title: Comparisons of multi b-value DWI signal analysis with pathological specimen of breast cancer.
abstract: Previous studies have reported that the signal attenuation of diffusion weighted magnetic resonance imaging for tumor tissues displays a non-monoexponential biexponential decay, and the apparent diffusion coefficients (ADCs) can be divided into a fast and slow diffusion component by using a simple biexponential decay model. The purpose of this study is to examine the non-monoexponential character of the diffusion weighted magnetic resonance imaging signal attenuations of breast cancers, estimate the fast and slow diffusion components, and compare them with the extra- and intracellular component information obtained from the pathological specimens. Twenty-two subjects having breast cancers underwent diffusion weighted magnetic resonance imaging using six b-values up to 3500 s/mm(2) and the signal attenuations were analyzed using the biexponential function. The derived slow component fraction correlated with the cellular fraction and the ADCs converged to 0.2-0.3 × 10(-3) mm(2) /s for the higher cellular fractions. The ADCs of the fast component ranged from 1.3 to 3.9 × 10(-3) mm(2) /s and showed no correlation with the extracellular components. This result suggests that the main reason for the decreasing ADC of a breast tumor is the decreasing fraction of the fast component and the increasing fraction of the slow component having a low ADC rather than the decreasing ADC of the fast component by the restricted water diffusion in the reduced extracellular spaces.
authors.affiliation: Department of Radiology, Hiroshima Atomic Bomb Casualty Council, Health Management & Promotion Center, Hiroshima, Japan. tamutaka@hicat.ne.jp
authors.forename: Takayuki
authors.initials: T
authors.lastname: Tamura
authors.forename: Shuji
authors.initials: S
authors.lastname: Usui
authors.forename: Shigeru
authors.initials: S
authors.lastname: Murakami
authors.forename: Koji
authors.initials: K
authors.lastname: Arihiro
authors.forename: Takashi
authors.initials: T
authors.lastname: Fujimoto
authors.forename: Tamaki
authors.initials: T
authors.lastname: Yamada
authors.forename: Kumiko
authors.initials: K
authors.lastname: Naito
authors.forename: Mitoshi
authors.initials: M
authors.lastname: Akiyama
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001943:Breast Neoplasms / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity