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The prime motivation of this work is to devise techniques that make the algebraic reconstruction technique (ART) and related methods more efficient for routine clinical use, while not compromising their accuracy. Since most of the computational effort of ART is spent for projection/backprojection operations, the authors first seek to optimize the projection algorithm. Existing projection algorithm...

这项工作的主要动机是设计技术，使代数重建技术（ART）及相关方法在日常临床使用中更加高效，同时不降低其准确性。由于ART的大部分计算工作量用于投影/反投影操作，作者首先寻求优化投影算法。现有的投影算法...

We give a new algorithm for reconstructing a density f in the plane from its projections along those lines making an angle greater than a fixed δ > 0 with the x axis. Of course, the performance of the algorithm depends on δ and on the smoothness of f, but it appears to give a practical and simple solution to the problem whenever one exists. The basic idea, which seems to be new, is to make an affi...

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Computational methods can be used to provide an initial screening or a second opinion in medical settings and may improve the sensitivity and specificity of diagnoses. In the current study, linear discriminant models and artificial neural networks are trained to detect breast cancer in suspicious masses using radiographic features and patient age. Results on 139 suspicious breast masses (79 malign...

计算方法可用于在医疗环境中提供初步筛查或第二意见，并可能提高诊断的敏感性和特异性。在本研究中，使用放射学特征和患者年龄训练线性判别模型和人工神经网络，以检测可疑肿块中的乳腺癌。对139个可疑乳腺肿块（79个恶性...）的结果...

Recently, an iterative reconstruction-reprojection (IRR) algorithm has been suggested for application to limited view computed tomography (CT). In the IRR, the interpolation operation is performed in the object space during backprojection-reprojection. The errors associated with the interpolation degrade the reconstructed image and may cause divergence unless a large number of rays is used. In thi...

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We present a novel algorithm for reconstructing interferograms acquired in optical frequency domain imaging (OFDI). The algorithm was developed specifically for processing in field programmable gate arrays (FPGAs) and featured the use of a finite-impulse-response (FIR) filter implementation of B-spline interpolation for efficiently re-sampling $k$-space. When implemented in FPGAs, the algorithm al...

我们提出了一种新颖的算法，用于重建在光学频域成像（OFDI）中获取的干涉图。该算法专门为现场可编程门阵列（FPGA）中的处理而开发，其特点是使用有限脉冲响应（FIR）滤波器实现的B样条插值，以高效地重新采样k空间。当在FPGA中实现时，该算法...

At the advent of multislice computed tomography (CT) a variety of approximate cone-beam algorithms have been proposed suited for reconstruction of small cone-angle CT data in a spiral mode of operation. The goal of this study is to identify a practical and efficient approximate cone-beam method, extend its potential for medical use, and demonstrate its performance at medium cone-angles required fo...

随着多层计算机断层扫描（CT）的出现，提出了多种适用于螺旋模式下小锥角CT数据重建的近似锥束算法。本研究旨在确定一种实用且高效的近似锥束方法，扩展其在医学应用中的潜力，并展示其在中等锥角（医学所需）下的性能...

An algorithm for the automatic contour detection of objects in CT images is presented. It requires little memory space, allows easy incorporation of different types of local digital filters, and is fast. Typical computation time with a minicomputer is less than one second. An implementation of the algorithm for the detection of bone contours from low dose CT images is given as an example.

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For pt. I see ibid., vol. 19, no. 9, p. 822-34 (2000). The recently introduced multislice data acquisition for computed tomography (CT) is based on multirow detector design, increased rotation speed, and advanced z-interpolation and z-filtering algorithms. The authors evaluated slice sensitivity profiles (SSPs) and noise of a clinical multislice spiral CT (MSCT) scanner with M=4 simultaneously acq...

参见第一部分（同上，卷19，第9期，第822-34页，2000年）。最近引入的用于计算机断层扫描（CT）的多层数据采集基于多排探测器设计、增加的旋转速度以及先进的z插值和z滤波算法。作者评估了具有同时采集M=4排的临床多层螺旋CT（MSCT）扫描仪的切片敏感度轮廓（SSP）和噪声...

A new class of interpolation kernels that are locally compact in signal space and "almost band-limited" in Fourier space is presented. The kernels are easy to calculate and lend themselves to problems in which the kernels must be analytically manipulated with other operations or operators such as convolutions and projection integrals. The interpolation kernels are comprised of a linear sum of a Ga...

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In this paper we analyze a result previously published about a comparison between two statistical tests used for evaluation of boundary detection algorithms on medical images. We conclude that the statement made by Chalana and Kim (1997) about the performance of the percentage test has a weak theoretical foundation, and according to our results, is not correct. In addition, we propose a one-sided ...

本文分析了一个先前发表的结果，该结果比较了两种用于评估医学图像边界检测算法的统计检验。我们得出结论，Chalana和Kim（1997）关于百分比检验性能的论述理论基础薄弱，并且根据我们的结果，该论述是不正确的。此外，我们提出了一种单侧...

The order in which the projections are applied in the algebraic reconstruction technique (ART) has a great effect on speed of convergence, accuracy, and the amount of noise-like artifacts in the reconstructed image. In this paper, a new projection ordering scheme for ART is presented: the weighted-distance scheme (WDS). It heuristically optimizes the angular distance of a newly selected projection...

在代数重建技术（ART）中，投影的应用顺序对收敛速度、精度以及重建图像中类似噪声的伪影数量有显著影响。本文提出了一种新的ART投影排序方案：加权距离方案（WDS）。它启发式地优化新选投影的角度距离...

Image processing was used as a fundamental tool to derive motion information from magnetic resonance (MR) images, which was fed back into prospective respiratory motion correction during subsequent data acquisition to improve image quality in coronary MR angiography (CMRA) scans. This reduces motion artifacts in the images and, in addition, enables the usage of a broader gating window than commonl...

图像处理被用作从磁共振（MR）图像中提取运动信息的基本工具，这些信息被反馈到后续数据采集过程中的前瞻性呼吸运动校正中，以改善冠状MR血管造影（CMRA）扫描的图像质量。这减少了图像中的运动伪影，此外，还允许使用比通常更宽的门控窗口...

A review is made of selected recent publications on three-dimensional image reconstruction for PET. A new algorithm is proposed which is designed to fully utilize all emitted gamma rays which can be detected in a truncated spherical detector. By such full utilization of emitted rays the new algorithm should produce images of better statistical accuracy than could be produced by previously known al...

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A general mathematical formalism for generating multiparametric NMR image encoding gradients is introduced. The new schematic approach enables one to construct any desired encoding gradient which may be used in an imaging sequence. Basic gradient waveforms which can be used as building blocks of the desired encoding gradients are presented. A matrix operator for obtaining the encoding gradient for...

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The methods of Bayesian statistics are applied to the analysis of fMRI data, Three specific models are examined. The first is the familiar linear model with white Gaussian noise. In this section, the Jeffreys' Rule for noninformative prior distributions is stated and it is shown how the posterior distribution may be used to infer activation in individual pixels. Next, linear time-invariant (LTI) s...

贝叶斯统计方法应用于fMRI数据分析。考察了三个特定模型。第一个是带有白高斯噪声的常见线性模型。在这一部分，介绍了无信息先验分布的杰弗里斯规则，并展示了如何使用后验分布来推断单个像素的激活。接下来，线性时不变（LTI）...

This paper demonstrates a time-saving, automated method that helps to segment the lateral ventricles and caudate nucleus in T1-weighted coronal magnetic resonance (MR) brain images of normal control subjects. The method involves choosing intensity thresholds by using anatomical information and by locating peaks in histograms. To validate the method, the lateral ventricles and caudate nucleus were ...

本文展示了一种省时、自动化的方法，有助于在正常对照受试者的T1加权冠状磁共振（MR）脑图像中分割侧脑室和尾状核。该方法通过利用解剖信息和定位直方图中的峰值来选择强度阈值。为了验证该方法，侧脑室和尾状核被...

The classical principal-axes transformation (PAT) has been used in numerous publications for three-dimensional (3-D) reconstructions by sequential alignment of histological sections. However, the PAT can determine at most 1/2n(n+1) parameters (scaling-rotation) in n dimensions. Distortions (shearing) of histological sections can be described by an affine transformation with n/sup 2/ parameters. An...

经典的主轴线变换（PAT）已被广泛用于通过组织学切片的连续对齐进行三维（3-D）重建。然而，PAT最多只能确定n维中的1/2n(n+1)个参数（缩放-旋转）。组织学切片的畸变（剪切）可以用具有n^2个参数的仿射变换来描述。

Discusses the inclusion of anatomical constraints and anisotropy in static Electrical Impedance Tomography (EIT) using a two-step approach to EIT. In the first step, the boundaries between regions of different conductivities are anatomically constrained using Magnetic Resonance Imaging (MRI) data. In the second step, the conductivity values in different regions are determined. Anisotropic conducti...

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Magnetic resonance (MR) tagging has been shown to be a useful technique for noninvasively measuring the deformation of an in vivo heart. An important step in analyzing tagged images is the identification of tag lines in each image of a cine sequence. Most existing tag identification algorithms require user defined myocardial contours. Contour identification, however, is time consuming and requires...

磁共振（MR）标记已被证明是一种非侵入性测量活体心脏变形的有用技术。分析标记图像的一个重要步骤是识别电影序列中每幅图像中的标记线。大多数现有的标记识别算法需要用户定义的心肌轮廓。然而，轮廓识别耗时且需要...

Bronchiolar obstruction is commonly manifested in computed tomography (CT) images as areas of decreased attenuation relative to adjacent normal lung parenchyma. The certain identification of such areas is difficult in practice, particularly if they are poorly marginated. This paper presents a novel approach to the enhancement of feature differences between normal and diseased lung parenchyma so th...

细支气管阻塞在计算机断层扫描（CT）图像上通常表现为相对于邻近正常肺实质的衰减减低区域。实际中，这类区域的确切识别很困难，尤其是当它们边缘不清时。本文提出了一种新方法，用于增强正常与病变肺实质之间的特征差异，以便...

A technique determines the optimal window width for orbiting rod transmission studies in positron emission tomography (PET). Windowing reduces noise in orbiting rod transmission studies. Lines-of-response (LOR) which intersect the rods generate primarily true coincidence events. LOR which pass far from the rods generate random and scatter events. Since the angular position of the orbiting rods is ...

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Evaluates a segmentation technique for magnetic resonance (MR) images of the brain based on fuzzy algorithms for learning vector quantization (FALVQ). These algorithms perform vector quantization by updating all prototypes of a competitive network through an unsupervised learning process. Segmentation of MR images is formulated as an unsupervised vector quantization process, where the local values...

评估了一种基于模糊学习矢量量化（FALVQ）算法的脑部磁共振（MR）图像分割技术。这些算法通过无监督学习过程更新竞争网络的所有原型来执行矢量量化。MR图像分割被表述为一个无监督的矢量量化过程，其中局部值...

This paper addresses one of the major problems in interventional magnetic resonance imaging (MRI): the visualization of interventional devices. For visualization locally induced magnetic fields are used, which disturb the homogeneity of the main magnetic field of the MR scanner. This results in signal loss in the vicinity of the device due to intravoxel dephasing, and leads to a disturbance of the...

本文讨论了介入性磁共振成像（MRI）中的一个主要问题：介入设备的可视化。可视化利用局部感应磁场，该磁场会干扰MR扫描器主磁场的均匀性。这导致由于体素内去相位而在设备附近出现信号丢失，并引起……

An upper bound is derived for the mutual information between a fixed image and a deformable template containing a fixed number of gray-levels. The bound can be calculated by maximizing the entropy of the template under the constraint that the conditional entropy of the template, given the fixed image, be zero. This bound provides useful insight into the properties of mutual information as a simila...

推导了固定图像与包含固定灰度级数的可变形模板之间互信息的上界。该界可以通过在给定固定图像条件下模板的条件熵为零的约束下最大化模板的熵来计算。该界为互信息作为相似度量的性质提供了有用的见解...