title: Assessment of silent embolism from carotid endarterectomy by use of diffusion-weighted imaging: work in progress.
abstract: OBJECTIVE
  Transcranial Doppler studies have suggested that microemboli are released into the arterial circulation during the majority of carotid endarterectomy (CEA) procedures. This, together with the observation that neuropsychological performance may decline postoperatively, has led to concern that cerebral infarction may occur unrecognized during CEA. Our objective was to examine this risk with diffusion-weighted imaging, a technique that is highly sensitive to acute cerebral infarction.
  
  
  METHODS
  Eighteen participants (median age, 68 years; age range, 56-87 years) were assessed with diffusion-weighted imaging and the National Institutes of Health Stroke Scale before and after CEA. Imaging was performed using single-shot echo-planar imaging with a maximum diffusion sensitivity of b = 1000 s/mm(2) applied to three orthogonal planes. Preoperative imaging was performed a median of 2.5 hours before surgery (range, 0.5-12.5 hours) and 15 hours after surgery (range, 1.5-58.5 hours). Two neuroradiologists independently interpreted the diffusion-weighted images, blinded to operative status and clinical findings.
  
  
  RESULTS
  There was no diffusion-weighted imaging evidence of silent embolism in this series of 18 participants (95% confidence interval limits, 0 to 10%). Clinical complications were confined to one case of confusion occurring after CEA; the diffusion-weighted imaging results were normal in this case.
  
  
  CONCLUSIONS
  There is no evidence from our series that silent cerebral infarction is a common occurrence during CEA. These data provide further support for the safety of CEA.
authors: Divisions of Neuroradiology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona 85013, USA.
authors: K P
authors: KP
authors: Forbes
authors: H A
authors: HA
authors: Shill
authors: P M
authors: PM
authors: Britt
authors: J M
authors: JM
authors: Zabramski
authors: R F
authors: RF
authors: Spetzler
authors: J E
authors: JE
authors: Heiserman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002544:Cerebral Infarction / Q000175:diagnosis*; D004058:Diffusion; D017352:Echo-Planar Imaging; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D007089:Image Enhancement; D020766:Intracranial Embolism / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis*; D011237:Predictive Value of Tests; D017585:Ultrasonography, Doppler, Transcranial