title: Evaluation of hepatic fibrosis with portal pressure gradient in rats.
abstract: MRI has the potential of providing a noninvasive assessment of liver pathology. This work introduces a portal pressure gradient (PPG) model derived from fluid mechanics, where the PPG is proportional to the average velocity and inversely proportional to the vessel area in the upper part of portal vein. Using a phase-contrast spoiled gradient echo sequence, the PPG model was verified in a phantom study and was tested in an animal study using 35 rats with various degrees of hepatic fibrosis induced by carbon tetrachloride (CCl(4)). Histological examination was conducted to determine the severity of hepatic fibrosis. The fibrosis score monotonically increased with the duration of CCl(4) treatment. The PPG was highly correlated with nonzero fibrosis scores (r(2) = 0.90, P < 0.05). There was a significant difference between control and cirrhosis groups (P < 0.0006, alpha < 0.0018). The difference between control and fibrosis (noncirrhosis) groups (P < 0.002, alpha < 0.006) was also significant. Without the administration of any contrast agent, the MRI-PPG approach shows promise as a noninvasive means of evaluating liver fibrosis.
authors.affiliation: Biomedical Engineering, Yale University, New Haven, CT 06520-8043, USA. yuenan.wang@yale.edu
authors.forename: Yuenan
authors.initials: Y
authors.lastname: Wang
authors.forename: Carmen J
authors.initials: CJ
authors.lastname: Booth
authors.forename: Hyeonjin
authors.initials: H
authors.lastname: Kim
authors.forename: Maolin
authors.initials: M
authors.lastname: Qiu
authors.forename: R Todd
authors.initials: RT
authors.lastname: Constable
mesh_terms: D000465:Algorithms; D000818:Animals; D001795:Blood Pressure Determination / Q000379:methods*; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008103:Liver Cirrhosis / Q000175:diagnosis* / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D011169:Portal Vein / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity