RESUMO
Objective To explore the value of the minimum apparent diffusion coefficient (ADC-min) value in the diagnosis of ductal carcinoma in situ (DCIS) and invasive cancer of breast.Methods One hundred and forty nine cases of breast cancer verified by histopathology were included in this retrospective study.All the patients underwent dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) and diffusion weighted imaging (DWI) before the biopsy.The ADC min value and its correlation with invasive ductal carcinoma(IDC),DCIS and IDC-DCIS were analyzed.Results The mean ADC-min values for IDC,IDC-DCIS and DCIS were (0.95±0.16)×10-3 mm2/s,(1.07±0.13)×10-3 mm2/s and (1.24±0.18)×10-3 mm2/s,respectively.The ADC-min value of the three groups showed an increasing trend and there were significant differences (F=32.08,P＜0.01).The optimal cutoff ADC-min value was 1.02 × 10-3 mm2/s to differentiate DCIS from invasive cancer with a sensitivity of 95.0％ and a specificity of 63.6％.Conclusion The ADC min values are significantly different among IDC,IDC-DCIS and DCIS.It may be used as a reliable tool to differentiate DCIS and invasive cancer of breast.