title: Comparison of susceptibility weighted imaging and TOF-angiography for the detection of Thrombi in acute stroke.
abstract: OBJECTIVE
  Time-of-flight (TOF) angiography detects embolic occlusion of arteries in patients with acute ischemic stroke due to the absence of blood flow in the occluded vessel. In contrast, susceptibility weighted imaging (SWI) directly enables intravascular clot visualization due to hypointense susceptibility vessel signs (SVS) in the occluded vessel. The aim of this study was to compare the diagnostic accuracy of both methods to determine vessel occlusion in patients with acute stroke.
  
  
  METHODS
  94 patients were included who presented with clinical symptoms for acute stroke and displayed a delay on the time-to-peak perfusion map in the territory of the anterior (ACA), middle (M1, M1/M2, M2/M3) or posterior (PCA) cerebral artery. The frequency of SVS on SWI and vessel occlusion or stenosis on TOF-angiography was compared using the McNemar-Test.
  
  
  RESULTS
  87 of 94 patients displayed a clearly definable SVS on SWI. In 72 patients the SVS was associated with occlusion or stenosis on TOF-angiography. Fifteen patients exclusively displayed SVS on SWI (14 M2/M3, 1 M1), whereas no patient revealed exclusively occlusion or stenosis on TOF-angiography. Sensitivity for detection of embolic occlusion within major vessel segments (M1, M1/M2, ACA, and PCA) did not show any significant difference between both techniques (97% for SWI versus 96% for TOF-angiography) while the sensitivity for detection of embolic occlusion within M2/M3 was significantly different (84% for SWI versus 39% for TOF-angiography, p<0.00012).
  
  
  CONCLUSIONS
  SWI and TOF-angiography provide similar sensitivity for central thrombi while SWI is superior for the detection of peripheral thrombi in small arterial vessel segments.
authors.affiliation: Department of Neuroradiology, University of Heidelberg, Heidelberg, Germany. a.radbruch@dkfz.de
authors.forename: Alexander
authors.initials: A
authors.lastname: Radbruch
authors.forename: Johanna
authors.initials: J
authors.lastname: Mucke
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Schweser
authors.forename: Andreas
authors.initials: A
authors.lastname: Deistung
authors.forename: Peter Alexander
authors.initials: PA
authors.lastname: Ringleb
authors.forename: Christian Herbert
authors.initials: CH
authors.lastname: Ziener
authors.forename: Matthias
authors.initials: M
authors.lastname: Roethke
authors.forename: Heinz-Peter
authors.initials: HP
authors.lastname: Schlemmer
authors.forename: Sabine
authors.initials: S
authors.lastname: Heiland
authors.forename: Jürgen R
authors.initials: JR
authors.lastname: Reichenbach
authors.forename: Martin
authors.initials: M
authors.lastname: Bendszus
authors.forename: Stefan
authors.initials: S
authors.lastname: Rohde
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000098:blood supply / Q000473:pathology; D005260:Female; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000175:diagnosis*; D020762:Infarction, Posterior Cerebral Artery / Q000175:diagnosis*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000473:pathology / Q000503:physiopathology; D020769:Posterior Cerebral Artery / Q000473:pathology / Q000503:physiopathology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity