Assessment of volumetric noise and resolution performance for linear and nonlinear CT reconstruction methods
Assessment of volumetric noise and resolution performance for linear and nonlinear CT reconstruction methods
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DOI：
10.1118/1.4881519
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发表时间：
2014-07-01
期刊：
影响因子：
3.8
通讯作者：
Samei, Ehsan
中科院分区：
文献类型：
--
作者：
Chen, Baiyu;Christianson, Olav;Samei, Ehsan
目的：对于非线性迭代图像重建（IR），计算机断层扫描（CT）的噪声和分辨率属性取决于特定的成像条件，如病变对比度和图像噪声水平。因此，开发一种可靠的方法来测量临床相关条件下的噪声和分辨率特性是势在必行的。本研究旨在开发一种可靠的方法来测量这种条件下的三维CT噪声和分辨率特性，并为达到理想的准确度和精度水平提供指导。方法：该方法是基于先前报道的CT图像质量幻象而开发的。在这种方法中，根据基于任务的3D噪声功率谱（NPStask）在幻像的均匀区域测量CT噪声特性。通过将径向边缘技术应用于模体中的杆插入，以任务传递函数（TTF）来测量平面内分辨率属性。z方向的分辨率属性是由一个补充的模体测量的，也是根据TTF。考虑到可能的红外非线性，NPStask相对于噪声大小进行测量，TTF相对于噪声大小和边缘对比度进行测量。为了确定该方法的准确性和精密度，对已知噪声和分辨率的图像进行了模拟。在模拟图像上测量NPStask和TTF，并与真实情况进行比较，建立标准以实现NPStask和TTF的测量
Purpose: For nonlinear iterative image reconstructions (IR), the computed tomography (CT) noise and resolution properties can depend on the specific imaging conditions, such as lesion contrast and image noise level. Therefore, it is imperative to develop a reliable method to measure the noise and resolution properties under clinically relevant conditions. This study aimed to develop a robust methodology to measure the three-dimensional CT noise and resolution properties under such conditions and to provide guidelines to achieve desirable levels of accuracy and precision.Methods: The methodology was developed based on a previously reported CT image quality phantom. In this methodology, CT noise properties are measured in the uniform region of the phantom in terms of a task-based 3D noise-power spectrum (NPStask). The in-plane resolution properties are measured in terms of the task transfer function (TTF) by applying a radial edge technique to the rod inserts in the phantom. The z-direction resolution properties are measured from a supplemental phantom, also in terms of the TTF. To account for the possible nonlinearity of IR, the NPStask is measured with respect to the noise magnitude, and the TTF with respect to noise magnitude and edge contrast. To determine the accuracy and precision of the methodology, images of known noise and The resolution properties were simulated. The NPStask and TTF were measured on the simulated images and compared to the truth, with criteria established to achieve NPStask and TTF measurements with