title: False-negative diffusion-weighted imaging in acute stroke and its frequency in anterior and posterior circulation ischemia.
abstract: OBJECTIVE
  We aimed to investigate the location and size of ischemic stroke lesions that were frequently overlooked by diffusion-weighted imaging (DWI).
  
  
  METHODS
  We retrospectively reviewed the medical records of 162 patients who had symptoms suggesting ischemic stroke. National Institutes of Health Stroke Scale and Modified Rankin Scale scores, lesion size, magnetic resonance imaging (MRI) findings, delay between onset of symptoms and initial MRI (MRI latency), and vascular distribution of the stroke lesions were analyzed in patients with false-negative DWI findings.
  
  
  RESULTS
  Of the 116 patients with a final diagnosis of acute ischemic stroke, 11 patients (9.48%) had false-negative DWI findings in the initial period. The mean (SD) MRI latency was 4.3 (1.2) hours. There was no statistically significant difference in point of lesion size, the National Institutes of Health Stroke Scale, and the Modified Rankin Scales scores.
  
  
  CONCLUSIONS
  False-negative DWI findings in acute stroke can be observed both in association with the posterior circulation/small lesions and the anterior circulation/large lesions.
authors.affiliation: From the Departments of *Radiology, †Physical Medicine and Rehabilitation, and ‡Neurology, Medical Faculty of Adiyaman University, Adiyaman, Turkey; §Department of Neurology, Adiyaman Education and Research Hospital, Adiyaman, Turkey; and ∥Department of Radiology, Samsun Education and Research Hospital, Samsun, Turkey.
authors.forename: Haci Taner
authors.initials: HT
authors.lastname: Bulut
authors.forename: Adem
authors.initials: A
authors.lastname: Yildirim
authors.forename: Burcu
authors.initials: B
authors.lastname: Ekmekci
authors.forename: Neslihan
authors.initials: N
authors.lastname: Eskut
authors.forename: Hediye Pinar
authors.initials: HP
authors.lastname: Gunbey
mesh_terms: D000328:Adult; D000368:Aged; D015984:Causality; D015897:Comorbidity; D038524:Diffusion Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D020762:Infarction, Posterior Cerebral Artery / Q000453:epidemiology* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020521:Stroke / Q000453:epidemiology* / Q000473:pathology*; D014421:Turkey / Q000453:epidemiology; D055815:Young Adult