title: Investigation of the optimal b-value to detect breast tumors with diffusion weighted imaging by 1.5-T MRI.
abstract: BACKGROUND
  Previous studies have reported that the signal attenuation of diffusion-weighted magnetic resonance imaging (DWI) for normal breast tissue and tumor were well fitted by a monoexponential and a biexponential function, respectively. The aim of this study was to investigate the optimal b-value to detect breast tumors from DWI signal attenuations.
  
  
  METHODS
  Sixty-four subjects with breast cancer underwent DWI using six b-values up to 3500 s/mm2. The signal attenuations of normal breast and tumor were fitted by mono- and biexponential functions, respectively. The maximum contrast b-values were estimated and compared in terms of frequency.
  
  
  RESULTS
  In almost all cases, the contrast increased with a b-value from 0 to approximately 1500 s/mm2. For b > 1500 s/mm2, the contrast decreased. The highest contrast b-value in the range of 0 to 2500 s/mm2 most frequently was b = 1500 and the next most frequent was 1400 s/mm2. Comparing sensitivity and specificity between b = 700 and b = 1400 s/mm2, b =1400 s/mm2 was slightly superior.
  
  
  CONCLUSIONS
  Based on these results, DWI with a b-value of approximately 1400-1500 s/mm2 is recommended for optimizing breast tumor detectability.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Tamura
authors.forename: Shigeru
authors.initials: S
authors.lastname: Murakami
authors.forename: Kumiko
authors.initials: K
authors.lastname: Naito
authors.forename: Tamaki
authors.initials: T
authors.lastname: Yamada
authors.forename: Takashi
authors.initials: T
authors.lastname: Fujimoto
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kikkawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000175:diagnosis*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008875:Middle Aged