中轴骨转移瘤的背景抑制磁共振弥散成像多线圈对比研究

The Study of Diffusion Weighted Imaging with Background Signal Suppression(DWIBS) in Metastatic Axial Bone Tumours: Using Different Coils

目的:研究磁体内置BODY线圈与全脊柱相控阵线圈获取的背景抑制磁共振弥散图像对中轴骨转移瘤显示的敏感性和特异性,探讨磁共振全身弥散技术(WB-DWI)临床应用价值。材料与方法:搜集本院有明确恶性肿瘤病史并辅助检查(包括X光平片及常规CT、MRI)诊断中轴骨转移患者39例,其中采用磁体内置BODY线圈行磁共振全身弥散扫描患者16例(实验A组),采用全脊柱相控阵线圈行背景抑制磁共振弥散成像扫描患者23例(实验B组);所有患者在3个月之后至少一次全脊柱MRI随访扫描(包括STIR序列扫描)。比较实验A组和B组背景抑制磁共振弥散图像的阳性率、病灶数目及所能现实的骨转移灶的最小直径,并进一步分析两组图像对病灶显示的敏感性和特异性。结果:实验A组和B组显示骨转移灶阳性率均为100%;实验A组显示病灶的数目、最小直径不如实验B组;实验A组和B组对骨转移灶显示的敏感性分别为87.14%和91.31%,特异性分别为90.36%和89.07%。结论:体部正交线圈获取的WB-DWI图像虽然空间分辨率和信号分辨率较局部体表相控阵线圈低,但对骨转移灶显示能力的差异无显著性统计学意义,而且具有大范围全身扫描的优势,值得在临床恶性肿瘤骨转移患者的诊断中推广使用;但临床应用该序列诊断时对可疑区域应采用局部线圈,如全脊柱相控阵线圈,加扫背景抑制磁共振弥散成像,以提高病变诊断的敏感性和小病灶的显示能力。

Purpose:To study diffusion weighted imaging with background signal suppression(DWIBS) in metastatic axial bone tumours,comparative study of MR built-in body coil and phase-arrayed total spine coil.Materials and Methods:The patients with metastatic axial bone tumours underwent DWIBS were divided into 2 groups,group A(n=16,using built-in body coil) and group B(n=23,using phase-arrayed total spine coil).All patients at least had one more whole spine MRI scan 3 months later and STIR series was necessary.Positive rate,number and minimum diameter of focus,sensitivity and specificity were compared between the two groups.Results:The positive rate of group A and group B were all 100%,the displaying ability of number and minimum diameter of focus in group A were better than group B.The sensitivity of group A and group B were 87.14% and 91.31%,and the specificity were 90.36% and 89.07%.Conclusion:DWIBS underwent by built-in body coil can get whole body DWI,but the space resolution and signal resolution were not good enough.To suspicious regions in axial bone,DWIBS got by phase-arrayed total spine coil is necessary to show the small focus and improve the sensitivity in detection of metastatic axial bone tumours.