title: Stroke mismatch volume with the use of ABC/2 is equivalent to planimetric stroke mismatch volume.
abstract: OBJECTIVE
  In the clinical setting, there is a need to perform mismatch measurements quickly and easily on the MR imaging scanner to determine the specific amount of treatable penumbra. The objective of this study was to quantify the agreement of the ABC/2 method with the established planimetric method.
  
  
  METHODS
  Patients (n = 193) were selected from the NINDS Natural History Stroke Registry if they 1) were treated with standard intravenous rtPA, 2) had a pretreatment MR imaging with evaluable DWI and PWI, and 3) had an acute ischemic stroke lesion. A rater placed the linear diameters to measure the largest DWI and MTT lesion areas in 3 perpendicular axes-A, B, and C-and then used the ABC/2 formula to calculate lesion volumes. A separate rater measured the planimetric volumes. Multiple mismatch thresholds were used, including MTT volume - DWI volume ≥50 mL versus ≥60 mL and (MTT volume - DWI volume)/MTT volume ≥20% versus MTT/DWI = 1.8.
  
  
  RESULTS
  Compared with the planimetric method, the ABC/2 method had high sensitivity (0.91), specificity (0.90), accuracy (0.91), PPV (0.90), and NPV (0.91) to quantify mismatch by use of the ≥50 mL definition. The Spearman correlation coefficients were 0.846 and 0.876, respectively, for the DWI and MTT measurements. The inter-rater Bland-Altman plots demonstrated 95%, 95%, and 97% agreement for the DWI, MTT, and mismatch measurements.
  
  
  CONCLUSIONS
  The ABC/2 method is highly reliable and accurate for quantifying the specific amount of MR imaging-determined mismatch and therefore is a potential tool to quickly calculate a treatable mismatch pattern.
authors: National Institute of Neurological Disorders and Stroke; Bethesda, Maryland.
authors: M
authors: M
authors: Luby
authors: J
authors: J
authors: Hong
authors: J G
authors: JG
authors: Merino
authors: J K
authors: JK
authors: Lynch
authors: A W
authors: AW
authors: Hsia
authors: A
authors: A
authors: Magadán
authors: S S
authors: SS
authors: Song
authors: L L
authors: LL
authors: Latour
authors: S
authors: S
authors: Warach
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards* / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D020127:Recovery of Function; D012042:Registries; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020521:Stroke / Q000188:drug therapy / Q000473:pathology*; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator