title: Quantitative diffusion weighted imaging for differentiation of benign and malignant breast lesions: the influence of the choice of b-values.
abstract: OBJECTIVE
  To evaluate the influence of the choice of different combinations of b-values on the ADC and on the diagnostic performance of quantitative diffusion weighted imaging (DWI) in breast lesions.
  
  
  METHODS
  Seventy-three patients (90 lesions) underwent 3 Tesla (T) breast MRI including a DWI-scan using b-values 0, 150, 499, and 1500 s/mm(2) and histological analysis. Five combinations of b-values were used to calculate the ADC, each with different sensitivities to perfusion and diffusion effects. The median ADC of benign lesions, noninvasive carcinomas and invasive carcinomas and the diagnostic performance of the five methods were compared.
  
  
  RESULTS
  Eighty-eight lesions were analyzed (37 benign, 13 noninvasive carcinomas, 38 invasive carcinomas). The median ADC was highest in benign lesions, intermediate in noninvasive carcinomas and lowest in invasive carcinomas for all methods. Calculating the ADC with the lowest 2 b-values yielded the highest ADC for all lesions types; the highest 2 b-values yielded the lowest ADC. The area under the receiver operating characteristic curve was approximately equal for all methods.
  
  
  CONCLUSIONS
  The ADC of breast lesions varied substantially with the choice of different b-values, indicating that absolute ADC threshold values to differentiate benign and malignant lesions should be interpreted with caution. However, the diagnostic performance of quantitative DWI was not affected by the choice of different b-values.
authors.affiliation: Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, E01.132 3584 CX Utrecht, the Netherlands. n.peters@umcutrecht.nl
authors.forename: Nicky H G M
authors.initials: NH
authors.lastname: Peters
authors.forename: Koen L
authors.initials: KL
authors.lastname: Vincken
authors.forename: Maurice A A J
authors.initials: MA
authors.lastname: van den Bosch
authors.forename: Peter R
authors.initials: PR
authors.lastname: Luijten
authors.forename: Willem P Th M
authors.initials: WP
authors.lastname: Mali
authors.forename: Lambertus W
authors.initials: LW
authors.lastname: Bartels
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000145:classification* / Q000473:pathology*; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult