Abstract #3014

Pitfalls of SPIO-Enhanced MR Lymphography in Sentinel Lymph Nodes: Pathogenesis of High Signals Mimicking Metastasis in Inflamed Lymph Nodes

Daisuke Suzuki¹,², Masayuki Yamaguchi¹, Toshihiro Furuta¹,³, Ryutaro Nakagami¹,⁴, Yasuo Okuyama², Kohki Yoshikawa², Hirofumi Fujii¹

¹Functional Imaging Division, National Cancer Center Hospital East, Kashiwa, Chiba, Japan; ²Graduate Division of Health Sciences, Komazawa University, Setagaya, Tokyo, Japan; ³Department of Radiology, The University of Tokyo, Tokyo, Japan; ⁴Research Fellow of the Japan Society for the Promotion of Science, Japan

Superparamagnetic iron oxide (SPIO)-enhanced MRI can differentiate sentinel lymph node (SLN) metastasis from inflammation by the presence and absence of high signals in lymph nodes according to previous reports. In this study, we revealed that high-signal areas mimicking metastatic foci could appear even in inflamed lymph nodes. We also investigated the pathogenesis of residual high signals in analyzing the relationship between SPIO doses and high signal areas using an animal model, and found that expanded paracortices not containing macrophages and inhomogeneous distribution of macrophages may cause these high signals in inflamed lymph nodes.