MR T1WI梯度回波同、反相位序列对肝脏病变的鉴别诊断价值

Evalution on the value of MR SPGR in-phase and opposed-phase T1-weighted sequences for the differential diagnosis of liver lesions

目的:评估同相位与反相位梯度回波T1WI在肝脏结节诊断中的应用价值。方法:回顾性分析76例肝脏结节在MRT1WI梯度回波同相位与反相位图像上的信号差别。将76例肝脏结节分为6组:肝癌组27例,肝内良性肿瘤组7例,肝内炎性病变组11例,海绵状血管瘤组11例,转移瘤组10例,囊肿组10例。测量各组病变在T1WI同、反相位图像上的信号强度比值,用方差分析比较6组病变在T1WI同、反相位图像上的信号强度比值有无差异性。结果:6组肝脏结节在T1WI同反相位图像上的信号强度比值分别为肝癌1.27±0.25,肝内良性肿瘤1.06±0.04,肝内炎性病变1.22±0.12,海绵状血管瘤1.02±0.12,转移瘤1.02±0.06,囊肿0.99±0.07。在T1WI同、反相位图像信号强度比值上,肝癌与肝内炎性病变两组之间差异无显著性(P>0.05),肝内良性肿瘤、转移瘤、海绵状血管瘤和囊肿四组之间差异亦无显著性(P>0.05),前两组与后四组病变之间差异有显著性(P<0.01)。结论:含有少量脂肪成分的肝脏病变在MRT1WI梯度回波同相位与反相位图像上有明显的信号强度差异,因此,MRT1WI梯度回波同相位与反相位序列在肝脏病变的鉴别诊断上有重要价值。

Objective： To assess the advantages of MR SPGR in-phase （IP） and opposed-phase （OP） T1-weighted sequences for the differentiation of focal hepatic lesions. Methods： Twenty-seven hepatocellular carcinomas, 7 benign hepatic neoplasms, 11 hepatic inflammatory lesions, 11 hepatic hemangiomas,10 liver metastases,and 10 hepatic cysts were retrospectively evaluated at 1.5T chemimal shift MRI using a double-echo SPGR （spoiled phase gradient echo,SPGR） sequence. SIR （signal intensity ratio,SIR） of 76 focal hepatic lesions on IP and OP images was calculated and compared using analysis of variance. Results： SIR of 76 focal hepatic lesions on IP and OP images was 1.27±0.25 in 27 hepatocellular carcinomas, 1.06±0.04 in 7 benign hepatic neoplasms, 1.22± 0.12 in 11 hepatic inflammatory lesions,1.02±0.12 in 11 hepatic hemangiomas,1.02±0.06 in 10 liver metastases, and 0.99±0.07 in 10 hepatic cysts, respectively. No difference was showed in the SIR between hepatocellular carcinomas and hepatic inflammatory lesions（P〉0.05）. There was no significant difference in the SIR among benign hepatic neoplasms,liver metastases,hepatic hemangiomas,and hepatic cyst（P〉0.05）. But the SIR of carcinomas and hepatic inflammatory lesions was significantly different from one of benign hepatic neoplasms, liver metastases, hepatic hemangiomas and hepatic cysts respectively（P〈0.01）. Conclusion： The signal intensities are significantly different between in-phase and opposed-phase images in fat-or lipid-containing liver lesions. MR SPGR in-phase and opposed-phase T1-weighted sequences are helpful in the differential diagnosis of liver lesions.