Most Cited Articles

Three-dimensional (3-D) imaging of the heart is a rapidly developing area of research in medical imaging. Advances in hardware and methods for fast spatio-temporal cardiac imaging are extending the frontiers of clinical diagnosis and research on cardiovascular diseases. In the last few years, many approaches have been proposed to analyze images and extract parameters of cardiac shape and function ...

心脏的三维（3-D）成像是医学成像中一个快速发展的研究领域。快速时空心脏成像的硬件和方法的进步正在拓展心血管疾病临床诊断和研究的边界。在过去几年中，许多方法被提出用于分析图像和提取心脏形状与功能的参数……

Image segmentation is the partition of an image into a set of nonoverlapping regions whose union is the entire image. The image is decomposed into meaningful parts which are uniform with respect to certain characteristics, such as gray level or texture. In this paper, we propose a methodology for evaluating medical image segmentation algorithms wherein the only information available is boundaries outlined by multiple expert observers. In this case, the results of the segmentation algorithm can be evaluated against the multiple observers' outlines. We have derived statistics to enable us to find whether the computer-generated boundaries agree with the observers' hand-outlined boundaries as much as the different observers agree with each other. We illustrate the use of this methodology by evaluating image segmentation algorithms on two different applications in ultrasound imaging. In the first application, we attempt to find the epicardial and endocardial boundaries from cardiac ultrasound images, and in the second application, our goal is to find the fetal skull and abdomen boundaries from prenatal ultrasound images.

图像分割是将图像划分为一组非重叠区域，这些区域的并集构成整个图像。图像被分解为具有某些特性（如灰度或纹理）一致的有意义部分。在本文中，我们提出了一种评估医学图像分割算法的方法，其中唯一可用的信息是由多位专家观察者勾画的边界。在这种情况下，分割算法的结果可以与多位观察者的勾画进行对比评估。我们推导了统计量，以判断计算机生成的边界与观察者手绘边界的一致性是否达到不同观察者之间的一致性水平。我们通过评估两种不同超声成像应用中的图像分割算法来说明该方法的使用。在第一个应用中，我们尝试从心脏超声图像中寻找心外膜和心内膜边界；在第二个应用中，我们的目标是从产前超声图像中寻找胎儿颅骨和腹部边界。

We propose the Learned Primal-Dual algorithm for tomographic reconstruction. The algorithm accounts for a (possibly non-linear) forward operator in a deep neural network by unrolling a proximal primal-dual optimization method, but where the proximal operators have been replaced with convolutional neural networks. The algorithm is trained end-to-end, working directly from raw measured data and it d...

我们提出了用于断层重建的学习型原始-对偶算法。该算法通过展开近端原始-对偶优化方法，将（可能非线性的）前向算子纳入深度神经网络中，其中近端算子被卷积神经网络取代。该算法以端到端方式训练，直接处理原始测量数据，并且...

Single photon emission computed tomography (SPECT) imaging with /sup 201/Tl or /sup 99m/Tc agent is used to assess the location or the extent of myocardial infarction or ischemia. A method is proposed to decrease the effect of operator variability in the visual or quantitative interpretation of scintigraphic myocardial perfusion studies. To effect this, the patient's myocardial images (target case...

使用/sup 201/Tl或/sup 99m/Tc试剂的单光子发射计算机断层扫描(SPECT)成像用于评估心肌梗死或缺血的位置或程度。提出了一种方法以减少操作员变异性在闪烁心肌灌注研究的视觉或定量解释中的影响。为了实现这一点，患者的心肌图像(目标病例...)

This paper presents a new supervised method for blood vessel detection in digital retinal images. This method uses a neural network (NN) scheme for pixel classification and computes a 7-D vector composed of gray-level and moment invariants-based features for pixel representation. The method was evaluated on the publicly available DRIVE and STARE databases, widely used for this purpose, since they contain retinal images where the vascular structure has been precisely marked by experts. Method performance on both sets of test images is better than other existing solutions in literature. The method proves especially accurate for vessel detection in STARE images. Its application to this database (even when the NN was trained on the DRIVE database) outperforms all analyzed segmentation approaches. Its effectiveness and robustness with different image conditions, together with its simplicity and fast implementation, make this blood vessel segmentation proposal suitable for retinal image computer analyses such as automated screening for early diabetic retinopathy detection.

本文提出了一种新的监督方法用于数字视网膜图像中的血管检测。该方法采用神经网络方案进行像素分类，并计算由灰度级和基于矩不变特征组成的7维向量用于像素表示。该方法在公开的DRIVE和STARE数据库上进行了评估，这两个数据库广泛用于此目的，因为它们包含由专家精确标记血管结构的视网膜图像。该方法在两个测试图像集上的性能优于文献中其他现有解决方案。该方法在STARE图像中的血管检测尤为准确。将其应用于该数据库（即使神经网络是在DRIVE数据库上训练的）也优于所有分析的分割方法。其在不同图像条件下的有效性和鲁棒性，以及简单性和快速实现，使得该血管分割方案适用于视网膜图像计算机分析，如早期糖尿病视网膜病变的自动筛查。

This paper deals with an automated method for the simultaneous correction of patient motion and gray values prior to subtraction in digitized angiography. The algorithm consists of maximizing the deterministic sign change (DSC) criterion with respect to three registration parameters (two translational shifts and one constant value added to the pixel values of the image with contrast medium). This ...

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It has been shown that employing multiple atlas images improves segmentation accuracy in atlas-based medical image segmentation. Each atlas image is registered to the target image independently and the calculated transformation is applied to the segmentation of the atlas image to obtain a segmented version of the target image. Several independent candidate segmentations result from the process, wh...

研究表明，使用多个图谱图像可以提高基于图谱的医学图像分割的准确性。每个图谱图像独立地配准到目标图像，计算出的变换应用于图谱图像的分割，以获得目标图像的分割版本。该过程产生多个独立的候选分割，...

Automatic segmentation in MR brain images is important for quantitative analysis in large-scale studies with images acquired at all ages. This paper presents a method for the automatic segmentation of MR brain images into a number of tissue classes using a convolutional neural network. To ensure that the method obtains accurate segmentation details as well as spatial consistency, the network uses ...

在MR脑图像中进行自动分割对于涉及所有年龄段图像的大规模研究中的定量分析非常重要。本文提出了一种使用卷积神经网络将MR脑图像自动分割成多个组织类别的方法。为了确保该方法获得准确的分割细节以及空间一致性，网络使用了...

Presents a new approach to the correction of intensity inhomogeneities in magnetic resonance imaging (MRI) that significantly improves intensity-based tissue segmentation. The distortion of the image brightness values by a low-frequency bias field impedes visual inspection and segmentation. The new correction method called parametric bias field correction (PABIC) is based on a simplified model of the imaging process, a parametric model of tissue class statistics, and a polynomial model of the inhomogeneity field. The authors assume that the image is composed of pixels assigned to a small number of categories with a priori known statistics. Further they assume that the image is corrupted by noise and a low-frequency inhomogeneity field. The estimation of the parametric bias field is formulated as a nonlinear energy minimization problem using an evolution strategy (ES). The resulting bias field is independent of the image region configurations and thus overcomes limitations of methods based on homomorphic filtering. Furthermore, PABIC can correct bias distortions much larger than the image contrast. Input parameters are the intensity statistics of the classes and the degree of the polynomial function. The polynomial approach combines bias correction with histogram adjustment, making it well suited for normalizing the intensity histogram of datasets from serial studies. The authors present simulations and a quantitative validation with phantom and test images. A large number of MR image data acquired with breast, surface, and head coils, both in two dimensions and three dimensions, have been processed and demonstrate the versatility and robustness of this new bias correction scheme.

提出了一种新的校正磁共振成像（MRI）中强度不均匀性的方法，该方法显著改善了基于强度的组织分割。图像亮度值由于低频偏置场而失真，妨碍了视觉检查和分割。这种新的校正方法称为参数化偏置场校正（PABIC），基于一个简化模型……

Magnetic particle imaging allows to determine the spatial distribution of magnetic nanoparticles in vivo. The system matrix in magnetic particle imaging is commonly acquired in a tedious calibration scan and requires to measure the system response at numerous positions in the field-of-view. In this paper, we propose a method that significantly reduces the number of required calibration scans. It e...

磁粒子成像能够确定体内磁性纳米颗粒的空间分布。磁粒子成像中的系统矩阵通常通过繁琐的校准扫描获取，需要在视场中的多个位置测量系统响应。在本文中，我们提出了一种显著减少所需校准扫描次数的方法。它...

This paper presents an automated method for the segmentation of the vascular network in retinal images. The algorithm starts with the extraction of vessel centerlines, which are used as guidelines for the subsequent vessel filling phase. For this purpose, the outputs of four directional differential operators are processed in order to select connected sets of candidate points to be further classif...

本文提出了一种自动方法用于视网膜图像中血管网络的分割。该算法从提取血管中心线开始，这些中心线作为后续血管填充阶段的指导。为此，处理四个方向微分算子的输出以选择连接的候选点集，以便进一步分类...

Sparse-view computed tomography (CT) holds great promise for speeding up data acquisition and reducing radiation dose in CT scans. Recent advances in reconstruction algorithms for sparse-view CT, such as iterative reconstruction algorithms, obtained high-quality image while requiring advanced computing power. Lately, deep learning (DL) has been widely used in various applications and has obtained ...

稀疏视角计算机断层扫描（CT）在加速数据采集和减少CT扫描辐射剂量方面具有很大前景。最近稀疏视角CT重建算法的进展，如迭代重建算法，在获得高质量图像的同时需要先进的计算能力。近来，深度学习（DL）已广泛应用于各种应用，并取得了...

Lossless compression techniques are essential in archival and communication of medical images. Here, a new segmentation-based lossless image coding (SLIC) method is proposed, which is based on a simple but efficient region growing procedure. The embedded region growing procedure produces an adaptive scanning pattern for the image with the help of a very-few-bits-needed discontinuity index map. Alo...

无损压缩技术对于医学图像的存档和通信至关重要。本文提出了一种新的基于分割的无损图像编码（SLIC）方法，该方法基于一个简单但高效的区域生长过程。嵌入的区域生长过程借助一个只需极少比特的不连续性指标图，为图像生成自适应扫描模式。

The authors propose a new 2-D point source scattering deconvolution method. The cross-plane scattering is incorporated into the algorithm by modeling a scattering point source function. In the model, the scattering dependence on axial and transaxial directions is reflected in the exponential fitting parameters, and these parameters are directly estimated from a limited number of measured point res...

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Medical image acquisition devices provide a vast amount of anatomical and functional information, which facilitate and improve diagnosis and patient treatment, especially when supported by modern quantitative image analysis methods. However, modality specific image artifacts, such as the phenomena of intensity inhomogeneity in magnetic resonance images (MRI), are still prominent and can adversely affect quantitative image analysis. In this paper, numerous methods that have been developed to reduce or eliminate intensity inhomogeneities in MRI are reviewed. First, the methods are classified according to the inhomogeneity correction strategy. Next, different qualitative and quantitative evaluation approaches are reviewed. Third, 60 relevant publications are categorized according to several features and analyzed so as to reveal major trends, popularity, evaluation strategies and applications. Finally, key evaluation issues and future development of the inhomogeneity correction field, supported by the results of the analysis, are discussed.

医学图像采集设备提供了大量的解剖和功能信息，这些信息在定量图像分析方法的支持下，便利并改善了诊断和患者治疗。然而，特定模态的图像伪影，例如磁共振图像（MRI）中的强度不均匀性现象，仍然显著，并可能对定量图像分析产生不利影响。本文回顾了已开发的众多用于减少或消除MRI强度不均匀性的方法。首先，根据不均匀性校正策略对方法进行分类。其次，回顾了不同的定性和定量评估方法。第三，根据若干特征对60篇相关出版物进行分类和分析，以揭示主要趋势、流行程度、评估策略和应用。最后，在分析结果的支持下，讨论了不均匀性校正领域的关键评估问题和未来发展。

We employ the new geometric active contour models, previously formulated, for edge detection and segmentation of magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound medical imagery. Our method is based on defining feature-based metrics on a given image which in turn leads to a novel snake paradigm in which the feature of interest may be considered to lie at the bottom of a p...

我们采用先前提出的新型几何主动轮廓模型，用于磁共振成像（MRI）、计算机断层扫描（CT）和超声医学图像的边缘检测与分割。我们的方法基于在给定图像上定义基于特征的度量，这进而导致一种新的蛇模型范式，其中感兴趣的特征可以被视为位于一个...的底部。

This paper addresses the long object problem in helical cone-beam computed tomography. The authors present the PHI-method, a new algorithm for the exact reconstruction of a region-of-interest (ROI) of a long object from axially truncated data extending only slightly beyond the ROI. The PHI-method is an extension of the Radon-method, published by Kudo et al. in Phys. in Med. and Biol., vol. 43, p. ...

本文解决了螺旋锥束计算机断层扫描中的长物体问题。作者提出了PHI方法，这是一种新算法，用于从仅略超出感兴趣区域（ROI）的轴向截断数据中精确重建长物体的感兴趣区域。PHI方法是Radon方法的扩展，由Kudo等人在《Phys. in Med. and Biol.》第43卷中发表。

Under the global pandemic of COVID-19, the use of artificial intelligence to analyze chest X-ray (CXR) image for COVID-19 diagnosis and patient triage is becoming important. Unfortunately, due to the emergent nature of the COVID-19 pandemic, a systematic collection of CXR data set for deep neural network training is difficult. To address this problem, here we propose a patch-based convolutional ne...

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We developed a general method for global conformal parameterizations based on the structure of the cohomology group of holomorphic one-forms for surfaces with or without boundaries (Gu and Yau, 2002), (Gu and Yau, 2003). For genus zero surfaces, our algorithm can find a unique mapping between any two genus zero manifolds by minimizing the harmonic energy of the map. In this paper, we apply the alg...

我们基于有界或无界曲面的全纯一次微分形式的同调群结构，发展了一种全局共形参数化的通用方法（Gu and Yau, 2002; Gu and Yau, 2003）。对于零亏格曲面，我们的算法可以通过最小化映射的调和能量，在任意两个零亏格流形之间找到唯一映射。在本文中，我们将该算法应用于...

Computerized analysis of the tongue surface movement can provide valuable information to speech and swallowing research. Ultrasound technology is currently the most attractive modality for the tongue imaging mainly because of its high video frame rate. However, problems with ultrasound imaging, such as noise and echo artifacts, refractions, and unrelated reflections pose significant challenges for...

舌头表面运动的计算机化分析可以为言语和吞咽研究提供有价值的信息。超声技术目前是舌头成像最具吸引力的模态，主要因为其高视频帧率。然而，超声成像的问题，如噪声和回声伪影、折射以及无关反射，给...带来了重大挑战。

An overview of the Shinnar-Le Roux (SLR) algorithm is presented. It is shown how the performance of SLR pulses can be very accurately specified analytically. This reveals how to design a pulse that produces a specified slice profile and allows the pulse designer to trade off analytically the parameters describing the pulse performance. Several examples are presented to illustrate the more importan...

中文摘要翻译待生成

Unsupervised domain adaptation has increasingly gained interest in medical image computing, aiming to tackle the performance degradation of deep neural networks when being deployed to unseen data with heterogeneous characteristics. In this work, we present a novel unsupervised domain adaptation framework, named as Synergistic Image and Feature Alignment (SIFA), to effectively adapt a segmentation ...

中文摘要翻译待生成

Based on the theory of approximation, this paper presents a unified analysis of interpolation and resampling techniques. An important issue is the choice of adequate basis functions. The authors show that, contrary to the common belief, those that perform best are not interpolating. By opposition to traditional interpolation, the authors call their use generalized interpolation; they involve a prefiltering step when correctly applied. The authors explain why the approximation order inherent in any basis function is important to limit interpolation artifacts. The decomposition theorem states that any basis function endowed with approximation order ran be expressed as the convolution of a B spline of the same order with another function that has none. This motivates the use of splines and spline-based functions as a tunable way to keep artifacts in check without any significant cost penalty. The authors discuss implementation and performance issues, and they provide experimental evidence to support their claims.

基于逼近理论，本文对插值和重采样技术进行了统一分析。一个重要问题是选择合适的基函数。作者表明，与普遍看法相反，表现最佳的基函数并非插值函数。与传统插值相反，作者称他们的使用为广义插值；当正确应用时，它涉及一个预滤波步骤。作者解释了任何基函数固有的逼近阶对于限制插值伪影的重要性。分解定理指出，任何具有逼近阶的基函数都可以表示为相同阶的B样条与另一个没有逼近阶的函数的卷积。这促使使用样条和基于样条的函数作为一种可调谐的方式来控制伪影，而无需显著增加成本。作者讨论了实现和性能问题，并提供了实验证据来支持他们的主张。

The forward electroencephalography (EEG) problem involves finding a potential V from the Poisson equation /spl nabla//spl middot/(/spl sigma//spl nabla/V)=f, in which f represents electrical sources in the brain, and /spl sigma/ the conductivity of the head tissues. In the piecewise constant conductivity head model, this can be accomplished by the boundary element method (BEM) using a suitable integral formulation. Most previous work uses the same integral formulation, corresponding to a double-layer potential. We present a conceptual framework based on a well-known theorem (Theorem 1) that characterizes harmonic functions defined on the complement of a bounded smooth surface. This theorem says that such harmonic functions are completely defined by their values and those of their normal derivatives on this surface. It allows us to cast the previous BEM approaches in a unified setting and to develop two new approaches corresponding to different ways of exploiting the same theorem. Specifically, we first present a dual approach which involves a single-layer potential. Then, we propose a symmetric formulation, which combines single- and double-layer potentials, and which is new to the field of EEG, although it has been applied to other problems in electromagnetism. The three methods have been evaluated numerically using a spherical geometry with known analytical solution, and the symmetric formulation achieves a significantly higher accuracy than the alternative methods. Additionally, we present results with realistically shaped meshes. Beside providing a better understanding of the foundations of BEM methods, our approach appears to lead also to more efficient algorithms.

前向脑电图问题涉及从泊松方程∇·(σ∇V)=f中求解电位V，其中f代表脑内的电源，σ代表头部组织的电导率。在分段恒定电导率头部模型中，可以通过边界元法使用合适的积分公式来实现。以往的大多数工作使用相同的积分公式，对应于双层电位。我们提出了一个基于一个著名定理（定理1）的概念框架，该定理描述了定义在有界光滑曲面补集上的调和函数的特征。该定理指出，这些调和函数完全由它们在曲面上的值及其法向导数的值确定。它使我们能够将先前的边界元方法统一在一个框架中，并开发出两种利用该定理的新方法。具体地，我们首先提出了一种涉及单层电位的对偶方法。然后，我们提出了一种对称公式，它结合了单层和双层电位，这对脑电图领域来说是新颖的，尽管它已应用于电磁学中的其他问题。使用已知解析解的球形几何体对这三种方法进行了数值评估，对称公式的精度显著高于其他方法。此外，我们展示了使用真实形状网格的结果。除了更好地理解边界元方法的基础外，我们的方法似乎也导致了更高效的算法。

The authors analyzed the noise characteristics of two-dimensional (2-D) and three-dimensional (3-D) images obtained from the GE Advance positron emission tomography (PET) scanner. Three phantoms were used: a uniform 20-cm phantom, a 3-D Hoffman brain phantom, and a chest phantom with heart and lung inserts. Using gated acquisition, the authors acquired 20 statistically equivalent scans of each pha...

作者分析了从GE Advance正电子发射断层扫描（PET）扫描仪获得的二维（2-D）和三维（3-D）图像的噪声特性。使用了三个体模：一个均匀的20厘米体模，一个3-D Hoffman脑体模，以及一个带有心脏和肺部插入物的胸部体模。使用门控采集，作者获得了每个相位的20个统计上等效的扫描...