Volume 19, Issue 12

Traditional computed tomography (CT) reconstructions of total joint prostheses are limited by metal artifacts from corrupted projection data. Published metal artifact reduction methods are based on the assumption that severe attenuation of X-rays by prostheses renders corresponding portions of projection data unavailable, hence the "missing" data are either avoided (in iterative reconstruction) or interpolated (in filtered back-projection with data completion; typically, with filling data "gaps" via linear functions). Here, the authors propose a wavelet-based multiresolution analysis method for metal artifact reduction, in which information is extracted from corrupted projection data. The wavelet method improves image quality by a successive interpolation in the wavelet domain. Theoretical analysis and experimental results demonstrate that the metal artifacts due to both photon starving and beam hardening can be effectively suppressed using the authors' method. As compared to the filtered back-projection after linear interpolation, the wavelet-based reconstruction is significantly more accurate for depiction of anatomical structures, especially in the immediate neighborhood of the prostheses. This superior imaging precision is highly advantageous in geometric modeling for fitting hip prostheses.

传统计算机断层扫描（CT）重建全关节假体时，因投影数据受损而产生的金属伪影限制了其应用。已发表的金属伪影减少方法基于以下假设：假体对X射线的严重衰减使得相应的投影数据部分不可用，因此“缺失”数据要么被避免（迭代重建），要么被插值（使用数据完成的滤波反投影；通常通过线性函数填充数据“间隙”）。本文作者提出了一种基于小波的多分辨率分析方法用于金属伪影减少，该方法从受损的投影数据中提取信息。小波方法通过在 wavelet 域中进行连续插值来提高图像质量。理论分析和实验结果表明，使用该方法可以有效抑制由光子饥饿和束硬化引起的金属伪影。与线性插值后的滤波反投影相比，基于小波的重建在描绘解剖结构方面显著更准确，尤其是在假体附近。这种优越的成像精度对于髋关节假体的几何建模非常有利。

Modeling the hemodynamic response in functional magnetic resonance (fMRI) experiments is an important aspect of the analysis of functional neuroimages. This has been done in the past using parametric response function, from a limited family. In this contribution, the authors adopt a semi-parametric approach based on finite impulse response (FIR) filters. In order to cope with the increase in the n...

在功能性磁共振（fMRI）实验中，对血流动力学反应进行建模是功能性神经图像分析的一个重要方面。过去，这一直使用来自有限族的参数响应函数来完成。在这项贡献中，作者采用了一种基于有限脉冲响应（FIR）滤波器的半参数方法。为了应对n...

Accurate detection of prostate boundaries is required in many diagnostic and treatment procedures for prostate disease. Here, a new paradigm for guided edge delineation is described, a which involves presenting automatically detected prostate edges as a visual guide to the observer, followed by manual editing. This approach enables robust delineation of the prostate boundaries, making it suitable ...

在许多前列腺疾病的诊断和治疗过程中，需要准确检测前列腺边界。本文描述了一种新的引导边缘描绘范式，该范式涉及将自动检测到的前列腺边缘作为视觉引导呈现给观察者，然后进行手动编辑。这种方法能够稳健地描绘前列腺边界，使其适用于...

During the last few years, optical coherence tomography (OCT) has demonstrated considerable promise as a method of high-resolution intravascular imaging. The goal of this study was to apply and to test the applicability of the rotating kernel transformation (RKT) technique to the speckle reduction and enhancement of OCT images. The technique is locally adaptive. It is based on sequential applicati...

在过去几年中，光学相干断层成像（OCT）已展现出作为高分辨率血管内成像方法的巨大潜力。本研究旨在应用并测试旋转核变换（RKT）技术对OCT图像进行散斑抑制和增强的适用性。该技术具有局部自适应性，基于连续应用...

Presents a fully automatic three-dimensional classification of brain tissues for Magnetic Resonance (MR) images. An MR image volume may be composed of a mixture of several tissue types due to partial volume effects. Therefore, the authors consider that in a brain dataset there are not only the three main types of brain tissue: gray matter, white matter, and cerebro spinal fluid, called pure classe...

提出了一种全自动的三维脑组织分类方法用于磁共振（MR）图像。由于部分体积效应，MR图像体素可能由多种组织类型混合而成。因此，作者认为在脑数据集中不仅存在三种主要脑组织类型：灰质、白质和脑脊液，称为纯类...

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。

An automatic method has been developed for segmentation of abdominal computed tomography (CT) images for virtual colonoscopy obtained after a bowel preparation of a low-residue diet with ingested contrast solutions to enhance the image intensities of residual colonic materials. Removal of the enhanced materials was performed electronically by a computer algorithm. The method is a multistage approa...

已开发一种自动方法，用于分割腹部计算机断层扫描（CT）图像，这些图像用于虚拟结肠镜，是在低残留饮食和摄入造影剂溶液以增强残留结肠材料图像强度的肠道准备后获得的。通过计算机算法电子去除增强的材料。该方法是一个多阶段方法...

A minimum-norm least-squares image-reconstruction method for the reconstruction of magnetic resonance images from non-Cartesian sampled data is proposed. The method is based on a general formalism for continuous-to-discrete mapping and pseudoinverse calculation. It does not involve any regridding or interpolation of the data and therefore the methodology differs fundamentally from existing regridd...

提出了一种从非笛卡尔采样数据重建磁共振图像的最小范数最小二乘图像重建方法。该方法基于连续到离散映射和伪逆计算的通用形式。它不涉及任何数据的重网格化或插值，因此该方法与现有的重网格化方法有根本区别。

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...

Magnetic resonance spectroscopic imaging requires a great deal of time to gather the data necessary to achieve satisfactory resolution. When the image has a limited region of support (ROS), it is possible to reconstruct the image from a subset of k-space samples. Therefore, the authors desire to choose the best possible combination of a small number of k-space samples to guarantee the quality of t...

磁共振波谱成像需要大量时间来收集必要的数据以达到满意的分辨率。当图像具有有限的支持区域（ROS）时，可以从k空间样本的子集中重建图像。因此，作者希望选择少量k空间样本的最佳组合以保证...

Describes the application of an amplitude modulation-frequency modulation (AM-FM) image representation in segmenting electron micrographs of skeletal muscle for the recognition of: (1) normal sarcomere ultrastructural pattern and (2) abnormal regions that occur in sarcomeres in various myopathies. A total of 26 electron micrographs from different myopathies mere used for this study. It is shown th...

描述了幅度调制-频率调制（AM-FM）图像表示在骨骼肌电子显微图分割中的应用，用于识别：（1）正常肌节超微结构模式，（2）各种肌病中肌节出现的异常区域。本研究共使用来自不同肌病的26张电子显微图。结果表明...

A thorough understanding of artifacts caused by metallic instruments is essential for the guidance of interventional procedures by magnetic resonance imaging (MRI), because the accurate localization of each instrument is mandatory for this. In the past, this problem has been addressed by several groups, using theoretical, as well as experimental approaches. The artifacts associated with MRI are ca...

全面理解由金属器械引起的伪影对于磁共振成像引导的介入手术至关重要，因为精确定位每个器械是必需的。过去，多个研究小组通过理论和实验方法探讨了这个问题。与MRI相关的伪影是……

Distributed computing that uses dynamic networks will change the way one works and communicates thanks to the interaction of devices and services, that are automatically added and removed from the network as needed. The Jini technology, which is built atop the Java programming language, provides a homogenous view of the network and extends the ability of code to migrate in Java. This software desi...

使用动态网络的分布式计算将改变人们工作和交流的方式，这得益于设备和服务的交互，它们会根据需要自动从网络中添加和移除。Jini技术建立在Java编程语言之上，提供了网络的同质视图，并扩展了代码在Java中迁移的能力。该软件设...

The keratoconus index (KI) is a new biometric parameter to make diagnosis and to follow the development of the keratoconus in human eyes. Using images from an ultrasound biomicroscope, the authors show a semi-automatic method to speed up the computation of the KI.

圆锥角膜指数（KI）是一种新的生物测量参数，用于诊断和跟踪人类眼睛中圆锥角膜的发展。利用超声生物显微镜的图像，作者展示了一种半自动方法来加速KI的计算。

In the above paper (see S. Haker et al., ibid., vol.19, p.665-70, 2000), Figs. 2-5 should have appeared in color as shown here.

在上述论文中（参见S. Haker等人，同上，第19卷，第665-70页，2000年），图2-5应以彩色显示，如下所示。

This index covers all technical items - papers, correspondence, reviews, etc. - that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items may also be covered if they have been judged to have archival value. The Author Index contains the primary entry for each item, listed under the first author's ...

本索引涵盖本年度期刊中出现的所有技术项目——论文、信函、评论等，以及往年曾被评论或在本年度得到纠正的项目。部门和其他项目如果被认为具有档案价值，也可能被收录。作者索引包含每个项目的主要条目，列在第一作者名下……

This index covers all technical items - papers, correspondence, reviews, etc. - that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items may also be covered if they have been judged to have archival value. The Author Index contains the primary entry for each item, listed under the first author's ...

本索引涵盖本年度该期刊中出现的所有技术项目——论文、通信、评论等，以及往年曾被评论或修正的项目。部门和其他项目如果被认为具有存档价值，也可能被收录。作者索引包含每个项目的主要条目，按第一作者的姓名列出……