Preoperative magnetic resonance imaging-based breast volumetry for immediate breast reconstruction.

BACKGROUND: Preoperative breast magnetic resonance imaging (MRI) is a routine test for oncologic evaluation. However, determining breast volume using a preoperative MRI obtained as a part of oncologic evaluation has not yet been attempted for immediate breast reconstruction. The study introduces the benefit of MRI-based volumetry, not only in autologous breast reconstruction but also in implant-based breast reconstruction.

METHODS: Forty patients preparing for autologous breast reconstruction with a deep inferior epigastric artery perforator (DIEP) flap and 30 patients for implant-based breast reconstruction from June 2011 to June 2012 were included in this study. In every DIEP case, we collected data about actual resected breast tissue weight during mastectomy and final flap weight inserted intraoperatively. Computed tomography (CT) was for preoperative CT angiography for microsurgical breast reconstruction, whereas MRI was performed for oncologic evaluation. In every implant-based reconstruction case, MRI-based breast volume was measured in the same way for DIEP patients and resected breast tissue weight was measured intraoperatively. In addition, we also added or subtracted the breast volume by any modification, such as reduction and augmentation on the ipsilateral or contralateral side. To determine the accuracy of MRI-based volumetry, Pearson correlation coefficients were calculated to quantify the correlation between CT and MRI-based volumetry data and intraoperative volume measurements.

RESULTS: For DIEP patients, the mean resected breast tissue weight during mastectomy was more closely related to the mean estimated breast volume using MRI than to the mean estimated breast volume using CT (Pearson coefficient 0.928 and 0.782; p = 0.001). MRI gave a closer correlation to final flap weight than CT (Pearson correlation coefficient 0.959 and 0.873; p = 0.001). For implant-based reconstruction patients, the breast volume measured by MRI correlated closely with the actual mean weight of resected breast specimens (0.937; p = 0.001). Mean net implanted volume was more closely related to mean estimated breast volume using MRI than to mean resected breast tissue weight during mastectomy (0.893 and 0.880; p = 0.001).

CONCLUSIONS: Reliable volumetric information can be obtained using MRI for breast implant volume and autologous tissue needed in optimizing symmetry in breast reconstruction.

LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .