title: Prediction of carotid plaque characteristics using non-gated MR imaging: correlation with endarterectomy specimens.
abstract: OBJECTIVE
  Electrocardiographic gating, commonly used in MR carotid plaque imaging, can negatively affect intraplaque contrast if the TR is inappropriate. The present study aimed to determine whether a non-gated technique with appropriate TRs can accurately evaluate intraplaque characteristics in specimens excised by CEA.
  
  
  METHODS
  We prospectively examined 40 consecutive patients who underwent CEA (59-82 years of age) by using a 1.5T scanner. Axial T1WI with a TR of 500 ms and PDWI and T2WI with a TR of 3000 ms with a self-navigated rotating-blade scan instead of cardiac gating were obtained. Signal intensities of the plaque and adjacent muscle were measured, and the CR on T1WI, PDWI, and T2WI as well as the gray-scale median on US were correlated with the pathologic findings of the CEA specimens.
  
  
  RESULTS
  On T1WI, the CRs of the carotid plaques differed significantly among groups in which the main components were histologically confirmed as fibrous tissue, lipid/necrosis, and hemorrhage (0.54-1.17, 1.16-1.53, and 1.40-2.29, respectively). The sensitivity and specificity for discriminating lipid/necrosis/hemorrhage from fibrous tissue were 96% and 100%, respectively. On T2WI, the CRs of plaques with lipid/necrosis were significantly higher than those of other groups, but the CRs on PDWI and the gray-scale median on US were not significantly different among the groups.
  
  
  CONCLUSIONS
  Non-gated MR plaque imaging, particularly T1WI, can readily predict the intraplaque main components of the carotid artery with high sensitivity and specificity.
authors: Department of Neurology and Gerontology, Iwate Medical University, Morioka, Japan. snarumi@iwate-med.ac.jp
authors: S
authors: S
authors: Narumi
authors: M
authors: M
authors: Sasaki
authors: H
authors: H
authors: Ohba
authors: K
authors: K
authors: Ogasawara
authors: M
authors: M
authors: Kobayashi
authors: J
authors: J
authors: Hitomi
authors: K
authors: K
authors: Mori
authors: K
authors: K
authors: Ohura
authors: M
authors: M
authors: Yamaguchi
authors: K
authors: K
authors: Kudo
authors: Y
authors: Y
authors: Terayama
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D055424:Cardiac-Gated Imaging Techniques; D016893:Carotid Stenosis / Q000473:pathology* / Q000601:surgery; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic