3D CISS after intravenous administration of the contrast material. Coronal plane at the level of the optic chiasm. Page 3 of 51

4 Fig. 3: Coronal plane schematic drawing of the venous compartments inside the cavernous sinus. Three vertical intercarotid lines (1 - medial line / 2- median line /3- lateral line) allow split each cavernous sinus in five venous compartments. Page 4 of 51

5 Background The cavernous sinuses are extradural venous sinus covered by dura mater and are located along the lateral aspect of the sella. The location of the venous sinuses and their connections make this structure a potential route of spread for inflammation and cancer. The most common causes (neoplastic, inflammatory / infectious and vascular) will be addressed in this essay. NEOPLASMS Schwannoma Represent about 8% of all intracranial tumors. It is most common in middle-aged women. It has a predilection for sensory roots, and the vestibular root of the eighth cranial nerve being the most affected (about 80%-90% of cases). In the middle cranial fossa, the schwannoma of the trigeminal nerve is the most common. Typically arise in Meckel's cave or cisternal segment of the nerve. Generally involve cavernous sinus, and in 50% of cases, has a typical dumbbell shape. Associated with cavernous hemangioma and meningioma is the most common primary tumor of cavernous sinuses. At MRI, classically appear as iso or hypointense lesions in T1 and variable signal intensity on T2. Predominantly Antoni A schwannomas are hypercellular and may appear as hypointense lesions on T2. Moreover, predominantly Antoni B schwannomas are hypocellular and may appear as hyperintense lesions T2. Larger lesions usually exhibit heterogeneous signal intensity with T2 hypointense areas probably related to intratumoral hemorrhage and hyperintense areas due to cystic necrosis. The administration of contrast material results in intense homogeneous impregnation of the solid component. Cavernous hemangioma Cavernous hemangioma is a vascular malformation formed by sinusoidal spaces with endothelial lining, containing stagnant or slow-flowing blood. It has an fibrous pseudocapsule that determines the well defined appearance of the lesion on imaging studies and is most commonly observed in young adult female. Page 5 of 51

6 The MRI study shows a lesion usually hypo / isointense to muscle on T1. Occasionally these lesions contain regions of high signal intensity on T1, corresponding to thrombosed vascular spaces. Characteristically, it has greatly increased signal on T2. After intravenous infusion of contrast and analysis in the late stages, the uptake is intense and homogeneous. In the early stages after the use of gadolinium the uptake can be heterogeneous. However images obtained dynamically can demonstrate a fairly typical finding: progressive, centripetal and intense enhancement. The main role of MRI in the evaluation of cavernous hemangiomas is to provide a precise anatomical definition of the lesion and its relationship with adjacent structures. Meningioma Meningioma is usually a benign slow growing tumor. Most cavernous sinus meningiomas arise from the lateral wall, juxtaposed to the dura mater. May extend posteriorly to Meckel's cave and cerebellopontine cistern. The dural tail sign is often observed. When it involves the internal carotid artery, usually determines stenosis. At MRI study meningiomas are most often isointensos the gray matter on T1 and less commonly hypointense. About 50% remain isointense on T2-weighted images, while 40% are hyperintense. After intravenous infusion of contrast material, meningiomas have intense homogeneous uptake. Often a dural linear and peripheral uptake can be seen ( dural tail sign ). Other secondary signs such as mass effect, thickening of the dura mater, adjacent white matter edema and hyperostosis are often used for diagnosing meningiomas. A clear separation between the tumor and the pituitary gland (which indicates that the tumor is non-pituitary origin) helps in the differential diagnosis with pituitary adenomas. Meningiomas characteristically determine constriction of the adjacent vessel lumen. This is rare in pituitary adenoma. En plaque meningioma originating in the sphenoid bone may affect the cavernous sinus. Involvement of the carotid and the optic canal are important findings and must be described on imaging studies. Pituitary adenoma Pituitary adenomas are benign pituitary neoplasms that generally affect middle-aged adults (20-40 years). Are classified according to size in microadenomas (<10 mm) and macroadenomas (> 10 mm). Page 6 of 51

7 Giant macroadenomas (> 4 cm) account for 0.5% of cases and are more likely to grow laterally to invade the cavernous sinus, and may take the characteristic number "8" or "snowman" shape. MRI typically demonstrates a hypo / isointense lesion in T1, iso / hyperintense on T2 and intense homogeneous enhancement. Intratumoral hemorrhage occurs in 20% to 30% of pituitary adenomas, mostly in macroadenomas. Cystic degeneration, with or without bleeding, can also occur. The cystic degeneration in an adenoma is evident as an area of very low signal intensity on T1 and markedly hyperintense on T2 weighted sequences. One of the critical points in the evaluation of this tumor is to determine cavernous sinus invasion. In this context, the cavernous sinus can be partitioned by three vertical lines. The imaging method of choice is MR, but the diagnosis of invasion can only be concluded surgically. Chordoma Chordomas are rare tumors that arise from remnant cells of the notochord along the neuraxis. Thirty five percent arise in the skull base, 50% in sacroiliac region, and 15% in the other levels of the spine. Generally are midline tumors and in the skull have the clivus as primary site, involving the cavernous sinus by direct invasion. Intracranial chordoma affect middle-aged adults (30-50 years), with no sex predilection. Exhibit locally invasive behavior and generally determine destruction / erosion of adjacent bone. MR imaging is more sensitive for detection of cavernous sinus involvement. These tumors are characteristically isointense (75%) or hypointense (25%) on T1, may contain small hyperintense foci related with hemorrhage and / or high protein content. Typically have high signal intensity on T2, and may contain small hypointense foci related calcifications and / or bone fragments. At angiography, avascular pattern is often observed. Metastasis are uncommon and recurrence after surgery is common. Necrosis and tumor volume greater than 70ml are indicative worse prognosis. Chondrosarcoma It is a tumor of cartilaginous origin and potentially lethal. Local recurrence and metastasis are common, being considered a tumor with poor prognosis. The petrooccipital fissure is the primary site at the skull's base, but can also originate from lacerus foramen, sphenoethmoidal complex, anterior cranial fossa and clivus. Chondrosarcomas can locally invade the cavernous sinuses. Page 7 of 51

8 The lesion shows low or intermediate signal intensity on T1 and high signal intensity on T2. As in chordoma, may contain hyperintense foci on T2 related calcifications and / or bone fragments. Generally shows intense contrast uptake. Multiple chondrosarcomas can be found in Ollier (multiple enchondromatosis) and Maffuci syndromes (multiple enchondromas with cutaneous hemangiomas). Chondrosarcoma can occur in patients with Paget disease. Nasopharyngeal carcinoma Nasopharyngeal carcinoma usually affects middle-aged adults (before 50 years) with a man / woman ratio of 2.5 / 1. Often originates in the pharynx lateral recess (Rosenmuller's fossa) with 90% of cases showing lymph node metastasis at diagnosis. It is considered the most common primary malignant tumor invading the cavernous sinus. Intracranial spread can occur directly through the erosion of the skull base or via perineural spread along branches of the trigeminal nerve. The tumor may also extend to the petrooccipital synchondrosis and lacerus foramen to the inferior aspect of the cavernous sinus or the carotid channel, reaching the cavernous sinus without determining bone destruction. At MR imaging, appears as a hypointense lesion on T1 and moderately hyperintense on T2-weighted images. The most aggressive tumors, including undifferentiated types, may appear hypointense on T2. Generally they have moderate and homogeneous enhancement by the contrast medium. Carcinoma of the sphenoid sinus Uncommon tumor that usually affects 50 to 70-year old people, with male predilection. They are aggressive tumors that often determine bone destruction and may directly invade the cavernous sinuses. The sphenoid sinus carcinomas are lesions with soft tissue attenuation at CT, with heterogeneous moderate / intense enhancement by the contrast medium. They are aggressive tumors that usually determine erosion / destruction of adjacent bone structures. Normally the area of bone destruction is extensive compared with the volume of the soft tissue component. Bone remodeling is uncommon. Present as iso / hypointense lesion on T1 and variable signal intensity on T2-weighted imagnes. Moderate / intense heterogeneous enhancement by gadolinium. Page 8 of 51

9 Signs of dural and perineural involvement are frequent. Sequences with fat saturation are important for the characterization of the lesions. Orbital invasion can also occur. Rhabdomyosarcoma Rhabdomyosarcoma is a malignant mesenchymal tumor that usually affects children (1st and 2nd decades), but rarely found in adults. It is the most common sarcoma in head and neck, compromising, in order of frequency, orbit, nasopharynx, temporal bone, sinonasal cavity and cervical neck. It is an aggressive tumor that determines bone destruction and that can directly invade the cavernous sinus, which is one sign of poor prognosis. MR imaging shows a isointense lesion on T1 with variable signal on T2 and moderate diffuse enhancement the by contrast medium. Larger lesions may have heterogeneous signal intensity in different sequences due to intratumoral bleeding. Lymphoma CNS lymphomas are uncommon neoplasms and represent about 2% of tumors at this location. However CNS tumors are more frequent in immunosuppressed patients. The preferred sites are cerebral hemispheres, but may compromise the cavernous sinus by direct extension of a primary lesion or hematogenous spread. They are generally isointense the muscle on T1 and iso / hypointense on T2. The low signal intensity on T2 is characteristic, but not very sensitive. They show diffuse homogeneous gadolinium enhancement. Metastasis Metastasis to the cavernous sinus can occur via hematogenous or perineural spread. Generally the tumors that determine hematogenous spread to the cavernous sinuses are from renal, gastric, thyroid, lung and mammary primary sites. Perineural spread is commonly seen over the trigeminal nerve branches and generally originates from squamous cell carcinoma, neurogenic tumors and lymphoma. Other tumors that potentially can reach the cavernous sinuses are juvenile angiofibroma, cystic adenoid carcinoma, melanoma and basal cell carcinoma. The metastases usually present as lesions with soft tissue attenuation at CT, expanding the cavernous sinus and variable enhancement after contrast medium administration. Bone destruction and foraminal enlargement can also be observed. Page 9 of 51

10 INFLAMMATORY AND INJURIES INFECTIOUS Tolosa-Hunt syndrome Also known as painful external ophthalmoplegia, Tolosa-Hunt syndrome is a term applied to an idiopathic inflammatory process involving the cavernous sinus and / or the upper orbital fissure similar to orbital pseudotumor. MR imaging has greater sensitivity (around 85%) and can show an isointense tissue to muscle on T1, iso / hyperintense on T2 and diffuse homogeneous enhancement by the contrast medium. The lesion determines enlargement of the cavernous sinus and, in most cases, extends to the orbital apex or superior orbital fissure, reinforcing the possibility of this syndrome to be part of the same disease with orbital pseudotumor. Involvement of the contralateral cavernous sinus (alternate form) is rare but may occur. Reduced caliber of the internal carotid artery can be demonstrated up to 50% of cases. An important finding that supports the clinical hypothesis and imaging findings is complete resolution of the lesions with corticoid therapy, especially during the course of six months of treatment. Cavernous Sinus Thrombosis Venous thrombosis can be classified into two forms, primary or aseptic found in cases of cachexia, dehydration, congestive heart failure, postoperative and postpartum contraceptive use, and secondary, or septic thrombophlebitis, which is more rare and potentially fatal. It is the result of complications of infections involving paranasal sinuses, cheek or periauricular region. Can occur also as a complication of orbital cellulitis, bacterial meningitis and subdural empyema. MR imaging is more sensitive and can more clearly demonstrate the peripheral enhancement of cavernous sinus associated with small central thrombi. Secondary signs should always be valued as: dilation / thrombosis of the superior ophthalmic vein, exophthalmos, prominence of the extraocular muscles and enhancement of the dura ipsilateral to the affected side. DWI may demonstrate restricted diffusion of water due to the purulent material within the cavernous sinus. Tuberculosis In Brazil, tuberculosis (TB) remains a relatively common cause of CNS lesions. Between 5% and 10% of TB patients will present CNS involvement that increase to about 20% Page 10 of 51

11 in patients with AIDS. Leptomeningitis is the most common presentation, in most cases, is secondary to hematogenous spread of a pulmonary focus. Skull base involvement is characteristic and focal or diffuse lesions may affect the cavernous sinus. Alone or in association with leptomeningitis, tuberculosis can involve the brain parenchyma, either in the form of cerebritis or tuberculoma. The most common imaging findings associated with tuberculous involvement include impregnation of the basal cisterns, tuberculomas, hydrocephalus, meningeal enhancement and infarcts, generally in the basal ganglia. The tuberculomas may calcify in up to 25% of cases. Coexistence with pulmonary tuberculosis is common and occurs in most cases. On CT, the most common finding of tuberculous meningitis is exudate, isoatenuating or slightly hyperattenuating, involving basal cisterns and presenting marked homogeneous or nodular enhancement. MR imaging shows more precisely the enhancement which may extend over the surface of the cerebral hemispheres. The sequence fluid attenuated inversion recovery (FLAIR) can be acquired after gadolinium and in this situation, is the most sensitive for the detection of leptomeningeal involvement. Tuberculomas are usually present as isointense lesions on T1 and characteristically hypointense on T2 and present nodular or rim enhancement by the contrast material. Sarcoidosis Sarcoidosis is a systemic granulomatous disease of unknown etiology and characterized by an inflammatory process involving multiple systems. The lung and hilar lymph nodes are the organs most frequently affected. CNS involvement occurs in 5% of patients. The most characteristic MR imaging findings are thickening or distortion of cranial nerves or meningeal surfaces, multiple small parenchymal lesions or large solitary masses and the finding of small hyperintense on T2 periventricular white matter lesions. At MR imaging, the lesions are most often isointense on T1, iso / hypointense on T2 and have homogeneous enhancement. VASCULAR INJURIES Aneurysm Aneurysms of the cavernous portion of the internal carotid artery have a relatively benign course with risk of subarachnoid hemorrhage estimated at 0.4%. Approximately 5% of giant aneurysms (> 2.5 cm) are found in the cavernous portion of the internal carotid Page 11 of 51

12 artery. The majority of the aneurysms is idiopathic, but can occasionally be traumatic or mycotic. Aneurysms of the cavernous sinus usually present as round or oval lesions, well defined limits and regular contours. May be patents or partially thrombosed. Calcifications can be found in aneurysm walls. The patent aneurysm presents as isoatenuanting lesion or slightly hyperattenuating and intense enhancement by the contrast medium. The thrombosed or partially thrombosed aneurysm usually features high density and peripheral enhancement. The lumen of the partially thrombosed aneurysm may show intense enhancement. At MR imaging, the patent aneurysm is presented primarily as a round / oval lesion with absence of signal (flow void). The trombosed or partially thrombosed aneurysm shows variable signal intensity due to the various stages of hemoglobin degradation. Typically, they are hyperintense on T2 or have a laminated appearance with hypointense halo. Magnetic resonance angiography (MRA) and CT angiography (angio - CT) have greater sensitivity to detect aneurysms. Furthermore, they are useful to characterize aneurysms and direct a more appropriate treatment. Fistula Carotidocavernosa Carotidcavernous fistula is an abnormal connection between the arterial carotid system and the cavernous sinus. It is classified into direct or indirect. Direct fistula is due to a high flow communication between the internal carotid artery and the cavernous sinus, which can occur after trauma or be secondary to rupture of an intracavernous aneurysm. Indirect or dural fistula is a low flow fistula that occurs between meningeal branches of the carotid artery (external and / or internal) and the cavernous sinus. CT may demonstrate a widening of the cavernous sinus (high flow fistulas due to the presence of intercavernous communications, can result in expansion of both cavernous sinuses). At MR imaging, dilation of venous structures, in particular the superior ophthalmic vein and the cavernous sinus, is usually much more visible. Asymmetrical increasing of the cavernous sinus and of the arterial caliber, prominent intraosseous vessels and dilated cortical veins can be identified. Cavernous sinus thrombosis is less common. Secondary signs should always be searched, such as: proptosis, orbital edema and thickening of the extraocular muscles. In an attempt to directly visualize the fistula, angio-mr imaging and / or CT angiography is necessary. These studies may also demonstrate early cavernous sinus, orbital veins Page 12 of 51

13 and ipsilateral petrosal sinus filling, since there is communication with the arterial system. Digital arteriography however remains the gold standard for characterizing the fistula. Images for this section: Page 13 of 51

14 Fig. 12: Chordoma. Axial post-gadolinium T1-weighted MR imaging demonstrates a slight enhancing expansive lesion with its epicenter in the clivus and extension to the left cavernous sinus. Fig. 16: Nasopharyngeal carcinoma. Axial post-gadolinium T1-weighted MR images. There is a lesion obliterating the pharyngeal left lateral recess and extending to the ipsilateral pterygopalatine fossa (A, B). From the pterygopalatine fossa it extends posteriorly and superiorly to reach the cavernous sinus (arrowhead in C). It also extends superiorly through the inferior orbital fissure and then through the superior orbital fissure to reach the cavernous sinus (black arrows in D). Page 14 of 51

15 Fig. 25: Tolosa-Hunt syndrome. 19-year-old adolescent female, presenting retroorbital pain and diplopia. The MR imaging study shows a lesion involving the right cavernous sinus. The lesion is isointense on T1 (arrowhead in A), hypointense on T2 (arrow in B) and demonstrates diffuse enhancement by gadolinium (C). The patient was treated with corticosteroids, improved clinically and control examination performed after 47 days demonstrated almost complete resolution of the lesion.(axial post-gadolinium T1weighed MR imaging)(arrowhead in D). Page 15 of 51

16 Fig. 30: Sarcoidosis. 52-year-old woman, with pulmonary sarcoidosis treated for three years, presenting right diplopia. There is a lesion with enhancement involving the right cavernous sinus (arrow in A). It is noticed enhancement of dura mater anteriorly to the cavernous sinuses, as well as in the frontoparietal high convexity, more evident on the right (arrowheads in B). Hyperintense lesions affecting the periventricular white matter, more evident on the left were also noticed on axial FLAIR MR imaging (C). Page 16 of 51

17 Fig. 34: Partially thrombosed aneurysm. Coronal post-contrast T1-weighted MR imaging demonstrates that patent lumen intensely enhances. Page 17 of 51

18 Fig. 4: Trigeminal schwannoma. Dumbbell shaped lesion occupies the cerebellopontine cistern and extending to the Meckel s cave and left cavernous sinus, with small areas of cystic / hemorrhagic degeneration. The lesion is hyperintense on T2. Page 18 of 51

19 Fig. 5: Trigeminal schwannoma. Axial post-gadolinium T1-weighted MR imaging shows a intense enhancing dumbbell shaped lesion occupying the cerebellopontine cistern and extending to the Meckel s cave and left cavernous sinus. Page 19 of 51

20 Fig. 6: Cavernous hemangioma. Axial T2-weighted MR imaging shows a markedly hyperintense lesion involving the right cavernous sinus. Page 20 of 51

21 Fig. 7: Cavernous hemangioma. Axial T1-post-gadolinium - intermediate phase demonstrates intense, progressive and centripetal enhancement. Page 21 of 51

22 Fig. 8: Meningioma. Axial T1-weighted contrast-enhanced MR imaging demonstrates a lesion involving the left cavernous sinus and determining ICA stenosis. It is also observed intraorbital lesion extension through the superior orbital fissure and the dural tail sign. Page 22 of 51

23 Fig. 9: Typical macroadenoma. Coronal T2-weighted MR imaging shows a isointense to the gray matter lesion with a "snowman" shape, completely surrounding the right ICA without determining stenosis. Page 23 of 51

24 Fig. 10: Typical macroadenoma. Coronal post-gadolinium T1-weighted MR imaging shows a lesion with intense homogeneous enhancement with a "snowman" shape, completely surrounding the right ICA without determining stenosis. Page 24 of 51

25 Fig. 11: Chordoma. Axial T2-weighted MR imaging demonstrates a heterogeneous and predominantly hyperintense expansive lesion with its epicenter in the clivus and extension to the left cavernous sinus. Page 25 of 51

26 Fig. 13: Chordoma. CT shows bone erosion / destruction with calcifications and bony fragments within the lesion. Page 26 of 51

27 Fig. 14: Chondrosarcoma. Axial T2-weighted MR imaging shows a hyperintense lesion with hypointense foci related with calcifications and epicenter in the left cavernous sinus. Page 27 of 51

28 Fig. 15: Chondrosarcoma. Axial post-gadolinium T1-weighted MR imaging shows a intense enhancing lesion with epicenter in the left cavernous sinus. Page 28 of 51

29 Fig. 17: Rhabdomyosarcoma. 16-year old adolescent male. Bulky expansive lesion involving the nasopharynx, sphenoid sinus, mid cranial fossa and the left cavernous sinus. The lesion is isointense on T1. Page 29 of 51

30 Fig. 18: Rhabdomyosarcoma. 16-year old adolescent male. Bulky expansive lesion involving the nasopharynx, sphenoid sinus, mid cranial fossa and the left cavernous sinus. The lesion is slightly hypointense on T2. There is opacification of the left mastoid cells resulting from obstruction of the ipsilateral Eustachian tube. Page 30 of 51

31 Fig. 19: Rhabdomyosarcoma. 16-year old adolescent male. Bulky expansive lesion involving the nasopharynx, sphenoid sinus, mid cranial fossa and the left cavernous sinus. The lesion shows diffuse moderate enhancement. Page 31 of 51

32 Fig. 20: Non-Hodgkin lymphoma. Axial T2-weighed MR imaging shows a hypointense lesion involving the left cavernous sinus. Page 32 of 51

33 Fig. 21: Non-Hodgkin lymphoma. Axial post-gadolinium T1-weighed MR imaging shows a diffuse homogeneous enhancing lesion involving the left cavernous sinus. Page 33 of 51

34 Fig. 22: Non-Hodgkin lymphoma. Other findings: gadolinium-enhancing dural lesion and diffuse bone infiltration characterized low signal on T1 (not shown). Page 34 of 51

35 Fig. 23: 56-year-old woman, complaining of diplopia and without pathological antecedents. Axial post-contrast T1-weighted MR imaging shows two nodular lesions in the brain parenchyma. The hypothesis of secondary lesions has been suggested and the diagnosis of inflammatory breast carcinoma was confirmed later. Page 35 of 51

36 Fig. 24: 56-year-old woman, complaining of diplopia and without pathological antecedents. Coronal post-contrast T1-weighted MR imaging shows a sellar lesion with extension to the suprasellar lateral aspect of the right cavernous sinus with Page 36 of 51

37 heterogeneous enhancement. The hypothesis of secondary lesion has been suggested and the diagnosis of inflammatory breast carcinoma was confirmed later. Page 37 of 51

38 Fig. 26: Thrombosis of the cavernous sinuses. Axial T2-weighted MR imaging. 15-yearold teenager male, with fever and headache for 10 days with significant worsening in the last 12 hours. Intravenous antibiotic treatment was initiated, but the evolution was not favorable and the patient developed thrombosis of the internal carotid arteries and consequent cerebral infarcts. Page 38 of 51

39 Fig. 27: Thrombosis of the cavernous sinuses. 15-year-old teenager male, with fever and headache for 10 days with significant worsening in the last 12 hours. Sagittal T1-weighed MR imaging (not shown) demonstrates secretions accumulation in the sphenoid sinus. Coronal T1-weighed (also not shown) and axial post-contrast T1-weighed MR imaging show enlargement of the cavernous sinuses with peripheral enhancement and central filling defects. It is also noticed enhancement of the adjacent dura and the mucosa of the sphenoid sinuses. Page 39 of 51

40 Fig. 28: Tuberculosis. 34-year-old HIV + male patient presented the bilateral cavernous sinus syndrome. Axial post-contrast T1-weighed MR imaging demonstrates diffuse and nodular leptomeningeal enhancement at the skull base. It is also noticed expansion of the fourth ventricle. Page 40 of 51

41 Fig. 29: Tuberculosis. 34-year-old HIV + male patient presented the bilateral cavernous sinus syndrome. Axial post-contrast T1-weighed MR imaging demonstrates diffuse and nodular leptomeningeal enhancement at the skull base. It is also noticed expansion of the fourth ventricle. Page 41 of 51

42 Fig. 31: Patent aneurysm. Axial T2-weighet MR imaging shows a rounded lesion in the left cavernous sinus with absence of signal (flow void). Page 42 of 51

43 Fig. 32: Patent aneurysm. Axial post-contrast T1-weighet MR imaging shows intense homogeneous enhancement of the entire lesion. Page 43 of 51

44 Fig. 33: Partially thrombosed aneurysm. Axial T2-weighted MR imaging demonstrates isointense areas (thrombus) and areas of flow void (patent lumen). Page 44 of 51

45 Fig. 35: Partially thrombosed aneurysm. MR angiography confirms the aneurysmal dilatation of the cavernous segment of the left internal carotid artery. Page 45 of 51

46 Page 46 of 51

47 Fig. 36: Direct carotidcavernous fistula. 45-year-old man, presenting acute right diplopia, chemosis and pulsatile exophthalmos. Arterial phase MR angiography demonstrates opacification and enlargement of the right cavernous sinus and significant dilation of the superior ophthalmic vein. Fig. 37: Direct carotidcavernous fistula. 45-year-old man, presenting acute right diplopia, chemosis and pulsatile exophthalmos. Arterial phase MR angiography demonstrates opacification and enlargement of the right cavernous sinus and significant dilation of the superior ophthalmic vein. Page 47 of 51

48 Fig. 38: Indirect carotidcavernous fistula. 62-year-old woman, presenting edema, conjunctival hyperemia and diplopia for 45 days. Axial T2-weighed MR imaging shows bilateral proptosis, more evident on the left and dilatation of the superior ophthalmic veins. Page 48 of 51

49 Fig. 39: Indirect carotidcavernous fistula. 62-year-old woman, presenting edema, conjunctival hyperemia and diplopia for 45 days. Arterial phase MR angiography shows early opacification of cavernous sinuses. Page 49 of 51

50 Findings and procedure details A 1.5 Tesla MR is used to perfor the exams. Protocol included systematically sagittal T1 pre contrast, axial T1 and T2 fast spin echo, axial FLAIR, axial gradient echo, diffusion wheighted with ADC map, and axial T1 post gadolinium injection. Conclusion Lesions of the cavernous sinus and parasellar regions encompass a wide variety of neoplastic lesions, inflammatory / infectious diseases and vascular diseases. Some show typical imaging characteristics, others are suspected by their topography and finally there are lesions with unspecific imaging characteristics but with secondary findings and clinical presentations that are key in the differential diagnosis. Personal information References 1. Amemiya S, Aoki S, Obtomo K. Cranial nerve assessment in cavernous sinus tumors with contrast-enhanced 3D fast-imaging cmploying steady-state acquisition MR imaging. Neuroradiology 2009;51(7): Cottier JP, Destrieux C, Bmnereau L, et ai. Cavernous sinus invasion by pituitary adenoma: MR imaging. Radiology 2000;215: Daniels DL, Mark LP, Ulmer J L, et ai. Osseous anatomy of the pterygopalatine fossa. Am J Neuroradiol 1998;19: Ginsberg LÊ, DeMonte F. Imaging of perineural tumor spread from palatal carcinoma. Am J Neuroradiol 1998;19: Júnior JOV, Cukiert A, Liberman B. Magnetic resonance imaging of cavernous sinus invasion by pituitary adenoma. Arq Neuropsiquiatr 2004;62(2-B): Lee JH, Lee HK, Park LK, et ai. Cavernous sinus syndrome: clinicai features and differential diagnosis with MR imaging. AJR 2003;! 81: Pisaneschi M, Kapoor G. Imaging the sella and parasellar region. Page 50 of 51

51 Neuroimag Clin N Am 2005;! 5: Razeka AAK, Castillo M. Imaging lesions of the cavernous sinus. Am J Neuroradiol 2009;30: Rhoton AL. The cavernous sinus, the cavernous venous plexus, and the carotid collar. Neurosurgery 2002;51:S lo.roberti F, Boari N, Mortini P, et ai. The pterygopalatine fossa: an anatomic report. J Craniofacial surg 2007;18(3): Page 51 of 51