MRI在肝脏占位性病变诊断中的应用

目的:探讨MRI在肝脏占位病变诊断中的应用价值。材料与方法:对98例肝肿瘤患者的MRI影像分析了图像质量、病灶显示清晰度及病变信号特征。全部病例均用1.0T超导磁共振机检查,采用自旋回波(SE)及快速自旋回波(TSE)序列摄取横轴位T_1及T_2加权像。36例患者接受了Gd-DTPA增强,其中12例进行了动态增强检查。结果:图像优良者89％,较差者占11％。MRI能显示的最小病灶为0.5～1.4cm。转移瘤均呈不同程度的长T_1、长T_2信号,信号不均匀,无包膜。肝细胞癌呈不均匀长T_2信号,T_1加权像上7例呈等信号或轻度高信号,其余呈轻度低信号。5例可清晰显示包膜,3例可见门静脉内瘤栓形成。海绵状血管瘤呈均匀性长T_1低信号、长T_2显著高信号,轮廓清晰,边缘光整或呈分叶状。结论:MRI对肝占位病变的诊断敏感度高,特异性好,对发现病变及定性、定量诊断均具有重要价值,值得广泛应用。

Evaluation of MR Imaging in Liver Tumors

Purpose: To evaluate the diagnostic value of MR imaging in the liver tumors. Materials and Methods: 98 liver tumor cases were examined by a 1. 0 T superconduct MR system with axial T1WI and T2WI using Spin Echo or Turbo Spin Echo sequences. Gd - DTPA enhancement was done in 36 cases and with in them 12 cases was dynamic contrast enhancement. Results: The image quality of 89% cases was excellent while 11% was poor. The smallest lesion which can be seen in MR images were 0.5 - 1.4 cm. The metastatic tumors were with different degree of hypointensity in T1WI and hyperintensity in T2WI. The margin of the tumors were irregular and no any capsules can be seen. All cases of hepatocellular carcinomas were hyperintensity in T2WI, 7 cases were hyper or isointensity in T1WI and the others were hypointensity. Capsules can be seen in 5 cases and tumor em-bolus can be seen in 3 cases. All cases of cavemous hemangioma were hypointensity in T1WI and very hyperintensity in T2WI with regular or lobular margins. Conclusion: Both the sensitivity and specificity of MR imaging in the evaluation of liver tumors is very high, it is useful in finding the liver tumors and can correctly differentiate them in most cases.