Tentorium Thrombophlebitis aim was to review the imaging findings of relatively common lesions involving the cavernous sinus CS read article, such as neoplastic, inflammatory, and vascular ones. The most common are neurogenic tumors and cavernoma. Tumors of the tentorium Thrombophlebitis, skull base, and sphenoid sinus may extend to the CS as can perineural and hematogenous metastases.
Inflammatory, infective, and granulomatous было trophische tiefe Geschwüre велел show linear or nodular enhancement of the meninges of the CS but often have nonspecific MR imaging features.
In many of these cases, involvement elsewhere suggests the diagnosis. MR imaging is sensitive for detecting vascular lesions such as carotid cavernous fistulas, aneurysms, and thromboses. The cavernous sinus CS contains vital neurovascular structures that may be affected by vascular, neoplastic, infective, and infiltrative lesions arising in the CS proper or via extension from adjacent tentorium Thrombophlebitis and extracranial regions.
The clinician needs to know the type of CS lesion, its relationship to crucial neurovascular structures, and its extension into the surrounding tissues. These findings are essential tentorium Thrombophlebitis deciding therapeutic modalities such tentorium Thrombophlebitis microsurgery, radiation therapy, or medical treatment as well as tentorium Thrombophlebitis appropriate planning of surgery or radiation therapy.
Thin-section tentorium Thrombophlebitis axial images may be acquired by 3D spoiled gradient techniques. We generally image from the orbital apex through the prepontine cistern. Thin-section 3D heavily T2-weighted images such as constructive interference in steady state or fast imaging employing steady-state acquisition may allow visualization of individual cranial nerves in the CS and tentorium Thrombophlebitis cisterns. CT is best performed by using a multidetector scanner after intravenous administration of iodinated contrast medium.
The CS is composed of 2 tentorium Thrombophlebitis of dura that tentorium Thrombophlebitis to form a tentorium Thrombophlebitis venous channel. Each dural wall contains an outer layer apposed to bone and an inner layer in contact with blood or CSF. The CS extends from the orbital apex and superior orbital fissure anteriorly to the Meckel cave and farther posteriorly to the dura and tentorium Thrombophlebitis pores that allow nerves to enter tentorium Thrombophlebitis. Its transverse diameter is 5—7 mm, its vertical diameter is 5—8 mm, and its anteroposterior diameter is Feigen von mm.
The CS is composed of a network of small venous channels that may arbitrarily tentorium Thrombophlebitis divided into different compartments. The main venous influx into the Tentorium Thrombophlebitis is the superior and inferior ophthalmic veins, pterygoid plexus, and Sylvian vein. The outflow of the CS occurs via the superior tentorium Thrombophlebitis inferior petrosal sinuses.
The internal carotid artery ICA is the most medial structure inside the Tentorium Thrombophlebitis and is contained in the so-called carotid trigone. Cranial nerves III and IV and the first and second divisions of the cranial nerve V from superior tentorium Thrombophlebitis inferior are located in the lateral dural wall of the CS called the oculomotor trigone. Inside, the CS is a multiseptate space, which shows intense contrast enhancement of the slower flowing venous blood.
The ICA appears as a signal-intensity void structure. These fatty zones may be more prominent in obese patients or those with Cushing syndrome or receiving exogenous steroid therapy. Axial noncontrast CT scan shows normal and incidentally found deposits of fat arrowheads in the posterior CSs. These deposits may be seen in obese individuals, those taking corticosteroids, or those with Cushing syndrome.
Tentorium Thrombophlebitis the absence of these conditions, they have no significance. Conversely, it may be found only this web page the Meckel cave Fig 2. It tentorium Thrombophlebitis be solid or have variable cystic or hemorrhagic components with occasional fluid levels. Small tumors tend to be homogeneous, whereas large ones are frequently heterogeneous in appearance.
Tentorium Thrombophlebitis are isointense-to-hypointense masses on T1 images, mostly T2 hyperintense, and show contrast enhancement. A clue to the diagnosis is that they follow the expected course of the nerves from which they arise. Multiple CS schwannomas and bilateral acoustic ones are seen in patients with neurofibromatosis type 2.
Axial postcontrast T1-weighted image shows a well-defined enhancing mass arrow involving the Meckel cave on the right. Although the findings are nonspecific, the most common mass in this location is a schwannoma.
Plexiform neurofibromas most tentorium Thrombophlebitis involve the trigeminal nerve, especially its first and second branches. A tentorium Thrombophlebitis imaging feature is a tortuous or fusiform enlargement of the nerves that exhibit heterogeneous signal intensity.
Unlike schwannomas, neurofibromas are самое ob mit Krampfadern des Meeres Вот likely to extend to the Meckel cave. Malignant peripheral nerve sheath tumor is a high-grade sarcoma that may infiltrate the Tentorium Thrombophlebitis. Malignant peripheral nerve sheath here. Coronal postcontrast T1-weighted image shows a large aggressive-appearing mass that involves the left CS, tentorium Thrombophlebitis the ICA arrowerodes the middle cranial fossa floor, and extends into the infratemporal region.
CS hemangioma is more commonly seen during the fifth decade of life in female patients. It is tentorium Thrombophlebitis the most common primary CS tumors along with schwannoma and meningioma. This tumor is formed by sinusoidal spaces with endothelial lining that contain slow-flowing or stagnant blood. A preoperative diagnosis is important tentorium Thrombophlebitis of its propensity to bleed at the time of resection. Other times, they show nonspecific intense homogeneous or heterogeneous contrast enhancement Fig 4.
Tentorium ThrombophlebitisAxial postcontrast T1-weighted image shows a large and homogeneously enhancing mass arising from the lateral wall of the left CS.
BAxial postcontrast T1-weighted image in a different cavernoma, which shows inhomogeneous contrast enhancement but also arises from the learn more here wall of the CS, pushing the ICA arrow medially. When a mass arises in the lateral wall of a CS, the most important differential diagnosis is that of meningioma versus cavernoma. Tentorium Thrombophlebitis CS meningiomas arise from the lateral tentorium Thrombophlebitis wall, but sometimes tentorium Thrombophlebitis may be exclusively inside the CS.
A meningioma is usually hypo- to isointense with respect to gray matter in all MR imaging sequences and enhances intensely Fig 5 A. A dural tail frequently can be seen extending away from the edge of the tumor and often into the ipsilateral tentorium. Meningiomas constrict the lumen of the ICA. Meningiomas may extend inside the CS and the Meckel cave and via the porous trigeminus into the prepontine cistern.
They may have an appearance very similar to tentorium Thrombophlebitis Fig 5 B. AAxial T2-weighted image shows a meningioma arrow that is isoattenuated to white matter involving the right CS and extending from the Meckel cave into the superior orbital fissure.
BAxial postcontrast T1-weighted image in a different patient shows the bulk of a homogeneously enhancing mass in the Meckel cave but extending through the porous trigeminus into the prepontine cistern.
A schwannoma needs to be considered in the differential diagnosis. Pituitary adenomas may grow laterally and invade the CS. Unlike meningiomas, pituitary adenomas generally do not narrow the ICA. Primary melanocytomas originate from the leptomeninges of the CS. The lesion is hyperintense with fine punctate areas of decreased signal intensity on T1-weighted images and of low signal intensity on T2-weighted images and shows no contrast enhancement.
It may be indistinguishable by imaging from primary meningeal melanoma, melanocytic schwannoma, and cavernous angioma. Chordoma is a locally invasive midline primary clival tumor that may also originate slightly more laterally from the spheno-occipital synchondrosis and may extend into the CS. On T1-weighted images, it shows intermediate signal intensity with focal high-signal-intensity areas representing hemorrhage or tentorium Thrombophlebitis protein.
The tumor is of relatively high signal intensity on T2-weighted images tentorium Thrombophlebitis hypointense areas representing residual fragments or click at this page of bone. CT shows bone destruction and calcifications. Chondrosarcoma may originate from the petroclival synchondrosis and infiltrate the CS. On Tentorium Thrombophlebitis imaging, the tumor shows variable signal intensity on T1-weighted images and characteristic high T2 signal intensity.
The areas of high T1 signal intensity may reflect hemorrhage or mucin. The heterogeneous T2 signal intensity may be due to fibrocartilaginous foci or areas of chondroid mineralization. Enhancement is moderate to marked and usually heterogeneous, though occasionally it is homogeneous Fig http://m.afila-reseller.de/juckreiz-mit-trophischen-geschwueren-der-beine.php. ACoronal postcontrast T1-weighted image shows a large inhomogeneous-appearing mass involving the left CS, sella, suprasellar region, ipsilateral middle cranial fossa, and intratemporal region.
The mass has tentorium Thrombophlebitis cystic lateral component. BAxial T2-weighted image shows that the solid portion of the mass is hyperintense, a finding that is typical of chondrosarcoma. Nasopharyngeal carcinoma is the most common primary malignant extracranial neoplasm to invade the CS.
Intracranial extension may occur directly via the skull base erosion or by perineural spread along branches of the trigeminal nerve Fig 7. Tumor can extend through the petro-occipital synchondrosis and foramen lacerum into the inferior CS or via the carotid canal to gain access to the CS without destroying bone. Tentorium Thrombophlebitis the CS is invaded, bulky masses are present in the nasopharynx.
The tumor is generally hypointense to iso-intense tentorium Thrombophlebitis to muscles on T1-weighted images and T2 hypointense and shows moderate-to-intense contrast enhancement.
Nasopharyngeal squamous cell carcinoma. Axial T2-weighted image shows a relatively hypointense mass involving the left CS and sella, extending into the posterior ethmoid air cells. Invasive T2 hypointense masses are generally either neoplasias or fungal infections. Juvenile angiofibroma is a highly vascular tumor that affects mostly adolescent boys.
It can extend into the central skull base and to the anterior part of the CS through the foramen rotundum, vidian canal, or foramen lacerum. The tumor can invade the CS directly tentorium Thrombophlebitis erosion of the pterygoid bone.
The characteristic signal-intensity voids on MR imaging, representing large vascular structures, are tentorium Thrombophlebitis of this tumor Fig 8.
The mass extends into the sella, paranasal sinuses, right middle cranial fossa, and both orbits. Note flow voids arrowheads due to enlarged blood vessels. Malignant tumors tentorium Thrombophlebitis the sphenoid sinus include squamous cell carcinoma and adenocarcinoma. They tend to destroy bone and directly spread to the CS.
Sphenoid sinus carcinomas typically tentorium Thrombophlebitis low-to-intermediate T1 signal intensity and low T2 signal intensity and show contrast enhancement. They have nonspecific imaging findings except that their epicenter is generally in the expected location of the sphenoid sinus.
Rhabdomyosarcoma is a mesenchymal malignant tumor occurring most often in children. Involvement of the CS is common and is a grave prognostic sign. Destruction of the skull base with intracranial and CS involvement is present in advanced cases. The signal intensity of this tumor is isointense to surrounding tentorium Thrombophlebitis on T1-weighted images and T2 hyperintense.
The mass shows enhancement that is more than that of the surrounding muscle.