title: 3D-liver perfusion MRI with the MS-325 blood pool agent: a noninvasive protocol to asses liver fibrosis.
abstract: OBJECTIVE
  To evaluate a 1.5T magnetic resonance imaging (MRI) protocol, including a dedicated acquisition sequence and a postprocessing tool for the quantitative analysis of hepatic tissue perfusion. Estimated perfusion parameters and histological results based on the METAVIR classification were prospectively compared for hepatic fibrosis assessment.
  
  
  METHODS
  The study protocol was approved by the experimentation Ethics Committee and informed consent was obtained. Sixteen patients (6 women, 10 men; average age, 52.4 ± 14.8 years) with chronic liver diseases were prospectively enrolled after a liver biopsy. MS-325 (paramagnetic blood pool agent)-enhanced MRI was performed using a free-breath 3D-VIBE T(1w) sequence. Image volumes were registered by an automatic rigid method. Liver perfusion was modeled by a dual-input-one-compartment model and quantitative perfusion parameters such as arterial, portal, and total perfusion mean transit time (MTT) and hepatic perfusion index (HPI) were obtained using in-house developed software.
  
  
  RESULTS
  Arterial perfusion increased with METAVIR stage, whereas portal perfusion decreased leading to an HPI increase with fibrosis stage. MTT increased with F3, F4. A nonparametric Mann-Whitney test demonstrated that HPI and portal perfusion were relevant in discriminating between advanced and nonadvanced fibrosis, between fibrosis and cirrhosis, then between nonfibrosis and fibrosis (P < 0.01). A strong correlation was found between portal perfusion fall-off and HPI increase (r = -0.97; P < 0.001). HPI and portal perfusion were strongly correlated with fibrosis stage (r = 0.83 and -0.88; P < 0.001, respectively).
  
  
  CONCLUSIONS
  HPI and portal perfusion could be relevant indicators for the clinical follow-up in patients with chronic liver diseases.
authors.affiliation: Université de Lyon, CREATIS, CNRS UMR 5220, Inserm U1044, INSA-Lyon, Université Lyon 1, Villeurbanne, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Leporq
authors.forename: Jérôme
authors.initials: J
authors.lastname: Dumortier
authors.forename: Frank
authors.initials: F
authors.lastname: Pilleul
authors.forename: Olivier
authors.initials: O
authors.lastname: Beuf
mesh_terms: D003287:Contrast Media; D005260:Female; D005682:Gadolinium; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008102:Liver Circulation; D008103:Liver Cirrhosis / Q000175:diagnosis* / Q000503:physiopathology*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D005682:Gadolinium; C109932:gadofosveset trisodium