title: Focal time-to-peak changes on perfusion MRI in children with Moyamoya disease: correlation with conventional angiography.
abstract: BACKGROUND
  Moyamoya disease is a chronic progressive steno-occlusion of the distal internal carotid arteries with unknown etiology. As the classical presentation of childhood Moyamoya disease is ischemic stroke, cerebral hemodynamic evaluation is important for patient selection for surgery to prevent recurrent ischemic attacks. Perfusion MR imaging has been applied to evaluate cerebral hemodynamics.
  
  
  OBJECTIVE
  To correlate the 'basal time-to-peak preservation sign', 'auto-synangiosis sign', and 'posterior involvement sign' on time-to-peak map of perfusion MRI with catheter angiography.
  
  
  METHODS
  Thirty-four children (6.91 ± 3.08 years) with Moyamoya disease who underwent both perfusion-weighted MRI and catheter angiography were enrolled in this study. Given catheter angiography as a reference standard, basal time-to-peak preservation sign, auto-synangiosis sign, and posterior involvement sign were evaluated on time-to-peak maps.
  
  
  RESULTS
  The basal time-to-peak preservation sign was accurate for the diagnosis of childhood Moyamoya disease; both sensitivity and specificity were 100%. The auto-synangiosis sign showed lower sensitivity (65%), however, with an acceptable specificity (98%). The posterior involvement sign showed lower sensitivity (61%) but had an acceptable specificity (96%).
  
  
  CONCLUSIONS
  The basal time-to-peak preservation sign may be a universal finding in childhood Moyamoya disease. The auto-synangiosis and posterior involvement sign may be useful in determining transdural collateral status and posterior circulation involvement in childhood Moyamoya disease.
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Hyun Seok
authors.initials: HS
authors.lastname: Choi
authors.forename: Dong-Seok
authors.initials: DS
authors.lastname: Kim
authors.forename: Kyu-Won
authors.initials: KW
authors.lastname: Shim
authors.forename: Jinna
authors.initials: J
authors.lastname: Kim
authors.forename: Eun Soo
authors.initials: ES
authors.lastname: Kim
authors.forename: Seung-Koo
authors.initials: SK
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D002533:Cerebral Angiography / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D009072:Moyamoya Disease / Q000175:diagnosis*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity