PVR: Patch-to-Volume Reconstruction for Large Area Motion Correction of Fetal MRI.
PVR: Patch-to-Volume Reconstruction for Large Area Motion Correction of Fetal MRI.
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DOI：
10.1109/tmi.2017.2737081
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发表时间：
2017-10
影响因子：
10.6
通讯作者：
Kainz B
中科院分区：
文献类型：
--
作者：
Alansary A;Rajchl M;McDonagh SG;Murgasova M;Damodaram M;Lloyd DFA;Davidson A;Rutherford M;Hajnal JV;Rueckert D;Kainz B
在本文中，我们提出了一种新的方法，用于纠正运动伪影，是目前在胎儿磁共振成像（MRI）扫描的整个子宫。与目前的切片到体积配准（SVR）方法，需要一个灵活的解剖外壳的一个单一的调查器官，建议补丁到体积重建（PVR）的方法是能够重建一个大的视野的非刚性变形结构。它通过引入特定量的冗余信息来放松刚性运动假设，这些冗余信息通过并行化的分片优化、超分辨率和自动离群值拒绝来利用。我们进一步描述并提供了一个有效的并行实现PVR，允许其在合理的时间内在市售的图形处理单元上执行，使其在临床实践中的使用。我们评估PVR的计算开销与标准方法相比，并观察到改进的重建精度的仿射运动伪影的存在下，与传统的SVR在合成实验。此外，我们已经评估了我们的方法定性和定量的真实的胎儿MRI数据受到母亲的呼吸和突然的胎动。我们评估峰值信噪比，结构相似性指数，和互相关相对于原始采集的数据，并提供了一种方法重建不确定性的视觉检查。我们进一步评估胎儿头部中所选解剖标志的距离误差，以及计算从自动非刚性配准到无运动地面实况图像的平均和最大位移。这些实验证明PVR运动补偿成功地应用于整个胎儿身体、子宫和胎盘。
In this paper, we present a novel method for the correction of motion artifacts that are present in fetal magnetic resonance imaging (MRI) scans of the whole uterus. Contrary to current slice-to-volume registration (SVR) methods, requiring an inflexible anatomical enclosure of a single investigated organ, the proposed patch-to-volume reconstruction (PVR) approach is able to reconstruct a large field of view of non-rigidly deforming structures. It relaxes rigid motion assumptions by introducing a specific amount of redundant information that is exploited with parallelized patchwise optimization, super-resolution, and automatic outlier rejection. We further describe and provide an efficient parallel implementation of PVR allowing its execution within reasonable time on commercially available graphics processing units, enabling its use in the clinical practice. We evaluate PVR’s computational overhead compared with standard methods and observe improved reconstruction accuracy in the presence of affine motion artifacts compared with conventional SVR in synthetic experiments. Furthermore, we have evaluated our method qualitatively and quantitatively on real fetal MRI data subject to maternal breathing and sudden fetal movements. We evaluate peak-signal-to-noise ratio, structural similarity index, and cross correlation with respect to the originally acquired data and provide a method for visual inspection of reconstruction uncertainty. We further evaluate the distance error for selected anatomical landmarks in the fetal head, as well as calculating the mean and maximum displacements resulting from automatic non-rigid registration to a motion-free ground truth image. These experiments demonstrate a successful application of PVR motion compensation to the whole fetal body, uterus, and placenta.