联合应用磁共振动态增强及弥散加权成像对乳腺癌的诊断价值

Clinical Application of Combined Application of Diffusion-weight MRI and Dynamic Contrast Enhancement on the Diagnosis of Breast Cancer

目的:探讨联合应用磁共振动态增强及弥散加权成像对乳腺癌的诊断价值。材料与方法:对临床门诊发现有乳腺肿块的80名女性患者(良性肿瘤40例,恶性肿瘤40例),采用德国西门子Avanto 1.5T超导磁共振扫描仪对所有患者首先行MRI动态增强扫描,包括平扫T1W1,T2W1,Flash-3D动态增强扫描,分别对良恶性病变的形态学特征与动态增强表现进行评估,绘制病变的时间-信号强度曲线,判断诊断敏感性、特异性;后行弥散加权成像,计算弥散加权成像在不同b值时乳腺良性、恶性肿瘤ADC值,利用ROC曲线判定诊断阈值,敏感性、特异性;最后动态MRI动态增强扫描及弥散加权成像联合对肿瘤良恶性进行判断,与手术病理结果相对照,研究联合应用磁共振动态增强及弥散加权成像对乳腺癌诊断的敏感性和特异性。结果:乳腺良恶性肿瘤MRI信号表达间无明显差异;动态增强扫描中,乳腺恶性肿瘤多为Ⅱ、Ⅲ曲线,乳腺良性肿瘤多为Ⅰ、Ⅱ曲线,差异有显著意义(P<0.05),诊断敏感度为90%,特异度为60%。磁共振弥散加权成像在不同b值下(b值分别取400,800s/mm2),当b值400 s/mm2时,灵敏度为82.5%,特异度为80%,b=800s/mm2时,灵敏度为92.65%,特异度为70%。随着特异度的升高,灵敏度下降。二者联合应用敏感性为80%,特异性为92.5%。结论:临床在诊断乳腺恶性肿瘤方面,动态增强扫描虽然能够较为准确区分,但是特异度较低;弥散加权信号特异度高,但是敏感度相对较差,实际应用过程中应当将二者结合起来,提高诊断特异度。

Purpose： To evaluate the clinical application of combined diffusion-weight imaging （DWI） and dynamic contrast enhancement in the diagnosis of breast cancer. Materials and Methods： 80 female patients containing 40 eases of begin and 40 cases of malignant breast lumps received MRI dynamic contrast-enhanced scans by Germany＇s Siemens Avanto 1.5T superconducting MRI scanner, including plain TIW1, T2WI, and Flash-3D dynamic contrast-enhanced scans, respectively. And then, lesion time-signal intensity curve were used to evaluate the diagnostic sensitivity and specificity. ADC values of diffusion-weighted imaging are calculated at different b values of benign and malignant tumors and then we use ROC curves to determine the diagnostic threshold, sensitivity, specificity. Finally Dynamic MRI scanning and dynamic contrast- enhanced diffusion-weighted imaging combined to judge the benign or malignant tumor, and then compared the different images with final pathological diagnosis to to determine the diagnostic threshold, sensitivity, specificity. Results： Benign and malignant mammary tumor could be tested in conventional MRI, but with poor effects in the distinction of benign and malignant mammary tumor. The dynamic contrast enhancement can accurately distinguish benign and malignant breast tumor, but with low specificity. Apparent Diffusion Coefficient （ ADC ） value of normal lesion, benign tumor, and malignant tumor was statistically analyzed. With b value of 400s/mm^2, the sensitivity, specificity was 82. 5%, 80%. With b value of 800s/mm^2, the sensitivity, specificity was 92. 65% , 70%. When combined the two test together, sensitivity, specificity was 80% , 92. 5%. Condusion： We should have combined application of DWI and ADC to increase the sensitivity, specificity of breast tumor.