肾上腺肿瘤不同b值DWI研究  

Study on Different b Values in MR Diffusion Weighted Imaging of Adrenal Tumors

作　　者：陈小龙[1] 马强华[2] 陈纲[2] 叶建军[2] 杨晓萍[2] 朱小花[2] 

机构地区：[1]兰州大学第二临床医学院,甘肃730030 [2]兰州军区兰州总医院MR室

出　　处：《放射学实践》2009年第5期518-521,共4页Radiologic Practice

摘　　要：目的:研究不同b值肾上腺肿瘤扩散加权成像(DWI)的表现,比较不同b值组表观扩散系数(ADC值)之间的差异,探讨最佳b值的选择及最佳b值组良恶性肿瘤的ADC值范围及阈值。方法:对23例经手术病理及临床证实的肾上腺肿瘤患者行平扫、DWI(b值分别取0、400、800和1000s/mm2),分别观察不同b值肿瘤信号的差异,同时测量不同b值肿瘤的ADC值并作统计学分析。结果:①b值为0s/mm2时,DWI肿瘤的信号和T2WI一致,b值分别为400、800和1000s/mm2,良性肿瘤随着b值的增高,信号逐渐减低,而恶性肿瘤随着b值的增高,信号变化不明显;②3个b值组,低b值组肾上腺肿瘤的平均ADC值最大,随着b值的增大,平均ADC值逐渐减小,并有统计学意义(F=13.543,P<0.05);③400～0s/mm2b值组肾上腺良恶性肿瘤ADC值之间无统计学意义(t=-2.033,P=0.054),而800～0s/mm2b值组及1000～0s/mm2b值组有统计学意义(t=-2.700,P=0.013;t=-3.529,P=0.002);④以800～0s/mm2b值组ADC值作为研究对象进行受试者工作特性(ROC)曲线分析,诊断阈值为0.986×10-3mm2/s,此阈值点对肾上腺良恶性病变诊断的敏感度为80%,特异度为78%。结论:b=800～0s/mm2为较佳选择,此时良性肿瘤的平均ADC值为(1.138±0.180)×10-3mm2/s,恶性肿瘤的平均ADC值为(0.916±0.218)×10-3mm2/s;DWI对肾上腺肿瘤性质鉴别具有价值,是对常规MR检查有益的补充。Objective： To study the manifestations of MR diffusion weighted imaging （DWI） and to compare the differences of apparent diffusion coefficient （ADC） values of adrenal tumor in different b factors, so as to investigate the selection of optimal b factor as well as the range and threshold of ADC values of benign and malignant adrenal tumors with optimal b factor. Methods：A total of 23 patients with pathology or clinical proven adrenal tumor underwent MR plain and DWI scanning. Various b factor were set as 0,400,800 and 1000s/mm^2. The signal differences of various tumors were studied,the ADC values of tumors with different b value were measured and statistically analyzed. Results： ①The signal intensi ties of tumor on T2WI were in consistent with that of DWI when b value was 0s/mm^2. With b value increased to 400,800, 1000s/mm^2, the DWI signal of benign tumor declined orderly, however, there was no significant change for malignant tumor as b values increased. ②f the 3 groups of adrenal tumors with different b values,the mean ADC value was the largest in the low b value group,yet reduced following the increase of b value with significant statistical difference （F=13. 543, P〈0.05）. ③There was no statistical difference between the ADC value of benign and malignant adrenal tumors with b value=400～0s/mm^2（t=-2.033,P=0.054）.Yet the meanADC value of the b value=800～0s/mm^2 group showed statistical difference when compared with that of 1000s/mm^2（t=2.700,P=0.013;t=3. 529,P=0.002）. ④Using the the ADC values with the b： 800～0s/mm^2 group for ROC curve analysis, the diagnosis threshold was 0. 986 × 10^-3 mm^2/s. With the sensitivity in differentiating benign or malignant adrenal tumor was 80%, the specificity was 78%. Conclusion： 800～0s/mm^2 was the optimal b factor for DWI of adrenal tumor. In the mean time. The mean ADC value of benign tumor was （1. 138±0. 180）×10^-3 mm^2/s, which of malignant tumor was （0. 916±0. 218） ）〈10^-3mm^2/s. DWlis valuable for different

关 键 词：肾上腺肿瘤 磁共振成像 图像处理 计算机辅助 

分 类 号：R736.6[医药卫生—肿瘤] R445.2[医药卫生—临床医学]