title: High signal intensity halo around the carotid artery on maximum intensity projection images of time-of-flight MR angiography: a new sign for intraplaque hemorrhage.
abstract: OBJECTIVE
  To evaluate the value of the high signal intensity halo sign as a new marker of a fresh or recent intraplaque hemorrhage on the maximum intensity projection (MIP) images of time-of-flight (TOF) MR angiography.
  
  
  METHODS
  A total of 135 consecutive patients were included in this study. High-resolution MRI using 3-inch surface coils was performed on a 1.5T scanner before the carotid endarterectomy. TOF MR angiograms and T2-weighted, T1-weighted pre- and postcontrast fast spin echo images were obtained. The surgical and pathological findings of the carotid artery were analyzed and correlated with the MRI findings.
  
  
  RESULTS
  A total of 42 atheromas (31.1%) had a fresh or recent intraplaque hemorrhage on the surgicopathological findings. A total of 38 (90.5%) of these patients showed high signal intensity halo around the carotid artery on the MIP images of TOF MR angiography. The high signal intensity halo sign, compared with the surgical and histopathological findings, demonstrated a sensitivity, specificity, positive predictive value, and negative predictive value of 91%, 83%, 72%, and 95%, respectively, with a 95% confidence interval (CI) in the detection of an intraplaque hemorrhage. The multisequence approach suggested the presence of an intraplaque hemorrhage with a sensitivity, specificity, positive predictive value, and negative predictive value of 93%, 85%, 74%, and 96%, respectively, with a 95% CI.
  
  
  CONCLUSIONS
  High signal intensity halo around the carotid artery on the MIP images of TOF MR angiography is useful in the noninvasive detection of a fresh or recent carotid intraplaque hemorrhage.
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Yoo Jeong
authors.initials: YJ
authors.lastname: Yim
authors.forename: Yeon Hyeon
authors.initials: YH
authors.lastname: Choe
authors.forename: Yonghyeh
authors.initials: Y
authors.lastname: Ko
authors.forename: Sung Tae
authors.initials: ST
authors.lastname: Kim
authors.forename: Keon Ha
authors.initials: KH
authors.lastname: Kim
authors.forename: Pyoung
authors.initials: P
authors.lastname: Jeon
authors.forename: Hong Sik
authors.initials: HS
authors.lastname: Byun
authors.forename: Dong-Ik
authors.initials: DI
authors.lastname: Kim
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D050197:Atherosclerosis / Q000175:diagnosis; D002339:Carotid Arteries / Q000473:pathology* / Q000601:surgery / Q000648:ultrastructure; D002340:Carotid Artery Diseases / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D016893:Carotid Stenosis / Q000150:complications* / Q000601:surgery; D003287:Contrast Media / Q000008:administration & dosage; D016894:Endarterectomy, Carotid; D005260:Female; D019786:Gadolinium DTPA; D006470:Hemorrhage / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA