Shi Caiyun, Cheng Jing, Su Shi, Zou Lixian, Chen Hanwei, Xie Guoxi, Liang Dong, Liu Xin, Wang Haifeng
Annu Int Conf IEEE Eng Med Biol Soc. 2019 Jul;2019:4824-4827. doi: 10.1109/EMBC.2019.8856573.
A susceptibility-based positive contrast MR technique is applied to image the MR compatible metallic devices by solving a regularized ℓ1 minimization problem. However, the previous SE/FSE sequence is used for the data acquisition which can result in high SAR and low sampling efficiency in 3D imaging. Therefore, a 3D single slab 3D FSE sequence with slab selective and variable excitation pulse is proposed to implement 3D positive contrast MR imaging for low SAR and acquiring high-resolution 3D images within a shorter timeframe. Furthermore, in order to achieve faster reconstruction and better imaging quality of the 3D positive contrast MRI, the primal-dual iteration algorithm is also used to solve the regularized ℓ1 minimization problem. The visualization of the positive contrast and convergence behaviour of the proposed reconstruction framework base on the first-order PD algorithm were tested and validated on phantom experiments, compared with the previous nonlinear conjugate gradient (NLCG), fast iterative soft thresholding (FISTA) and alternating direction method of multipliers (ADMM) algorithms.
一种基于敏感性的正性对比磁共振技术通过求解正则化的ℓ1最小化问题来对磁共振兼容金属装置进行成像。然而，之前的数据采集使用的是自旋回波/快速自旋回波（SE/FSE）序列，这在三维成像中会导致高比吸收率（SAR）和低采样效率。因此，提出了一种具有层面选择和可变激发脉冲的三维单层三维快速自旋回波序列，以实现低SAR的三维正性对比磁共振成像，并在更短的时间内获取高分辨率三维图像。此外，为了实现三维正性对比磁共振成像更快的重建速度和更好的成像质量，还使用原始对偶迭代算法来求解正则化的ℓ1最小化问题。基于一阶原始对偶算法的所提出的重建框架的正性对比可视化和收敛行为在体模实验中进行了测试和验证，并与之前的非线性共轭梯度（NLCG）、快速迭代软阈值（FISTA）和交替方向乘子法（ADMM）算法进行了比较。
