Harmonization of in-plane resolution in CT using multiple reconstructions from single acquisitions.
Harmonization of in-plane resolution in CT using multiple reconstructions from single acquisitions.
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DOI：
10.1002/mp.15186
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发表时间：
2021-11
期刊：
影响因子：
3.8
通讯作者：
Estépar RSJ
中科院分区：
文献类型：
--
作者：
Vegas-Sánchez-Ferrero G;Ramos-Llordén G;Estépar RSJ
提供一种方法，使用不同的CT重建消除平面内分辨率的空间变异性。该方法不需要任何培训、正弦图或特定的重建方法。该方法被制定为一个重建问题。所需的清晰图像被建模为一个不可观测的变量，从任意数量的空间变化的分辨率的观察估计。该方法包括三个步骤：（1）密度协调，消除重建过程中的密度变化;（2）点扩散函数（PSF）估计，估计具有任意形状的空间变化PSF;（3）反卷积，将其表示为正则化最小二乘问题。使用三种不同的Siemens扫描仪（定义AS、定义AS+、驱动器）采集的体模CT扫描进行评估。四个低剂量采集重建与反投影和迭代方法用于分辨率协调。使用锐利的高剂量（HD）重建作为验证参考。影响面内分辨率（径向，角度和纵向）的不同因素进行了研究与边缘衰减（10%和90%之间的边缘扩展函数（ESF）幅度）的回归分析。结果表明，在不影响噪声特性的情况下，面内分辨率显著提高，空间变异性显著降低。调制传递函数（MTF）也证实了分辨率的显著增加。还通过测量模拟气道的管的壁厚来测试分辨率的提高。在所有扫描仪中，分辨率协调获得了比HD更好的性能，锐利重建用作参考（高达50个百分点）。该方法还在临床扫描中进行了评估，实现了降噪和薄层结构的明显改善。估计的ESF和MTF证实了分辨率的提高。我们提出了一种通用的方法，以减少空间变异性的平面分辨率在CT扫描，利用不同的重建在临床研究中。该方法不需要任何正弦图、训练或特定重建，并且不限于固定数量的输入图像。因此，易于在多中心研究和临床实践中采用。与我们的分辨率协调方法获得的结果证明其适用性，以减少在临床CT扫描的空间变化的平面内分辨率，而不损害重建的噪声特性。我们相信，通过我们的方法实现的分辨率增加可能有助于更准确和可靠地测量小结构，如血管系统，气道和壁厚。
To providea methodology that removes the spatial variability of in-plane resolution using different CT reconstructions. The methodology does not require any training, sinogram, or specific reconstruction method. The methodology is formulated as a reconstruction problem. The desired sharp image is modeled as an unobservable variable to be estimated from an arbitrary number of observations with spatially variant resolution. The methodology comprises three steps: (1) density harmonization, which removes the density variability across reconstructions; (2) point spread function (PSF) estimation, which estimates a spatially variant PSF with arbitrary shape; (3) deconvolution, which is formulated as a regularized least squares problem. The assessment was performed with CT scans of phantoms acquired with three different Siemens scanners (Definition AS, Definition AS+, Drive). Four low-dose acquisitions reconstructed with backprojection and iterative methods were used for the resolution harmonization. A sharp, high-dose (HD) reconstruction was used as a validation reference. The different factors affecting the in-plane resolution (radial, angular, and longitudinal) were studied with regression analysis of the edge decay (between 10% and 90% of the edge spread function (ESF) amplitude). Results showed that the in-plane resolution improves remarkably and the spatial variability is substantially reduced without compromising the noise characteristics. The modulated transfer function (MTF) also confirmed a pronounced increase in resolution. The resolution improvement was also tested by measuring the wall thickness of tubes simulating airways. In all scanners, the resolution harmonization obtained better performance than the HD, sharp reconstruction used as a reference (up to 50 percentage points). The methodology was also evaluated in clinical scans achieving a noise reduction and a clear improvement in thin-layered structures. The estimated ESF and MTF confirmed the resolution improvement. We propose a versatile methodology to reduce the spatial variability of in-plane resolution in CT scans by leveraging different reconstructions available in clinical studies. The methodology does not require any sinogram, training, or specific reconstruction, and it is not limited to a fixed number of input images. Therefore, it can be easily adopted in multicenter studies and clinical practice. The results obtained with our resolution harmonization methodology evidence its suitability to reduce the spatially variant in-plane resolution in clinical CT scans without compromising the reconstruction’s noise characteristics. We believe that the resolution increase achieved by our methodology may contribute in more accurate and reliable measurements of small structures such as vasculature, airways, and wall thickness.
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影响因子：
10.6
作者：
Galatsanos, Nikolas P.;Katsaggelos, Aggelos K.
通讯作者：
Katsaggelos, Aggelos K.
DOI：
10.1016/j.ejmp.2011.02.001
发表时间：
2012-01-01
影响因子：
3.4
作者：
Martinez, Luis C.;Calzado, Alfonso;Manzanas, Maria J.
通讯作者：
Manzanas, Maria J.
DOI：
10.1364/josaa.28.001145
发表时间：
2011-06-01
影响因子：
1.9
作者：
Platisa, Ljiljana;Goossens, Bart;Philips, Wilfried
通讯作者：
Philips, Wilfried
影响因子：
4.3
作者：
Charbonnier, Jean-Paul;Pompe, Esther;Lynch, David A.
通讯作者：
Lynch, David A.
影响因子：
3.8
作者：
Chen-Mayer HH;Fuld MK;Hoppel B;Judy PF;Sieren JP;Guo J;Lynch DA;Possolo A;Fain SB
通讯作者：
Fain SB