title: Simultaneous acquisition of high-contrast and quantitative liver T1images using 3D phase-sensitive inversion recovery: a feasibility study.
abstract: Background Tumor-to-liver contrast is low in images of chronically diseased livers because gadolinium-based hepatocyte-specific contrast agents (Gd-EOB-DTPA) accumulate less to hepatocytes. Purpose To determine whether phase-sensitive inversion recovery (PSIR) could improve the T1contrasts of Gd-based contrast agents and liver parenchyma and simultaneously provide accurate T1values for abdominal organs. Material and Methods The image contrasts of phantoms with different Gd concentrations that were obtained using PSIR were compared to conventional turbo field echo (TFE) results. T1value was estimated using PSIR by performing iterations to investigate the two IR magnetization evolutions. The estimated T1values were validated using IR-spin echo (IR-SE) and Look-Locker (L-L) sequences. In an in vivo study, the liver-to-spleen and liver-to-muscle contrasts of the PSIR and TFE images of seven volunteers were compared, as were the T1values of liver parenchyma, spleen, and muscle obtained using PSIR and L-L sequences. Results The PSIR images showed T1contrasts higher than those in the TFE results. The PSIR and IR-SE T1values were linearly correlated. Additionally, the R1estimated using PSIR were correlated with those measured using IR-SE and L-L. In the in vivo study, the liver-to-spleen and liver-to-muscle contrasts of PSIR were significantly higher than those obtained using TFE. T1values of abdominal organs obtained using PSIR and L-L were clearly correlated. Conclusion PSIR may be capable of improving liver image T1contrasts when Gd-based contrast agents are employed and simultaneously yielding accurate T1values of abdominal organs.
authors.affiliation: 1 Department of Medical Imaging, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Fujiwara
authors.affiliation: 2 Radiological Center, National Hospital Organization Kumamoto Medical Center, Kumamoto, Japan.
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Maruyama
authors.affiliation: 3 Department of Radiology, Faculty of Medical Sciences, University of Fukui, Fukui, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kosaka
authors.affiliation: 4 Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, Ibaraki, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Ishimori
mesh_terms: D003287:Contrast Media / Q000008:administration & dosage*; D005240:Feasibility Studies; D019786:Gadolinium DTPA / Q000008:administration & dosage*; D064368:Healthy Volunteers; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008099:Liver / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging; D019047:Phantoms, Imaging; D013154:Spleen / Q000000981:diagnostic imaging
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA
keywords: Magnetic resonance imaging (MRI); T1 mapping; liver imaging; phase-sensitive inversion recovery (PSIR); quantitative MRI