title: Assessment of carotid plaque stability based on the dynamic enhancement pattern in plaque components with multidetector CT angiography.
abstract: OBJECTIVE
  Recent studies have investigated plaque morphology to determine patients who are at high risk of carotid atherosclerosis. In this study, we investigated whether a difference in dynamic enhancement pattern in plaque components could be useful to assess plaque stability with multidetector CT angiography.
  
  
  METHODS
  Fifty-nine lesions with moderate to severe carotid atherosclerosis in 51 patients (33 symptomatic, 18 asymptomatic) were consecutively included. Early- and delayed-phase images were obtained in 3 equivalent axial slices with multidetector CT angiography. Hounsfield units (HU) in the early phase were subtracted from those in the delayed phase in plaques (ΔHU) and compared with clinical features, MRI-based plaque characteristics, and histological findings with 20 surgical specimens acquired from carotid endarterectomy.
  
  
  RESULTS
  The ΔHU was significantly higher in asymptomatic than that in symptomatic presentation (P=0.02). With MRI, a higher ΔHU was negatively correlated with signal intensity on T1-weighted imaging (r=-0.56, P<0.0001). Histology confirmed that ΔHU was positively correlated with fibrous tissue (r=0.67, P=0.001) and negatively correlated with a lipid-rich necrotic core with hemorrhage (r=-0.70, P<0.001). Moreover, less neovascularization and inflammation was found in plaques with a higher ΔHU.
  
  
  CONCLUSIONS
  Delayed-phase images provide information regarding the dynamic change in contrast media from the early arterial phase. An increase in HU from the early phase on multidetector CT angiography indicates plaque stability with more fibrous tissue and a less lipid-rich necrotic core, intraplaque hemorrhage, and neovascularization.
authors.affiliation: Department of Neurosurgery, Nagasaki University School of Medicine, 1-7-1, Sakamoto, Nagasaki 852-8501, Japan. nobstanford@gmail.com
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Horie
authors.forename: Minoru
authors.initials: M
authors.lastname: Morikawa
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Ishizaka
authors.forename: Tomonori
authors.initials: T
authors.lastname: Takeshita
authors.forename: Gohei
authors.initials: G
authors.lastname: So
authors.forename: Kentaro
authors.initials: K
authors.lastname: Hayashi
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Suyama
authors.forename: Izumi
authors.initials: I
authors.lastname: Nagata
mesh_terms: D000368:Aged; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D002533:Cerebral Angiography; D002543:Cerebral Hemorrhage / Q000000981:diagnostic imaging; D003287:Contrast Media; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007249:Inflammation / Q000473:pathology; D002546:Ischemic Attack, Transient / Q000000981:diagnostic imaging; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D009389:Neovascularization, Pathologic / Q000150:complications / Q000000981:diagnostic imaging; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging* / Q000473:pathology; D020521:Stroke / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media