It is considered that whether or not the accompanying invasive cancer classified through MRI images of breast cancer patients identified as Ductal Carcinoma in situ (DCIS) through preoperative tissue biopsy is significantly consistent with the postoperative stage.

Therefore, this study intend to evaluate the effectiveness as a diagnostic tool that can help determine the axillary lymph node surgery by predicting the possibility of post-operative up-staging using magnetic resonance imagings of breast cancer patients who have been identified as ductal carcinoma in situ and are scheduled for surgery.

1. To date, there is no significant research data on the value of the Apparent Diffusion Coefficient (ADC) that can distinguish between pure Ductal Carcinoma in situ (pure DCIS) and invasive cancer (DCIS-IC), from June 2019 to 2020 1 Of the 144 patients who obtained Diffusion Weighted images (b=0,800,1200) with 3.0-T MRI equipment and diagnosed with ductal carcinoma in situ on the biopsy, among 144 patients who did not undergo preoperative chemotherapy using a CAD program, the 3-dimensional Apparent Diffusion Coefficient value of the tumor is measured and compared with whether or not there is invasive cancer after surgery, and the optimal Apparent Diffusion Coefficient reference value that can predict the invasive cancer will be retrospectively derived.
2. Scheduled MRI tests will be performed on patients enrolled from July 2020, and will be performed using the standard protocols (3T, contrast enhancement and diffuse enhancement images DWI b0,800,1200). Among the MRI images taken, the range of lesions is evaluated in contrast-enhanced T1-highlighted images, and the Apparent Diffusion Coefficient values of the lesions are three-dimensionally mapped using a CAD program and histogram analysis on diffused images. The ADC reference value derived from the retrospective analysis is used to predict prospectively for invasive cancer in all lesions.
3. Mastectomy is performed according to the existing surgical method. Axillary lymph node surgery is determined according to the existing decision method (tumor location, size, range, histological grade, etc.).

Inclusion Criteria:

• Adult over 19 years-old
• Breast Ductal Carcinoma in-situ patients who diagnosed preoperative tissue biopsy
• A person who understands this study and agrees with willingness to participate

Exclusion Criteria:

• Ductal Carcinoma in-situ which diagnosed excisional biopsy
• When there is no lesion that can be discriminated from magnetic resonance imaging
• Neoadjuvant chemotherapy patients
• Patients who have complication (hematoma, abscess etc.) after preoperative biopsy