title: Carotid plaque signal differences among four kinds of T1-weighted magnetic resonance imaging techniques: a histopathological correlation study.
abstract: BACKGROUND
  Several magnetic resonance (MR) imaging techniques are used to examine atherosclerotic plaque of carotid arteries; however, the best technique for visualizing intraplaque characteristics has yet to be determined. Here, we directly compared four kinds of T1-weighted (T1W) imaging techniques with pathological findings in patients with carotid stenosis.
  
  
  METHODS
  A total of 31 patients who were candidates for carotid endarterectomy were prospectively examined using a 1.5-T MRI scanner, which produced four kinds of T1W images, including non-gated spin echo (SE), cardiac-gated black-blood (BB) fast-SE (FSE), magnetization-prepared rapid acquisition with gradient echo (MPRAGE), and source image of three-dimensional time-of-flight MR angiography (SI-MRA). The signal intensity of the carotid plaque was manually measured, and the contrast ratio (CR) against the adjacent muscle was calculated. CRs from the four imaging techniques were compared to each other and correlated with histopathological specimens.
  
  
  RESULTS
  CRs of the carotid plaques mainly containing fibrous tissue, lipid/necrosis, and hemorrhage were significantly different with little overlaps (range: 0.92-1.15, 1.22-1.52, and 1.55-2.30, respectively) on non-gated SE. However, BB-FSE showed remarkable overlaps among the three groups (0.89-1.10, 1.07-1.23, and 1.01-1.42, respectively). MPRAGE could discriminate fibrous plaques from hemorrhagic plaques but not from lipid/necrosis-rich plaques: (0.77-1.07, 1.45-2.43, and 0.85-1.42, respectively). SI-MRA showed the same tendencies (1.01-1.39, 1.45-2.57, and 1.12-1.39, respectively).
  
  
  CONCLUSIONS
  Among T1W MR imaging techniques, non-gated SE images can more accurately characterize intraplaque components in patients who underwent CEA when compared with cardiac-gated BB-FSE, MPRAGE, and SI-MRA images.
authors.affiliation: Department of Neurology and Gerontology, Iwate Medical University, 19-1 Uchimaru, Morioka, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Saito
authors.forename: Makoto
authors.initials: M
authors.lastname: Sasaki
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Ogasawara
authors.forename: Masakazu
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Jiro
authors.initials: J
authors.lastname: Hitomi
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Narumi
authors.forename: Hideki
authors.initials: H
authors.lastname: Ohba
authors.forename: Mao
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Kohsuke
authors.initials: K
authors.lastname: Kudo
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Terayama
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002340:Carotid Artery Diseases / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D058226:Plaque, Atherosclerotic / Q000473:pathology*; D011446:Prospective Studies