Methods are described for preparing magnetic resonance imaging (MRI) and/or magnetic resonance spectroscopy contrast agents where the contrast agents are prepared from precursor molecules having at least four non-zero-spin nuclei that form two pairs of chemically equivalent or effectively equivalent nuclei, e.g., diphenylacetylene or diethyl oxalate. The precursor molecule is hyperpolarized and a sequence of one or more radiofrequency pulses is applied to transfer spin state population between the first and second pair of nuclei, thereby providing a non-equilibrium single state nuclear spin population. To detect the contrast agent, another sequence of one or more radiofrequency pulses is applied to transfer singlet order to polarization. No transformation of the molecular structure of the contrast agent is necessary for detection. Also described are methods of imaging targets using the contrast agents.
本文描述了制备磁共振成像(MRI)和/或磁共振波谱学对比剂的方法,其中对比剂是由至少四个非零自旋核形成的前体分子制备而成,这些核形成两对
化学等价或有效等价的核,例如二
苯乙炔或
草酸二乙酯。前体分子被超极化,然后应用一个或多个无线电频率脉冲序列来在第一对核和第二对核之间转移自旋状态,从而提供非平衡单态核自旋种群。为了检测对比剂,另一个或多个无线电频率脉冲序列被应用来将单态序转移到极化。不需要对比剂的分子结构进行转换以进行检测。还描述了使用对比剂成像目标的方法。