Hemosiderin cap sign
The hemosiderin cap sign refers to an MR imaging feature in some spinal tumors where a cap of T2 hypointense hemosiderin is above and/or below the tumor due to previous hemorrhage.
It is most often associated with spinal cord ependymomas (20-33% of cases) . It may also be seen in hemangioblastomas and paragangliomas and therefore it is suggestive — but not pathognomonic of ependymoma.
In addition, larger cavernous malformations of the spine may appear to lack a complete hemosiderin ring where they reach the pial surface, and thus develop a hemosiderin cap.
Siehe auch:
Assoziationen und Differentialdiagnosen zu Hemosiderin cap sign: