title: Comparison of 3D multi-echo gradient-echo and 2D T2* MR sequences for the detection of arterial thrombus in patients with acute stroke.
abstract: OBJECTIVE
  We compared a multi-echo gradient-echo magnetic resonance sequence (susceptibility-weighted angiography [SWAN]) with the T2* sequence for the detection of an arterial thrombus in acute ischaemic stroke.
  
  
  METHODS
  Seventy-four consecutive patients with acute ischaemic stroke were included. Proximal arterial occlusions were diagnosed using time-of-flight (TOF) magnetic resonance angiography (MRA). Two-dimensional (2D) axial reformats from 3D SWAN were generated to match with 2D T2* images. For arterial thrombus detection, each set of MR images (T2*, 2D SWAN reformats and 3D multiplanar SWAN images) was examined independently and separately by three observers who assigned the images to one of three categories: (0) absence of thrombus, (1) uncertain thrombus, (2) certain thrombus. Agreement and diagnostic accuracy were calculated.
  
  
  RESULTS
  Twenty-four proximal arterial occlusions involving the anterior (n = 20) or posterior (n = 4) circulation were found. Inter-observer agreement was moderate using T2* images (κ = 0.58), good using 2D SWAN reformats (κ = 0.83) and excellent using multiplanar SWAN images (κ = 0.90). For the diagnosis of thrombus, T2* images were 54% sensitive and 86% specific, 2D SWAN reformats were 83% sensitive and 94% specific and SWAN multiplanar analysis was 96% sensitive and 100% specific.
  
  
  CONCLUSIONS
  Three-dimensional SWAN sequence improves the detection of arterial thrombus in patients with acute ischaemic stroke in comparison with the 2D T2* sequence.
  
  
  CONCLUSIONS
  • Multi-echo gradient-echo MR (e.g. susceptibility-weighted angiograph, [SWAN]) is increasingly used in neuroradiology. • Compared with conventional T2* sequences, SWAN improves detection of arterial thrombus. • Multiplanar SWAN analysis had the best diagnostic performance for arterial thrombus detection. • Sensitivity was 96% and specificity 100%. • Findings support combination of time-of-flight and susceptibility effects in suspected acute stroke.
authors.affiliation: Department of Radiology, Hôpital Saint Joseph, 186, rue Raymond Losserand, Paris, France, jerome.hodel@gmail.com.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Hodel
authors.forename: Xavier
authors.initials: X
authors.lastname: Leclerc
authors.forename: Wassef
authors.initials: W
authors.lastname: Khaled
authors.forename: Ruben
authors.initials: R
authors.lastname: Tamazyan
authors.forename: Mathieu
authors.initials: M
authors.lastname: Rodallec
authors.forename: Sophie
authors.initials: S
authors.lastname: Gerber
authors.forename: Raphael
authors.initials: R
authors.lastname: Blanc
authors.forename: Mohamed
authors.initials: M
authors.lastname: Benadjaoud
authors.forename: Oriane
authors.initials: O
authors.lastname: Lambert
authors.forename: Cécile
authors.initials: C
authors.lastname: Rabrait
authors.forename: Mathieu
authors.initials: M
authors.lastname: Zuber
authors.forename: Alain
authors.initials: A
authors.lastname: Rahmouni
authors.forename: Marc
authors.initials: M
authors.lastname: Zins
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020771:Anterior Cerebral Artery / Q000473:pathology; D002545:Brain Ischemia / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000592:standards; D018810:Magnetic Resonance Angiography / Q000379:methods* / Q000592:standards; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000473:pathology; D015588:Observer Variation; D020769:Posterior Cerebral Artery / Q000473:pathology; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020521:Stroke / Q000175:diagnosis* / Q000473:pathology; D013927:Thrombosis / Q000175:diagnosis* / Q000473:pathology