Sukstanskii Alexander L, Quirk James D, Yablonskiy Dmitriy A
Department of Radiology, Washington University, St. Louis, MO, USA.
NMR Biomed. 2014 Dec;27(12):1451-60. doi: 10.1002/nbm.3150. Epub 2014 Jun 11.
In this paper we demonstrate that gradient echo MRI with hyperpolarized (3)He gas can be used for simultaneously extracting in vivo information about lung ventilation properties, alveolar geometrical parameters, and blood vessel network structure. This new approach is based on multi-gradient-echo experimental measurements of hyperpolarized (3)He gas MRI signal from human lungs and a proposed theoretical model of this signal. Based on computer simulations of (3)He atoms diffusing in the acinar airway tree in the presence of an inhomogeneous magnetic field induced by the susceptibility differences between lung tissue (alveolar septa, blood vessels) and lung airspaces, we derive analytical expressions relating the time-dependent MR signal to the geometrical parameters of acinar airways and the blood vessel network. Data obtained on eight healthy volunteers are in good agreement with literature values. This information is complementary to the information obtained by means of the in vivo lung morphometry technique with hyperpolarized 3He diffusion MRI previously developed by our group, and opens new opportunities to study lung microstructure in health and disease.
在本文中，我们证明了利用超极化（3）He气体的梯度回波磁共振成像（MRI）可同时提取有关肺通气特性、肺泡几何参数和血管网络结构的体内信息。这种新方法基于对来自人体肺部的超极化（3）He气体MRI信号的多梯度回波实验测量以及针对该信号提出的理论模型。基于对（3）He原子在腺泡气道树中扩散的计算机模拟，该模拟考虑了由肺组织（肺泡间隔、血管）和肺气腔之间的磁化率差异所引起的非均匀磁场，我们推导了将随时间变化的MR信号与腺泡气道和血管网络的几何参数相关联的解析表达式。在八名健康志愿者身上获得的数据与文献值高度吻合。该信息与我们团队先前开发的利用超极化3He扩散MRI的体内肺形态测量技术所获得的信息互为补充，并为研究健康和疾病状态下的肺微观结构提供了新的机会。
