3.0T质子磁共振波谱在评价胰腺疾病中的临床应用

Clinical Application of 3.0 T Proton MR Spectroscopy in Evaluation of Pancreatic Diseases

目的研究3.0 T磁共振波谱(MRS)对胰腺疾病的诊断价值。资料与方法在3.0 T磁共振系统下,应用单体素点分辨波谱(PRESS)序列,采集50例非癌受试者(包括25例正常胰腺,15例急性胰腺炎,10例慢性胰腺炎)及20例胰腺癌患者的胰腺质子磁共振波谱(1H-MRS)。通过SAGE软件分析非癌组与癌组胰腺波谱中代谢物的表现,比较两组的代谢物峰显示率,计算每一组胰腺波谱中胆固醇和不饱和脂肪酸的混合峰(Chol+Unsat)与脂肪峰(Lip)峰高的比值(Chol+Unsat/Lip),在胰腺癌与非癌胰腺的比值之间进行受试者工作特征(ROC)分析。结果胰腺1H-MRS显示的主要代谢物峰有Lip峰,Chol+Unsat峰和胆碱(Cho)峰。胰腺癌组与非癌组的Chol+Un-sat/Lip比值均数分别为0.325±0.187和0.199±0.095,两组比值的差异有统计学意义(t=2.855,P=0.009)。经计算得出ROC曲线下面积为0.72(P=0.005)。曲线上Chol+Unsat/Lip比值的临界点取0.295时,1H-MRS诊断胰腺癌与非癌胰腺的敏感性为55%,特异性为86%,准确性为77%。结论胰腺1H-MRS中Chol+Unsat/Lip比值升高对诊断胰腺癌有一定参考价值。

Objective To study the usefulness of 3.0 T 1H-MRS in diagnosis of pancreatic diseases.Materials and Methods Pancreas spectroscopies of 70 subjects were acquired by single voxel PRESS sequence on 3.0 T MR scanner.The subjects included normal pancreas（n= 25）,acute pancreatitis（n= 15）,chronic pancreatitis（n= 10） and pancreatic cancer（n= 20）.The spectral appearances were analyzed,and metabolites visibility rates between pancreatic cancer and non cancer group were compared.The ratio of cholesterol and the olefinic region of fatty acids（Chol＋Unsat） peak height to lipid（Lip） peak height（Chol＋Unsat/Lip） was calculated in each 1H-MRS,and a ROC analysis was performed between the ratios of two groups.Results There were three major resonance peaks in the spectra,i.e.,Lip,Chol＋Unsat,and choline.The mean value of Chol＋Unsat/Lip in 1H-MRS was 0.199±0.095 for non cancer group,0.325±0.187 for pancreatic cancer group.Statistically significant difference was found in the values of Chol＋Unsat/Lip ratios between cancer and non cancer group（t= 2.855,P= 0.009）.The area under the ROC curve was 0.72（P= 0.005）.With ROC cut point setting to 0.295,the diagnostic sensitivity,specificity,accuracy for pancreatic cancer were 55 %,86 %,77 %,respectively.Conclusion 1H-MRS of pancreatic cancer has a higher ratio of Chol＋Unsat/Lip,and this may be useful in differentiating pancreatic cancer from other pancreatic diseases.