O'Halloran Rafael L, Holmes James H, Wu Yu-Chien, Alexander Andrew, Fain Sean B
Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53792, USA.
Magn Reson Med. 2010 Jan;63(1):41-50. doi: 10.1002/mrm.22158.
An undersampled diffusion-weighted stack-of-stars acquisition is combined with iterative highly constrained back-projection to perform hyperpolarized helium-3 MR q-space imaging with combined regional correction of radiofrequency- and T1-related signal loss in a single breath-held scan. The technique is tested in computer simulations and phantom experiments and demonstrated in a healthy human volunteer with whole-lung coverage in a 13-sec breath-hold. Measures of lung microstructure at three different lung volumes are evaluated using inhaled gas volumes of 500 mL, 1000 mL, and 1500 mL to demonstrate feasibility. Phantom results demonstrate that the proposed technique is in agreement with theoretical values, as well as with a fully sampled two-dimensional Cartesian acquisition. Results from the volunteer study demonstrate that the root mean squared diffusion distance increased significantly from the 500-mL volume to the 1000-mL volume. This technique represents the first demonstration of a spatially resolved hyperpolarized helium-3 q-space imaging technique and shows promise for microstructural evaluation of lung disease in three dimensions.
欠采样扩散加权星状堆叠采集与迭代高约束反投影相结合，在单次屏气扫描中进行超极化氦-3磁共振q空间成像，并对射频和T1相关信号损失进行联合区域校正。该技术在计算机模拟和体模实验中进行了测试，并在一名健康志愿者中进行了演示，在13秒屏气内实现了全肺覆盖。使用500毫升、1000毫升和1500毫升的吸入气体量评估三种不同肺容积下的肺微结构测量值，以证明其可行性。体模结果表明，所提出的技术与理论值以及全采样二维笛卡尔采集结果一致。志愿者研究结果表明，均方根扩散距离从500毫升容积显著增加到1000毫升容积。该技术是空间分辨超极化氦-3 q空间成像技术的首次演示，显示了在三维空间中对肺部疾病进行微结构评估的潜力。
