title: Assessment of cerebrovascular reactivity using real-time BOLD fMRI in children with moyamoya disease: a pilot study.
abstract: OBJECTIVE
  This pilot study aims to test the reliability and clinical validity of the assessment of cerebrovascular reactivity (CVR) with real-time blood-oxygen-level-dependent (BOLD) fMRI (rtCVR) in comparison with standard off-line processing in children with moyamoya disease.
  
  
  METHODS
  Eight consecutive pediatric patients with moyamoya cerebral arteriopathy underwent BOLD fMRI CVR studies either on a 1.5-T or on a 3-T scanner with breath-holding techniques in six patients and under general anesthesia (GA) in three patients. One patient had undergone CVR study initially without and later with GA, and another had undergone CVR study before and after a revascularization procedure. The off-line and real-time processing of the data was done, and the results were compared for general quality and adequacy of the study (scale 0-3, 3 being the best) and for the presence or absence of abnormal reactivity and the location, pattern, and extent of abnormal reactivity.
  
  
  RESULTS
  A total of 20 CVR series each was studied on real-time functional MRI and off-line analysis (eight patients, ten sessions, two series per session). All eight sessions done under GA were rated as quality class 3 (100 %), whereas only 5 of the 12 (41.7 %) studies with breath-holding technique were considered to be of best quality (class 3). In comparison to the off-line processing, the overall sensitivity of the rtCVR technique was 90 % with a specificity of 100 %.
  
  
  CONCLUSIONS
  rtCVR assessment in children with moyamoya disease is feasible, and the results are comparable to that of standard off-line analysis. The results from off-line analysis are only available, at the earliest, several hours after the MRI has been completed. rtCVR can overcome this difficulty and may be equally reliable.
authors.affiliation: Department of Diagnostic Imaging, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada.
authors.forename: Bejoy
authors.initials: B
authors.lastname: Thomas
authors.forename: William
authors.initials: W
authors.lastname: Logan
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Donner
authors.forename: Manohar
authors.initials: M
authors.lastname: Shroff
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001921:Brain / Q000098:blood supply / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D002648:Child; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009072:Moyamoya Disease / Q000097:blood / Q000503:physiopathology*; D010100:Oxygen / Q000097:blood; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D010100:Oxygen