title: Carotid intraplaque hemorrhage imaging at 3.0-T MR imaging: comparison of the diagnostic performance of three T1-weighted sequences.
abstract: OBJECTIVE
  To compare the diagnostic performances of three T1-weighted 3.0-T magnetic resonance (MR) sequences at carotid intraplaque hemorrhage (IPH) imaging, with histo logic analysis as the reference standard.
  
  
  METHODS
  Institutional review board approval and informed consent were obtained for this HIPAA-compliant study. Twenty patients scheduled for carotid endarterectomy underwent 3.0-T carotid MR imaging, including two-dimensional fast spin-echo, three-dimensional time-of-flight (TOF), and three-dimensional magnetization-prepared rapid acquisition gradient-echo (RAGE) sequences. Two reviewers blinded to the histologic findings assessed the presence, area, and signal intensity of IPH with each sequence. Detection statistics (sensitivity, specificity, and Cohen kappa values) and agreement between area measurements (Pearson correlation coefficient [r] values) were calculated for each sequence.
  
  
  RESULTS
  When all 231 available MR sections were included for analysis, the magnetization-prepared RAGE (kappa = 0.53) and fast spin-echo (kappa = 0.42) sequences yielded moderate agreement between MR and histologic measurements, while the TOF sequence yielded fair agreement (k = 0.33). However, when 47 sections with either small IPHs or heavily calcified IPHs were excluded, sensitivity, specificity, and kappa values, respectively, were 80%, 97%, and 0.80 for magnetization-prepared RAGE imaging; 70%, 92%, and 0.63 for fast spin-echo imaging; and 56%, 96%, and 0.57 for TOF imaging. MR imaging-histologic analysis correlation for IPH area was highest with magnetization-prepared RAGE imaging (r = 0.813), followed by TOF (r = 0.745) and fast spin-echo (r = 0.497) imaging. The capability of these three sequences for IPH detection appeared to be in good agreement with the quantitative contrast of IPH versus background plaque tissue.
  
  
  CONCLUSIONS
  The magnetization-prepared RAGE sequence, as compared with the fast spin-echo and TOF sequences, demonstrated higher diagnostic capability for the detection and quantification of IPH. Potential limitations of 3.0-T IPH MR imaging are related to hemorrhage size and coexisting calcification.
authors.affiliation: Department of Radiology, University of Washington, 815 Mercer St, Box 358050, Room 124, Seattle, WA 98109, USA.
authors.forename: Hideki
authors.initials: H
authors.lastname: Ota
authors.forename: Vasily L
authors.initials: VL
authors.lastname: Yarnykh
authors.forename: Marina S
authors.initials: MS
authors.lastname: Ferguson
authors.forename: Hunter R
authors.initials: HR
authors.lastname: Underhill
authors.forename: J Kevin
authors.initials: JK
authors.lastname: Demarco
authors.forename: David C
authors.initials: DC
authors.lastname: Zhu
authors.forename: Minako
authors.initials: M
authors.lastname: Oikawa
authors.forename: Li
authors.initials: L
authors.lastname: Dong
authors.forename: Xihai
authors.initials: X
authors.lastname: Zhao
authors.forename: Alonso
authors.initials: A
authors.lastname: Collar
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Hatsukami
authors.forename: Chun
authors.initials: C
authors.lastname: Yuan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002340:Carotid Artery Diseases / Q000473:pathology*; D016009:Chi-Square Distribution; D005260:Female; D006470:Hemorrhage / Q000175:diagnosis*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity