纽约路透社健康新闻9月22日消息：根据8月份Radiology报道，磁共振弹性成像可以无创性定量研究肝纤维化。
“常规影像技术，例如CT，MRI和超声不能显示肝硬化前的肝纤维化，可靠的无创性肝纤维化检查方法对慢性肝病病人的治疗具有巨大影响，”，Rochester Minnesota的Mayo医院Richard L. Erman博士说道。
Ehman博士小组发展了一种通过MR弹性成像测量肝硬度的技术，并利用该技术对12例正常对照和12例病人进行了前瞻性研究。
正常对照组的肝脏硬度在2.0kPa，不论是与肋骨平行还是垂直，都发现肋骨下和肋骨间图像没有显著性差别。
慢性肝病进行肝脏活检的病人中，1例没有发现肝纤维化，4例为1度肝纤维化，3例为2度肝纤维化，3例为3度肝纤维化，1例为4度肝纤维化。
研究者注意到，没有肝纤维化的病人的肝脏硬度在2.7kPa，具有不同程度肝纤维化病变的11例病人肝脏平均硬度为5.6kPa。
本研究结束以后，“我们进一步提高了本技术，尤其是对肝脏施加机械波的技术”。Ehman博士说，“现在在很短的时间内，我们就可以获得整个肝脏的横断弹性图像”。
“使用改进的技术，我们进一步扩展了临床研究范围，”，Ehman博士解释说：“不久，我们就会有足够的数据，结合活检结果，报道磁共振弹性成像诊断肝纤维化的敏感性和特异性。”
Ehman博士总结说：“目前的结果很有发展前景。”
MR elastography quantitatively assesses liver fibrosis
NEW YORK (Reuters Health), Sep 22 - Magnetic resonance (MR) elastography noninvasively provides a quantitative assessment of liver fibrosis, according to a report in the August issue of Radiology.
"Conventional imaging modalities such as CT, MRI, and ultrasonography are not capable of demonstrating liver fibrosis prior to the onset of cirrhosis," Dr. Richard L. Ehman from Mayo Clinic, Rochester, Minnesota, told Reuters Health. "The availability of a reliable, noninvasive method for detecting liver fibrosis could have a substantial impact on the management of patients with chronic liver disease."
Dr. Ehman and colleagues developed a method for measuring liver stiffness with MR elastography and prospectively tested the technique on 12 healthy volunteers and 12 patients with liver fibrosis.
The mean liver stiffness in healthy volunteers was 2.0 kPa, the authors report, with no significant difference between subcostal and transcostal images, whether they were orthogonal or oblique.
Among the patients with chronic liver disease who underwent liver biopsy, one had no detectable fibrosis, four had stage 1 liver fibrosis, three had stage 2 fibrosis, three had stage 3 fibrosis, and one had stage 4 fibrosis.
The liver stiffness in the patient without fibrosis was 2.7 kPa, the researchers note, compared with a mean liver shear stiffness of 5.6 kPa among the 11 patients with varying degrees of liver disease.
Since this study was completed, "we have substantially improved the technology, especially in the way that mechanical waves are applied to the liver," Dr. Ehman said. "As a result, we are now able to generate cross-sectional maps of the elasticity of the entire liver in a very brief acquisition time."
"We have expanded our clinical trial with the technique, using the improved methods," Dr. Ehman explained. "Shortly, we will have enough additional data, together with biopsy results, to be able to report the sensitivity and specificity of MR elastography for diagnosing liver fibrosis in this larger series."
"The current results are extremely promising," Dr. Ehman concluded.
Radiology 2006;240:440-448.
相关背景
磁共振弹性成像使“影像触诊”成为可能
弹性是人体组织的重要物理特性。正常组织与病理组织相比，两者的弹性存在较大差异。磁共振弹性成像（Magnetic Resonance Elastography, MRE）能直观显示和量化组织弹性的非侵入性成像方法。临床触诊是一种主观的判断，缺乏客观的量化指标，实际上是评价人体组织对抗变形的物理特性，这种特性称为弹性模量。MRE作为一种新的能直观显示和量化组织弹性的非侵入性成像方法显示出了良好的研究和应用前景，使“影像触诊”成为了可能，弥补了临床医生触诊的局限性。
各医疗设备公司尚未推出有关MRE技术的装置、序列和图像软件。少数科研机构正在从事该技术的研究。尽管尚处于起步阶段，但显示出良好的应用前景，目前研究者已开展了初步临床研究，包括乳腺、脑、前列腺、和肌肉等。在乳腺方面的研究相对较多，应用相对较成熟。McKnight等应用MRE检测了6名健康志愿者和6名确诊的乳腺癌患者，结果显示，健康志愿者中乳腺纤维腺组织的剪切模量稍高于脂肪组织，在乳腺癌患者病变部位显示了局灶性剪切模量增高区域，其平均值比周围乳腺组织的平均值高4.18倍。
编辑：蓝色幻想
