Volume 26, Issue 8

A method for vessel segmentation and tracking in ultrasound images using Kalman filters is presented. A modified Star-Kalman algorithm is used to determine vessel contours and ellipse parameters using an extended Kalman filter with an elliptical model. The parameters can be used to easily calculate the transverse vessel area which is of clinical use. A temporal Kalman filter is used for tracking the vessel center over several frames, using location measurements from a handheld sensorized ultrasound probe. The segmentation and tracking have been implemented in real-time and validated using simulated ultrasound data with known features and real data, for which expert segmentation was performed. Results indicate that mean errors between segmented contours and expert tracings are on the order of 1%-2% of the maximum feature dimension, and that the transverse cross-sectional vessel area as computed from estimated ellipse parameters a, b as determined by our algorithm is within 10% of that determined by experts. The location of the vessel center was tracked accurately for a range of speeds from 1.4 to 11.2 mm/s.

提出了一种利用卡尔曼滤波器进行超声图像中血管分割与追踪的方法。采用改进的Star-Kalman算法，通过带有椭圆模型的扩展卡尔曼滤波器确定血管轮廓和椭圆参数。这些参数可用于轻松计算临床上所需的横向血管面积。使用时间卡尔曼滤波器，利用手持传感器化超声探头的位置测量值，对多帧图像中的血管中心进行追踪。该分割与追踪已实现实时，并使用具有已知特征的模拟超声数据和专家分割的真实数据进行验证。结果表明，分割轮廓与专家描迹之间的平均误差约为最大特征尺寸的1%-2%，且根据算法估计的椭圆参数a、b计算的横向血管截面积与专家确定的面积相差在10%以内。血管中心位置在1.4至11.2毫米/秒的速度范围内被准确追踪。

In this paper, we present a new formulation for recovering the fiber tract geometry within a voxel from diffusion weighted magnetic resonance imaging (MRI) data, in the presence of single or multiple neuronal fibers. To this end, we define a discrete set of diffusion basis functions. The intravoxel information is recovered at voxels containing fiber crossings or bifurcations via the use of a linea...

在本文中，我们提出了一种新的方法，用于从扩散加权磁共振成像（MRI）数据中恢复体素内的纤维束几何结构，包括单个或多个神经元纤维。为此，我们定义了一组离散的扩散基函数。通过使用线性...

A new generic model-based segmentation algorithm is presented, which can be trained from examples akin to the active shape model (ASM) approach in order to acquire knowledge about the shape to be segmented and about the gray-level appearance of the object in the image. Whereas ASM alternates between shape and intensity information during search, the proposed approach optimizes for shape and intens...

提出了一种新的通用基于模型的分割算法，该算法可以像主动形状模型（ASM）方法一样从示例中训练，以获取关于待分割形状和图像中物体灰度外观的知识。ASM在搜索过程中交替使用形状和强度信息，而所提出的方法同时优化形状和强度...

Virtual colonoscopy (VC) is becoming a more prevalent method to detect and diagnose colorectal cancer. An essential component of using VC to detect cancerous polyps, especially in conjunction with computer-aided diagnosis, is the accurate calculation of the centerline of the colon. While the colon is often modeled as a simple cylinder, the amount of colonic distention may vary between patients and...

虚拟结肠镜检查（VC）正成为检测和诊断结直肠癌的更普遍方法。使用VC检测癌性息肉，特别是结合计算机辅助诊断时，一个关键组成部分是准确计算结肠的中心线。虽然结肠通常被建模为简单的圆柱体，但结肠扩张的程度可能因患者而异……

An analytical framework of error propagation for diffusion tensor imaging (DTI) is presented. Using this framework, any uncertainty of interest related to the diffusion tensor elements or to the tensor-derived quantities such as eigenvalues, eigenvectors, trace, fractional anisotropy (FA), and relative anisotropy (RA) can be analytically expressed and derived from the noisy diffusion-weighted sign...

提出了一种针对扩散张量成像（DTI）的误差传播分析框架。利用该框架，任何与扩散张量元素或张量衍生量（如特征值、特征向量、迹、分数各向异性（FA）和相对各向异性（RA））相关的不确定性都可以从噪声扩散加权信号中解析表达和推导出来。

Parallel imaging is a powerful technique to speed up magnetic resonance (MR) image acquisition via multiple coils. Both the received signal of each coil and its sensitivity map, which describes its spatial response, are needed during reconstruction. Widely used schemes such as SENSE assume that sensitivity maps of the coils are noiseless while the only errors are in coil outputs. In practice, howe...

并行成像是一种通过多个线圈加速磁共振（MR）图像采集的强大技术。在重建过程中，需要每个线圈的接收信号及其灵敏度图（描述其空间响应）。广泛使用的方案如SENSE假设线圈的灵敏度图是无噪声的，而唯一的误差来自线圈输出。然而在实际中...

It has been previously observed that independent component analysis (ICA), if applied to data pooled in a particular way, may lessen the need for spatial alignment of scans in a functional neuroimaging study. In this paper, we seek to determine analytically the conditions under which this observation is true, not only for spatial ICA, but also for temporal ICA and for principal component analysis ...

先前已经观察到，如果以特定方式合并数据，独立成分分析（ICA）可能会减少功能神经影像研究中扫描空间对齐的需求。在本文中，我们试图确定这一观察成立的分析条件，不仅适用于空间ICA，也适用于时间ICA和主成分分析……

In the early stages of some retinal diseases, such as glaucoma, loss of retinal activity may be difficult to detect with current clinical instruments. Because current instruments require unattainable levels of patient cooperation, high sensitivity and specificity are difficult to attain. We have devised a new retinal imaging system that detects intrinsic optical signals which reflect functional ch...

在某些视网膜疾病（如青光眼）的早期阶段，使用当前的临床仪器可能难以检测到视网膜活动丧失。由于当前仪器需要无法达到的患者合作水平，难以获得高灵敏度和特异性。我们设计了一种新的视网膜成像系统，可检测反映功能变化的内源性光学信号...

A method for fully automated morphological and topological quantification of microvascular structures in confocal laser scanning microscopy (CLSM) volume datasets is presented. Several characteristic morphological and topological quantities are calculated in a series of image-processing steps and can be used to compare single components as well as whole networks of microvascular structures to each...

提出了一种完全自动化的形态学和拓扑学量化方法，用于共聚焦激光扫描显微镜（CLSM）体积数据集中的微血管结构。通过一系列图像处理步骤计算多个特征形态和拓扑量，可用于比较微血管结构的单个组件以及整个网络。

Provides instructions and guidelines to prospective authors who wish to submit manuscripts.

为有意投稿的作者提供说明和指南。

Prospective authors are requested to submit new, unpublished manuscripts for inclusion in the upcoming event described in this call for papers.

诚邀有意投稿的作者提交新的、未发表的稿件，以便纳入本次征文通知所述即将举行的会议。

This page or pages intentionally left blank.

本页或这些页故意留空。

Provides a listing of current staff, committee members and society officers.

提供当前工作人员、委员会成员和学会官员的列表。

Provides notice of upcoming special issue(s) of interest to practitioners and researchers.

提供即将出版的、对从业者和研究人员感兴趣的特刊通知。

Prospective authors are requested to submit new, unpublished manuscripts for inclusion in the upcoming event described in this call for papers.

诚邀有意投稿的作者提交未发表的新稿件，以收录于本次征稿通知所描述的即将举行的会议中。

Presents the table of contents for this issue of the periodical.

介绍本期期刊的目录。