3.0 T乳腺动态增强MRI联合钼靶X线对直径≤2 cm乳腺小结节良恶性鉴别诊断价值

Value of 3.0 T dynamic contrast-enhanced MRI of breast combined with mammography in the differential diagnosis of benign and malignant small breast nodules with diameter ≤2 cm

目的评价3.0 T乳腺动态对比增强MRI (dynamic contrast-enhanced magnetic resonance imaging,DCE-MRI)联合钼靶X线下直径≤2 cm乳腺小结节影像特征及诊断价值。材料与方法回顾性分析2018年1月至2020年9月收治的135例直径≤2 cm的乳腺小结节患者临床资料,所有患者经手术病理或组织穿刺病理活检证实,且术前均有钼靶X线、DCE-MRI检查。分析DCE-MRI检查下乳腺癌及良性病变形态学特征、时间-信号强度曲线(time-signal intensity curve,TIC)分型及TIC最大信号强度值(SImax)、强化峰值(peak height,PH)、最大线性斜率(Slope)、Slope比值(SlopeR)。以病理检查结果为金标准,结合钼靶X线诊断结果,探究DCE-MRI对直径≤2 cm小乳腺癌的诊断价值。结果乳腺癌组DCE-MRI边缘、内部强化形态学特征及TIC分型、早期增强率与良性组比较差异均有统计学意义(P<0.05),其中乳腺癌组边缘毛刺征、内部不均匀强化、TIC分型Ⅲ型、早期增强率≥60%比例分别为73.49%、59.04%、75.90%、83.13%,而良性组对应比例为3.85%、34.62%、7.69%、28.85%。乳腺癌组Slope及SlopeR值均明显高于良性组(P<0.05)。以病理诊断结果为金标准,DCE-MRI诊断直径≤2 cm乳腺癌的敏感度、特异度、准确度及与病理诊断Kappa值分别为0.964、0.904、0.941、0.874,优于钼靶X线的0.832、0.885、0.852、0.696,而二者联合诊断对应值分别为0.988、0.860、0.940、0.869。结论 DCE-MRI下小乳腺结节良恶性病变在形态学、TIC分型及相关参数值方面比较差异均有统计学意义,其对直径≤2 cm小乳腺癌诊断效能优于钼靶X线,且二者联合检查诊断价值更高。

Objective:To evaluate the imaging characteristics and diagnostic value of 3.0 T dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI) of breast combined with mammography on small breast nodules with diameter≤2 cm.Materials and Methods:A retrospective analysis was performed on the clinical data of 135 patients with small breast nodules with diameter≤2 cm who were admitted between January 2018 and September 2020.All patients were confirmed by surgical pathology or tissue biopsy,and they performed mammography and DCE-MRI examination before surgery.The morphological characteristics,time-signal intensity curve(TIC) classification,TIC maximum signal intensity value(SImax),peak height(PH),maximum linear slope(Slope) and Slope ratio(SlopeR) of breast cancer and benign lesions were analyzed under DCE-MRI examination.Taking pathological examination results as the gold standard,mammography diagnosis results were combined to explore the diagnostic value of DCE-MRI on small breast cancer with diameter≤2 cm.Results:There were statistical differences in the morphological characteristics of DCE-MRI margin and internal enhancement and TIC classification and early enhancement rate between breast cancer group and benign group(P<0.05),and the proportions of marginal burr sign,internal uneven enhancement,TIC classification of type Ⅲ and early enhancement rate≥60% were 73.49%,59.04%,75.90% and 83.13% in breast cancer group and were 3.85%,34.62%,7.69% and 28.85% in benign group.The Slope and SlopeRvalue in breast cancer group was significantly higher than those in benign group(P<0.05).Taking pathological diagnosis results as the gold standard,the sensitivity,specificity,accuracy rate and Kappa value with pathological diagnosis of DCE-MRI in diagnosing breast cancer with diameter≤2 cm were 0.964,0.904,0.941 and0.874 respectively,which were better than 0.832,0.885,0.852 and 0.696 of mammography,and the corresponding values of the combined diagnosis of the two were 0.988,0.860,0.940 and 0.869 respectively.Conclusions:The benign and malignant lesions of small breast nodules under DCE-MRI are significantly different in morphology,TIC classification and related parameters.The diagnostic efficacy of DCE-MRI on small breast cancer with diameter≤2 cm is better than that of mammography,and the combination of the two has higher diagnostic value.