title: [Influence of b value on the measurement of contrast and apparent diffusion coefficient in 3.0 Tesla breast magnetic resonance imaging].
abstract: Diffusion-weighted imaging (DWI) has been used to characterize not only the brain, but also the breast by implementation of faster imaging techniques and higher magnetic field strengths. However, the optimum b value, which is an important scan parameter for DW images contrast on 3 T breast magnetic resonance imaging (MRI) has not been established. The purpose of this study was to investigate the influence of different b value combinations on the image contrast and apparent diffusion coefficient (ADC) in patients with known invasive carcinoma, ductal carcinoma in situ (DCIS), and normal mammary gland in breast DWI. The analysis procedure consisted of the following methods: 1) T(2) correction of DW images with echo-planar imaging (EPI) T(2)-weighted images; 2) contrast measurement between normal mammary gland and tumor tissues; 3) ADC measurement of normal mammary gland and tumor tissues. In many cases, the highest contrast between normal mammary gland and tumor tissues was obtained using a b value of 1500 s/mm(2). Our results indicated that when only one b value is used, the b value in which signal intensities of normal mammary gland decreases down to noise level, and the contrast between normal mammary gland and tumor tissues is recommended. ADC value decreased with increasing b value. Therefore, when determining the ADC threshold level, it is important to perform the evaluation using ADC values calculated from DW images with the same b value in clinical studies.
authors.affiliation: Department of Radiological Technology, Kanazawa University Hospital.
authors.forename: Masako
authors.initials: M
authors.lastname: Takanaga
authors.forename: Norio
authors.initials: N
authors.lastname: Hayashi
authors.forename: Tosiaki
authors.initials: T
authors.lastname: Miyati
authors.forename: Hiroko
authors.initials: H
authors.lastname: Kawashima
authors.forename: Takashi
authors.initials: T
authors.lastname: Hamaguchi
authors.forename: Naoki
authors.initials: N
authors.lastname: Ohno
authors.forename: Shigeru
authors.initials: S
authors.lastname: Sanada
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Osamu
authors.initials: O
authors.lastname: Matsui
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging; D005260:Female; D006801:Humans; D008327:Mammography / Q000379:methods*; D008875:Middle Aged