title: Ipsilateral plaques display higher T1 signals than contralateral plaques in recently symptomatic patients with bilateral carotid intraplaque hemorrhage.
abstract: Prospective studies have shown a strong association between carotid intraplaque hemorrhage (IPH), detected by magnetic resonance imaging (MRI), and cerebrovascular ischemic events. However, IPH is also observed in a substantial number of asymptomatic patients. We hypothesized that there are differences in the characteristics of IPH+ plaques associated with recent symptoms, compared to IPH+ plaques not associated with recent symptoms.
  
  
  
  Patients with recent (≤2 weeks) anterior circulation ischemic events were scanned using a standardized multisequence protocol. Those showing IPH bilaterally were included and analyzed for differences in T1/T2 signals, plaque morphology, and coexisting plaque characteristics between the ipsilateral symptomatic and contralateral asymptomatic sides.
  
  
  
  Thirty-one subjects (67 ± 9 years, 97% males) with bilateral IPH were studied. Despite comparable luminal stenosis (53 ± 42% vs. 53 ± 39%, p = 0.99), T1 signal of IPH measured as signal-intensity-ratio compared to muscle was stronger (SIRIPH-to-muscle: 5.8 ± 2.4 vs. 4.7 ± 1.8, p = 0.004) and tended to be more extensively distributed (IPH volume: 150 ± 199 vs. 88 ± 106 mm3, p = 0.071) on the symptomatic side. IPH+ plaques on the symptomatic side were longer (24 ± 6 vs. 21 ± 7 mm, p = 0.026) and associated with larger necrotic core volume (406 ± 354 vs. 291 ± 293 mm3, p = 0.039) than those on the asymptomatic side.
  
  
  
  In recently symptomatic patients with bilateral carotid IPH, the symptomatic side showed stronger T1 signals, larger necrotic cores, and longer plaque length than the asymptomatic side. Serial studies on the temporal relationship between these imaging features and clinical events will eventually establish their diagnostic and prognostic value beyond the mere presence of IPH.
authors.affiliation: Department of Radiology, University of Washington, Seattle, WA, USA; Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.
authors.forename: Xianling
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Radiology, University of Washington, Seattle, WA, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Sun
authors.affiliation: Department of Biomedical Engineering, Tsinghua University, Beijing, China.
authors.forename: Xihai
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Department of Radiology, University of Washington, Seattle, WA, USA.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Hippe
authors.affiliation: Department of Surgery, University of Washington, Seattle, WA, USA.
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Hatsukami
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, WA, USA.
authors.forename: Jin
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Biomedical Engineering, Tsinghua University, Beijing, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Li
authors.affiliation: Department of Mechanical Engineering, University of Washington, Seattle, WA, USA.
authors.forename: Gador
authors.initials: G
authors.lastname: Canton
authors.affiliation: Department of Radiology, University of Washington, Seattle, WA, USA; Department of Radiology, Beijing Hospital, Beijing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Song
authors.affiliation: Department of Radiology, University of Washington, Seattle, WA, USA; Department of Biomedical Engineering, Tsinghua University, Beijing, China; Department of Bioengineering, University of Washington, Seattle, WA, USA. Electronic address: cyuan@uw.edu.
authors.forename: Chun
authors.initials: C
authors.lastname: Yuan
mesh_terms: D000368:Aged; D002545:Brain Ischemia / Q000209:etiology; D002339:Carotid Arteries / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000473:pathology; D016893:Carotid Stenosis / Q000150:complications / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D002681:China; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D006470:Hemorrhage / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008055:Lipids / Q000032:analysis; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D058226:Plaque, Atherosclerotic; D011237:Predictive Value of Tests; D012307:Risk Factors; D012720:Severity of Illness Index
chemical_list: D008055:Lipids
keywords: Carotid artery; Ischemic stroke; Magnetic resonance imaging; Plaque progression