Masayuki Yamaguchi1, Daisuke Suzuki1,2, Ryosuke Shimizu1,2, Ryutaro Nakagami1,3, Keisuke Tsuda1, Izumi Ogihara Umeda1, Yasuo Okuyama2, Kohki Yoshikawa2, Hirofumi Fujii1,4
1Functional Imaging Division, National Cancer Center Hospital East, Kashiwa, Chiba, Japan; 2Faculty of Health Sciences, Komazawa University, Setagaya, Tokyo, Japan; 3Graduate School of Human Health Sciences, Tokyo Metropolitan University, Arakawa, Tokyo, Japan; 4Institute for Bioinformatics Research and Development-Japan Science and Technology Agency, Chiyoda, Tokyo, Japan
We tested the SPECT-MRI fusion technique to visualize regional lymph nodes involved in subacute inflammation arising from the lymphatic basin using a mouse model. Two to three weeks after the administration of Freund complete adjuvant to the foot pad, 99mTc phytate high-resolution SPECT images of the hind limb were obtained using a small animal SPECT scanner equipped with 4 detectors with multi-pinhole collimators. These SPECT images were merged with MR images to provid precise anatomical information. SPECT-MRI fusion images showed swollen popliteal lymph nodes and the accumulation of 99mTc at the periphery, suggesting the inhomogeneous distribution of macrophages within the swollen lymph nodes.