Chen Liyong, Adluru Ganesh, Schabel Matthias C, McGann Chris J, Dibella Edward V R
Department of Bioengineering, University of Utah, Salt Lake City, Utah 84108, USA.
Med Phys. 2012 Aug;39(8):5204-11. doi: 10.1118/1.4738965.
To determine the feasibility of three-dimensional (3D) hybrid radial (stack-of-stars) MRI with spatiotemporal total variation (TV) constrained reconstruction for dynamic contrast enhanced myocardial perfusion imaging.
An ECG-triggered saturation recovery turboFLASH sequence with undersampled stack-of-stars sampling with spatiotemporal TV constrained reconstruction was developed for dynamic contrast enhanced myocardial perfusion imaging. Simulations were performed to study the dependence of the approach to steady state on flip angle and saturation recovery time for this stack-of-stars acquisition. Phantom studies were used to show the effect of the flip angle selection and imperfect spoiling on image qualities. Studies were done in three humans to test the feasibility of the approach for myocardial perfusion imaging.
The simulation and phantom studies showed that imperfect spoiling and magnetization changes during the readout were a function of flip angle and nonoptimized selection of flip angle could degrade the images. Low flip angle acquisitions in the human subjects result in images with good quality similar to multislice radial 2D images.
3D stack-of-stars sampling with spatiotemporal TV constrained reconstruction provides a promising alternative for myocardial perfusion imaging.
确定采用时空全变分（TV）约束重建的三维（3D）混合径向（星状堆叠）磁共振成像（MRI）用于动态对比增强心肌灌注成像的可行性。
开发了一种心电图触发的饱和恢复快速低角度激发（turboFLASH）序列，采用欠采样星状堆叠采样并结合时空TV约束重建，用于动态对比增强心肌灌注成像。进行模拟研究，以探讨该星状堆叠采集方式达到稳态的方法对翻转角和饱和恢复时间的依赖性。通过体模研究来展示翻转角选择和不完全扰相对图像质量的影响。对三名受试者进行研究，以测试该方法用于心肌灌注成像的可行性。
模拟和体模研究表明，读出期间的不完全扰相和磁化变化是翻转角的函数，翻转角选择不当会降低图像质量。在人体受试者中采用低翻转角采集可获得与多层径向二维图像质量相当的图像。
采用时空TV约束重建的3D星状堆叠采样为心肌灌注成像提供了一种有前景的替代方法。
