title: The hyperdense anterior cerebral artery sign (HACAS) as a computed tomography marker for acute ischemia in the anterior cerebral artery territory.
abstract: BACKGROUND
  Hyperdense arteries in cranial CT of acute stroke patients have been described as a sign for acute ischemia in various brain-feeding arteries. However, only 1 case of a hyperdense anterior cerebral artery sign (HACAS) has been published to date. In this study, the frequency and association of HACAS with clinical symptoms and outcome are described.
  
  
  METHODS
  Our radiological databases were searched for patients with infarcts in the territory of the anterior cerebral artery (ACA). Only patients who received an initial CT and a follow-up CT or MRI were included. The presence of a HACAS was rated by 2 independent observers using the Cohen kappa-statistics. Further data recorded were early ischemic signs, final size of infarct, symptoms, initial NIHSS (National Institute of Health Stroke Scale) score, latency between symptom onset and initial CT, etiology, modified Rankin Scale (mRS) score at discharge and secondary hemorrhage.
  
  
  RESULTS
  A HACAS could be visualized in 11/24 patients (46%). Interobserver agreement was substantial with Cohen's kappa = 0.66. Patients with a HACAS had a significantly higher NIHSS score (9.45 +/- 8.41; median: 8) than those without (3.69 +/- 2.09; median: 4). A HACAS was visible more frequently when the CT was performed early (<2.5 h after symptom onset). There was no correlation with single symptoms, size of infarct, etiology, mRS or the tendency to hemorrhage.
  
  
  CONCLUSIONS
  HACAS is associated with a higher NIHSS score. It is an early sign of ischemia which can be reversible over time. It can be helpful in the detection of ischemia in the territory of the ACA.
authors.affiliation: Institute of Neuroradiology, University of Schleswig-Holstein, Campus Kiel, Kiel, Germany. u.jensen@neurorad.uni-kiel.de
authors.forename: Ulf R
authors.initials: UR
authors.lastname: Jensen
authors.forename: Michael
authors.initials: M
authors.lastname: Weiss
authors.forename: Philip
authors.initials: P
authors.lastname: Zimmermann
authors.forename: Olav
authors.initials: O
authors.lastname: Jansen
authors.forename: Christian
authors.initials: C
authors.lastname: Riedel
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D020771:Anterior Cerebral Artery / Q000000981:diagnostic imaging*; D002545:Brain Ischemia / Q000150:complications / Q000000981:diagnostic imaging*; D002533:Cerebral Angiography / Q000379:methods*; D019992:Databases as Topic; D038524:Diffusion Magnetic Resonance Imaging; D018450:Disease Progression; D005260:Female; D006801:Humans; D020243:Infarction, Anterior Cerebral Artery / Q000150:complications / Q000000981:diagnostic imaging*; D020300:Intracranial Hemorrhages / Q000000981:diagnostic imaging / Q000209:etiology; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013997:Time Factors; D014057:Tomography, X-Ray Computed