1/2. "Ivy sign" on fluid-attenuated inversion-recovery images in childhood moyamoya disease.We report on MR studies of a 15-year-old girl with moyamoya disease in whom diffuse leptomeningeal enhancement ("ivy sign") was revealed by fluid-attenuated inversion-recovery (FLAIR) and contrast-enhanced imaging. We speculate that the mechanism behind this enhancement is caused by a retrograde slow flow of engorged pial vasculature via leptomeningeal anastomosis. Nevertheless, it remains unknown whether the precise source of a high signal on FLAIR images is attributable to pial vessels themselves or congested thickening of the leptomeninges or both.- - - - - - - - - - ranking = 1keywords = ivy (Clic here for more details about this article) |
2/2. Diffuse leptomeningeal enhancement, "ivy sign," in magnetic resonance images of moyamoya disease in childhood: case report.We report three cases of children with moyamoya disease who revealed prominent leptomeningeal enhancement on postcontrast magnetic resonance (MR) images. Two of the children underwent bilateral extracranial-intracranial bypass operations because of ischemic symptoms. During the operations, a profuse pial arterial network was observed, which was considered to be the origin of the enhancement. The ischemic episodes disappeared after the operations, and the follow-up MR images showed marked reduction of the leptomeningeal enhancement. One of the three patients had an extracranial-intracranial bypass operation on one side, but postoperative MR images have not yet been obtained. We named this finding on postcontrast MR images "ivy sign," because it resembles ivy creeping on stones. Ivy sign seems to be a unique, characteristic feature of the pial network observed in moyamoya disease.- - - - - - - - - - ranking = 6keywords = ivy (Clic here for more details about this article) |