title: Ivy signs on FLAIR images before and after STA-MCA anastomosis in patients with Moyamoya disease.
abstract: BACKGROUND
  Leptomeningeal high signal intensity (ivy sign) on fluid-attenuated inversion-recovery (FLAIR) MR imaging is one of the features of Moyamoya disease. However, the correlation between ivy sign and cerebral perfusion status has not been fully evaluated.
  
  
  OBJECTIVE
  To characterize ivy sign on FLAIR images in Moyamoya disease and compare this finding with hemodynamic alterations on perfusion single-photon emission CT (SPECT) obtained before and after bypass surgery.
  
  
  METHODS
  Sixteen patients with angiographically confirmed Moyamoya disease who underwent superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis were included in the study. The presence of ivy sign on FLAIR images was classified as 'negative', 'minimal' and 'positive'. We evaluated the relationship between ivy sign and findings of SPECT, including cerebral vascular reserve (CVR) before and after surgery.
  
  
  RESULTS
  Minimal or positive ivy sign was seen in 13 (81%) of 16 patients, and 21 (66%) of 32 hemispheres. CVR in the areas with positive or minimal ivy sign was lower than that in the areas with negative ivy sign. After STA-MCA anastomosis, ivy sign disappeared or decreased in all 21 hemispheres demonstrating ivy sign. SPECT demonstrated apparent hemodynamic improvement in areas demonstrating disappearance or decrease of ivy sign.
  
  
  CONCLUSIONS
  Ivy sign on FLAIR image is seen in areas with decreased cerebral perfusion. The sign is useful for non-invasive assessment of cerebral hemodynamic status before and after surgery.
authors.affiliation: Department of Radiological Sciences, Nagasaki University Graduate School of Biomedical Sciences, Japan. qqtt37gd9@forest.ocn.ne.jp
authors.forename: Reiko
authors.initials: R
authors.lastname: Ideguchi
authors.forename: Minoru
authors.initials: M
authors.lastname: Morikawa
authors.forename: Mikako
authors.initials: M
authors.lastname: Enokizono
authors.forename: Yoji
authors.initials: Y
authors.lastname: Ogawa
authors.forename: Izumi
authors.initials: I
authors.lastname: Nagata
authors.forename: Masataka
authors.initials: M
authors.lastname: Uetani
mesh_terms: D000086:Acetazolamide; D000293:Adolescent; D000328:Adult; D000714:Anastomosis, Surgical; D000927:Anticonvulsants; D002533:Cerebral Angiography; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007223:Infant; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009072:Moyamoya Disease / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D019275:Radiopharmaceuticals; D018709:Statistics, Nonparametric; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D000927:Anticonvulsants; D003287:Contrast Media; D019275:Radiopharmaceuticals; D000086:Acetazolamide