title: Identification of intraplaque hemorrhage on MR angiography images: a comparison of contrast-enhanced mask and time-of-flight techniques.
abstract: OBJECTIVE
  MRA is widely used to measure carotid narrowing. Standard CE- and TOF-MRA techniques use highly T1-weighted gradient-echo sequences that can detect T1 short blood products, so they have the potential to identify IPH, an indicator of plaque rupture. We sought to determine the accuracy and reliability of these MRA sequences to detect IPH.
  
  
  METHODS
  3D TOF and CE carotid MRA scans were obtained at 3T on 15 patients (age range, 58-86 years; 13 men) scheduled for CEA. The source images from the precontrast (mask) CE-MRA and the TOF sequences were reviewed by 2 independent readers for IPH presence (identified as hyperintense signal intensity compared with adjacent muscle). CEA specimens were stained with antibody against glycophorin A and Mallory stain to detect IPH and were correlated with MR images.
  
  
  RESULTS
  Nine of 15 CEA specimens (61 of 144 MR images) contained IPH confirmed by histology. Compared with TOF, CE-MRA mask demonstrated greater sensitivity, specificity, PPV, and NPV for IPH detection. The accuracy for correctly identifying IPH by using CE-MRA mask images and TOF images was 94% and 84%, respectively. Inter- and intraobserver agreement for IPH detection was excellent by mask images (κ = 0.91 and κ = 0.94, respectively) and TOF images (κ = 0.77 and κ = 0.84, respectively).
  
  
  CONCLUSIONS
  CE-MRA mask images are highly accurate and reliable for identifying IPH, more so than the TOF sequence, and can potentially provide valuable information about risk for rupture.
authors.affiliation: The Russell H. Morgan Department of Radiology and Radiological Sciences, The Johns Hopkins Hospital, Baltimore, Maryland, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Qiao
authors.forename: M
authors.initials: M
authors.lastname: Etesami
authors.forename: S
authors.initials: S
authors.lastname: Malhotra
authors.forename: B C
authors.initials: BC
authors.lastname: Astor
authors.forename: R
authors.initials: R
authors.lastname: Virmani
authors.forename: F D
authors.initials: FD
authors.lastname: Kolodgie
authors.forename: H H
authors.initials: HH
authors.lastname: Trout
authors.forename: B A
authors.initials: BA
authors.lastname: Wasserman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016893:Carotid Stenosis / Q000150:complications* / Q000175:diagnosis*; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006470:Hemorrhage / Q000175:diagnosis* / Q000209:etiology*; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA