title: Evaluation of Fibrous Cap Rupture of Atherosclerotic Carotid Plaque with Thin-Slice Source Images of Time-of-Flight MR Angiography.
abstract: OBJECTIVE
  To investigate the ability of source image of time-of-flight magnetic resonance angiography (TOF-MRA) in the detection of fibrous cap rupture of atherosclerotic carotid plaques.
  
  
  METHODS
  From the database of radiological information in our hospital, 35 patients who underwent carotid MR imaging and subsequent carotid endoarterectomy within 2 weeks were included in this retrospective study. MR imaging included thin-slice time-of-flight MR angiography, black-blood T1- and T2-weighted imaging. Sensitivity, specificity and accuracy were calculated for the detection of fibrous cap rupture with source image of TOF-MRA. The Cohen k coefficient was also calculated to quantify the degree of concordance of source image of TOF-MRA with histopathological data.
  
  
  RESULTS
  Sensitivity, specificity and accuracy in the detection of fibrous cap rupture were 90% (95%CI: 81-98), 69% (95%CI: 56-82) and 79% (95%CI: 71-87) with a k value of 0.59. The false positives (n = 15) were caused by partial-volume averaging between fibrous cap and lumen at the shoulder of carotid plaque. The false negatives (n = 5) were underestimated as partial thinning of fibrous cap.
  
  
  CONCLUSIONS
  Source image of TOF-MRA can be useful in the detection of fibrous cap rupture with high sensitivity, but further technical improvement should be necessary to overcome shortcomings causing image degradation.
authors.affiliation: Department of Radiology, Kurashiki Central Hospital, Kurashiki, Okayama, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Watanabe
authors.affiliation: Department of Radiology, Kurashiki Central Hospital, Kurashiki, Okayama, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Nagayama
authors.affiliation: Department of Radiology, Kurashiki Central Hospital, Kurashiki, Okayama, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Sakata
authors.affiliation: Department of Radiology, Kurashiki Central Hospital, Kurashiki, Okayama, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Okumura
authors.affiliation: Department of Radiology, Kurashiki Central Hospital, Kurashiki, Okayama, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Amoh
authors.affiliation: Department of Radiology, Kurashiki Central Hospital, Kurashiki, Okayama, Japan.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Ishimori
authors.affiliation: Department of Radiology, Kurashiki Central Hospital, Kurashiki, Okayama, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Nakashita
authors.affiliation: Department of Radiology, Kurashiki Central Hospital, Kurashiki, Okayama, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Dodo
keywords: MR imaging; atherosclerotic plaque; carotid artery; fibrous cap; time of flight MR angiography