Department of Radiology, New York University Medical Center, New York, NY, USA.
Radiology. 2010 Jan;254(1):47-66. doi: 10.1148/radiol.09090021.
Magnetic resonance (MR) imaging plays an increasingly important role in the evaluation of patients with liver disease because of its high contrast resolution, lack of ionizing radiation, and the possibility of performing functional imaging sequences. With advances in hardware and coil systems, diffusion-weighted (DW) MR imaging can now be applied to liver imaging with improved image quality. DW MR imaging enables qualitative and quantitative assessment of tissue diffusivity (apparent diffusion coefficient) without the use of gadolinium chelates, which makes it a highly attractive technique, particularly in patients with severe renal dysfunction at risk for nephrogenic systemic fibrosis. In this review, acquisition parameters, postprocessing, and quantification methods applied to liver DW MR imaging will be discussed. The current clinical uses of DW MR imaging (liver lesion detection and characterization, compared and combined with conventional sequences) and the emerging applications of DW MR imaging (tumor treatment response and diagnosis of liver fibrosis and cirrhosis) will be reviewed. Also, limitations, mainly image quality and reproducibility of diffusion parameters, and future directions of liver DW MR imaging will be discussed.
磁共振（MR）成像由于其高对比度分辨率、无电离辐射以及进行功能成像序列的可能性，在肝病患者的评估中发挥着越来越重要的作用。随着硬件和线圈系统的进步，扩散加权（DW）MR 成像现在可以应用于肝脏成像，从而提高图像质量。DW MR 成像可以在不使用钆螯合物的情况下对组织扩散性（表观扩散系数）进行定性和定量评估，这使其成为一种极具吸引力的技术，特别是在有发生肾源性系统性纤维化风险的严重肾功能不全的患者中。在这篇综述中，将讨论应用于肝脏 DW MR 成像的采集参数、后处理和量化方法。将回顾 DW MR 成像的当前临床应用（肝病变检测和特征，与常规序列比较和结合）以及 DW MR 成像的新兴应用（肿瘤治疗反应以及肝纤维化和肝硬化的诊断）。还将讨论扩散参数的局限性，主要是图像质量和可重复性，以及肝脏 DW MR 成像的未来方向。
