Hyperpolarized 83Kr MRI of lungs
Hyperpolarized 83Kr MRI of lungs
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DOI：
10.1016/j.jmr.2008.09.020
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发表时间：
2008-12-01
影响因子：
2.2
通讯作者：
Meersmann, Thomas
中科院分区：
文献类型：
--
作者：
Cleveland, Zackary I.;Pavlovskaya, Galina E.;Meersmann, Thomas
超极化（hp）Kr-83（自旋I = 9/2）是一种有前途的气相造影剂，其对周围环境的表面化学、表面体积比和表面温度显示出灵敏度。该原理验证研究证明了使用天然丰度氪气（11.5%Kr-83）和位于定制设计的通风室内的切除但其他方面完整的大鼠肺进行离体hp Kr-83肺磁共振成像（MRI）的可行性。将来自肺部的Kr-83 MR信号强度与来自没有内部结构的气囊的信号强度进行比较的实验表明，所观察到的信号大多数来自肺泡，而不仅仅是传导气道。Kr-83的纵向弛豫时间在大鼠肺的范围从0.7至3.7秒，但可重现的给定的肺。虽然在这项工作中没有探索这些变化的来源，但hp Kr-83 T-1差异可能最终导致肺部MRI造影剂的新形式。目前获得的1200倍的信号增强hp Kr-83在9.4 T场强被发现是180倍低于理论上限。(C)2008年爱思唯尔公司All rights reserved.
Hyperpolarized (hp) Kr-83 (spin I = 9/2) is a promising gas-phase contrast agent that displays sensitivity to the surface chemistry, surface-to-volume ratio, and surface temperature of the surrounding environment. This proof-of-principle study demonstrates the feasibility of ex vivo hp Kr-83 magnetic resonance imaging (MRI) of lungs using natural abundance krypton gas (11.5% Kr-83) and excised, but otherwise intact, rat lungs located within a custom designed ventilation chamber. Experiments comparing the Kr-83 MR signal intensity from lungs to that arising from a balloon with no internal structure inflated to the same volume with krypton gas mixture suggest that most of the observed signal originated from the alveoli and not merely the conducting airways. The Kr-83 longitudinal relaxation times in the rat lungs ranged from 0.7 to 3.7 s but were reproducible for a given lung. Although the source of these variations was not explored in this work, hp Kr-83 T-1 differences may ultimately lead to a novel form of MRI contrast in lungs. The currently obtained 1200-fold signal enhancement for hp Kr-83 at 9.4 T field strength is found to be 180 times below the theoretical upper limit. (C) 2008 Elsevier Inc. All rights reserved.