Sano, Katsuhiro

PurposeTo evaluate the effect of imaging sequence (spin‐echo echo‐planar imaging [EPI] and gradient‐echo [GRE]) and postprocessing method (two‐dimensional [2D] and 3D inversion algorithms) on liver MR elastography (MRE) and to validate the diagnostic performance of EPI‐MRE3D versus conventional GRE‐MRE2D for liver fibrosis staging.Materials and MethodsThree MRE methods (EPI‐MRE3D, EPI‐MRE2D, and GRE‐MRE2D) were performed on soft and mildly stiff phantoms and 58 patients with chronic liver disease using a 3 Tesla clinical MRI scanner, and stiffness values were compared among the three methods. A validation study comprised 73 patients with histological liver fibrosis (F0–4, METAVIR system). Areas under the receiver operating characteristic curves (AUCs) and accuracies for diagnosing significant fibrosis (F3–4) and cirrhosis (F4) were compared between EPI‐MRE3D and GRE‐MRE2D.ResultsStiffness values of the soft and mildly stiff phantoms were 2.4 kPa and 4.0 kPa by EPI‐MRE3D; 2.6 kPa and 4.2 kPa by EPI‐MRE2D; and 2.7 kPa and 4.2 kPa by GRE‐MRE2D. In patients, EPI‐MRE3D provided significantly lower stiffness values than other methods (P < 0.001). However, there was no significant difference between GRE‐MRE2D and EPI‐MRE2D (P = 0.12). The AUCs and accuracies of EPI‐MRE3D and GRE‐MRE2D were statistically equivalent in the diagnoses of significant fibrosis (F3–4) and cirrhosis (F4) (all P < 0.005).ConclusionEPI‐MRE3D showed modestly lower liver stiffness values than conventional GRE‐MRE2D. The diagnostic performances of EPI‐MRE3D and GRE‐MRE2D were equivalent for liver fibrosis staging.Level of Evidence: 3J. Magn. Reson. Imaging 2017;45:1163–1170