The present invention provides the use of a persistent .pi.-system free radical for the manufacture of a contrast medium for use in magnetic resonance imaging, wherein the electron delocalising .pi.-system of said radical comprises at least one homo or heterocyclic ring, said radical being other than the chloranil semiquinone anion radical or a trityl radical. Also provided are magnetic resonance imaging contrast media containing and methods using such radicals.
本发明提供了使用一种持久的π-系统自由基制造用于磁共振成像的对比剂的方法,其中所述自由基的电子离域π-系统包括至少一个同源或异源环,所述自由基不同于
氯氧化苯半醌阴离子自由基或三苯
甲基自由基。还提供了包含这种自由基的磁共振成像对比剂和使用这种自由基的方法。