LANTHANIDE(ІІІ) CHELATES AS MRI CONTRAST AGENTS: A BRIEF DESCRIPTION
H. Ur Rashid, K. Yu, J. Zhou
Huazhong University of Science and Technology, Wuhan, P. R. China
haroongold@gmail.com
Ключевые слова: magnetic resonance imaging (MRI), gadolinium, relaxivity, nuclear relaxation, mean residence lifetime, contrast agents, hydration number, nephrogenic systemic fibrosis (NSF)
Страницы: 1181-1206
Аннотация
Magnetic resonance imaging (MRI) has become a prominent imaging technique in medicine. Gadolinium-based contrast agents are extensively used to enhance the contrast between normal and diseased tissues through MRI scans. The article illustrates the paramount significance of such contrast agents in MRI applications. Clinically approved contrast agents as well as those in trial period are discussed. Important parameters, i.e. hydration number, rotational correlation time, and mean residence lifetime, influencing the relaxivity (sensitivity) of such agents are described in detail. Various approaches towards relaxivity enhancement are discussed with appropriate examples from the recent literature. A decrease in the Gd-water proton distance results in significant relaxivity enhancement. A comprehensive classification and explanation of Gd3+-based contrast agents are presented. Each class is explained with suitable examples. The stability of contrast agents is dependent on their chemical structure. Future contrast agents need to be tissue specific of high relaxivity, low toxicity, and lower administered dose for in vivo use.
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