Magnetic Resonance Elastography for the Evaluation of Liver Fibrosis in Chronic Hepatitis B and C by Using Both Gradient Recalled Echo and Spin Echo Echo Planar Imaging: A Prospective Study
Objectives:Magnetic resonance elastography (MRE) with three dimensional spin echo echo planar imaging (3D SE EPI) is a newly emerging noninvasive method for assessing liver fibrosis. We hypothesized that 3D SE EPI might have better diagnostic accuracy than conventional two dimensional gradient recalled echo (2D GRE).Methods:We prospectively included 179 consecutive patients with chronic hepatitis B (CHB) or C (CHC) who underwent both MRE and liver biopsy. Liver stiffness was measured by both 3D SE EPI and 2D GRE for staging biopsy proven liver fibrosis (using METAVIR scores) A receiver operating characteristic analysis using the area under the receiver operating characteristic curve (AUC) was used to compare the diagnostic performance in predicting liver fibrosis between these two techniques, and compared them to serum markers of fibrosis.Results:The technical failure rate of 3D SE EPI (2.2% n=4/179) was lower compared with 2D GRE (8.3% n=15/179) The stiffness measured by 3D SE EPI was slightly lower compared with 2D GRE, with the mean difference of 0.57 kPa (Bland and Altman plot, 95% limits of agreement: 0.32 and 1.45 kPa) AUCs for the characterization of =F1, =F2, =F3, and F4 were 0.957 (95% confidence interval (CI) 0.913 0.983) 0.971 (0.932 0.991) 0.991 (0.961 0.999) and 0.979 (0.942 0.995) for 3D SE EPI, which was slightly higher compared with the AUCs for 2D GRE at each fibrosis stage (0.948 (0.901 0.977) 0.959 (0.915 0.981) 0.979 (0.943 0.995) and 0.976 (0.938 0.994) respectively) although none reached statistical significance (P=0.160 0.585) In an "intention to diagnose" analysis, the diagnostic accuracy (the proportion of well classified patients) by EPI (86.7 91.3% n=169) was higher compared with GRE (80.9 82.1% n=158) after applying optimal cutoffs. Both 3D SE EPI and 2D GRE performed better than serum fibrosis markers.Conclusions:With respect to 2D GRE, 3D SE EPI has the advantage of lower failure rate with equivalent high diagnostic performance for staging liver fibrosis in CHB/CHC patients, and thus more helpful for those challenging cases in 2D GRE.
The American Journal of Gastroenterology