OBJECTIVES: To compare the sensitivity of mammogram and breast dedicated MRI in detecting ductal carcinoma in situ with microinvaion (DCIS-MI) and ductal carcinoma in situ (DCIS) lesions, and to further investigate the independent predictive factors of mammogram and MRI sensitivity. METHODS: From August 2009 to November 2011, 122 consecutive confirmed breast cancer patients who had received operations were recruited for this clinical research. These patients were divided into two groups including DCIS (72 cases) and DCIS-MI (50 cases) based on pathologic reports. All the patients were female, with mean ages of 52.6 years and 54.4 years. Preoperative bilateral breast mammogram, breast dedicated MRI depictions and reports as well as histopathological reports were collected. RESULTS: Sensitivity of MRI outstood mammogram in each subgroups: 84.7% vs. 42.4% in DCIS (χ(2) = 27.028, P = 0.000), 94.0% vs. 80.0% in DCIS-MI group (χ(2) = 4.540, P = 0.040). And further analysis showed that MRI was more sensitive to high nuclear grade DCIS and DCIS-MI lesions than low nuclear grade ones (OR = 3.471, P = 0.031). RESULTS: of logistic regression analysis proved microcalcification was an independent predictive factor of mammogram sensitivity (OR = 11.287, P = 0.001). CONCLUSIONS: Sensitivity of breast dedicated MRI is superior to mammogram in detecting DCIS and DCIS-MI groups. Lesions with microcalcifiation is an independent predictive marker which meant that mammogram would achieve high detection rate in cancers presented calcification on mammogram image when compared with non-calcification. Diagnostic performance of breast MRI is less affected by clinical and pathological characteristics of the early stage breast cancer patients but further increased detection rate is observed in DCIS and DCIS-MI with high nuclear grade lesions which indicated that MRI could detect more early stage cancers with relative more aggression biological behaviour and provide these patients with early surgical interventions before possible progression to invasive breast cancers.