Volume 35, Issue 2

This paper presents the culmination of our research in designing a system for computer-aided detection (CAD) of polyps in colonoscopy videos. Our system is based on a hybrid context-shape approach, which utilizes context information to remove non-polyp structures and shape information to reliably localize polyps. Specifically, given a colonoscopy image, we first obtain a crude edge map. Second, we remove non-polyp edges from the edge map using our unique feature extraction and edge classification scheme. Third, we localize polyp candidates with probabilistic confidence scores in the refined edge maps using our novel voting scheme. The suggested CAD system has been tested using two public polyp databases, CVC-ColonDB, containing 300 colonoscopy images with a total of 300 polyp instances from 15 unique polyps, and ASU-Mayo database, which is our collection of colonoscopy videos containing 19,400 frames and a total of 5,200 polyp instances from 10 unique polyps. We have evaluated our system using free-response receiver operating characteristic (FROC) analysis. At 0.1 false positives per frame, our system achieves a sensitivity of 88.0% for CVC-ColonDB and a sensitivity of 48% for the ASU-Mayo database. In addition, we have evaluated our system using a new detection latency analysis where latency is defined as the time from the first appearance of a polyp in the colonoscopy video to the time of its first detection by our system. At 0.05 false positives per frame, our system yields a polyp detection latency of 0.3 seconds.

本文介绍了我们在设计用于结肠镜视频中息肉计算机辅助检测（CAD）系统的研究成果。我们的系统基于一种混合上下文-形状方法，利用上下文信息去除非息肉结构，并利用形状信息可靠地定位息肉。具体来说，给定一张结肠镜图像，我们首先获取粗略的边缘图。其次，通过我们独特的特征提取和边缘分类方案，从边缘图中去除非息肉边缘。第三，利用我们新颖的投票方案，在精细化的边缘图中以概率置信度分数定位息肉候选区域。所提出的CAD系统使用两个公开的息肉数据库进行了测试：CVC-ColonDB包含300张结肠镜图像，来自15个不同息肉的共300个息肉实例；以及ASU-Mayo数据库，这是我们收集的结肠镜视频，包含19,400帧，来自10个不同息肉的共5,200个息肉实例。我们使用自由响应受试者工作特征（FROC）分析评估了系统。在每帧0.1个假阳性时，系统在CVC-ColonDB上的灵敏度为88.0%，在ASU-Mayo数据库上的灵敏度为48%。此外，我们使用一种新的检测延迟分析来评估系统，延迟定义为从息肉首次出现在结肠镜视频中到系统首次检测到它的时间。在每帧0.05个假阳性时，系统的息肉检测延迟为0.3秒。

Computer-aided image analysis of histopathology specimens could potentially provide support for early detection and improved characterization of diseases such as brain tumor, pancreatic neuroendocrine tumor (NET), and breast cancer. Automated nucleus segmentation is a prerequisite for various quantitative analyses including automatic morphological feature computation. However, it remains to be a c...

计算机辅助的组织病理学标本图像分析可能为早期检测和改善诸如脑肿瘤、胰腺神经内分泌肿瘤（NET）和乳腺癌等疾病的特征描述提供支持。自动细胞核分割是包括自动形态特征计算在内的各种定量分析的前提。然而，它仍然是一个...

Variations in the color and intensity of hematoxylin and eosin (H&E) stained histological slides can potentially hamper the effectiveness of quantitative image analysis. This paper presents a fully automated algorithm for standardization of whole-slide histopathological images to reduce the effect of these variations. The proposed algorithm, called whole-slide image color standardizer (WSICS), uti...

苏木精和伊红（H&E）染色组织切片的颜色和强度变化可能妨碍定量图像分析的有效性。本文提出了一种完全自动化的算法，用于标准化全切片组织病理学图像以减少这些变化的影响。该算法称为全切片图像颜色标准化器（WSICS），利用...

The proportions of muscle and fat tissues in the human body, referred to as body composition is a vital measurement for cancer patients. Body composition has been recently linked to patient survival and the onset/recurrence of several types of cancers in numerous cancer research studies. This paper introduces a fully automatic framework for the segmentation of muscle and fat tissues from CT images...

人体中肌肉和脂肪组织的比例，即身体成分，是癌症患者的一项重要测量指标。最近的多项癌症研究已将身体成分与患者生存及多种癌症的发生/复发联系起来。本文介绍了一种从CT图像中自动分割肌肉和脂肪组织的全自动框架。

This paper proposes a new method to correct beam hardening artifacts caused by the presence of metal in polychromatic X-ray computed tomography (CT) without degrading the intact anatomical images. Metal artifacts due to beam-hardening, which are a consequence of X-ray beam polychromaticity, are becoming an increasingly important issue affecting CT scanning as medical implants become more common in...

本文提出了一种新方法，用于校正多色X射线计算机断层扫描（CT）中由金属引起的射束硬化伪影，同时不破坏完整的解剖图像。由射束硬化引起的金属伪影是X射线束多色性的结果，随着医疗植入物在CT扫描中变得越来越普遍，这一问题正日益重要。

Many brain disorders and diseases exhibit heterogeneous symptoms and imaging characteristics. This heterogeneity is typically not captured by commonly adopted neuroimaging analyses that seek only a main imaging pattern when two groups need to be differentiated (e.g., patients and controls, or clinical progressors and non-progressors). We propose a novel probabilistic clustering approach, CHIMERA, ...

许多脑部疾病和障碍表现出异质性的症状和成像特征。这种异质性通常未被常用的神经影像分析所捕捉，这些分析在区分两组（例如患者与对照组，或临床进展者与非进展者）时仅寻求一个主要成像模式。我们提出了一种新颖的概率聚类方法CHIMERA，...

In microwave breast cancer imaging magnetic nanoparticles have been recently proposed as contrast agent. Due to the non-magnetic nature of human tissues, magnetic nanoparticles make possible the overcoming of some limitations of conventional microwave imaging techniques, thus providing reliable and specific diagnosis of breast cancer. In this paper, a Compressive Sensing inspired inversion techniq...

在微波乳腺成像中，磁性纳米粒子最近被提出作为对比剂。由于人体组织的非磁性特性，磁性纳米粒子使得克服传统微波成像技术的一些局限性成为可能，从而为乳腺癌提供可靠且特异的诊断。本文提出了一种受压缩感知启发的反演技术...

Quantitative ultrasound (QUS) techniques using radiofrequency (RF) backscattered signals have been used for tissue characterization of numerous organ systems. One approach is to use the magnitude and frequency dependence of backscatter echoes to quantify tissue structures. Another approach is to use first-order statistical properties of the echo envelope as a signature of the tissue microstructure...

利用射频背向散射信号的定量超声（QUS）技术已被用于众多器官系统的组织表征。一种方法是利用背向散射回波的幅度和频率依赖性来量化组织结构。另一种方法是利用回波包络的一阶统计特性作为组织微结构的特征...

Classification of clustered breast microcalcifications into benign and malignant categories is an extremely challenging task for computerized algorithms and expert radiologists alike. In this paper we apply a multi-view-classifier for the task. We describe a two-step classification method that is based on a view-level decision, implemented by a logistic regression classifier, followed by a stochas...

将簇状乳腺微钙化分类为良性和恶性类别对于计算机算法和放射科专家来说都是一项极具挑战性的任务。在本文中，我们应用多视图分类器来完成这项任务。我们描述了一种两步分类方法，该方法基于视图级决策，由逻辑回归分类器实现，随后是随机...

Fast automatic image registration is an important prerequisite for image-guided clinical procedures. However, due to the large number of voxels in an image and the complexity of registration algorithms, this process is often very slow. Stochastic gradient descent is a powerful method to iteratively solve the registration problem, but relies for convergence on a proper selection of the optimization...

快速自动图像配准是图像引导临床手术的重要前提。然而，由于图像中体素数量庞大以及配准算法的复杂性，该过程往往非常缓慢。随机梯度下降是一种迭代求解配准问题的有效方法，但其收敛依赖于优化参数的适当选择...

Tissue deformation plays an important role in lung physiology, as lung parenchyma largely deforms during spontaneous ventilation. However, excessive regional deformation may lead to lung injury, as observed in patients undergoing mechanical ventilation. Thus, the accurate estimation of regional strain has recently received great attention in the intensive care community. In this work, we assess th...

组织变形在肺生理中起着重要作用，因为在自主通气过程中肺实质会发生较大变形。然而，过度的区域变形可能导致肺损伤，正如接受机械通气的患者中所观察到的那样。因此，区域应变的准确估计最近在重症监护领域受到了极大关注。在这项工作中，我们评估了...

Electrophysiology (EP) studies and catheter ablation have become important treatment options for several types of cardiac arrhythmias. We present a novel image-based approach for automatic detection and 3-D reconstruction of EP catheters where the physician marks the catheter to be reconstructed by a single click in each image. The result can be used to provide 3-D information for enhanced navigat...

电生理研究和导管消融已成为多种类型心律失常的重要治疗选择。我们提出了一种新颖的基于图像的方法，用于自动检测和三维重建电生理导管，其中医生通过在每个图像中单击一次来标记要重建的导管。该结果可用于提供三维信息，以增强导航...

Imaging with ultrasonic plane waves enables the combination of Doppler and microbubble contrast-enhanced imaging without compromising the Doppler ensemble length, as is the case for conventional line-by-line imaging, thus maintaining flow sensitivity. This permits the separation of conduit flow in large vessels from the perfusion background and the presentation of velocity estimates in real-time. ...

利用超声平面波成像，可以在不牺牲多普勒集合长度的情况下结合多普勒和微泡造影成像，这与传统的逐线成像不同，从而保持血流敏感性。这使得大血管中的传导血流与灌注背景分离，并实时呈现速度估计。...

The imaging performance of fluorescence molecular tomography (FMT) improves when information from the underlying anatomy is incorporated into the inversion scheme, in the form of priors. The requirement for incorporation of priors has recently driven the development of hybrid FMT systems coupled to other modalities, such as X-ray CT and MRI. A critical methodological aspect in this modality relate...

当将底层解剖信息以先验形式纳入反演方案时，荧光分子断层成像（FMT）的成像性能得到改善。纳入先验的需求最近推动了与其他模态（如X射线CT和MRI）耦合的混合FMT系统的发展。该模态中的一个关键方法学方面涉及...

Registration and fusion of magnetic resonance (MR) and 3D transrectal ultrasound (TRUS) images of the prostate gland can provide high-quality guidance for prostate interventions. However, accurate MR-TRUS registration remains a challenging task, due to the great intensity variation between two modalities, the lack of intrinsic fiducials within the prostate, the large gland deformation caused by th...

磁共振（MR）和三维经直肠超声（TRUS）图像的前列腺配准与融合可为前列腺介入提供高质量引导。然而，由于两种模态间强度差异大、前列腺内缺乏固有标记、腺体大变形以及...准确的MR-TRUS配准仍是一项具有挑战性的任务。

Color tissue Doppler imaging (TDI) is a well-established methodology to assess local myocardial motion/deformation. Typically, a frame rate of ~ 200 Hz can be achieved by imaging a narrow sector ( ~ 30°, covering one cardiac wall) at moderate line density, using a dedicated pulse sequence and multi-line acquisition. However, a wide angle field-of-view is required in some clinical applications to i...

彩色组织多普勒成像（TDI）是一种评估局部心肌运动/变形的成熟方法。通常，通过使用专用脉冲序列和多线采集，以中等线密度成像窄扇形区（约30°，覆盖一个心壁），可实现约200 Hz的帧率。然而，在某些临床应用中需要宽角视野以...

Myocardial deformation imaging can provide valuable insights in myocardial mechanics and help in the diagnosis, prognosis and follow-up of cardiac diseases. However, extracting these indices in 3D is challenging due to the limitations in spatial and temporal resolution of the current volumetric ultrasound systems. For this purpose, we developed an anatomical free-form deformation image registratio...

心肌变形成像可以提供对心肌力学的宝贵见解，并有助于心脏疾病的诊断、预后和随访。然而，由于当前体积超声系统在空间和时间分辨率上的限制，在三维中提取这些指标具有挑战性。为此，我们开发了一种解剖自由形态变形图像配准方法，利用体积守恒来评估来自三维超声记录的心脏变形。

In this paper, we propose a novel method to estimate the confidence of a registration that does not require any ground truth, is independent from the registration algorithm and the resulting confidence is correlated with the amount of registration error. We first apply a local search to match patterns between the registered image pairs. Local search induces a cost space per voxel which we explore ...

本文提出了一种新的方法来估计配准的置信度，该方法不需要任何真实值，独立于配准算法，且得到的置信度与配准误差的大小相关。我们首先应用局部搜索来匹配配准图像对之间的模式。局部搜索会为每个体素引入一个代价空间，我们对其进行探索……

We propose a fully automatic segmentation method called nested graph cut to segment images (2D or 3D) that contain multiple objects with a nested structure. Compared to other graph-cut-based methods developed for multiple regions, our method can work well for nested objects without requiring manual selection of initial seeds, even if different objects have similar intensity distributions and some ...

我们提出了一种全自动分割方法，称为嵌套图割，用于分割包含多个具有嵌套结构的对象的图像（2D或3D）。与其他针对多区域开发的基于图割的方法相比，我们的方法能够很好地处理嵌套对象，无需手动选择初始种子，即使不同对象具有相似的强度分布且某些对象具有弱边缘。

We propose a new method for the joint design of k-space trajectory and RF pulse in 3D small-tip tailored excitation. Designing time-varying RF and gradient waveforms for a desired 3D target excitation pattern in MRI poses a non-linear, non-convex, constrained optimization problem with relatively large problem size that is difficult to solve directly. Existing joint pulse design approaches are ther...

我们提出了一种用于三维小角度定制激励中k空间轨迹和RF脉冲联合设计的新方法。在MRI中，为所需的三维目标激励模式设计时变RF和梯度波形，是一个非线性、非凸、有约束的优化问题，且问题规模较大，难以直接求解。现有的联合脉冲设计方法存在一定的局限性。

We present a method that quantifies point-wise changes in surface morphology of the bones of the human wrist. The proposed method, referred to as Registration-based Bone Morphometry (RBM), consists of two steps: an atlas selection step and an atlas warping step. The atlas for individual wrist bones was selected based on the shortest l2 distance to the ensemble of wrist bones from a database of a h...

我们提出了一种量化人类腕骨表面形态逐点变化的方法。该方法称为基于配准的骨形态测量学（RBM），包括两个步骤：图谱选择步骤和图谱扭曲步骤。单个腕骨的图谱选择基于到数据库中腕骨集合的最短l2距离...

We propose a new algorithm, called line integral alternating minimization (LIAM), for dual-energy X-ray CT image reconstruction. Instead of obtaining component images by minimizing the discrepancy between the data and the mean estimates, LIAM allows for a tunable discrepancy between the basis material projections and the basis sinograms. A parameter is introduced that controls the size of this dis...

我们提出了一种新算法，称为线积分交替最小化（LIAM），用于双能X射线CT图像重建。与通过最小化数据与均值估计之间的差异来获取分量图像不同，LIAM允许在基材料投影与基正弦图之间具有可调节的差异。引入了一个参数来控制这一差异的大小...

The concept of sparsity is extensively exploited in the fields of data acquisition and image processing, contributing to better signal-to-noise and spatio-temporal performance of the various imaging methods. In the field of optoacoustic tomography, the image reconstruction problem is often characterized by computationally extensive inversion of very large datasets, for instance when acquiring volu...

稀疏性的概念在数据采集和图像处理领域被广泛利用，有助于提高各种成像方法的信噪比和时空性能。在光声断层成像领域，图像重建问题通常以非常大的数据集的计算密集型反演为特征，例如当获取体积...

Ultrasound-modulated optical tomography is an emerging biomedical imaging modality which uses the spatially localised acoustically-driven modulation of coherent light as a probe of the structure and optical properties of biological tissues. In this work we begin by providing an overview of forward modelling methods, before deriving a linearised diffusion-style model which calculates the first-harm...

超声调制光学断层扫描是一种新兴的生物医学成像模态，它利用声学驱动的空间局部调制相干光作为生物组织结构和光学性质的探针。在这项工作中，我们首先概述了正向建模方法，然后推导了一个线性化扩散风格的模型，该模型计算基波...

Confidence in the accuracy of dynamic contrast enhanced ultrasound (DCEUS) quantification parameters is imperative for the correct diagnosis of liver lesion perfusion characteristics. An important source of uncertainty in liver DCEUS acquisitions is artifacts introduced by respiratory motion. The objective of this study is to construct a respiratory motion simulation model (RMSM) of dual contrast ...

对动态对比增强超声（DCEUS）定量参数准确性的信心对于正确诊断肝脏病变灌注特征至关重要。肝脏DCEUS采集中的一个重要不确定性来源是呼吸运动引入的伪影。本研究的目的是构建一个双对比剂呼吸运动模拟模型（RMSM）...