title: Early diffusion-weighted imaging and perfusion-weighted imaging lesion volumes forecast final infarct size in DEFUSE 2.
abstract: OBJECTIVE
  It is hypothesized that early diffusion-weighted imaging (DWI) lesions accurately estimate the size of the irreversibly injured core and thresholded perfusion-weighted imaging (PWI) lesions (time to maximum of tissue residue function [Tmax] >6 seconds) approximate the volume of critically hypoperfused tissue. With incomplete reperfusion, the union of baseline DWI and posttreatment PWI is hypothesized to predict infarct volume.
  
  
  METHODS
  This is a substudy of Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution Study 2 (DEFUSE 2); all patients with technically adequate MRI scans at 3 time points were included. Baseline DWI and early follow-up PWI lesion volumes were determined by the RAPID software program. Final infarct volumes were assessed with 5-day fluid-attenuated inversion recovery and were corrected for edema. Reperfusion was defined on the basis of the reduction in PWI lesion volume between baseline and early follow-up MRI. DWI and PWI volumes were correlated with final infarct volumes.
  
  
  RESULTS
  Seventy-three patients were eligible. Twenty-six patients with >90% reperfusion show a high correlation between early DWI volume and final infarct volume (r=0.95; P<0.001). Nine patients with <10% reperfusion have a high correlation between baseline PWI (Tmax >6 seconds) volume and final infarct volume (r=0.86; P=0.002). Using all 73 patients, the union of baseline DWI and early follow-up PWI is highly correlated with final infarct volume (r=0.94; P<0.001). The median absolute difference between observed and predicted final volumes is 15 mL (interquartile range, 5.5-30.2).
  
  
  CONCLUSIONS
  Baseline DWI and early follow-up PWI (Tmax >6 seconds) volumes provide a reasonable approximation of final infarct volume after endovascular therapy.
authors: Stanford Stroke Center, Stanford University School of Medicine, Stanford, CA 94305, USA. hayleyw@stanford.edu
authors: Hayley M
authors: HM
authors: Wheeler
authors: Michael
authors: M
authors: Mlynash
authors: Manabu
authors: M
authors: Inoue
authors: Aaryani
authors: A
authors: Tipirneni
authors: John
authors: J
authors: Liggins
authors: Greg
authors: G
authors: Zaharchuk
authors: Matus
authors: M
authors: Straka
authors: Stephanie
authors: S
authors: Kemp
authors: Roland
authors: R
authors: Bammer
authors: Maarten G
authors: MG
authors: Lansberg
authors: Gregory W
authors: GW
authors: Albers
mesh_terms: D000368:Aged; D020520:Brain Infarction / Q000175:diagnosis / Q000473:pathology*; D015331:Cohort Studies; D038524:Diffusion Magnetic Resonance Imaging; D057510:Endovascular Procedures; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016014:Linear Models; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D020521:Stroke / Q000175:diagnosis / Q000473:pathology*
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