Generalized MRI reconstruction including elastic physiological motion and coil, sensitivity encoding
Generalized MRI reconstruction including elastic physiological motion and coil, sensitivity encoding
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DOI：
10.1002/mrm.21520
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发表时间：
2008-06-01
影响因子：
3.3
通讯作者：
Felblinger, Jacques
中科院分区：
文献类型：
--
作者：
Odille, Freddy;Cindea, Nicolae;Felblinger, Jacques
本文介绍了一个通用的框架，多线圈MRI重建弹性生理运动的存在。假设运动是已知的或可以预测的，它示出的重建问题是相当于解决一个积分方程已知的文献中作为Fredholm方程的第一类广义内核包括傅立叶和线圈灵敏度编码，修改的生理运动信息。使用迭代线性系统求解器找到数值解。在数值分辨率的不同步骤进行了讨论，特别是它示出了如何过确定可以用来改善广义编码算子的条件。实际实施需要位移场的先验知识，因此描述了患者运动的模型，其允许从各种输入信号（例如，呼吸带、ECG、导航回波）。实际实施证明了一个移动的幻影设置和两个自由呼吸的健康受试者，从胸腹部的图像。结果表明，该方法有效地抑制了运动模糊/重影伪影，扫描重复可以用作过确定的来源，以改善重建。
This article describes a general framework for multiple coil MRI reconstruction in the presence of elastic physiological motion. On the assumption that motion is known or can be predicted, it is shown that the reconstruction problem is equivalent to solving an integral equation-known in the literature as a Fredholm equation of the first kind-with a generalized kernel comprising Fourier and coil sensitivity encoding, modified by physiological motion information. Numerical solutions are found using an iterative linear system solver. The different steps in the numerical resolution are discussed, in particular it is shown how over-determination can be used to improve the conditioning of the generalized encoding operator. Practical implementation requires prior knowledge of displacement fields, so a model of patient motion is described which allows elastic displacements to be predicted from various input signals (e.g., respiratory belts, ECG, navigator echoes), after a free-breathing calibration scan. Practical implementation was demonstrated with a moving phantom setup and in two free-breathing healthy subjects, with images from the thoracic-abdominal region. Results show that the method effectively suppresses the motion blurring/ghosting artifacts, and that scan repetitions can be used as a source of over-determination to improve the reconstruction.