title: Black blood T1rho MR imaging may diagnose early stage liver fibrosis: a proof-of-principle study with rat biliary duct ligation model.
abstract: To explore black blood T1rho (T1ρ) liver imaging and investigate the earliest stage when biliary duct ligation (BDL) induced liver fibrosis can be diagnosed.
  
  
  
  MR was performed at 3 Tesla. A T1ρ prepared 2D fast spin echo (FSE) sequence with acquisition of four spin lock times (TSLs: 1, 10, 30, and 50 msec) and spin-lock frequency of 500 Hz was applied. Inherent black blood effect of FSE and double inversion recovery (DIR) achieved blood signal suppression, and 3 axial sections per liver were obtained. Male Sprague-Dawley rats were scanned at baseline (n=32), and on day-3 (n=13), day-5 (n=11), day-7 (n=10), day-10 (n=4) respectively after BDL. Hematoxylin-eosin (HE) and picrosirius red staining liver histology was obtained at these time points.
  
  
  
  The physiological liver parenchyma T1ρ was 38.38±1.53 msec (range, 36.05-41.53 msec). Liver T1ρ value elevated progressively after BDL. On day-10 after BDL all experimental animals can be separated from normal liver based on T1ρ measurement with lowest value being 42.82 msec. Day-7 and day-10 liver resembled METAVIR stage-F1/F2 fibrosis, and fibrous area counted for 0.22%±0.13% and 0.38%±0.44% of liver parenchyma area, respectively.
  
  
  
  This study provides the first proof-of-principle that T1ρ might diagnose early stage liver fibrosis.
authors.affiliation: Institute of Chinese Medicine, the Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China;; State Key Laboratory of Phytochemistry and Plant Resources in West China, the Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China.
authors.forename: Chi-Man
authors.initials: CM
authors.lastname: Koon
authors.affiliation: Institute of Chinese Medicine, the Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China;; State Key Laboratory of Phytochemistry and Plant Resources in West China, the Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Imaging and Interventional Radiology, the Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR, China.
authors.forename: Weitian
authors.initials: W
authors.lastname: Chen
authors.affiliation: Institute of Digestive Disease and Department of Medicine and Therapeutics, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR, China.
authors.forename: Eagle Siu Hong
authors.initials: ES
authors.lastname: Chu
authors.affiliation: Institute of Chinese Medicine, the Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China;; State Key Laboratory of Phytochemistry and Plant Resources in West China, the Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China.
authors.forename: Clara Bik
authors.initials: CB
authors.lastname: San Lau
authors.affiliation: Department of Imaging and Interventional Radiology, the Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR, China.
authors.forename: Yì-Xiáng J
authors.initials: YX
authors.lastname: Wáng
keywords: T1rho (T1ρ); bile duct obstruction; black blood; fibrosis; liver