磁共振弹性成像可以对肝纤维化进行准确分级

张医生

　　病理学检查是诊断肝纤维化的金标准，但磁共振（MR）弹性成像等无创检查更易于患者接受。比利时Huwart等学者的研究显示，MR弹性成像可对肝纤维化进行准确分级，优于天冬氨酸氨基转移酶/血小板比值指数（APRI）检查。

　　研究纳入88例疑似慢性肝病患者，其中男性患者37例，女性51例，平均年龄为54.0±13.1岁。所有受试者均接受肝活检，并于肝活检后2天内接受MR弹性成像和APRI检查。根据患者的肝活检病理表现进行肝纤维化METAVIR评分，并根据评分对患者的病情进行分级（F0级为无纤维化病变，F4级为存在肝硬化病变），比较不同分级之间患者的MR弹性成像和APRI检查结果的受试者工作特征（ROC）曲线下面积的A（z）值。

　　结果显示，通过比较MR弹性成像和APRI检查结果的受试者工作特征（ROC）曲线下面积，MR弹性成像的A（z）值显著高于APRI，METAVIR评分≥F2者的A（z）值为0.854（P<0.001），评分≥F3者的A（z）值为0.886（P=0.003），评分=F4者的A（z）值为0.851（P=0.004）。当评分≥F2时，MR弹性成像的阴性判断值为2.5kPa，评分≥F3时为3.1kPa，评分=F4为4.3kPa。

Radiology. 2007 Nov;245(2):458-66.

Liver fibrosis: noninvasive assessment with MR elastography versus aspartate aminotransferase-to-platelet ratio index.

Huwart L, Sempoux C, Salameh N, Jamart J, Annet L, Sinkus R, Peeters F, ter Beek LC, Horsmans Y, Van Beers BE.

Diagnostic Radiology Unit, Department of Pathology, and Laboratory of Gastroenterology, Université Catholique de Louvain, St-Luc University Hospital, B-1200, Brussels, Belgium.

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 < .001; 0.886 at scores > 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.