Zhang W, Zhao J, Guo D, Zhong W, Shu J, Luo Y
Département de Radiologie, Deuxième Hôpital Affilié à la Faculté de Médecine de Chongqing, Chongqing, Chine.
J Radiol. 2010 Apr;91(4):485-90. doi: 10.1016/s0221-0363(10)70063-9.
Susceptibility weighted imaging (SWI) is a novel imaging method that utilizes the magnetic susceptibility differences between tissues. The purpose of our study was to evaluate the application of SWI for revealing inratumoral blood products and diagnosing high-grade gliomas.
Conventional MR sequences and SWI were performed in 32 patients, 10 low-grade gliomas (1 grade I and 9 grade II) and 22 high-grade gliomas (8 grade III and 14 grade IV). The ability of SWI for detecting inratumral blood products was analyzed and compared with conventional MR sequences. Logistic regression and Receiver operating characteristic (ROC) curve analysis were used to evaluate the diagnostic value of SWI for high-grade gliomas.
SWI was sensitive for showing intrtumoral blood products (P=0.00) and depicted much more micro bleeds. No statistical difference was found in detection rate of blood products between low-grade and high-grade group. According to the result of logistic regression, the frequency of blood products and the diameter of maximum blood products were significant determinants of high-grade gliomas. The result of ROC analysis indicated that with an optimal cut-off point (0.67), the sensitivity, specificity, positive predictive value and negative predictive value for diagnosing high-grade gliomas with blood products detected by SWI were 81.8%, 80.0%, 90.0%, and 66.6%, respectively.
SWI can accurately detect blood products with superlative contrast. With a high-grade gliomas risk estimation model based on two variables, satisfied sensitivity, specificity, PPV and NPV were obtained. Thus, SWI could be a useful adjunct sequence in glioma grading.
磁敏感加权成像（SWI）是一种利用组织间磁敏感性差异的新型成像方法。本研究的目的是评估SWI在显示脑肿瘤内血液产物及诊断高级别胶质瘤方面的应用。
对32例患者进行了常规磁共振序列和SWI检查，其中10例为低级别胶质瘤（1例I级和9例II级），22例为高级别胶质瘤（8例III级和14例IV级）。分析了SWI检测脑肿瘤内血液产物的能力，并与常规磁共振序列进行比较。采用逻辑回归和受试者操作特征（ROC）曲线分析评估SWI对高级别胶质瘤的诊断价值。
SWI对显示肿瘤内血液产物敏感（P = 0.00），且能显示出更多的微出血。低级别和高级别组血液产物的检出率无统计学差异。根据逻辑回归结果，血液产物的频率和最大血液产物的直径是高级别胶质瘤的重要决定因素。ROC分析结果表明，最佳截断点为0.67时，SWI检测到血液产物诊断高级别胶质瘤的敏感性、特异性、阳性预测值和阴性预测值分别为81.8%、80.0%、90.0%和66.6%。
SWI能够以卓越的对比度准确检测血液产物。基于两个变量的高级别胶质瘤风险评估模型获得了满意的敏感性、特异性、阳性预测值和阴性预测值。因此，SWI可能是胶质瘤分级中一种有用的辅助序列。
