title: Comparison of T2, T1rho, and diffusion metrics in assessment of liver fibrosis in rats.
abstract: To evaluate the value of T2, T1rho, and diffusion metrics in assessment of liver fibrosis in rats.
  
  
  
  Liver fibrosis in a rat model (n = 72) was induced by injection of carbon tetrachloride (CCl4) at 3T. T2, T1rho, and diffusion parameters (apparent diffusion coefficient (ADC), Dtrue) via spin echo (SE) diffusion-weighted imaging (DWI) and stimulated echo acquisition mode (STEAM) DWI with three diffusion times (DT: 80, 106, 186 msec) were obtained in surviving rats with hepatic fibrosis (n = 52) and controls (n = 8). Liver fibrosis stage (F0-F6) was identified based on pathological results using the traditional liver fibrosis staging method for rodents. Nonparametric statistical methods and receiver operating characteristic (ROC) curve analysis were employed to determine the diagnostic accuracy.
  
  
  
  Mean T2, T1rho, ADC, and Dtruewith DT = 186 msec correlated with the severity of fibrosis with r = 0.73, 0.83, -0.83, and -0.85 (all P < 0.001), respectively. The average areas under the ROC curve at different stages for T1rho and diffusion parameters (DT = 186 msec) were larger than those of T2and SE DWI (0.92, 0.92, and 0.92 vs. 0.86, 0.82, and 0.83). The corresponding average sensitivity and specificity for T1rho and diffusion parameters with a long DT were larger (89.35 and 88.90, 88.36 and 89.97, 90.16 and 87.13) than T2and SE DWI (90.28 and 79.93, 85.30 and 77.64, 78.21 and 82.41). The performances of T1rho and Dtrue(DT = 186 msec) were comparable (average AUC: 0.92 and 0.92).
  
  
  
  Among the evaluated sequences, T1rho and STEAM DWI with a long DT may serve as superior imaging biomarkers for assessing liver fibrosis and monitoring disease severity.
  
  
  
  1 J. Magn. Reson. Imaging 2017;45:741-750.
authors.affiliation: Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, Beijing, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China.
authors.forename: Qihua
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China.
authors.forename: Taihui
authors.initials: T
authors.lastname: Yu
authors.affiliation: Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, Beijing, China.|Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China.|Department of Radiology, Affiliated hospital of Guangdong Medical College, Guangdong, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China.
authors.forename: Jingwen
authors.initials: J
authors.lastname: Huang
authors.affiliation: Department of Pathology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China.
authors.forename: Cui
authors.initials: C
authors.lastname: Tan
authors.affiliation: Department of Radiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China.
authors.forename: Biling
authors.initials: B
authors.lastname: Liang
authors.affiliation: Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, Beijing, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Guo
mesh_terms: D000465:Algorithms; D000818:Animals; D004058:Diffusion; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008103:Liver Cirrhosis / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology*; D060526:Magnetic Fields; D008297:Male; D011829:Radiation Dosage; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: STEAM DWI; T1rho mapping; T2 mapping; diffusion time; fibrosis staging; liver fibrosis