不同场强和序列的超顺磁性氧化铁磁共振增强扫描在肝癌检出中的比较

比较不同的场强和扫描序列对超顺磁性氧化铁增强前后肝癌检出的影响。材料和方法：46例104个肝癌病灶在1．0T或1．5T场强下行磁共振T1加权及四个T2加权的平扫及SPIO增强扫描，比较不同场强下各扫描序列的信噪比、对比噪声比以及肝癌病灶的检出率。结果：SPIO增强扫描后，所有序列的信噪比均下降，但对比噪声比和肝癌检出率均增加。1．0T场强下，最佳的SPIO增强序列为SE和TSE的T2加权；1．5T场强下最佳的SPIO增强序列为HASTE和FS－HASTE的T2加权。结论：不同场强下最合适SPIO增强扫描的都是信噪比较好的、中等权重的T2加权序列，1．5T更适合屏气的快速序列，1．0T更适合非屏气的SE序列。

Comparative Study with Different Field Strength and Sequences in Detect Hepatic Carcinoma Using Superparamagnetic Iron Oxide Enhanced MR Imaging

Purpose:To compare the influence of different field strength and sequences in detect hepatic carcinoma using superparamagnetic iron oxide(SPIO) enhanced MR imaging.Materials and Methods:In 46 patients with 104 hepatic carcinoma focus,1.0T or 1.5T MR imaging was performed before and after superparamagnetic iron oxide enhanced MR imaging using T1 weighted and four T2 weighted sequences.The signal to noise ratio(SNR),contrast to noise ratio(CNR) and the rate of detection of hepatic carcinoma were compared.Results:After SPIO enhanced MR imaging,the SNR declined in all sequences,but the CNR and the rate of detection of hepatic carcinoma raised without exception.On a 1.0T system,the optimal sequences for SPIO enhanced MR imaging were T2 weighted SE and TSE.On a 1.5T system,the optimal sequences were T2 weighted HASTE and FS-HASTE.Conclusion:Under different field strength,the optimal sequences for SPIO enhanced MR imaging are all belong to moderate T2 weighted MR imaging,which have preferable SNR.A 1.5T system is more suitable for breathhold fast sequences,and a 1.0T system is more suitable for unbreathhold ones.