title: Comparison between enhanced susceptibility-weighted angiography and time of flight sequences in the detection of arterial occlusion in acute ischemic stroke.
abstract: OBJECTIVE
  Optimizing the MRI protocol in acute ischemic stroke remains a challenging issue. In this field, susceptibility-weighted sequences have proved their superiority over T2*. Besides the strengthened susceptibility effect, enhanced susceptibility-weighted angiography (eSWAN) sequence provides also a time-of-flight (TOF) effect, allowing the exploration of the intracranial arterial circulation. The objective of our study was to compare eSWAN and 3D TOF, considered as the reference, in the detection of arterial occlusion in acute stroke.
  
  
  METHODS
  Patients who underwent MRI between March and July 2014 for suspected acute stroke with an acute ischemic lesion on diffusion-weighted imaging (DWI) were prospectively included in this study. eSWAN and TOF images were analyzed under double-blind conditions by a junior radiologist and a senior neuroradiologist for the detection of arterial occlusion. eSWAN images were assessed in order to estimate the inter-observer agreement. After a consensus, eSWAN and TOF data were compared to calculate inter-modality agreement.
  
  
  RESULTS
  Thirty-four patients were included. Inter-observer agreement was excellent (kappa: 0.96) for eSWAN detection of occlusion. After consensus, comparison between TOF and eSWAN showed substantial agreement (kappa: 0.71). eSWAN provided better detection of distal occlusions, but poorer performance for detection of siphon occlusions.
  
  
  CONCLUSIONS
  Shortest echoes eSWAN images enabled detection of arterial occlusion with substantial agreement with TOF images. The susceptibility vessel sign associated with the TOF effect improved the identification of distal occlusions. In acute stroke protocol, eSWAN may represent a valuable alternative to T2* and TOF sequences.
authors.affiliation: Department of radiology, Catholic university hospitals, 115, rue du Grand-But-Lomme, 59160 Lille, France. Electronic address: ovanaerde@gmail.com.
authors.forename: O
authors.initials: O
authors.lastname: Vanaerde
authors.affiliation: Department of radiology, Catholic university hospitals, 115, rue du Grand-But-Lomme, 59160 Lille, France.
authors.forename: J-F
authors.initials: JF
authors.lastname: Budzik
authors.affiliation: Department of neurology, Stroke unit, Catholic university hospitals, 59160 Lille, France.
authors.forename: A
authors.initials: A
authors.lastname: Mackowiak
authors.affiliation: Clinical research department, Catholic university hospitals, 59160 Lille, France.
authors.forename: L
authors.initials: L
authors.lastname: Norberciak
authors.affiliation: GE Healthcare, 59000 Lille, France.
authors.forename: M
authors.initials: M
authors.lastname: Uettwiller
authors.affiliation: Neuroimaging department, CHU de Lille, 59000 Lille, France.
authors.forename: X
authors.initials: X
authors.lastname: Leclerc
authors.affiliation: Department of radiology, Catholic university hospitals, 115, rue du Grand-But-Lomme, 59160 Lille, France.
authors.forename: S
authors.initials: S
authors.lastname: Verclytte
mesh_terms: D000368:Aged; D002533:Cerebral Angiography / Q000379:methods*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D011446:Prospective Studies; D020521:Stroke / Q000000981:diagnostic imaging*
keywords: Acute stroke; Arterial occlusion; Susceptibility-weighted imaging; Time of flight