超顺磁性氧化铁在肝脏局灶性病变中的定性研究

目的 探讨超顺磁性氧化铁（SPIO）增强MRI在肝脏局灶性病变的定性能力。材料与方法 43例怀疑肝占位者经常规MRI和Gd-DTPA增强后1－7后，行SPIO增强检查。其中31例经手术病理证实，12例经随访、实验室生化检查及临床资料证实。分析平扫MRI及SPIO增强后病灶的信号变化，并与Gd-DTPA动态增强结果相对照。结果 43例共12种病变、单发病灶21例，多病灶22例。包括原发性肝细胞肝癌22例，血管瘤5例，囊肿4例，转移性肝癌5例，肝硬化结节4例，局灶性结节增生（FNH）5例，其他病变6例。22例多发病灶中有8例合并1或2种病变。SPIO增强后，肝细胞肝癌T1WI为等或略高信号，T2WI为较高信号；血管瘤T1WI为较高信号，T2WI信号同平扫为高信号；囊肿T1WI、T2WI信号无改变；肝硬化结节T2WI为等信号同正常肝实质；FNH T2WI信号明显下降。其余病变的诊断SPIO增强不具有特征性，须与Gd-DTPA动态增强相结合。结论 SPIO具有一定的定性能力Gd-DTPA增强相结合，可帮助提高肝局灶性病变诊断和鉴别诊断的准确性。

Diagnostic Value of Superparamagnetic Iron Oxide for Focal Hepatic Lesions

Objective　To evaluate superparamagnetic iron oxide (SPIO) enhanced MRI in the diagnosis of focal hepatic lesions.　Materials and Methods　This study included 43 cases with suspected focal hepatic lesions. All patients underwent plain and Gd-DTPA enhanced MRI, SPIO enhanced MRI was taken 1～7 days later. The diagnosis was pathologically confirmed in 31 cases, while clinically proved in the other 12 cases. The changes in signal intensity (SI) of the lesions before and after SPIO enhancement were analyzed and compared with that of Gd-DTPA enhancement.　Results　Multiple lesions were seen in 22 cases, of which 8 cases were accompanied by one or two diseases. Hepatic lesions included following diseases: primary hepatocellular carcinoma (HCC, n=22), hemangioma (n=5), cyst (n=4), metastases (n=5), cirrhotic nodule (n=4), focal nodular hyperplasia (FNH, n=5), and miscellaneous diseases (n=6). After SPIO enhancement, some lesions showed certain changes in SI. For HCC, the lesions displayed iso- or slightly hyperintense on T1WI and moderate hyperintense on T2WI. For hemangioma, the lesions showed moderate hyperintense on T1WI and marked hyperintense on T2WI similar to that on plain scan. For cyst, no changes in SI were seen on both T1WI and T2WI, while cirrhotic nodules demonstrated iso-intense on T2WI same as the normal hepatic parenchyma. The SI of FNH decreased significantly on T2WI. For the other 6 lesions no specific menifastations were found after SPIO enhancement, and the diagnosis had to be based on the findings with Gd-DTPA dynamic enhancement. 　Conclusion　A combination of SPIO enhancement and the Gd-DTPA dynamic enhancement can improve the accuracy in diagnosing focal hepatic lesions.