title: SPECT evaluation of cerebral blood flow during arm exercise in patients with subclavian steal.
abstract: OBJECTIVE
  To explore the cerebral hemodynamics in subclavian steal syndrome, we examined the cerebral perfusion of seven patients with subclavian steal (one symptomatic and six asymptomatic) using single-photon emission computed tomography (SPECT) during resting, arm exercise, and acetazolamide-activated conditions.
  
  
  METHODS
  The regional CBF (rCBF) was measured with SPECT under all conditions, and region of interest (ROI) analysis was performed using a three-dimensional stereotaxic ROI template (3DSRT). We evaluated the relationship between arm exercise-induced rCBF change and (1) presence of subclavian artery stenosis, (2) vertebral reverse flow severity, (3) presence of vertebro-basilar insufficiency (VBI) symptoms, and (4) cerebrovascular reactivity (CVR) to acetazolamide.
  
  
  RESULTS
  Overall, no arm exercise-induced rCBF reduction was observed on either the affected or the unaffected side, even in patients with severe vertebral reverse flow. One patient with VBI symptoms showed an arm exercise-induced global rCBF reduction in the cerebrum and cerebellum, whereas the other asymptomatic patients did not. The %rCBF changes in segments with severely impaired CVR (-8.6%+/-10.7%, mean+/-SD) were significantly lower than those in other segments with less impaired CVR (P<0.01).
  
  
  CONCLUSIONS
  Our results suggest that subclavian steal is a benign condition in asymptomatic patients. On the other hand, arm exercise-induced rCBF reduction can occur in the cerebrum and cerebellum in patients with VBI symptoms possibly related to low CVR.
authors.affiliation: Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan. kkaneko-kyu@umin.ac.jp
authors.forename: Koichiro
authors.initials: K
authors.lastname: Kaneko
authors.forename: Shigeru
authors.initials: S
authors.lastname: Fujimoto
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Okada
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshiura
authors.forename: Kotaro
authors.initials: K
authors.lastname: Yasumori
authors.forename: Toru
authors.initials: T
authors.lastname: Muranaka
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sasaki
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Koga
authors.forename: Koichiro
authors.initials: K
authors.lastname: Abe
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Sawamoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Honda
mesh_terms: D000368:Aged; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013349:Subclavian Steal Syndrome / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*