title: Luminal thrombosis in middle cerebral artery occlusions: a high-resolution MRI study.
abstract: OBJECTIVE
  High signals within occluded vessels on T1-weighted fat-suppressed images (HST1) are highly suggestive of luminal thrombosis. We sought to investigate the feasibility of in vivo identification of luminal thrombosis in middle cerebral artery (MCA) occlusions using high-resolution magnetic resonance imaging (HR-MRI).
  
  
  METHODS
  We retrospectively reviewed the HR-MRI data of 25 patients with unilateral symptomatic MCA occlusion. HST1 were defined as an area of high signal within the cross-section of occluded MCA, the intensity of which was >150% of the signal of adjacent muscles. The prevalence of HST1 and their relationship to infarct sizes and infarct patterns were analyzed.
  
  
  RESULTS
  The average time from stroke onset to HR-MRI examination was 9±6 days. There were 18 (72%) occluded vessels with HST1 on HR-MRI. HST1 were observed in 5/7 patients with a large territory infarct (≥1/3 MCA distribution) and 13/18 patients without (P=0.37). In the patients with non-large territory infarcts, the presence of HST1 was similar in those with and without border zone infarcts (9/13 vs. 4/5, P=0.42).
  
  
  CONCLUSIONS
  It's feasible to in vivo identify luminal thrombosis in occluded MCA. HR-MRI is a potentially powerful tool for investigating the mechanisms of stroke due to MCA occlusions.
authors.affiliation: 1 Departments of Neurology, 2 Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Wei-Hai
authors.initials: WH
authors.lastname: Xu
authors.affiliation: 1 Departments of Neurology, 2 Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Ming-Li
authors.initials: ML
authors.lastname: Li
authors.affiliation: 1 Departments of Neurology, 2 Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Jing-Wen
authors.initials: JW
authors.lastname: Niu
authors.affiliation: 1 Departments of Neurology, 2 Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Feng
authors.affiliation: 1 Departments of Neurology, 2 Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Zheng-Yu
authors.initials: ZY
authors.lastname: Jin
authors.affiliation: 1 Departments of Neurology, 2 Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Gao
keywords: Middle cerebral artery occlusion (MCA occlusion); cerebral infarct; magnetic resonance imaging; thrombosis