Magnetic resonance imaging of liver and spleen with superparamagnetic contrast agents

摘要: A method of imaging a tumor by magnetic resonance (MRI) liver and/or spleen is provided which employes microspheres composed biodegradeable matrix material with particulate superparamagnetic contrast agent therein. The have diameters less than 1.5 microns, and the ferromagnetic agent, such as magnetite, has particle size below 300 Angstroms. when administered intravenously segregate through reticuloendothelial system in where they reduce T 2 relaxation time to obtain improved MR imaging. In or mixed 1 images obtained MRI examination, normal tissues appear dark appears light distinct margins therebetween.