Volume 20, Issue 7

Presents a new method for image registration based on jointly estimating the forward and reverse transformations between two images while constraining these transforms to be inverses of one another. This approach produces a consistent set of transformations that have less pairwise registration error, i.e., better correspondence, than traditional methods that estimate the forward and reverse transformations independently. The transformations are estimated iteratively and are restricted to preserve topology by constraining them to obey the laws of continuum mechanics. The transformations are parameterized by a Fourier series to diagonalize the covariance structure imposed by the continuum mechanics constraints and to provide a computationally efficient numerical implementation. Results using a linear elastic material constraint are presented using both magnetic resonance and X-ray computed tomography image data. The results show that the joint estimation of a consistent set of forward and reverse transformations constrained by linear-elasticity give better registration results than using either constraint alone or none at all.

提出了一种新的图像配准方法，该方法基于联合估计两幅图像之间的正向和反向变换，同时限制这些变换互为逆变换。这种方法产生了一致性的变换集，其配准误差小于传统方法独立估计正向和反向变换的误差，即具有更好的对应性。变换通过迭代估计，并通过约束其遵循连续介质力学定律来限制拓扑保持。变换通过傅里叶级数参数化，以对角化连续介质力学约束施加的协方差结构，并提供计算高效的数值实现。使用线性弹性材料约束的结果在磁共振和X射线计算机断层扫描图像数据上展示。结果表明，在线性弹性约束下联合估计一致性的正向和反向变换，比单独使用任一约束或完全不使用约束给出更好的配准结果。

The purpose of this study is to develop a technique for computer-aided diagnosis (CAD) systems to detect lung nodules in helical X-ray pulmonary computed tomography (CT) images. The authors propose a novel template-matching technique based on a genetic algorithm (GA) template matching (GATM) for detecting nodules existing within the lung area; the GA was used to determine the target position in th...

本研究旨在为计算机辅助诊断（CAD）系统开发一种技术，用于检测螺旋X射线肺部计算机断层扫描（CT）图像中的肺结节。作者提出了一种基于遗传算法（GA）模板匹配（GATM）的新型模板匹配技术，用于检测肺区域内的结节；遗传算法用于确定目标位置...

Analyzes B-spline interpolation techniques of degree 2, 4, and 5 with respect to all criteria that have been applied to evaluate various interpolation schemes in a recently published survey on image interpolation in medical imaging (Lehmann et al., 1999). It is shown that high-degree B-spline interpolation has superior Fourier properties, smallest interpolation error, and reasonable computing time...

分析了次数为2、4和5的B样条插值技术，这些技术均符合最近发表的关于医学成像中图像插值的综述（Lehmann等人，1999年）中用于评估各种插值方案的所有标准。研究表明，高次B样条插值具有优越的傅里叶性质、最小的插值误差以及合理的计算时间。

Cancerous tumor mass is one of the major types of breast cancer. When cancerous masses are embedded in and camouflaged by varying densities of parenchymal tissue structures, they are very difficult to be visually detected on mammograms. This paper presents an algorithm that combines several artificial intelligent techniques with the discrete wavelet transform (DWT) for detection of masses in mammo...

癌性肿瘤肿块是乳腺癌的主要类型之一。当癌性肿块嵌入并隐藏在密度不同的实质组织结构中时，很难在乳房X光摄影上视觉检测出来。本文提出了一种将多种人工智能技术与离散小波变换相结合用于检测乳房X光摄影中肿块的算法...

Reports a new automated method for the segmentation of internal cerebral structures using an information fusion technique. The information is provided both by images and expert knowledge, and consists in morphological, topological, and tissue constitution data. All this ambiguous, complementary and redundant information is managed using a three-step fusion scheme based on fuzzy logic. The informat...

报告了一种使用信息融合技术分割大脑内部结构的新自动化方法。信息由图像和专家知识共同提供，包括形态、拓扑和组织构成数据。所有这些模糊、互补和冗余的信息通过基于模糊逻辑的三步融合方案进行管理。

Modern video based endoscopes offer physicians a wide-angle field of view (FOV) for minimally invasive procedures, Unfortunately, inherent barrel distortion prevents accurate perception of range. This makes measurement and distance judgment difficult and causes difficulties in emerging applications, such as virtual guidance of endoscopic procedures. Such distortion also arises in other wide FOV ca...

现代基于视频的内窥镜为医生提供了用于微创手术的宽视场（FOV）。不幸的是，固有的桶形畸变阻碍了距离的准确感知。这使得测量和距离判断变得困难，并导致在新兴应用（如内窥镜手术的虚拟引导）中出现困难。这种畸变也出现在其他宽视场中…

Presents coincidence-list-ordered set expectation-maximisation (COSEM), an algorithm for iterative image reconstruction directly from list-mode coincidence acquisition data. The COSEM algorithm is based on the ordered sets EM algorithm for binned data but has several extensions that makes it suitable for rotating two planar detector tomographs. The authors develop the COSEM algorithm and extend it...

介绍了符合列表有序集期望最大化（COSEM）算法，该算法直接从列表模式符合采集数据中进行迭代图像重建。COSEM算法基于分箱数据的有序集EM算法，但具有若干扩展，使其适用于旋转双平面探测器断层成像系统。作者开发了COSEM算法并对其进行了扩展...

This paper presents a new variational method for the segmentation of a moving object against a still background, over a sequence of [two-dimensional or three-dimensional (3-D)] image frames. The method is illustrated in application to myocardial gated single photon emission computed tomography (SPECT) data, and incorporates a level set framework to handle topological changes while providing closed...

本文提出了一种新的变分方法，用于在二维或三维图像帧序列中，从静止背景中分割运动对象。该方法以心肌门控单光子发射计算机断层扫描（SPECT）数据为例进行说明，并采用水平集框架处理拓扑变化，同时提供闭合...

This paper describes a region-growing algorithm for the segmentation of large lesions in T/sub 1/-weighted magnetic resonance (MR) images of the head. The algorithm involves a gray level similarity criterion to expand the region and a size criterion to prevent from over-growing outside the lesion. The performance of tile algorithm is evaluated and validated on a series of pathologic three-dimensio...

本文描述了一种用于头部T1加权磁共振（MR）图像中大病变分割的区域生长算法。该算法采用灰度相似性准则来扩展区域，并利用尺寸准则防止区域过度生长到病变外部。该算法的性能在一系列病理三维...上进行了评估和验证。

Inclusion of brain tissues with different rates of blood flow and metabolism within a voxel or region of interest is an unavoidable problem with positron emission tomography due to its limited spatial resolution. Because regional cerebral blood flow (rCBF) is higher in gray matter than in white matter, the partial volume effect leads to underestimation of rCBF in gray matter when rCBF in the regio...

由于正电子发射断层扫描的空间分辨率有限，在体素或感兴趣区域内包含不同血流和代谢速率的脑组织是一个不可避免的问题。由于灰质的局部脑血流量（rCBF）高于白质，当区域内的rCBF...

The stationary long-wavelength sound wave computed tomography is a nonlinear inverse problem that requires the use of prior information of the object. However, the prior assumptions that are usually used in similar inverse problems are more or less inappropriate. Here, a new reconstruction algorithm using the prior information is proposed and compared with subspace regularization method and Marqua...

稳态长波声波计算机断层扫描是一个非线性逆问题，需要利用物体的先验信息。然而，类似逆问题中通常使用的先验假设或多或少是不合适的。在此，提出了一种利用先验信息的新重建算法，并与子空间正则化方法和Marqua...