MR Elastography for the Assessment of Hepatic Fibrosis in Patients with Chronic Hepatitis B Infection: Does Histologic Necroinflammation Influence the Measurement of Hepatic Stiffness?

Abstract

Purpose:To determine the diagnostic performance of magnetic resonance (MR) elastography for the staging of hepatic fibrosis and to evaluate the influence of necroinflammation on hepatic stiffness in patients with chronic hepatitis B virus (HBV) infection by using histopathologic findings as the reference standard. Materials and Methods:One hundred thirteen consecutive patients with chronic HBV infection were recruited prospectively in this institutional review board-approved study after providing written informed consent between March 2012 and October 2013. The stiffness measurements were obtained by using two-dimensional gradient-echo MR elastography with a 3.0-T MR system. The METAVIR scoring system was used for the assessment of fibrosis ("F" stage) and necroinflammation ("A" grade). The predictive ability of MR elastography was evaluated by using the receiver operating characteristic (ROC) curve and the area under the ROC curve (AUC). Multiple linear regression analyses were conducted to determine the relationship between hepatic stiffness and the variables that showed a significant association in the univariate analysis or those that were of interest for comparison with earlier work (histologic scores, sex, age, aspartate aminotransferase level, and aspartate aminotransferase/alanine aminotransferase ratio). Results:MR elastography showed excellent performance for characterization of F1, F2, F3, and F4 findings, with AUC values of 0.961, 0.986, 1.000, and 0.998, respectively. It showed a moderate capability for evaluation of necroinflammatory activity of A1, A2, and A3 (AUC = 0.806, 0.834, and 0.906, respectively). Multiple linear regression analysis showed that fibrosis, necroinflammation, and sex were independently associated with hepatic stiffness (b = 0.799, 0.277, and 0.070, respectively; P , .05). For pairwise comparisons, log-transformed hepatic stiffness showed no difference between (a) groups F0/A2-3 and F1/A0-1 and (b) groups F1/ A2-3 and F2/A0-1 (P . .99 and P = .486, respectively). Conclusion:MR elastography demonstrated excellent performance for distinguishing the stages of hepatic fibrosis in patients with chronic HBV infection. For hepatic tissue with F2 fibrosis, necroinflammation can account for a substantial fraction of the increase in hepatic stiffness.q RSNA, 2014

Validity and Reliability of Magnetic Resonance Elastography for Staging Hepatic Fibrosis in Patients with Chronic Hepatitis B

“…[32][33][34] However, in the current and previous reports, the capacity to discriminate stages of liver fibrosis was consistently higher for MRE than fibrosis markers. 13,17,35,36 Our cut-off values in subjects were in accord with those reported by Venkatesh and associates 17 but lower than the values reported by Shi's group, 18 even though both studies involved CHB patients. Hepatitis activity may be a confounder of liver stiffness measurement during liver fibrosis staging using MRE.…”

“…16 It is believed that CHB has a tendency to involve more advanced focal necrosis and inflammatory cell infiltration than CHC. Unfortunately, the number of MRE studies is limited for groups with a single etiology, such as CHC, 13 CHB, 17,18 alcoholic hepatitis, 19 nonalcoholic steatohepatitis (NASH), 20,21 and Gaucher disease. 22 Accordingly, it appears that more evidence would have to be collected using subjects with single-etiology liver disease to establish the use of MRE in clinical settings.…”

Fibrosis assessment in patients with chronic hepatitis B virus (HBV) infection

“…It is a non-invasive, reproducible, advanced diagnostic technique for staging hepatic fibrosis (116 (116). While the diagnostic performance of MRE in HBV patients appears similar to that in HCV (117,118) necroinflammation may contribute to increased hepatic stiffness by MRE in HBV patients with ≤F2 fibrosis (119). MRE using threedimensional spin-echo echo planar imaging (3D-SE-EPI) is a novel approach associated with a 2.2% failure rate and high diagnostic accuracy (AUROC values for ≥F1, ≥F2, ≥F3, and F4 of 0.957 to 0.991) in 179 patients with HBV or HCV (120).…”

MR elastography of the liver at 3.0 T in diagnosing liver fibrosis grades; preliminary clinical experience

“…The usefulness of ultrasound-based elastography, including transient or shear-wave elastography, has been described and reported for this purpose [3][4][5]. Shear-wave MR elastography (MRE) has also been reported to be useful in assessing the pathological grades of liver fibrosis [6][7][8][9][10][11][12][13][14][15][16][17][18][19]; however, most of these data have been obtained on 1.5-T systems and those with 3.0-T clinical systems have rarely been presented [20][21][22][23]. In particular, clinical application of 3.0-T MRE to patients with chronic liver diseases has been limited [22,23].…”

“…Shear-wave MR elastography (MRE) has also been reported to be useful in assessing the pathological grades of liver fibrosis [6][7][8][9][10][11][12][13][14][15][16][17][18][19]; however, most of these data have been obtained on 1.5-T systems and those with 3.0-T clinical systems have rarely been presented [20][21][22][23]. In particular, clinical application of 3.0-T MRE to patients with chronic liver diseases has been limited [22,23]. There are several technical differences between MRE systems of 1.5 T and 3.0 T, including the pulse sequences used (gradient-echo vs echo planar), the number of slices obtained (one vs four) and the cross-hatching marks on stiffness maps (absent vs present) [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23].…”