磁共振体素内不相干运动对于肿块样乳腺良恶性病变的诊断价值

目的通过与常规磁共振动态增强扫描(DCE-MRI)比较,探讨体素内不相干运动(IVIM)是否能进一步提高肿块样乳腺良恶性病变的诊断能力。方法 24例良性乳腺病变(22例女性)和31例恶性乳腺病变(27例女性)均进行DCE-MRI和IVIM检查。在常规DCE-MRI中计算初始强化率(IER)和时间-信号强度曲线(TIC)。在IVIM中计算组织弥散系数(D)。结果恶性病变IER的平均值均高于良性病变(P<0.001),但D平均值均低于良性病变(P<0.001)。恶性病变中Ⅲ型TIC更为常见而Ⅰ型TIC更为少见。在鉴别诊断肿块样乳腺良恶性病变方面,D的曲线下面积(AUC)(0.98)、敏感性(93.55%)、特异性(100.00%)和诊断准确率(96.36%)最高。D和TIC联合使用的AUC高达0.99。结论在肿块样乳腺良恶性病变的鉴别诊断方面,IVIM较常规DCE-MRI更具优势。而IVIM和DCE-MRI结合使用将进一步提高肿块样乳腺良恶性病变诊断准确性。

The value of intravoxel incoherent motion in differentiating mass-like benign from malignant breast lesions

Objective To determine whether the parameters obtained from intravoxel incoherent motion （IVIM） can improve the characterization of mass-like benign and malignant breast lesions, compared with dynamic contrast-enhanced magnetic resonance imaging （DCE-MRI）. Methods Twenty-four benign breast lesions （22 women） and thirty-one malignant breast lesions （27 women） underwent DCE-MRI and IVIM. Initial enhancement ratio （IER） and time-signal intensity curve （TIC） were calculated in DCE-MRI. Tissue diffusivity （D）, pseudo diffusivity （D＊） and perfusion fraction （f） were calculated in IVIM. Results Malignant lesions exhibited higher mean values of IER （P〈0.001）, but lower mean values of D （P〈0.001） than benign lesions. Malignant lesions showed more TICs of Type Ⅲ （washout） and less TICs of TypeⅠ（persistent） than benign lesions （P〈0.001）. D had the highest AUC （0.98）, sensitivity （93.55%）, specificity （100.00%） and diagnostic accuracy （96.36%）. The combination of D and TIC had an AUC up to 0.99. Conclusion Compared with conventional DCE-MRI, isolated quantitative D of IVIM can improve the speficicity in differentiating between mass -like benign and malignant lesions. IVIM combined with DCE-MRI can provide a robust means of evaluating breast lesions.