Ronot Maxime, Lambert Simon A, Wagner Mathilde, Garteiser Philippe, Doblas Sabrina, Albuquerque Miguel, Paradis Valérie, Vilgrain Valérie, Sinkus Ralph, Van Beers Bernard E
Department of Radiology, Beaujon University Hospitals Paris Nord Val de Seine, Clichy, France; University Paris Diderot, Sorbonne Paris Cité, France; IPMA, INSERM U773, Centre de Recherche Biomédicale Bichat-Beaujon, Paris, France.
University Paris Diderot, Sorbonne Paris Cité, France; IPMA, INSERM U773, Centre de Recherche Biomédicale Bichat-Beaujon, Paris, France.
PLoS One. 2014 Apr 10;9(4):e94679. doi: 10.1371/journal.pone.0094679. eCollection 2014.
To assess in a high-resolution model of thin liver rat slices which viscoelastic parameter at three-dimensional multifrequency MR elastography has the best diagnostic performance for quantifying liver fibrosis.
The study was approved by the ethics committee for animal care of our institution. Eight normal rats and 42 rats with carbon tetrachloride induced liver fibrosis were used in the study. The rats were sacrificed, their livers were resected and three-dimensional MR elastography of 5 ± 2 mm liver slices was performed at 7T with mechanical frequencies of 500, 600 and 700 Hz. The complex shear, storage and loss moduli, and the coefficient of the frequency power law were calculated. At histopathology, fibrosis and inflammation were assessed with METAVIR score, fibrosis was further quantified with morphometry. The diagnostic value of the viscoelastic parameters for assessing fibrosis severity was evaluated with simple and multiple linear regressions, receiver operating characteristic analysis and Obuchowski measures.
At simple regression, the shear, storage and loss moduli were associated with the severity of fibrosis. At multiple regression, the storage modulus at 600 Hz was the only parameter associated with fibrosis severity (r = 0.86, p<0.0001). This parameter had an Obuchowski measure of 0.89+/-0.03. This measure was significantly larger than that of the loss modulus (0.78+/-0.04, p = 0.028), but not than that of the complex shear modulus (0.88+/-0.03, p = 0.84).
Our high resolution, three-dimensional multifrequency MR elastography study of thin liver slices shows that the storage modulus is the viscoelastic parameter that has the best association with the severity of liver fibrosis. However, its diagnostic performance does not differ significantly from that of the complex shear modulus.
在薄肝大鼠切片的高分辨率模型中评估三维多频磁共振弹性成像的哪个粘弹性参数在量化肝纤维化方面具有最佳诊断性能。
本研究经本机构动物护理伦理委员会批准。研究中使用了8只正常大鼠和42只四氯化碳诱导的肝纤维化大鼠。将大鼠处死，切除肝脏，并在7T下对5±2mm的肝切片进行三维磁共振弹性成像，机械频率为500、600和700Hz。计算复剪切模量、储能模量和损耗模量以及频率幂律系数。在组织病理学方面，用METAVIR评分评估纤维化和炎症，用形态计量学进一步量化纤维化。通过简单和多元线性回归、受试者操作特征分析和奥布霍夫斯基测量法评估粘弹性参数对评估纤维化严重程度的诊断价值。
在简单回归中，剪切模量、储能模量和损耗模量与纤维化严重程度相关。在多元回归中，600Hz时的储能模量是与纤维化严重程度相关的唯一参数（r = 0.86，p<0.0001）。该参数的奥布霍夫斯基测量值为0.89±0.03。该测量值显著大于损耗模量的测量值（0.78±0.04，p = 0.028），但不大于复剪切模量的测量值（0.88±0.03，p = 0.84）。
我们对薄肝切片进行的高分辨率、三维多频磁共振弹性成像研究表明，储能模量是与肝纤维化严重程度相关性最佳的粘弹性参数。然而，其诊断性能与复剪切模量的诊断性能无显著差异。
