Effect of NC100150 injection on the H-1 NMR linewidth of human whole bloodex vivo: Dependency on blood oxygen tension

The linewidth of the H-1 NMR signal (7.05 T) of human whole blood titrated with a superparamagnetic contrast agent (NC100150 injection) was evaluated at different blood oxygen tensions. In deoxygenated blood and low contrast agent concentrations, NC100180 injection caused a decrease in linewidth. Af ter reaching a minimum, the linewidth increased as the concentration of NC1 00150 injection increased. At the concentration corresponding to the minimu m linewidth, the magnetization of the extracellular space containing the NC 100150 injection was equal to that of the paramagnetic (deoxygenated hemogl obin) intracellular space. The minimum linewidth is therefore consistent wi th a complete elimination of the local microscopic susceptibility effect, t he major cause of linebroadening, Additionally, phantom studies were perfor med at 1.5 T, confirming that the contrast enhancement of NC100150 injectio n in blood is dependent on oxygen tension. The data suggest that NC100150 i njection may be useful in differentiating vessels with varying relative oxy gen tensions. (C) 2000 Wiley-Liss, Inc.