浸润性乳腺癌肿块与非肿块强化方式的表观扩散系数分布特点

目的分析浸润性乳腺癌肿块与非肿块两种强化方式的表观扩散系数(ADC)值分布特点。资料与方法回顾性分析经病理证实为浸润性乳腺癌的170例患者,共170个病灶,术前有完整的磁共振动态增强扫描及扩散加权成像影像资料。在动态增强图像上依据乳腺影像报告和数据系统(BI-RADS)标准将病灶分为肿块强化(116例)及非肿块强化(54例)。对关注病灶测量3次ADC值,取其中最小ADC值纳入研究,比较两种强化方式ADC值的差异和频数分布特点,并比较两种强化方式的时间-信号强度曲线(TIC)类型有无差异。结果170个浸润性乳腺癌平均ADC值为(0.99±0.18)×10^-3mm^2/s;肿块强化病灶的ADC值低于非肿块强化病灶[(0.96±0.15)×10^-3mm^2/s比(1.08±0.22)×10^-3mm^2/s,P<0.001];ADC直方图显示肿块病灶的ADC值比非肿块病灶分布更集中。肿块病灶的TIC曲线分别为Ⅰ型1例、Ⅱ型10例、Ⅲ型105例,非肿块强化病灶的TIC曲线分别为Ⅰ型5例、Ⅱ型13例、Ⅲ型36例,两组TIC曲线分布差异有统计学意义(P<0.001)。结论肿块和非肿块强化浸润性乳腺癌的ADC值存在系统性差异,非肿块的ADC值分布离散可能来自于非肿块测量的部分容积效应,应用ADC作为界值时应区别对待两者的ADC值。

Distribution Characteristics of Apparent Diffusion Coefficient Difference Between Mass and Non-Mass-Enhancement of Invasive Breast Cancer

Purpose To analyze the distribution characteristics of apparent diffusion coefficient(ADC)values between the mass and the non-mass-enhancement types of the invasive breast carcinoma.Materials and Methods 170 patients with pathologically confirmed invasive breast cancer with a total of 170 lesions were retrospectively analyzed,all patients had complete preoperative magnetic resonance dynamic enhanced scanning and DWI data.170 lesions were divided into mass-enhancement(116 cases)and non-mass-enhancement(54 cases)according to the breast imaging reporting and data system(BI-RADS)standard on dynamic enhancement images.The ADC value for the focus of interest was measured for three times,and the smallest ADC value was admitted for the study.The differences in the ADC values and frequency distribution characteristics of the two enhancement methods,and the time-signal intensity curve(TIC)types of the two enhancement methods were compared.Results The average ADC value of 170 invasive breast cancers was(0.99±0.18)×10^-3 mm^2/s;the ADC value of mass-enhancement lesions was lower than that of non-mass-enhancement lesions[(0.96±0.15)×10^-3 mm2/s vs.(1.08±0.22)×10^-3 mm^2/s,P<0.001].ADC histogram showed that the ADC value of the mass-enhancement lesion was more concentrated than that of the non-massenhancement lesion.The TIC curves for mass-enhancement lesion were 1 case of typeⅠ,10 cases of typeⅡand 105 cases of type Ⅲ.The TIC curves for non-mass-enhancement lesions were 5 cases of typeⅠ,13 cases of type Ⅱand 36 cases of type Ⅲ,with statistical difference in distribution between the two groups(P<0.001).Conclusion ADC value is systematically different between mass and non-massenhancement types of invasive breast cancer lesions.The wider distribution of the non-mass-enhancement type may due to the partial effect during measurement on non-mass-enhancement lesions,thus the ADC values of the two should be treated differently when applying ADC as the cutoff.