title: B1Field Correction of T1 Estimation Should Be Considered for Breast Dynamic Contrast-enhanced MR Imaging Even at 1.5 T.
abstract: Purpose To prospectively quantify the effect of T1 estimation in fat by B1correction in breast magnetic resonance (MR) imaging at 1.5 T and to examine the subsequent quantitative dynamic contrast material-enhanced parameters in breast cancer with and without B1correction. Materials and Methods This study had institutional review board approval, and informed consent was obtained from 72 patients with breast cancer before breast MR imaging studies were performed between January and July 2015. B1+field and variable flip angle (FA) mapping were included in the dynamic contrast-enhanced breast MR imaging protocol with a 1.5-T MR imaging system. Precontrast T1 relaxation in fat and breast tumors was computed with and without B1correction. The pharmacokinetic parameters of breast cancer were calculated by using the Tofts model with T1 values before and after B1correction. The Mann-Whitney U test and linear regression model were used for statistical analysis. Results The FA was 19% higher in the left breast and 3% lower in the right breast than the prescribed value. This 22% average FA difference created a 43% T1 estimation bias in fat between the breasts. The T1 variation in fat was reduced to 0.96% after B1correction. There was a 50% overestimation and a 7% underestimation of tumor T1 in the left breast and the right, respectively, associated with B1error. Assuming T1 after B1correction represents the true tumor T1, 41% underestimation in the left breast and 10% overestimation in the right without B1correction were seen in the dynamic contrast-enhanced parameters (including the volume transfer constant, or Ktrans, fraction of extracellular extravascular space, or ve, and blood normalized initial area under the gadolinium concentration curve to 90 seconds, or IAUGCBN90). Conclusion B1correction for more accurate T1 values should be considered for quantitative dynamic contrast-enhanced breast MR imaging, even at 1.5 T, to offset significant systemic error.©RSNA, 2016.
authors.affiliation: From the Departments of Radiology (W.C.T.), Research (K.J.K., K.M.C.), Clinical Research (C.F.H.), and Surgery (C.M.C.), Koo Foundation Sun Yat-Sen Cancer Center, 125 Lider Rd, Pei-Tou District, Taipei 112, Taiwan; School of Medicine, National Yang-Ming University, Taipei, Taiwan (W.C.T.); Apollo Medical Imaging Technology, Melbourne, Australia (Q.Y.); and Department of Research, GE Healthcare, Taipei, Taiwan (C.Y.E.L.).
authors.forename: Wan-Chen
authors.initials: WC
authors.lastname: Tsai
authors.affiliation: From the Departments of Radiology (W.C.T.), Research (K.J.K., K.M.C.), Clinical Research (C.F.H.), and Surgery (C.M.C.), Koo Foundation Sun Yat-Sen Cancer Center, 125 Lider Rd, Pei-Tou District, Taipei 112, Taiwan; School of Medicine, National Yang-Ming University, Taipei, Taiwan (W.C.T.); Apollo Medical Imaging Technology, Melbourne, Australia (Q.Y.); and Department of Research, GE Healthcare, Taipei, Taiwan (C.Y.E.L.).
authors.forename: Kuo-Jang
authors.initials: KJ
authors.lastname: Kao
authors.affiliation: From the Departments of Radiology (W.C.T.), Research (K.J.K., K.M.C.), Clinical Research (C.F.H.), and Surgery (C.M.C.), Koo Foundation Sun Yat-Sen Cancer Center, 125 Lider Rd, Pei-Tou District, Taipei 112, Taiwan; School of Medicine, National Yang-Ming University, Taipei, Taiwan (W.C.T.); Apollo Medical Imaging Technology, Melbourne, Australia (Q.Y.); and Department of Research, GE Healthcare, Taipei, Taiwan (C.Y.E.L.).
authors.forename: Kai-Ming
authors.initials: KM
authors.lastname: Chang
authors.affiliation: From the Departments of Radiology (W.C.T.), Research (K.J.K., K.M.C.), Clinical Research (C.F.H.), and Surgery (C.M.C.), Koo Foundation Sun Yat-Sen Cancer Center, 125 Lider Rd, Pei-Tou District, Taipei 112, Taiwan; School of Medicine, National Yang-Ming University, Taipei, Taiwan (W.C.T.); Apollo Medical Imaging Technology, Melbourne, Australia (Q.Y.); and Department of Research, GE Healthcare, Taipei, Taiwan (C.Y.E.L.).
authors.forename: Chen-Fang
authors.initials: CF
authors.lastname: Hung
authors.affiliation: From the Departments of Radiology (W.C.T.), Research (K.J.K., K.M.C.), Clinical Research (C.F.H.), and Surgery (C.M.C.), Koo Foundation Sun Yat-Sen Cancer Center, 125 Lider Rd, Pei-Tou District, Taipei 112, Taiwan; School of Medicine, National Yang-Ming University, Taipei, Taiwan (W.C.T.); Apollo Medical Imaging Technology, Melbourne, Australia (Q.Y.); and Department of Research, GE Healthcare, Taipei, Taiwan (C.Y.E.L.).
authors.forename: Qing
authors.initials: Q
authors.lastname: Yang
authors.affiliation: From the Departments of Radiology (W.C.T.), Research (K.J.K., K.M.C.), Clinical Research (C.F.H.), and Surgery (C.M.C.), Koo Foundation Sun Yat-Sen Cancer Center, 125 Lider Rd, Pei-Tou District, Taipei 112, Taiwan; School of Medicine, National Yang-Ming University, Taipei, Taiwan (W.C.T.); Apollo Medical Imaging Technology, Melbourne, Australia (Q.Y.); and Department of Research, GE Healthcare, Taipei, Taiwan (C.Y.E.L.).
authors.forename: Chien-Yuan E
authors.initials: CE
authors.lastname: Lin
authors.affiliation: From the Departments of Radiology (W.C.T.), Research (K.J.K., K.M.C.), Clinical Research (C.F.H.), and Surgery (C.M.C.), Koo Foundation Sun Yat-Sen Cancer Center, 125 Lider Rd, Pei-Tou District, Taipei 112, Taiwan; School of Medicine, National Yang-Ming University, Taipei, Taiwan (W.C.T.); Apollo Medical Imaging Technology, Melbourne, Australia (Q.Y.); and Department of Research, GE Healthcare, Taipei, Taiwan (C.Y.E.L.).
authors.forename: Chii-Ming
authors.initials: CM
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D003287:Contrast Media / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000000981:diagnostic imaging* / Q000473:pathology; D009942:Organometallic Compounds / Q000493:pharmacokinetics; D011446:Prospective Studies; D016217:Ultrasonography, Mammary
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C090600:gadobutrol