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PURPOSE: To prospectively compare the sensitivity and specificity of magnetic resonance (MR) elastography with those of the routinely available aspartate aminotransferase-to-platelet ratio index (APRI) test for staging hepatic fibrosis in patients who have undergone liver biopsy for suspicion of chronic liver disease, with histopathologic examination as the reference standard. MATERIALS AND METHODS: The study was approved by the ethics committee. All patients gave written informed consent. Eighty-eight patients (37 men, 51 women; mean age, 54.0 years +/- 13.1 [standard deviation]) who underwent liver biopsy for suspicion of chronic liver disease underwent MR elastography and APRI testing within 2 days after liver biopsy. At histopathologic examination, the fibrosis stage was assessed according to METAVIR scores (fibrosis scores F0 [no fibrosis] to F4 [cirrhosis]). MR elastography was performed by transmitting mechanical waves within the liver and measuring the small cyclic displacement of the liver spins with a phase-contrast spin-echo sequence. The performances of MR elastography and APRI testing were assessed, and the optimal cutoff values for fibrosis stage were determined with receiver operating characteristic (ROC) curve analysis. RESULTS: At MR elastography, areas under the ROC curves (A(z)) for elasticity and viscosity, respectively, were 0.999 and 0.863 at fibrosis scores greater than or equal to F2, 0.997 and 0.962 at scores greater than or equal to F3, and 1.000 and 0.986 at score F4. A(z) values for elasticity at MR were significantly larger than those for the APRI (0.854 at scores > or = F2, P or = F3, P = .003; and 0.851 at score F4, P = .004). Optimal cutoff values of elasticity were 2.5 kPa for fibrosis scores greater than or equal to F2, 3.1 kPa for scores greater than or equal to F3, and 4.3 kPa for score F4. CONCLUSION: Large A(z) values for elasticity (>0.990 for scores > or = F2, > or = F3, and F4) show that MR elastography was accurate in liver fibrosis staging and superior to biochemical testing with APRIs.

PURPOSE: To prospectively use transesophageal magnetic resonance (MR) imaging to determine the morphologic and hemodynamic characteristics of esophageal varices. MATERIALS AND METHODS: The study was approved by the ethics committee. All patients gave written informed consent. Forty-two patients (29 men, 13 women; mean age, 58 years +/- 11 [standard deviation]) with esophageal varices that were recently demonstrated at endoscopy were included in the study. MR imaging was performed by using a receiver probe that was placed in the esophagus. Black-blood T2-weighted MR images were obtained with cardiac triggering and navigator gating of the right hemidiaphragm. On these images, the maximal diameter, minimal diameter, and surface area of the largest esophageal varix were measured. Periesophageal and paraesophageal varices were recorded. A hemodynamic examination was performed in the last 21 patients to undergo MR imaging, which was used to obtain measurements of flow velocity and rate before and after intravenous injection of 50 mug of octreotide or a placebo. A Kruskal-Wallis test was used to assess differences in the diameter and surface area of the varices according to endoscopic grade. Hemodynamic changes observed after octreotide or placebo injection were compared by using an analysis of variance and a 95% confidence interval. RESULTS: Periesophageal varices were observed in 36 patients, and paraesophageal varices were observed in 32 patients. The minimal diameter, maximal diameter, and surface area of the esophageal varices at MR imaging differed significantly according to endoscopic grade (P < .001). In the periesophageal varices, the velocity and flow changes caused by octreotide differed significantly from those caused by the placebo (P < .001). A decrease in velocity (mean velocity change, -2.766 cm.sec(-1)) and flow (mean flow change, -0.455 mL.sec(-1)) was noted after octreotide injection, but no significant change in velocity (mean velocity change, 0.252 cm.sec(-1)) or flow (mean flow change, 0.018 mL.sec(-1)) was noted after placebo injection. The surface area of the varices did not change significantly after octreotide (mean change, -0.771 mm2) or placebo (mean change, -0.015 mm2) injection. CONCLUSION: Transesophageal MR imaging is a feasible method to assess the morphologic and hemodynamic characteristics of esophageal varices before and after pharmacologic treatment.