磁共振扩散加权成像在乳腺肿瘤的初步应用

目的利用扩散加权成像(diffusion weighted imaging,DWI)的表观扩散系数(apparent diffusion coefficient,ADC),探讨其在诊断乳腺良恶性肿物方面的价值. 方法患者28人,良性8人,恶性20人.均经手术病理证实.DWI采用两组序列(分别为扩散敏感系数b=0,1000s/mm2,和b=30,300,1100s/mm2),并计算ADC值. 结果在b=1000-0s/mm2 时,正常腺体的ADC值(1.75±0.54)×10-3mm2/s]与良性肿物的ADC值(1.53±0.34)×10-3mm2/s]间无显著统计学意义,正常腺体与恶性肿物的ADC值(1.22±0.28)×10-3mm2/s]间有显著统计学意义,良恶性肿物间有显著统计学意义.在b=300,30s/mm2 时,三者间无显著统计学意义.在b=1100,300s/mm2 时,良恶性肿物间无显著统计学意义.我们把良恶性病变ADC值的界值定为1.35×10-3mm2/s,即<1.35为恶性,>1.35为良性,诊断的敏感性为69.6%,特异性为75.0%. 结论 DWI图像(尽量选择TE时间与肿瘤的T2相近的序列)有助于检出病变,可作为常规检查序列之一.大b值差的ADC值能够鉴别良恶性乳腺肿瘤.

Initial Study of Diagnostic Value in Diffusion Weighted Imaging of Breast Neoplasm

Objective To evaluate the value of diffusion weighted imaging (DWI) and apparent diffusion coefficients (ADC) in distinguishing benign and malignant breast lesions. Methods Twenty-eight patients, 8 of them with benign lesions,and 20 with malignant lesions were examined. All cases were confirmed by pathologic diagnosis. Two sequences of echo planar diffusion imaging were used, b value (×10^-3mm²/s) was 1000, 0 and 1100,300,30 respectively. Then the ADC value were calculated. Results There was no statistical difference between the ADC value of normal breast tissue and benign lesions, and the ADC value of malignant lesions was statistically different from that of normal breast tissue, and so was between benign and malignant lesions at b value of 0 and 1000. Three of them were not statistically different at b value of 30 and 300. Benign and malignant lesions were not statistically different at b value of 300 and 1100. The sensitivity and specificity of diagnostic indices of ADC were 69.6% and 75.0%. Conclusion DWI is a rapid and feasible method in detecting breast lesions. The ADC value with large difference can be used to differentiate malignant and benign lesions.