PURPOSE: Our purpose was to investigate the utility of superparamagnetic iron-oxide nanoparticles (SPIO) as a blood-pooling contrast agent at magnetic resonance imaging (MRI). MATERIALS AND METHODS: We studied four contrast agents: carboxymethyl-diethylaminoethyl dextran magnetite SPIO (CMEADM-S, diameter 54 nm), negatively charged CMEADM ultrasmall SPIO (CMEADM-U, 32 nm), alkali-treated dextran magnetite SPIO (ATDM-S, 55 nm), and ATDM ultrasmall SPIO (ATDM-U, 28 nm) carrying a neutral charge. Each contrast agent (80 μmol/kg) was injected intraperitoneally into apolipoprotein E (apoE) mice and the tissue iron concentration was measured 30-, 60-, 180-, and 300-min later by nuclear MR. For MR angiographic (MRA) evaluation, we injected the agents into the auricular vein of four groups of 15 rabbits. Immediately and 30-, 60-, 180-, and 300-min later, three rabbits from each group were subjected to MRI. The organ/background signal ratio (SR) was calculated. Statistical analyses were performed with Tukey's honestly significant difference (HSD) test. RESULTS: At 60 and 180 min, blood-iron concentration of CMEADM-U was significantly different from other contrast agents. In the abdominal aorta and inferior vena cava, SR of CMEADM-U was higher at 180 and 300 min than of the other contrast agents. In the thoracic aorta, there was no difference in SR at 300 min between CMEADM-U and CMEADM-S. CONCLUSION: Negatively charged SPIO nanoparticles may be useful as a blood-pooling contrast agent.
PURPOSE: Our purpose was to investigate the utility of superparamagnetic iron-oxide nanoparticles (SPIO) as a blood-pooling contrast agent at magnetic resonance imaging (MRI). MATERIALS AND METHODS: We studied four contrast agents: carboxymethyl-diethylaminoethyl dextran magnetite SPIO (CMEADM-S, diameter 54 nm), negatively charged CMEADM ultrasmall SPIO (CMEADM-U, 32 nm), alkali-treated dextran magnetite SPIO (ATDM-S, 55 nm), and ATDM ultrasmall SPIO (ATDM-U, 28 nm) carrying a neutral charge. Each contrast agent (80 μmol/kg) was injected intraperitoneally into apolipoprotein E (apoE) mice and the tissue iron concentration was measured 30-, 60-, 180-, and 300-min later by nuclear MR. For MR angiographic (MRA) evaluation, we injected the agents into the auricular vein of four groups of 15 rabbits. Immediately and 30-, 60-, 180-, and 300-min later, three rabbits from each group were subjected to MRI. The organ/background signal ratio (SR) was calculated. Statistical analyses were performed with Tukey's honestly significant difference (HSD) test. RESULTS: At 60 and 180 min, blood-iron concentration of CMEADM-U was significantly different from other contrast agents. In the abdominal aorta and inferior vena cava, SR of CMEADM-U was higher at 180 and 300 min than of the other contrast agents. In the thoracic aorta, there was no difference in SR at 300 min between CMEADM-U and CMEADM-S. CONCLUSION: Negatively charged SPIO nanoparticles may be useful as a blood-pooling contrast agent.
Authors: Anuradha Saokar; Michael S Gee; Tina Islam; Peter R Mueller; Mukesh G Harisinghani Journal: Clin Imaging Date: 2010 Nov-Dec Impact factor: 1.605
Authors: Hye Jin Yoo; Jeong Min Lee; Jae Young Lee; Se Hyung Kim; Soo Jin Kim; Joon Koo Han; Byung Ihn Choi Journal: Invest Radiol Date: 2009-12 Impact factor: 6.016