Spinal canal meningioma mimicking posterior fossa ischemia on CT perfusion: A CT perfusion pitfall.

The recent approach to treat acute stroke is to extend treatment window in patients with salvageable peri-infarct ischemia which increases the application of the perfusion imaging, specifically computed tomography perfusion (CTP). In this paper, I am presenting a case of left middle cerebral artery infarction which was evaluated by CTP under "code stroke." The patient had an incidental spinal canal meningioma which was out of field of view in CTP but mimicked right cerebellar ischemia on CTP. Although ischemia has been previously reported within the peripheral parenchymal edema surrounding a meningioma, in this patient there was no evidence of edema in the right cerebellum on magnetic resonance imaging. I believe the CTP findings are secondary to steal phenomena at right vertebral artery or compression upon the venous plexus. Recently, by using modern computed tomography scanners, it is common to cover the entire brain in CTP. The emergency radiologist should be aware of this pitfall that spinal canal pathologies which are out of field of view can mimic posterior fossa ischemia.