German Cancer Research Center - DKFZ, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
Neuroradiology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany.
Phys Rev E. 2017 Feb;95(2-1):022415. doi: 10.1103/PhysRevE.95.022415. Epub 2017 Feb 24.
We propose a surface model of spin dephasing in lung tissue that includes both susceptibility and diffusion effects to provide a closed-form solution of the Bloch-Torrey equation on the alveolar surface. The nonlocal susceptibility effects of the model are validated against numerical simulations of spin dephasing in a realistic lung tissue geometry acquired from synchotron-based μCT data sets of mouse lung tissue, and against simulations in the well-known Wigner-Seitz model geometry. The free induction decay is obtained in dependence on microscopic tissue parameters and agrees very well with in vivo lung measurements at 1.5 Tesla to allow a quantification of the local mean alveolar radius. Our results are therefore potentially relevant for the clinical diagnosis and therapy of pulmonary diseases.
我们提出了一种肺部组织中自旋去相位的表面模型，该模型同时包含磁化率和扩散效应，可以为肺泡表面的布洛赫-托里方程提供封闭形式的解。该模型的非局部磁化率效应通过对基于同步加速器的小鼠肺部组织 μCT 数据集获得的真实肺部组织几何形状中的自旋去相位的数值模拟进行了验证，并与著名的威格纳-塞茨模型几何形状中的模拟进行了验证。自由感应衰减取决于微观组织参数，并与 1.5T 下的体内肺部测量结果非常吻合，从而可以定量计算局部平均肺泡半径。因此，我们的结果对于肺部疾病的临床诊断和治疗具有潜在的相关性。
