title: Diffusion-Weighted Breast Magnetic Resonance Imaging: A Semiautomated Voxel Selection Technique Improves Interreader Reproducibility of Apparent Diffusion Coefficient Measurements.
abstract: OBJECTIVE
  To determine whether a semiautomated voxel selection technique improves interreader reproducibility for breast apparent diffusion coefficient (ADC) measurements.
  
  
  METHODS
  Three readers retrospectively performed ADC measurements of 31 breast lesions (16 malignant, 15 benign) and contralateral normal tissue in 26 women both unassisted (manual method) and assisted by a semiautomated software tool that excludes voxels below a dynamically specified signal intensity threshold. Reproducibility between readers for each technique was assessed by Bland-Altman analysis and concordance correlation coefficients (CCCs).
  
  
  RESULTS
  Differences between readers' measured ADCs of lesions were smaller with the semiautomated tool vs the manual method. Concordance correlation coefficients for each reader pair were greater with the semiautomated tool for lesions (mean CCC difference, 0.11; 95% confidence interval, 0.04-0.26). For normal tissue, reader agreement was lower than for lesions and did not differ based on software tools (mean CCC difference, 0.00; 95% confidence interval, -0.14 to 0.13).
  
  
  CONCLUSIONS
  A semiautomated voxel selection tool can improve interreader reproducibility of breast lesion ADC measures.
authors.affiliation: From the *Breast Imaging Section, Department of Radiology, Seattle Cancer Care Alliance, University of Washington, Seattle, WA; †Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA.
authors.forename: Habib
authors.initials: H
authors.lastname: Rahbar
authors.forename: Brenda F
authors.initials: BF
authors.lastname: Kurland
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Olson
authors.forename: Averi E
authors.initials: AE
authors.lastname: Kitsch
authors.forename: John R
authors.initials: JR
authors.lastname: Scheel
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Chai
authors.forename: Joshua
authors.initials: J
authors.lastname: Usoro
authors.forename: Constance D
authors.initials: CD
authors.lastname: Lehman
authors.forename: Savannah C
authors.initials: SC
authors.lastname: Partridge
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000592:standards*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D000069550:Machine Learning; D008875:Middle Aged; D015588:Observer Variation; D010363:Pattern Recognition, Automated; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D047368:Tumor Burden