Wolf G L, Joseph P M, Goldstein E J
AJR Am J Roentgenol. 1986 Aug;147(2):367-71. doi: 10.2214/ajr.147.2.367.
Chelates of paramagnetic metals have been developed for use as contrast agents for MRI. Several such agents are cleared by biliary excretion and significantly reduce proton T1 and T2 of liver and bile. These influences on proton-relaxation rates also influence the choice of pulsing sequences. In studies on rabbits, with and without contrast agents, the influence of repetition time (TR) and echo-delay time (TE) are demonstrated. Excellent liver images were obtained with an imaging time of 20 sec using TR = 80 msec, TE = 10 msec, and two excitations. The effects of such contrast agents are best imaged at short TR and short TE.
顺磁性金属螯合物已被开发用作磁共振成像（MRI）的造影剂。几种此类造影剂通过胆汁排泄清除，并显著降低肝脏和胆汁的质子T1和T2。这些对质子弛豫率的影响也会影响脉冲序列的选择。在对有或没有造影剂的兔子进行的研究中，展示了重复时间（TR）和回波延迟时间（TE）的影响。使用TR = 80毫秒、TE = 10毫秒和两次激发，在20秒的成像时间内获得了出色的肝脏图像。此类造影剂的效果在短TR和短TE时成像最佳。
