Ginkgo leaf sign: a highly predictive imaging feature of spinal meningioma.

OBJECT Spinal meningioma and schwannoma are the most common spinal intradural extramedullary tumors, and the differentiation of these 2 tumors by CT and MRI has been a matter of debate. The purpose of this article is to present a case series of spinal meningiomas showing unique imaging features: a combination of a fan-shaped spinal cord and a streak in the tumor. The authors termed the former imaging feature "ginkgo leaf sign" and evaluated its diagnostic value. METHODS The authors present 7 cases of spinal meningioma having the ginkgo leaf sign. Thirty spinal extramedullary tumors arising lateral or ventrolateral to the spinal cord were studied to evaluate the diagnostic value of the ginkgo leaf sign for spinal meningiomas. Among 30 cases, 12 tumors were spinal meningiomas and 18 tumors from the control group were all schwannomas. RESULTS Seven of the 12 spinal meningiomas were positive for the ginkgo leaf sign. The sign was not present in the control group tumors. The overall ability to use the ginkgo leaf sign to detect meningioma indicated a sensitivity of 58%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 78%. CONCLUSIONS The ginkgo leaf sign is highly specific to spinal meningiomas arising lateral or ventrolateral to the spinal cord. In the present series, the ginkgo leaf sign was perfectly predictive for spinal meningioma.