Luo Jieying, Addy Nii Okai, Ingle R Reeve, Baron Corey A, Cheng Joseph Y, Hu Bob S, Nishimura Dwight G
Department of Electrical Engineering, Magnetic Resonance Systems Research Laboratory, Stanford University, Stanford, California, USA.
Palo Alto Medical Foundation, Palo Alto, California, USA.
Magn Reson Med. 2017 May;77(5):1884-1893. doi: 10.1002/mrm.26273. Epub 2016 May 13.
To develop a retrospective nonrigid motion-correction method based on 3D image-based navigators (iNAVs) for free-breathing whole-heart coronary magnetic resonance angiography (MRA).
The proposed method detects global rigid-body motion and localized nonrigid motion from 3D iNAVs and compensates them with an autofocusing algorithm. To model the global motion, 3D rotation and translation are estimated from the 3D iNAVs. Two sets of localized nonrigid motions are obtained from deformation fields between 3D iNAVs and reconstructed binned images, respectively. A bank of motion-corrected images is generated and the final image is assembled pixel-by-pixel by selecting the best focused pixel from this bank. In vivo studies with six healthy volunteers were conducted to compare the performance of the proposed method with 3D translational motion correction and no correction.
In vivo studies showed that compared to no correction, 3D translational motion correction and the proposed method increased the vessel sharpness by 13% ± 13% and 19% ± 16%, respectively. Out of 90 vessel segments, 75 segments showed improvement with the proposed method compared to 3D translational correction.
We have developed a nonrigid motion-correction method based on 3D iNAVs and an autofocusing algorithm that improves the vessel sharpness of free-breathing whole-heart coronary MRA. Magn Reson Med 77:1884-1893, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
开发一种基于三维图像导航器（iNAV）的回顾性非刚性运动校正方法，用于自由呼吸全心冠状动脉磁共振血管造影（MRA）。
所提出的方法从三维iNAV中检测全局刚体运动和局部非刚性运动，并用自动聚焦算法对其进行补偿。为了对全局运动进行建模，从三维iNAV中估计三维旋转和平移。分别从三维iNAV与重建的分箱图像之间的变形场中获得两组局部非刚性运动。生成一组运动校正图像，并通过从该组中选择最佳聚焦像素逐像素地组装最终图像。对六名健康志愿者进行了体内研究，以比较所提出的方法与三维平移运动校正和无校正的性能。
体内研究表明，与无校正相比，三维平移运动校正和所提出的方法分别使血管清晰度提高了13%±13%和19%±16%。在90个血管节段中，与三维平移校正相比，所提出的方法使75个节段有改善。
我们开发了一种基于三维iNAV和自动聚焦算法的非刚性运动校正方法，该方法提高了自由呼吸全心冠状动脉MRA的血管清晰度。《磁共振医学》77:1884 - 1893, 2017。©2016国际磁共振医学学会。
