Magnetic resonance imaging appearance of oxidized regenerated cellulose in breast cancer surgery

To describe magnetic resonance imaging (MRI) findings in patients who underwent breast-conserving surgery followed by oxidized regenerated cellulose (ORC) implantation in surgical cavity. We retrospectively reviewed 51 MRI examinations performed between January 2009 and January 2014 in 51 patients who underwent BCS with ORC implantation. In 29/51 (57 %) cases, MRIs showed abnormal findings with three main MRI patterns: (1) complex masses: hyperintense collections on T2-weighted (w) images with internal round hypointense nodules without contrast enhancement (55 %); (2) completely hyperintense collections (17 %); and (3) completely hypointense lesions (28 %). All lesions showed rim enhancement on T1w images obtained in the late phase of the dynamic study with a type 1 curve. Diffusion-weighted imaging was negative in all MRIs and, in particular, 22/29 (76 %) lesions were hyperintense but showing ADC values > 1.4 x 10(-3) mm(2)/s, while the remaining 7/29 (24 %) lesions were hypointense. In four cases, linear non-mass-like enhancement was detected at the periphery of surgical cavity; these patients were addressed to a short-term follow-up, and the subsequent examinations showed the resolution of these findings. When applied to surgical residual cavity, ORC can lead alterations in surgical scar. This could induce radiologists to misinterpret ultrasonographic and mammographic findings, addressing patients to MRI or biopsy; so knowledge of MRI specific features of ORC, it is essential to avoid misdiagnosis of recurrence.