超顺磁性氧化铁在大鼠诱癌模型磁共振诊断与鉴别诊断中的作用

目的研究超顺磁性氧化铁(SPIO)在大鼠诱癌模型的磁共振成像中对增生性结节与肝癌的鉴别作用，以及SPIO增强前后对各型肝癌的检出率。材料与方法42只诱发型肝癌模型鼠在肝硬化多发增生性结节基础上，共计生成379个肝癌，行平扫及SPIO增强扫描，分析增生性结节与肝癌的不同强化方式，并与病理对照统计平扫与增强扫描各型肝癌的检出率。结果增生性结节在SPIO增强扫描T2WI上信号明显降低，而肝癌的信号无明显改变；肝癌SPIO增强扫描T2WI检出率与病理接近，而平扫T2WI检出率与病理相差显著，其中平扫微癌与小癌的漏检率分别达32．9％与12．9％。结论SPIO是一种有效的检测肝癌的磁共振对比剂，不仅能提高小肝癌的检出率而且对增生性结节与肝癌的鉴别提供帮助。

Evaluation of SPIO-enhanced MRI in the Diagnosis and Differentiation of Chemically-induced HCC in Rats

Objective To evaluate the potentiality of superparamagnetic iron oxide (SPIO) enhanced MR imaging in differentiating hepatocellular carcinomas (HCC) from hyperplastic nodules which were chemically induced in experimental rats, and to compare the detecting rate before and after SPIO enhancement for HCC of different type.Materials and Methods Forty two rats with 379 chemically induced liver tumors underwent T 1 and T 2 weighted MR imaging before and after the injection of SPIO. The enhanced patterns of the tumors and hyperplastic nodules were observed and analyzed. The detecting rate of each type of HCC was compared between MRI and pathological results.Results The signal of HCC was unchanged after enhancement on T 2WI, while the signal of hyperplastic nodule was markedly decreased. Significant difference in detecting rate of HCC existed between plain T 2WI and pathologic results, although no significant difference was found between SPIO enhanced T 2WI and pathology. The missed diagnosis rate of small HCC and micro HCC for plain T 2WI was 32.9% and 12.9%, respectively. Conclusion SPIO is an effective MR contrast agent for detecting HCC. The use of it can increase the detecting rate of small HCC and is helpful for the differentiation of HCC with hyperplastic nodule.