Enhanced 4D cone-beam CT with inter-phase motion model
Enhanced 4D cone-beam CT with inter-phase motion model
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DOI：
10.1118/1.2767144
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发表时间：
2007-09-01
期刊：
影响因子：
3.8
通讯作者：
Xing, Lei
中科院分区：
文献类型：
--
作者：
Li, Tianfang;Koong, Albert;Xing, Lei
四维(4D)锥束CT(CBCT)通常是通过对投影进行呼吸相合并，然后在每个相框中对重新合并的数据进行独立重建来获得的。由于每次重建的投影数量显著减少，4DCBCT图像的质量往往会受到轴向视图中容易看到的视图混叠伪影的影响。使用多个机架旋转或缓慢机架旋转的采集可以增加投影的数量并显著改善4D图像。然而，扫描时间的额外成本可能会从根本上限制它们在临床上的应用。改善图像质量和扫描时间之间的权衡是使4D星载成像实用化和更有用的关键。在本文中，我们提出了一种在不延长采集时间的情况下获得高质量4DCBCT图像的新技术，称为增强型4DCBCT。该方法将不同相位箱中的数据进行关联，并将内部运动整合到4DCBCT图像公式中。讨论了运动推导的几种策略，并用数值模拟和临床病例对生成的图像进行了评估。(C)2007年美国医学物理学家协会。
Four-dimensional (4D) cone-beam CT (CBCT) is commonly obtained by respiratory phase binning of the projections, followed by independent reconstructions of the rebinned data in each phase bin. Due to the significantly reduced number of projections' per reconstruction, the quality of the 4DCBCT images is often degraded by view-aliasing artifacts easily seen in the axial view. Acquisitions using multiple gantry rotations or slow gantry rotation can increase the number of projections and substantially improve the 4D images. However, the extra cost of the scan time may set fundamental limits to their applications in clinics. Improving the trade-off between image quality and scan time is the key to making 4D onboard imaging practical and more useful. In this article, we present a novel technique toward high-quality 4DCBCT imaging without prolonging the acquisition time, referred to as the "enhanced 4DCBCT". The method correlates the data in different phase bins and integrates the internal motion into the 4DCBCT image formulation. Several strategies of the motion derivation are discussed, and the resultant images are assessed with numerical simulations as well as a clinical case. (c) 2007 American Association of Physicists in Medicine.