全容积ADC直方图评估乳腺癌淋巴管侵犯的价值

Value of apparent diffusion coefficient histogram in predicting lymphovascular invasion in breast cancer

目的探讨表观扩散系数(ADC)直方图对乳腺癌淋巴管侵犯(LVI)的预测价值。方法回顾性分析51例女性乳腺癌病人的常规MRI及扩散加权成像(DWI)资料,根据病理结果将病人分为LVI阳性组[19例,平均年龄(54.89±7.64)岁]和LVI阴性组[32例,平均年龄(53.66±9.12)岁],测量并记录2组乳腺癌的ADC直方图各参数值(最大值、最小值、平均值、中位数、偏度值、峰度值),以独立样本t检验或Mann-Whitney U检验比较2组乳腺癌ADC直方图各参数的差异。采用受试者操作特征(ROC)曲线计算ADC直方图各参数值对乳腺癌LVI的诊断效能。结果 2组乳腺癌病人ADC直方图最大值和峰度值差异均无统计学意义(均P>0.05);LVI阳性组ADC直方图最小值、平均值、中位数均低于LVI阴性组,且以正偏态分布为主(均P<0.05)。ADC直方图各参数值对乳腺癌LVI阳性的诊断效能中最小值的曲线下面积最大(0.817),且敏感度(89.47%)及阴性预测值(92.59%)最高;而偏度值的特异度最高(87.50%)。结论全容积ADC直方图对乳腺癌LVI具有较高的预测价值,ADC最小值与偏度值各具较优的诊断效能。

Objective To investigate the predictive value of apparent diffusion coefficient(ADC) histogram for lymphovascular invasion(LVI) in breast cancer. Methods Conventional MRI and diffusion-weighted imaging from 51 patients with breast cancer were retrospectively analyzed. The patients were divided into LVI positive group(19 cases, 54.89±7.64 years) and LVI negative group(32 cases, 53.66±9.12 years) according to the pathological results. The ADC histogram parameters including maximum, minimum, average, median, skewness, and kurtosis were recorded for the two groups. The differences in ADC histogram parameters between the two groups were compared using independent sample t test or MannWhitney U test. The diagnostic efficacy of ADC histogram parameters for LVI was calculated using ROC curve. Results There was no significant difference in ADC histogram maximum and peak value between the two groups(P>0.05);the ADC histogram minimum, average, and median values of the LVI positive group were lower than those of the LVI negative group,and the distributions of those parameters were positive skewness(P<0.05). The minimum ADC value achieved the largest area under the curve(0.817), the highest sensitivity(89.47%) and negative predictive value(92.59%), while the skewness value achieved the highest specificity(87.50%) for LVI positive breast cancer. Conclusion ADC histogram has high predictive value for LVI of breast cancer. The minimum and skewness values of ADC have better diagnostic efficiency.