Distinguishing Lipid Subtypes by Amplifying Contrast from J-Coupling.
Distinguishing Lipid Subtypes by Amplifying Contrast from J-Coupling.
复制标题
通过放大 J 耦合对比度来区分脂质亚型。
DOI：
10.1038/s41598-019-39780-4
复制
发表时间：
2019
影响因子：
4.6
通讯作者：
Galiana,Gigi
中科院分区：
文献类型：
--
作者：
Uche,IfeanyiK;Galiana,Gigi
以前的工作强调了在一系列自旋回波过程中设置信号演变的复杂而独特的动力学，特别是在回波间隔不均匀的情况下，应用于脂肪等复杂分子。本文介绍的工作将这些信号模式视为可以用作对比机制的代码，能够区分具有成像序列的分子混合物，从而绕过了光谱学的许多挑战。对于特定的回波间隔阵列，可以增强非单调和独特的信号进化，以改善目标物种之间的对比度。这项工作提供的模拟显示了两个分子之间的对比度：(A)取决于特定的回波间隔序列，(B)与J耦合的存在直接相关，以及(C)对B0、T2和B1的变化相对不敏感。对油的成像研究在实验上证明了这一现象，也表明自旋回波码可以用于量化。最后，初步实验将该方法应用于人体活体肝脏，验证了脂肪的存在可以导致非单调密码，就像在体外看到的那样。总而言之，非均匀间隔的回声序列引入了一种新的J偶联物种的分子成像方法，例如脂类，这可能对诊断代谢性疾病有意义。
Previous work has highlighted the complicated and distinctive dynamics that set signal evolution during a train of spin echoes, especially with nonuniform echo spacing applied to complex molecules like fats. The work presented here regards those signal patterns as codes that can be used as a contrast mechanism, capable of distinguishing mixtures of molecules with an imaging sequence, sidestepping many challenges of spectroscopy. For particular arrays of echo spacings, non-monotonic and distinctive signal evolution can be enhanced to improve contrast between target species. This work presents simulations that show how contrast between two molecules: (a) depends on the specific sequence of echo spacing, (b) is directly linked to the presence of J-coupling, and (c) can be relatively insensitive to variations in B0, T2 and B1. Imaging studies with oils demonstrate this phenomenon experimentally and also show that spin echo codes can be used for quantification. Finally, preliminary experiments apply the method to human liverin vivo, verifying that the presence of fat can lead to nonmonotonic codes like those seenin vitro. In summary, nonuniformly spaced echo trains introduce a new approach to molecular imaging of J-coupled species, such as lipids, which may have implications diagnosing metabolic diseases.