title: Loss of labelling efficiency caused by carotid stent in pseudocontinuous arterial spin labelling perfusion study.
abstract: OBJECTIVE
  To elucidate the cause of cerebral hypoperfusion on the stent placement side after carotid artery stent placement (CAS) measured by pseudocontinuous arterial spin labelling (PCASL) perfusion imaging.
  
  
  METHODS
  Consecutive patients with symptomatic internal carotid artery stenosis receiving CAS were included in the study. Cerebral blood flow (CBF) was measured by PCASL perfusion imaging at 3 T magnetic resonance imaging (MRI) the day before and 3 days after the procedure. Changes in cerebral haemodynamics after CAS were assessed.
  
  
  RESULTS
  Twenty-two patients were included; 17 patients had increased or stationary CBF after CAS and five patients had significantly reduced CBF on the stenting side after CAS whereas CBF increased on the contralateral side. High stent position was noticed in the five patients. After labelling plane adjustment to avoid labelling on the stent, no more cerebral hypoperfusion was noticed.
  
  
  CONCLUSIONS
  When using PCASL perfusion imaging to monitor post-stenting CBF, the stent may cause an artefact that leads to a low CBF in the territory of the stented vessel. Routinely adding a fast T2 star gradient-echo echo-planar-imaging covering the upper neck region before PCASL perfusion imaging to identify the stent position and avoid the stent-related artefact is recommended.
authors.affiliation: Department of Radiology and Brain and Consciousness Research Center, Taipei Medical University Shuang-Ho Hospital, New Taipei City, Taiwan.
authors.forename: D Y-T
authors.initials: DY
authors.lastname: Chen
authors.affiliation: Department of Radiology and Brain and Consciousness Research Center, Taipei Medical University Shuang-Ho Hospital, New Taipei City, Taiwan.
authors.forename: Y-S
authors.initials: YS
authors.lastname: Kuo
authors.affiliation: Department of Radiology and Brain and Consciousness Research Center, Taipei Medical University Shuang-Ho Hospital, New Taipei City, Taiwan.
authors.forename: H-L
authors.initials: HL
authors.lastname: Hsu
authors.affiliation: Department of Radiology and Brain and Consciousness Research Center, Taipei Medical University Shuang-Ho Hospital, New Taipei City, Taiwan.
authors.forename: F-X
authors.initials: FX
authors.lastname: Yan
authors.affiliation: Department of Imaging Physics, The University of Texas M. D. Anderson Cancer Center, Houston, TX, USA.
authors.forename: H-L
authors.initials: HL
authors.lastname: Liu
authors.affiliation: Department of Radiology and Brain and Consciousness Research Center, Taipei Medical University Shuang-Ho Hospital, New Taipei City, Taiwan.
authors.forename: C-J
authors.initials: CJ
authors.lastname: Chen
authors.affiliation: Department of Radiology and Brain and Consciousness Research Center, Taipei Medical University Shuang-Ho Hospital, New Taipei City, Taiwan. Electronic address: x2mickey@yahoo.com.tw.
authors.forename: Y-C
authors.initials: YC
authors.lastname: Tseng
mesh_terms: D000368:Aged; D016477:Artifacts; D002343:Carotid Artery, Internal; D016893:Carotid Stenosis / Q000473:pathology* / Q000601:surgery*; D002560:Cerebrovascular Circulation; D017352:Echo-Planar Imaging; D006439:Hemodynamics; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008875:Middle Aged; D013113:Spin Labels; D015607:Stents
chemical_list: D013113:Spin Labels