Signal decay correction in 2D ultra-short echo time imaging
Signal decay correction in 2D ultra-short echo time imaging
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DOI：
10.1007/s10334-006-0028-0
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发表时间：
2006-05-01
影响因子：
2.3
通讯作者：
Eggers, H
中科院分区：
文献类型：
--
作者：
Mentrup, D;Eggers, H
目的：在超短回波时间（UTE）成像中，在数据采集过程中，横向磁化经历了显著的衰减，这导致了常规重建图像中信号强度和空间分辨率的损失。本工作提出了一种迭代算法来纠正这些不利影响。材料和方法：该算法涉及求解一个大型线性方程组，需要单独的参考扫描来映射空间变化的横向弛豫时间。它被实现并应用于模拟和实验与定制分辨率的幽灵。评估的重点是它对实际点扩散函数（PSF）的改善能力和对局部信噪比（SNR）的影响。结果：该算法几乎可以恢复采集到的理想PSF。如果足够精确地知道横向弛豫时间，则证明它提供的图像具有更好的信号强度和空间分辨率，但信噪比降低。结论：本研究显示了在超声成像中校正信号衰减效应的基本可行性。
Objectives: In ultra-short echo time (UTE) imaging, the transverse magnetization experiences significant decay during data acquisition, which gives rise to a loss of signal intensity and spatial resolution in conventionally reconstructed images. The present work proposes an iterative algorithm to correct these adverse effects. Materials and methods: The algorithm involves solving a large linear system of equations and requires a separate reference scan to map the spatially variant transverse relaxation time. It was implemented and applied to simulations and to experiments with custom-built resolution phantoms. The evaluation focused on its ability to improve the actual point-spread function (PSF) and on its influence upon the local signal-to-noise ratio (SNR). Results: The algorithm is demonstrated to virtually restore the ideal PSF of the acquisition. It proves to provide images with better signal intensity and spatial resolution but reduced SNR, if the transverse relaxation time is known with sufficient accuracy. Conclusions: The present work shows the basic feasibility of correcting signal decay effects in UTE imaging.