摘要
目的探讨直肠癌患者术前体素内不相干运动(IVIM)磁共振成像中不同感兴趣区(ROI)选择方法对参数测量准确性的影响。方法病理诊断为直肠腺癌患者43例,术前行盆腔常规磁共振扫描和IVIM检查。在b=1000s/mm2的IVIM原始图像上采用三层法和单层法勾画ROI获得IVIM参数值:纯扩散系数(D)值,灌注分数(f)值,灌注相关假扩散系数(D*)值。比较2种ROI勾画法之间以及其与正常肠壁的参数值之间的差异;采用ROC曲线分析ROI勾画法测得的参数值与正常肠壁的区分效能。结果三层法和单层法勾画直肠癌病灶ROI测得的D值、f值和D*值差异均无统计学意义(P>0.05)。与正常肠壁比较,三层法和单层法勾画直肠癌病灶ROI测得的D值均较低(P<0.05);单层法勾画直肠癌病灶测得的f值亦较低(P<0.05)。三层法的诊断准确性和特异度更高。结论直肠癌病灶采用三层法和单层法勾画ROI得出的IVIM各参数间无显著差异;采用三层法得到的病灶数据与正常肠壁区分度更高。
Objective To evaluate the effect interest（ROI） on the measurement accuracy of resonance（MR） imaging of rectal cancers. Methods of two different selection methods of the region of intra-voxel incoherent motion （IVIM） magnetic The pelvic MR imaging IVIM was performed in 43 patients with rectal cancer confirmed pathologically before operation. IV1M-related parameters including pure diffusion coefficient （D）, perfusion fraction（f） and infusion-related false diffusion coefficient（D＊ ） values were measured with two distinct ROI drawing protocols of three-laye^methvyd and single-layer-method. The differences of IVIM-related parameters obtained from two protocols were compared. The IVIM-related parameters of rectal cancers were compared to those of normal rectal walls. Diagnostic performance of those parameters in differentiating rectal cancers from normal tissues was assessed using ROC analysis. Results The values of D, f and D＊ of rectal cancers obtained from two protocols were not significantly different（P〉0. 05）. Compared with normal rectal wall, the D values of rectal cancer measured by two protocols were lower（P〈0.05）. The f value obtained from single-layer-method was lower in rectal cancer than that in normal rectal tissue （P〈0. 05）. ROC analysis showed that diagnostic accuracy and specificity of three-layer-method were higher than those of single-layer-method. Conclusion There are no significant differences in IV1M-related parameters measured with the two methods of ROI drawing within rectal cancers. Compared with single-layer- method, three-layer-method may be better in differentiating rectal cancers from normal rectal tissues.
出处
《江苏医药》
CAS
2016年第12期1344-1347,共4页
Jiangsu Medical Journal
基金
国家自然科学基金(81371516)
国家卫生计生委科研专项(W201306)
江苏省科技项目(BE2015605)
关键词
直肠癌
磁共振成像
体素内不相干运动
感兴趣区
Region of interest Rectal cancer
Magnetic resonance imaging
Intra-voxel incoherent motion
