原发性肝癌的MRI增强表现临床分析

摘要

Objective To investigate the imaging features of hypovascular hypointense nodules on hepatobiliary phase gadoxetic acid-enhanced magnetic resonance imaging (MRI) in patients with cirrhosis that may be associated with progression to hypervascular primary liver cancer (PLC). Methods Our hospital institutional review board approved this retrospective study. This study included 135 patients with a diagnosis of hepatitis B-induced liver cirrhosis and 214 hypovascular hypointense nodules on hepatobiliary phase gadoxetic acid-enhanced MRI. MRI were analyzed with respect to nodule size, degree of hypointensity at hepatobiliary phase (four grades), presence of fat, and signal intensity on T1-and T2-weighted and diffusion-weighted (DW) images. Univariate and multivariate Cox regression analyses were used to identify variables that are associated with developing hypervascular PLC. Results On follow-up MRI, 139 nodules (65.0%) had no evidence of PLC (mean follow-up, 522 days) (group 1), but 75 (35.0%) became hypervascular PLC (mean follow-up, 388 days) (group 2). Univariable Cox analysis revealed that the degree of hypointensity on hepatobiliary phase images (P=0.001) and hyperintensity on T2-weighted and DW images (P=0.001, 0.0001) was signiifcantly related to the development of hypervascular PLC. According to the multivariable Cox analysis, no other variable signiifcantly adjusted the model once hyperintensity at initial DW imaging was already included as an associated variable, (hazard ratio, 7.44;95%CI 4.28, 12.94;P=0.0001). conclusions Hyperintensity on DW images in hypovascular hypointense nodules on hepatobiliary phase gadoxetic acid-enhanced MRI in patients with cirrhosis is strongly associated with progression to hypervascular PLC.%目的：分析肝胆期表现为乏血管低信号结节有可能转变为富血管原发性肝癌（PLC）的MRI增强影像表现。方法135例乙型肝炎合并肝硬化患者的肝胆期增强MRI中，发现214个乏血管低信号结节灶。分析每一个结节的大小，在肝胆期的低信号程度（分为4度），有无脂肪成分，在T1加权、T2加权及弥散成像序列的信号强度。将这些变量进行多变量单变量回归分析，来确认再生结节转变为PLC最有价值的影像特征。结果在135例214个结节的MRI随访系列图像上，139个结节（65.0%）无PLC形成的迹象（稳定组，平均随访522天），转变组75个结节（35.0%）则最终转变为富血管高信号PLC结节。单变量回归分析显示与PLC形成明显相关的为在MRI增强肝胆期结节灶的低信号程度（P=0.001），T2加权高信号（P=0.001）与弥散成像高信号（P=0.0001）。多变量回归分析显示首次MRI弥散成像结节高信号为PLC形成最有价值的影像特征（危害比7.44；95%CI 4.28，12.94）。结论肝硬化患者MRI增强肝胆期结节灶信号最低而在弥散成像序列表现为高信号，强烈提示富血管PLC已经形成。