Volume 25, Issue 5

This paper presents a new three-dimensional electromechanical model of the two cardiac ventricles designed both for the simulation of their electrical and mechanical activity, and for the segmentation of time series of medical images. First, we present the volumetric biomechanical models built. Then the transmembrane potential propagation is simulated, based on FitzHugh-Nagumo reaction-diffusion equations. The myocardium contraction is modeled through a constitutive law including an electromechanical coupling. Simulation of a cardiac cycle, with boundary conditions representing blood pressure and volume constraints, leads to the correct estimation of global and local parameters of the cardiac function. This model enables the introduction of pathologies and the simulation of electrophysiology interventions. Moreover, it can be used for cardiac image analysis. A new proactive deformable model of the heart is introduced to segment the two ventricles in time series of cardiac images. Preliminary results indicate that this proactive model, which integrates a priori knowledge on the cardiac anatomy and on its dynamical behavior, can improve the accuracy and robustness of the extraction of functional parameters from cardiac images even in the presence of noisy or sparse data. Such a model also allows the simulation of cardiovascular pathologies in order to test therapy strategies and to plan interventions.

本文提出了一种新的三维心脏双心室电机械模型，旨在模拟其电学和机械活动，以及分割医学图像时间序列。首先，我们构建了体积生物力学模型。然后，基于FitzHugh-Nagumo反应扩散方程模拟跨膜电位传播。通过包含电机械耦合的本构定律模拟心肌收缩。模拟一个心动周期，边界条件代表血压和容积约束，从而正确估计心脏功能的全局和局部参数。该模型能够引入病理学和模拟电生理干预。此外，它可以用于心脏图像分析。介绍了一种新的主动变形心脏模型，用于分割心脏图像时间序列中的两个心室。初步结果表明，该主动模型整合了心脏解剖结构和动态行为的先验知识，即使在有噪声或稀疏数据的情况下，也能提高从心脏图像提取功能参数的准确性和鲁棒性。这样的模型还允许模拟心血管病理，以测试治疗策略和规划干预。

The purpose of this paper is to determine the benefit that can be achieved in image quality for a time-of-flight (TOF) fully three-dimensional (3-D) whole-body positron emission tomography (PET) scanner. We simulate a 3-D whole-body time-of-flight PET scanner with a complete modeling of spatial and energy resolutions. The scanner is based on LaBr/sub 3/ Anger-logic detectors with which 300ps timin...

本文旨在确定使用飞行时间（TOF）全三维（3-D）全身正电子发射断层扫描（PET）扫描仪所能实现的图像质量改进。我们模拟了一台3-D全身TOF PET扫描仪，完整建模了空间和能量分辨率。该扫描仪基于LaBr3 Anger逻辑探测器，具有300皮秒的时间分辨率...

This paper is motivated by the analysis of serial structural magnetic resonance imaging (MRI) data of the brain to map patterns of local tissue volume loss or gain over time, using registration-based deformation tensor morphometry. Specifically, we address the important confound of local tissue contrast changes which can be induced by neurodegenerative or neurodevelopmental processes. These not on...

本文旨在分析脑部序列结构磁共振成像（MRI）数据，通过基于配准的变形张量形态测量，绘制局部组织体积随时间增减的模式。具体而言，我们解决了局部组织对比度变化这一重要混杂因素，这些变化可能由神经退行性或神经发育过程引起。这些不仅...

Intravascular ultrasound (IVUS) is a catheter based medical imaging technique particularly useful for studying atherosclerotic disease. It produces cross-sectional images of blood vessels that provide quantitative assessment of the vascular wall, information about the nature of atherosclerotic lesions as well as plaque shape and size. Automatic processing of large IVUS data sets represents an impo...

血管内超声（IVUS）是一种基于导管的医学成像技术，特别适用于研究动脉粥样硬化疾病。它产生血管的横截面图像，提供血管壁的定量评估，以及关于动脉粥样硬化病变性质、斑块形状和尺寸的信息。自动处理大型IVUS数据集代表着重要的...

Cardiovascular diseases remain the primary cause of death in developed countries. In most cases, exploration of possibly underlying coronary artery pathologies is performed using X-ray coronary angiography. Current clinical routine in coronary angiography is directly conducted in two-dimensional projection images from several static viewing angles. However, for diagnosis and treatment purposes, co...

心血管疾病仍然是发达国家的主要死亡原因。在大多数情况下，使用X射线冠状动脉造影来探索可能存在的冠状动脉病变。目前的临床常规冠状动脉造影直接使用来自多个静态视角的二维投影图像。然而，为了诊断和治疗目的，co...

The task of segmenting the posterior ribs within the lung fields of standard posteroanterior chest radiographs is considered. To this end, an iterative, pixel-based, supervised, statistical classification method is used, which is called iterated contextual pixel classification (ICPC). Starting from an initial rib segmentation obtained from pixel classification, ICPC updates it by reclassifying eve...

考虑在标准后前位胸部X光片的肺野内分割后肋的任务。为此，使用了一种迭代的、基于像素的、有监督的统计分类方法，称为迭代上下文像素分类（ICPC）。从通过像素分类获得的初始肋骨分割开始，ICPC通过重新分类每...

We are developing methods to characterize atherosclerotic disease in human carotid arteries using multiple MR images having different contrast mechanisms (T1W, T2W, PDW). To enable the use of voxel gray values for interpretation of disease, we created a new method, local entropy minimization with a bicubic spline model (LEMS), to correct the severe (/spl ap/80%) intensity inhomogeneity that arises...

我们正在开发使用具有不同对比机制（T1W、T2W、PDW）的多幅磁共振图像来表征人类颈动脉动脉粥样硬化疾病的方法。为了能够利用体素灰度值进行疾病解释，我们创建了一种新方法，即基于双三次样条模型的局部熵最小化（LEMS），以校正出现的严重（约80%）强度不均匀性...

We propose a method to simulate atrophy and other similar volumetric change effects on medical images. Given a desired level of atrophy, we find a dense warping deformation that produces the corresponding levels of volumetric loss on the labeled tissue using an energy minimization strategy. Simulated results on a real brain image indicate that the method generates realistic images of tissue loss. ...

我们提出了一种方法，用于模拟医学图像上的萎缩和其他类似的体积变化效应。给定所需的萎缩水平，我们使用能量最小化策略，找到一种密集的扭曲变形，在标记的组织上产生相应水平的体积损失。在实际脑图像上的模拟结果表明，该方法生成了逼真的组织损失图像。

Optical coherence tomography (OCT) uses retroreflected light to provide micrometer-resolution, cross-sectional scans of biological tissues. OCT's first application was in ophthalmic imaging where it has proven particularly useful in diagnosing, monitoring, and studying glaucoma. Diagnosing glaucoma is difficult and it often goes undetected until significant damage to the subject's visual field has...

光学相干断层扫描（OCT）利用反向反射光提供生物组织的微米分辨率横截面扫描。OCT的第一个应用是在眼科成像中，已被证明在诊断、监测和研究青光眼方面特别有用。诊断青光眼很困难，通常直到受试者的视野出现显著损伤才被发现……

Fourier-based forward and back-projection methods can reduce computation in iterative tomographic image reconstruction. Recently, an optimized nonuniform fast Fourier transform (NUFFT) approach was shown to yield accurate parallel-beam projections. In this paper, we extend the NUFFT approach to describe an O(N/sup 2/ log N) projector/backprojector pair for fan-beam transmission tomography. Simulat...

基于傅里叶的正向和反向投影方法可以减少迭代断层图像重建中的计算量。最近，一种优化的非均匀快速傅里叶变换（NUFFT）方法被证明能生成精确的平行束投影。本文扩展了NUFFT方法，描述了一对用于扇形束透射断层成像的 O(N^2 log N) 投影器/反投影器对。仿真...

Receiver operating characteristic (ROC) analysis is well established in the evaluation of systems involving binary classification tasks. However, medical tests often require distinguishing among more than two diagnostic alternatives. The goal of this work was to develop an ROC analysis method for three-class classification tasks. Based on decision theory, we developed a method for three-class ROC ...

接收者操作特征(ROC)分析在涉及二分类任务的系统评估中已得到广泛应用。然而，医学测试常常需要区分超过两种诊断选项。本研究的目标是开发一种用于三分类任务的ROC分析方法。基于决策理论，我们开发了一种三分类ROC...方法。

Region of interest (ROI) quantification is an important task in emission tomography (e.g., positron emission tomography and single photon emission computed tomography). It is essential for exploring clinical factors such as tumor activity, growth rate, and the efficacy of therapeutic interventions. Statistical image reconstruction methods based on the penalized maximum-likelihood (PML) or maximum ...

感兴趣区域（ROI）量化是发射断层成像（例如正电子发射断层扫描和单光子发射计算机断层扫描）中的一项重要任务。它对于探索肿瘤活性、生长率以及治疗干预效果等临床因素至关重要。基于惩罚最大似然（PML）或最大...的统计图像重建方法

The development of methods to detect slowly progressing diseases is often hampered by the time-consuming acquisition of a sufficiently large data set. In this paper, a method is presented to model the change in images acquired by scanning laser polarimetry, for the detection of glaucomatous progression. The model is based on image series of 23 healthy eyes and incorporates colored noise, incomplet...

缓慢进展性疾病的检测方法开发往往受到获取足够大数据集的耗时阻碍。本文提出了一种方法，用于模拟通过扫描激光偏振测量获取的图像变化，以检测青光眼进展。该模型基于23只健康眼睛的图像序列，并包含有色噪声、不完全...

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

提供出版人员、现任委员会成员和学会官员的列表。

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本页或这些页面特意留空。

Provides notice of upcoming special issues of interest to practitioners and researchers.

提供关于即将到来的特刊的通知，这些特刊对从业者和研究人员感兴趣。

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

介绍本期刊物目录。

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

为希望提交手稿的潜在作者提供说明和指南。