title: Comparisons of Apparent Diffusion Coefficient Values in Penumbra, Infarct, and Normal Brain Regions in Acute Ischemic Stroke: Confirmatory Data Using Bootstrap Confidence Intervals, Analysis of Variance, and Analysis of Means.
abstract: OBJECTIVE
  There is no consensus about apparent diffusion coefficient (ADC) values in acute stroke regions that could be used by clinicians in a day-to-day clinical practice; regional measures using confidence intervals (CIs) and a graphic representation of means are scarce in the literature. Our aim in this study was to compare ADC values in infarct, penumbra, and normal brain regions in patients with acute ischemic stroke (AIS).
  
  
  METHODS
  This is a retrospective study of 100 magnetic resonance imaging data sets from AIS patients. ADC values were measured in the infarct, penumbra, and normal regions. Three hundred measurements underwent 1-way analysis of variance, analysis of means, and calculation of 95% and 84% CIs.
  
  
  RESULTS
  There was a statistically significant difference at the P level less than .025 in ADC values for the 3 regions (F[2, 297] = 168.039, P ≤ .001), with no overlap of the CIs for the means among the regions: normal brain (mean [M] = .847, standard deviation [SD] = .103, 95% CI: .825-.866), infarct (M = .533, SD = .157, 95% CI: .501-.563), and penumbra (M = .764, SD = .110, 95% CI: .740-.787).
  
  
  CONCLUSIONS
  ADC values might be used as reference data in acute stroke-specific populations; CIs would provide radiologists and clinicians with additional quantitative tools to evaluate penumbra, infarct, and normal brain tissue and to tailor follow-up and treatment options for selected patients.
authors.affiliation: Magnetic Resonance Unit, Medica Sur Clinic and Foundation, Mexico City, Mexico.
authors.forename: Mariana
authors.initials: M
authors.lastname: Lopez-Mejia
authors.affiliation: Magnetic Resonance Unit, Medica Sur Clinic and Foundation, Mexico City, Mexico. Electronic address: ernest.roldan@usa.net.
authors.forename: Ernesto
authors.initials: E
authors.lastname: Roldan-Valadez
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D020520:Brain Infarction / Q000000981:diagnostic imaging* / Q000209:etiology; D002545:Brain Ischemia / Q000150:complications; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000502:physiology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D020521:Stroke / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology*
keywords: Acute stroke; brain ischemia; cerebral infarction; diffusion magnetic resonance imaging; perfusion imaging