Central nervous system disorders

VII./3.2.: Computed tomography – CT

CT demonstrates meningeomas as an isodense structure compared to the cerebral parenchyma, however, it can be hyperdense or mildly hypodense compared to the cerebrum occasionally. Specifically the en-plaque flatly growing meningeomas (these meningeomas grow along the tuberculum sellae, planum sphenoideale and greater wing of sphenoid bone) evolve a hyperostotic effect on the bone located below them, but ingrowth is also possible. Bone destruction is rather charateristic of malignant meningeomas. Psammomatous calcification, which is characteristic of at least one-fourth of meningeomas, can be demonstrated by CT. (Forms of calcification: nodular, gently dispergated, tiny nodular, annular or very tight, hyperdense). Necrosis can also occur in meningeomas (as hypodense, non enhancing area) and fat content is also feasible (very hypodense). I.v. iodinated contrast agent is usually well enhanced. Pattern of contrast enhancement can be nodular, mixed inhomogeneous or annular. (perfusion scan: see below)