What is the most common intradural extramedullary tumor in the thoracic spine, and what are its key imaging characteristics?

Meningioma is the most common intradural extramedullary tumor in the thoracic spine. On MRI, meningiomas typically appear as well-circumscribed, dural-based masses that are isointense to slightly hyperintense on T1-weighted images and iso- to hyperintense on T2-weighted images. They often enhance homogeneously with gadolinium. A key clinical pearl is the 'dural tail' sign, which is suggestive but not pathognomonic of meningioma. Common pitfalls include confusing meningiomas with schwannomas, which also occur in this region but are more often associated with nerve roots.