Susceptibility-weighted MR imaging in the grading of liver fibrosis: a feasibility study.
OBJECTIVE
To assess the feasiblity of magnetic resonance (MR) susceptibility-weighted (SW) imaging as a tool to evaluate liver fibrosis grades in patients with chronic liver diseases (CLD) utilizing signal intensity (SI) measurements, with histopathologic findings as the reference standard.


METHODS
This retrospective study was approved by the local ethics committee. All subjects gave written informed consent. Eighty consecutive patients (mean age, 56.8 years), 60% of whom were male [n = 48] and 40% of whom were female [n = 32], with CLD due to various underlying causes and histopathologically proved liver fibrosis were included. Biopsies were evaluated for liver fibrosis and necroinflammatory activity (according to METAVIR scoring system), iron load, and steatosis. Two radiologists, blinded to the clinical data, assessed regions of interest in the liver and spinal muscle in consensus. Liver-to-muscle SI ratios were calculated and correlated to histopathologic findings and clinical data by using univariate and multivariate regression analysis.


RESULTS
Liver-to-muscle SI ratio decreased in parallel with the increasing grade of liver fibrosis and correlated strongly with liver fibrosis (r = -0.81, P < .0001) and moderately with necroinflammatory activity (r = -0.52, P < .0001) and iron load (r = -0.37, P = .0002) but did not correlate with steatosis (r = -0.18, P = .11). In multiple regression analysis, liver fibrosis and iron load independently influenced SW imaging measurements, explaining 69% of the variance of liver-to-muscle SI ratio (R(2) = 0.69, P < .001). Liver-to-muscle SI ratio performed well in grading liver fibrosis, with an area under the receiver operating characteristic curve of 0.92 for scores of F2 or higher and 0.93 for score of F4 (liver cirrhosis).


CONCLUSIONS
SW imaging is a feasible noninvasive tool to detect moderate and advanced liver fibrosis in CLD patients.
From the Departments of Radiology (C.B., D.F., A.B.), Gastroenterology (M.P.), Pathology (F.W.), and Nuclear Medicine (S.W.), Medical University of Vienna, General Hospital of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria; Department of Radiology, Medical University of Cluj Napoca, Cluj Napoca, Romania (D.F.); Siemens Healthcare, Erlangen, Germany (B.K.); Siemens Healthcare, Graz, Austria (G.R.); and Siemens Healthcare, Shanghai, China (Y.D.).
Csilla
C
Balassy
Diana
D
Feier
Markus
M
Peck-Radosavljevic
Friedrich
F
Wrba
Stephan
S
Witoszynskyj
Berthold
B
Kiefer
Gert
G
Reiter
Yongming
Y
Dai
Ahmed
A
Ba-Ssalamah
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008103:Liver Cirrhosis / Q000473:pathology*; D008111:Liver Function Tests; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology; D012189:Retrospective Studies