Meningiomas typically appear as a broad-based, extra-axial masses displacing normal brain parenchyma. They have distinct tumor margins especially in cats. Meningiomas are isodense to slightly hyperdense on CT, typically with uniform contrast enhancement. Occasionally meningiomas may have a cystic component extending from or contained within the primary tumor and may also have areas of mineralisation based on subtype. Contrast enhancement of meningiomas varies upon presence of cysts and areas necrosis or miniseralization. Mineralisation can be detected on non-contrast CT images (Sturges et. al 2008). Most meningiomas have minimal peritumoral oedema. Hyperostosis is associated with bone erosion caused by pressure atrophy of the calvarium and subsequent bony thickening due to aggregations of tumor cells in the meduallry spaces, it is not pathognomonic for meningiomas but occurs frequently and is reported in approximately 50% of feline cases (Gordon et.
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On MRI, meningiomas are usually iso- to hypointense compared to grey matter on T1 weighted images and are iso- to hyperintense compared to grey matter on T2 weighted images. “Dural tail sign” is often seen where a contrast-enhancing meningeal tail extending from the primary tumor. This is a thickening of the dura adjacent to intracranial pathology, not pathognomonic to meningiomas and may occur with lymphoma and dural metastasis. The tail sign is seen in approximately 30% of cases (Sturges et. al 2008; Kraft et al 1997). A study by Sturges et. al to determine whether MRI characteristics would allow for prediction of subtype or grade found MRI characteristics did not allow for the prediction for meningioma subtype or grade in the study, emphasizing the necessity of histopathology for antemortem diagnosis (Sturges et. al,
On MRI, meningiomas are usually iso- to hypointense compared to grey matter on T1 weighted images and are iso- to hyperintense compared to grey matter on T2 weighted images. “Dural tail sign” is often seen where a contrast-enhancing meningeal tail extending from the primary tumor. This is a thickening of the dura adjacent to intracranial pathology, not pathognomonic to meningiomas and may occur with lymphoma and dural metastasis. The tail sign is seen in approximately 30% of cases (Sturges et. al 2008; Kraft et al 1997). A study by Sturges et. al to determine whether MRI characteristics would allow for prediction of subtype or grade found MRI characteristics did not allow for the prediction for meningioma subtype or grade in the study, emphasizing the necessity of histopathology for antemortem diagnosis (Sturges et. al,