title: Microembolic signal monitoring and the prediction of thromboembolic events following coil embolization of unruptured intracranial aneurysms: diffusion-weighted imaging correlation.
abstract: BACKGROUND
  Microembolic signal (MES) monitoring with transcranial Doppler ultrasonography (TCD) may allow for early prediction of thromboembolisms following endovascular coiling of unruptured intracranial aneurysms (UIAs). However, the method has not gained widespread use and may benefit from correlation with diffusion-weighted imaging (DWI) of acute ischemic lesions after coiling. This purposed to evaluate the relationship between MESs and DWI-positive lesions more precisely.
  
  
  METHODS
  We conducted a prospective study on 45 consecutive patients. TCD was performed over the artery that is dependent on the site of aneurysm, but seven patients (15.6%) could not be examined due to the lack of an adequate cranial window. Consequently, 38 patients were available to detect MESs immediately (MES-1) and 24 h (MES-2) after coiling for UIAs. We also checked DWI 1 day after the coiling and analyzed correlations between the TCD and DWI findings.
  
  
  RESULTS
  MES-1 and MES-2 were positive in 25 (65.7%) and 14 (36.8%) patients, respectively. DWI-positive lesions were seen in 20 (52.6%) patients, and only 1 (2.6%) patient was symptomatic. MES-1 and MES-2 were strongly correlated with the number of DWI-positive lesions (Spearman's correlation coefficient = 0.79 and 0.70, P < 0.01 and P < 0.01, respectively). Additionally, there was a significant correlation between MES-1 and MES-2 (Spearman's correlation coefficient = 0.70).
  
  
  CONCLUSIONS
  Based upon the significant correlation between MES and DWI findings, MES may have a role for early detection of ischemic complications after coiling of UIAs. In addition, future study for further validation with clinical application seems requiring.
authors.affiliation: Department of Neurosurgery, Kyungpook National University Hospital, 130, Dongduk-ro, Jung-gu, Daegu, 700-721, Republic of Korea.
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Cho
authors.forename: Dong-Hun
authors.initials: DH
authors.lastname: Kang
authors.forename: Yong-Won
authors.initials: YW
authors.lastname: Kim
authors.forename: Jaechan
authors.initials: J
authors.lastname: Park
authors.forename: Yong-Sun
authors.initials: YS
authors.lastname: Kim
mesh_terms: D017542:Aneurysm, Ruptured / Q000150:complications; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications / Q000175:diagnosis / Q000628:therapy*; D020766:Intracranial Embolism / Q000175:diagnosis* / Q000209:etiology*; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D061185:Mechanical Thrombolysis / Q000009:adverse effects*; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D016896:Treatment Outcome; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*