In vivo MR tracking of magnetically labeled mesenchymal stem cells in rabbit liver

    XU Jian1, ZHENG Minª²Wen1,HUAN Yi1, CHENG Kang2, ZHAO Haiª²Tao1, ZHENG Minª²Juan3, GE Yaª²Li1, SUN Liª²Jun1

    1Department of Radiological Diagnosis, 2Department of Cardiovasology, 3Department of Ultrasonography, Xijing Hospital, Fourth Military Medical University, Xi¬ðan 710033, China

    ¡¾Abstract¡¿ AIM£º To label bone marrowª²derived stem cells with superparamagnetic iron oxid (SPIO) and to explore the image characteristics and signal attenuation rules of in vivo the magnetic resonance imaging(MRI) of the labeled cells in rabbit liver. METHODS£º Marrow stem cells (MSCs) were isolated from rabbit and incubated with SPIO(Resovist).Cell injections into rabbit liver were conducted under the leading of ultrasound. Rabbit livers were imaged at multiple time points by MRI including T1 weighted imaging(T1WI), T2 weighted imaging(T2WI) and fast field echo(FFE) sequences to study SPIOª²labeled MSCs in vivo after liver injection. RESULTS£º Labeled cells remained viable for multiple passages and retained in vitro the abilities of proliferation and differentiation. SPIO labeling caused a lower signal on MRI and a more obvious attenuation effect on FFE than on T1WI and T2WI. The signal attenuation persisted until day 30, 30 and 45 after injection and the low signal disappeared at 38,38,60 d after injection on T1WI and T2WI and FFE respectively. CONCLUSION£º SPIO labeling for MSCs is convenient and effective without hurting cell viability. MR tracking of SPIOª²labeled MSCs is feasible and the ability to identify noninvasively intraliver cell implantation may be determinant for future experimental studies. ......