MR扩散加权成像对乳腺良恶性疾病的应用研究

The Application of MR Diffusion Weighted Imaging in Differentiation of Benign from Malignant Breast Lesions

目的探讨MR扩散加权成像(DWI)的技术方法及表观扩散系数(ADC)值对乳腺良、恶性疾病的诊断及鉴别诊断价值。资料与方法经病理证实的乳腺病变50例,58个病灶,其中恶性32个,良性26个。检查使用Siemens1.5T磁共振仪、专用双穴乳腺表面线圈。所有病例采用单次激发自旋回波-回波平面成像(SE-EPI)序列行DWI,扩散敏感系数(b值)取0、400、600、800、1000s/mm2。以恶性病变ADC值95%可信区间的上界作为诊断病变良、恶性的界值,所得结果与病理结果比较。结果DWI显示92.3%(24/26)的良性病变和96.9%(31/32)的恶性病变,敏感性为94.8%(55/58)。各b值良性组、恶性组和正常组之间的ADC值差异均有统计学意义(P<0.05)。取b=1000s/mm2,以恶性病变ADC值95%可信区间的上界1.4276×10-3mm/s为界诊断良、恶性的敏感性为90.6%,特异性为84.6%,准确性为87.9%。结论(1)DWI对乳腺疾病的敏感性非常高。(2)ADC值是诊断和鉴别诊断乳腺良、恶性疾病的有价值的参数。(3)b=1000s/mm2时对乳腺疾病的诊断最有价值。

Objective To discuss the technique of DWI and its diagnostic ability to differentiate benign from malignant breast lesions. Materials and Methods 50 eases （58 lesions） proved by pathologic results included 32 malignant lesions and 26 benign lesions. Siemens Magnetom Avanto 1.5T MR and a proprietary phase array breast coil were used. DWI was done with single shot SE EPI sequence, b= 0s/mm^2, 400s/mm^2, 600s/mm^2, 800 s/mm^2, 1000s/mm^2. Regard the upper bound of 95% confidence interval of ADC value as standard to diagnose benign and malignant, results were compared with pathology. Results DWI showed 92.3% benign lesions （24/26） and 96.9% malignant lesions （31/32）. The ADC values had statistic significance among benign lesions, malignant lesions and normal tissues, （ F-test, SNK-q-test, P 〈 0.05）, b = 1000, x = 1.4276 ×10^-3mm/s as standard to diagnose benign and malignant lesions, the sensitivity was 90.6%, specificity was 84.6% and accuracy was 87.9%. Conclusion DWI has high sensitivity to breast lesions. ADC value is an important parameter to diagnose breast benign and malignant lesions, especially using b = 1000 s/mm^2.