摘要
目的评价超顺磁氧化铁(SPIO)增强MR成像对肝脏占位性病变的诊断价值。方法制作20只大鼠肝癌模型,注射SPIO前后行MR扫描,扫描序列包括SE T1WI(390 ms/14 ms)、TSE T2WI(4 100 ms/99 ms)、SE PDWI和T2WI(1 800 ms/20 ms/70 ms)、FLASH T2*WI(600 ms/15 ms/15°)、FLASH T1WI(150 ms/14 ms/70°),分析不同病灶的强化特点。5只正常大鼠作为空白对照,扫描序列与实验组相同。结果注射SPIO后,正常肝组织和硬化肝组织的信号强度都下降,以GRE T2*WI最为显著。SPIO增强T1WI上,肝细胞癌、肝硬化再生结节、灶性结节增生都出现阳性强化;T2WI上,肝细胞癌仍保持较高的信号强度,而再生结节、灶性结节增生出现负性强化现象。SPIO增强后GRE T2*WI中,肝细胞癌的增强噪声比高于其他扫描序列,TSE和SE T2WI在显示肝细胞癌的信噪比、增强噪声比方面没有显著性差异。结论SPIO对比剂在T1、T2WI的强化特性有助于肝脏占位性病变的显示,对于良、恶性结节的定性诊断有着重要意义。
Objective To evaluate the value of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging in the diagnoses of focal liver lesions. Methods Twenty rat models of hepatocellular carcinoma were induced by feeding the rats with N-nitrosodiethylamine. Before and after SPIO injection into the rats, MR imaging was performed including the sequences of spin-echo (SE) T1WI (390 ms/14 ms), TSE T2WI (4 100 ms/99 ms), SE Dual-echoes (1 800 ms/20 ms/70 ms), GRE FLASH T2*WI (600 ms/15 ms/15°), and GRE FLASH T1WI (150 ms/14 ms/70°). Another 5 normal rats were selected as negative control, which also received SPIO and MR imaging in the same manner as described above. The characteristics of SPIO-enhanced MRI of different liver lesions were analyzed. Results After SPIO enhancement, the signal intensity of normal liver and cirrhotic liver both decreased, especially on GRE T2*WI. The signal intensity of hepatocellular carcinoma (HCC), regenerative nodules (RN), and focal nodule hyperplasia (FNH) all increased on T1WI images. On T2WI and T2*-weighted images, the signal intensity of HCC remained high, while significant signal loss occurred in RN and FNH. After SPIO administration, the contrast-to-noise (CNR) of HCC on GRE T2*-weighted images was greater than that of other sequences. Conclusions SPIO has not only considerable T2-negative effect but also slightly T1-shortening effect, which is of great value in the differential diagnosis of focal liver lesions.
出处
《第一军医大学学报》
CSCD
北大核心
2002年第12期1061-1065,共5页
Journal of First Military Medical University
基金
国家重点科技项目(96-901-05-10)
关键词
肝癌
肝脏肿瘤
磁共振成像
超顺磁氧化铁
对比剂
增强效应
carcinoma, hepatic
magnetic resonance imaging
superparamagnetic iron oxide
contrast agent
enhancement effect
