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The current trend in attenuation correction for single photon emission computed tomography (SPECT) is to measure and reconstruct the attenuation coefficient map using a transmission scan, performed either sequentially or simultaneously with the emission scan. This approach requires dedicated hardware and increases the cost (and in some cases the scanning time) required to produce a clinical SPECT ...

当前单光子发射计算机断层扫描（SPECT）衰减校正的趋势是使用透射扫描测量和重建衰减系数图，该扫描可与发射扫描顺序或同时进行。这种方法需要专用硬件，并增加了临床SPECT...

The fast Hartley transform (FHT) is used to transform two-dimensional image data. Because the Hartley transform is real-valued, it does not require complex operations. Both spectra and autocorrelations of two-dimensional ultrasound images of normal and abnormal livers were computed.<>

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Exact reconstruction from axially truncated cone-beam projections acquired with a helical vertex path is a challenging problem for which solutions are currently under investigation by some researchers. This paper deals with a difficult class of this problem called the long-object problem. Its purpose is to reconstruct a central region of interest (ROI) of a long object when the helical path extend...

从螺旋顶点路径获取的轴向截断锥束投影中进行精确重建是一个具有挑战性的问题，目前一些研究人员正在研究解决方案。本文讨论了该问题中的一个困难类别，称为长物体问题。其目的是在螺旋路径延伸时重建长物体的中心感兴趣区域。

Presents a model-based phase unwrapping method which represents the unwrapped phase function by a truncated Taylor series and a residual function. An efficient, noniterative computational algorithm is also proposed for calculating the model parameters from the phase derivatives. Sample experimental results are shown to demonstrate the effectiveness of the algorithm for extracting unwrapped phase i...

提出了一种基于模型的相位展开方法，该方法通过截断的泰勒级数和残差函数来表示展开的相位函数。还提出了一种高效的非迭代计算算法，用于从相位导数计算模型参数。示例实验结果表明了该算法在提取展开相位方面的有效性……

Rat brain images acquired with a small animal positron emission tomography (PET) camera and reconstructed with the three-dimensional (3-D) ordered-subsets expectation-maximization (OSEM) algorithm with resolution recovery have better quality when the brain is imaged by itself than when inside the head with surrounding background activity. The purpose of this study was to characterize the dependenc...

使用小动物正电子发射断层扫描（PET）相机获取并经三维有序子集期望最大化（OSEM）算法（具有分辨率恢复功能）重建的大鼠脑图像，当单独成像时比在头部内且有周围背景活动时质量更好。

Proliferative diabetic retinopathy is a rare condition likely to lead to severe visual impairment. It is characterized by the development of abnormal new retinal vessels. We describe a method for automatically detecting new vessels on the optic disc using retinal photography. Vessel-like candidate segments are first detected using a method based on watershed lines and ridge strength measurement. F...

增殖性糖尿病视网膜病变是一种罕见的疾病，可能导致严重的视力损伤。其特征是异常新生视网膜血管的生成。我们描述了一种使用视网膜摄影自动检测视盘上新血管的方法。首先，基于分水岭线和脊强度测量的方法检测血管样候选段。

A new statistical approach to phase correction in NMR imaging is proposed. The proposed scheme consists of first-and zero-order phase corrections each by the inverse multiplication of estimated phase error. The first-order error is estimated by the phase of autocorrelation calculated from the complex valued phase distorted image while the zero-order correction factor is extracted from the histogra...

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An optical model for imaging the retina through cataracts has been developed. The images are treated as sample functions of stochastic processes. On the basis of the model a homomorphic Weiner filter can be designed that will optimally restore the cataractous image (in the mean-square-error sense). The design of the filter requires a priori knowledge of the statistics of either the cataract transm...

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High-resolution micro-computed tomography (CT) scanners now exist for imaging small animals. In particular, such a scanner can generate very large three-dimensional (3-D) digital images of the rat's hepatic vasculature. These images provide data on the overall structure and function of such complex vascular trees. Unfortunately, human operators have extreme difficulty in extracting the extensive v...

高分辨率显微计算机断层扫描（CT）扫描仪现已可用于小动物成像。特别是，这种扫描仪可以生成大鼠肝脏血管系统的非常大的三维（3-D）数字图像。这些图像提供了此类复杂血管树的整体结构和功能数据。不幸的是，人类操作员在提取广泛的血管结构时面临极大困难...

Algebraic reconstruction methods, such as the algebraic reconstruction technique (ART) and the related simultaneous ART (SART), reconstruct a two-dimensional (2-D) or three-dimensional (3-D) object from its X-ray projections. The algebraic methods have, in certain scenarios, many advantages over the more popular Filtered Backprojection approaches and have also recently been shown to perform well f...

代数重建方法，如代数重建技术(ART)及其相关的同步ART(SART)，通过X射线投影重建二维或三维物体。在某些情况下，代数方法比更流行的滤波反投影方法具有许多优点，并且最近也被证明在...中表现良好。

A direct (noniterative) reconstruction algorithm for electrical impedance tomography in the two-dimensional (2-D), cross-sectional geometry is reviewed. New results of a reconstruction of a numerically simulated phantom chest are presented. The algorithm is based on the mathematical uniqueness proof by A.I. Nachman [1996] for the 2-D inverse conductivity problem. In this geometry, several of the c...

回顾了一种用于二维（2-D）横截面几何的电阻抗断层成像的直接（非迭代）重建算法。给出了数值模拟的胸部体模重建的新结果。该算法基于A.I. Nachman [1996] 对二维逆电导率问题的数学唯一性证明。在这种几何结构中，几个...

The maximum intensity projection (MIP) is a popularly used algorithm for display of MRA images, but its performance has not been rigorously analyzed before. In this paper, four measures are proposed for the performance of the MIP algorithm and the quality of images projected from three-dimensional (3-D) data, which are vessel voxel projection probability, vessel detection probability, false vessel...

最大强度投影（MIP）是一种广泛用于显示MRA图像的算法，但其性能此前尚未得到严格分析。本文提出了四个指标来评估MIP算法的性能以及从三维（3-D）数据投影的图像质量，这些指标包括血管体素投影概率、血管检测概率、假血管...

An artificial neural network has been developed to reconstruct quantitative single photon emission computed tomographic (SPECT) images. The network is trained with an ideal projection-image pair to learn a shift-invariant weighting (filter) for the projections. Once trained, the network produces weighted projections as a hidden layer when acquired projection data are presented to its input. This h...

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It is known that when a tissue is subjected to movements such as rotation, shearing, scaling, etc., changes in speckle patterns that result act as a noise source, often responsible for most of the displacement-estimate variance. From a modeling point of view, these changes can be thought of as resulting from two mechanisms: one is the motion of the speckles and the other, the alterations of their ...

已知当组织受到旋转、剪切、缩放等运动时，产生的散斑图案变化会作为噪声源，通常是位移估计方差的主要来源。从建模角度来看，这些变化可归因于两种机制：一是散斑的运动，二是其形状的改变。

By exploiting the correlation of ultrasound speckle patterns that result from scattering by underlying tissue elements, two-dimensional tissue motion theoretically can be recovered by tracking the apparent movement of the associated speckle patterns. Speckle tracking, however, is an ill-posed inverse problem because of temporal decorrelation of the speckle patterns and the inherent low signal-to-n...

通过利用由底层组织元素散射产生的超声斑点模式的相关性，理论上可以通过跟踪相关斑点模式的表观运动来恢复二维组织运动。然而，由于斑点模式的时间去相关性和固有的低信噪比，斑点跟踪是一个不适定的逆问题。

The authors derives an algorithm for reconstructing contours of an object from 3D cone beam X-ray data. By reducing the amount of the searched-for information, contours, or density jumps instead of the densities themselves, the authors are able to develop fast algorithms for data incomplete with respect to both the movement of the X-ray source and the detector reading. The method is related to loc...

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We show an iterative reconstruction framework for diffraction ultrasound tomography. The use of broad-band illumination allows significant reduction of the number of projections compared to straight ray tomography. The proposed algorithm makes use of forward nonuniform fast Fourier transform (NUFFT) for iterative Fourier inversion. Incorporation of total variation regularization allows the reducti...

我们展示了一种用于衍射超声层析成像的迭代重建框架。与直射线层析成像相比，使用宽带照明可以显著减少投影数量。所提出的算法利用前向非均匀快速傅里叶变换（NUFFT）进行迭代傅里叶反演。结合总变差正则化可以减少...

A new tomographic reconstruction method is proposed which permits the reconstruction of a region of interest within a slice from partially truncated scanning data. This method utilizes two types of source data, namely a series of truncated projections and the outline of the object's cross section. The principle of this algorithm is to estimate the outside area of truncation in one projection from ...

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The ISRA of [1] is shown to be an iterative algorithm that aims to converge to the least-squares estimates of emission densities. Convergence is established in the case where a unique least-squares estimate exists that is, elementwise, strictly positive. It is pointed out that, in terms of asymptotic theory, the resulting estimators are inferior to the maximum likelihood estimators, for which the ...

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Functional magnetic resonance images (fMRI's) provide high-resolution datasets which allow researchers to obtain accurate delineation and sensitive detection of activation areas involved in cognitive processes. To preserve the resolution of this noninvasive technique, refined methods are required in the analysis of the data. In this paper, the authors first discuss the widely used methods based on...

功能磁共振成像（fMRI）提供高分辨率数据集，使研究人员能够获得认知过程中激活区域的准确描绘和敏感检测。为了保持这种无创技术的分辨率，在数据分析中需要精细的方法。本文首先讨论了基于...的广泛使用的方法。

Conventional X-ray tomosynthesis with film can provide a sagittal slice image with a single scan. This technique has the advantage of enabling reconstruction of a sagittal slice which is difficult to obtain from the X-ray CT system. However, only an image on the focal plane is obtained by a single scan. Furthermore, the image is degraded by superimpositions of the structures outside of the focal p...

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Within-subject analysis in fMRI essentially addresses two problems, the detection of brain regions eliciting evoked activity and the estimation of the underlying dynamics. In Makni , 2005 and Makni , 2008, a detection-estimation framework has been proposed to tackle these problems jointly, since they are connected to one another. In the Bayesian formalism, detection is achieved by modeling activat...

fMRI的个体内分析主要解决两个问题：检测诱发活动的脑区域以及估计潜在的动态过程。在Makni等人2005年和Makni等人2008年的研究中，提出了一种检测-估计框架来联合处理这些问题，因为它们相互关联。在贝叶斯形式中，通过建模激活来实现检测……

A method is introduced to compensate for missing projection data that can result from gas between detectors or from malfunctioning detectors. This method uses constraints in the Fourier domain to estimate the missing data, thus completing the data set so that the filtered backprojection algorithm can be used to reconstruct artifact-free images. The image reconstructed from estimates using this tec...

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We studied dielectrical properties of canine myocardium during acute ischemia and hypoxia using dielectrical spectroscopy method at frequency spectrum from 100 kHz to 6 GHz. This study was conducted on a group of six canines with acute ischemia and seven canines with hypoxia. Hypoxia (10% for 30 min) decreases myocardial resistance (/spl rho/), while the dielectrical permittivity (/spl epsi/') of ...

我们采用介电谱方法，在100 kHz至6 GHz频率范围内研究了犬心肌在急性缺血和缺氧时的介电特性。本研究在一组六只急性缺血犬和七只缺氧犬上进行。缺氧（10% 30分钟）降低心肌电阻抗（ρ），而介电常数（ε'）...

Leg ulcers are chronic skin a wounds that affect many people and take a long time to heal. The progress of wound healing and the effect of clinical treatments can he monitored partly by measuring the area of the wound. Measurements taken via manually based methods, such as using a computer pointing device to delineate the wound boundary in a digitized image, suffer from variations due to manual de...

腿部溃疡是影响许多人的慢性皮肤伤口，需要很长时间才能愈合。伤口愈合的进展和临床治疗效果可以通过测量伤口面积部分监测。通过手动方法进行的测量，例如使用计算机指点设备在数字化图像中描绘伤口边界，存在由于手动操作而导致的变异...