Volume 23, Issue 6

Scatterer properties like the average effective scatterer diameter and acoustic concentration were determined in vivo using a quantitative ultrasound (QUS) technique from two tumor phenotypes grown in animal models. These tumor models included spontaneously occurring mammary fibroadenomas in rats and transplanted 4T1 mammary carcinomas in mice. The scatterer properties of average scatterer diameter and acoustic concentration were estimated using a Gaussian form factor from the backscattered ultrasound measured from both types of tumors. QUS images of the tumors were constructed utilizing estimated scatterer properties from regions in the tumors. The QUS images showed a clear distinction between the two types of tumors and a statistically significant difference existed between their estimated scatterer properties. The average scatterer diameter and acoustic concentration for the mammary fibroadenomas were estimated to be 105/spl plusmn/25 /spl mu/m and -15.6/spl plusmn/5 dB (mm/sup -3/), respectively. The average scatterer diameter and acoustic concentration for the carcinomas was estimated to be 28/spl plusmn/4.6 /spl mu/m and 10.6/spl plusmn/6.9 dB (mm/sup -3/), respectively. The distinctions in the scattering properties are clearly seen in the QUS images of the tumors and indicate that QUS imaging can be useful in differentiating between different types of mammary tumors.

使用定量超声（QUS）技术，在动物模型中生长的两种肿瘤表型上，原位测定了散射体特性，如平均有效散射体直径和声浓度。这些肿瘤模型包括大鼠自发发生的乳腺纤维腺瘤和小鼠移植的4T1乳腺癌。利用高斯形状因子，从两种肿瘤测量的背向散射超声中估算了平均散射体直径和声浓度等散射体特性。利用肿瘤内区域估算的散射体特性构建了肿瘤的QUS图像。QUS图像显示两种肿瘤之间存在明显区别，且其估算的散射体特性之间存在统计学显著差异。乳腺纤维腺瘤的平均散射体直径和声浓度估计分别为105±25微米和-15.6±5分贝（毫米^-3）。癌的平均散射体直径和声浓度估计分别为28±4.6微米和10.6±6.9分贝（毫米^-3）。散射特性的差异在肿瘤的QUS图像中清晰可见，表明QUS成像可用于区分不同类型的乳腺肿瘤。

We developed a novel computer-aided detection (CAD) algorithm called the surface normal overlap method that we applied to colonic polyp detection and lung nodule detection in helical computed tomography (CT) images. We demonstrate some of the theoretical aspects of this algorithm using a statistical shape model. The algorithm was then optimized on simulated CT data and evaluated using a per-lesion...

我们开发了一种新颖的计算机辅助检测（CAD）算法，称为表面法线重叠方法，并将其应用于螺旋计算机断层扫描（CT）图像中的结肠息肉检测和肺结节检测。我们使用统计形状模型展示了该算法的一些理论方面。然后对模拟CT数据进行了优化，并使用每病灶评估...

Computational modeling of human arteries has been broadly employed to investigate the relationships between geometry, hemodynamics and vascular disease. Recent developments in modeling techniques have made it possible to perform such analyses on realistic geometries acquired noninvasively and, thus, have opened up the possibility to extend the investigation to populations of subjects. However, for...

人体动脉的计算模型已被广泛用于研究几何、血流动力学和血管疾病之间的关系。建模技术的最新发展使得在无创获取的真实几何结构上进行此类分析成为可能，从而将研究扩展到人群成为可能。然而，对于...

To account for photon penetration, the formulas used to calculate the geometric resolution of a pinhole collimator use an equivalent diameter d/sub e/ rather than the physical diameter of the aperture. The expression commonly used for d/sub e/, however, was originally derived to account for penetration in sensitivity calculations. In this paper, we show that the concept of equivalent diameter is a...

为了考虑光子穿透，用于计算针孔准直器几何分辨率的公式使用等效直径d/sub e/而不是孔径的物理直径。然而，通常用于d/sub e/的表达式最初是为了在灵敏度计算中考虑穿透而推导的。在本文中，我们展示了等效直径的概念是……

It was recently reported that the real-time flat panel detector-based cone-beam computed tomography (CBCT) breast imaging can help improve the detectability of small breast tumors with an X-ray dose comparable to that of the conventional mammography. In this paper, an efficient denoising algorithm is proposed to further reduce the X-ray exposure level required by a CBCT scan to acquire acceptable ...

最近有报道称，基于实时平板探测器的锥束计算机断层扫描（CBCT）乳腺成像有助于提高对小乳腺肿瘤的检测能力，其X射线剂量与传统乳房X线摄影相当。本文提出了一种高效的去噪算法，以进一步降低CBCT扫描所需的X射线暴露水平，从而获得可接受的...

This paper presents a novel segmentation technique for extracting cavity contours from ultrasound images. The problem is first discretized by projecting equispaced radii from an arbitrary seed point inside the cavity toward its boundary. The distance of the cavity boundary from the seed point is modeled by the trajectory of a moving object. The motion of this moving object is assumed to be governe...

本文提出了一种新的分割技术，用于从超声图像中提取腔体轮廓。首先通过从腔体内任意种子点向边界投射等间距半径将问题离散化。腔体边界到种子点的距离被建模为运动物体的轨迹。该运动物体的运动被假定为受控于...

It is observed that when the homogeneity property of the ramp filter is used to derive a filtered backprojection algorithm in fan-beam tomography, the reconstructed images have nonstationary frequency components and nonstationary noise. When a short focal-length is used, higher frequency components are amplified more at the edge of the image than at the center of the image, resulting in higher noi...

观察到在扇束断层扫描中，利用斜坡滤波器的同质性推导滤波反投影算法时，重建图像具有非平稳的频率分量和非平稳噪声。使用短焦距时，图像边缘的高频分量比中心放大更多，导致更高噪声...

We have been developing a virtual surgery system that is capable of simulating surgical maneuvers on elastic organs. In order to perform such maneuvers, we have created a deformable organ model using a sphere-filled method instead of the finite element method. This model is suited for real-time simulation and quantitative deformation. Furthermore, we have equipped this model with a sense of touch ...

我们一直在开发一种虚拟手术系统，能够模拟对弹性器官的手术操作。为了执行此类操作，我们使用球填充方法而非有限元方法创建了一个可变形器官模型。该模型适用于实时仿真和定量变形。此外，我们为该模型配备了触觉感知...

In this paper, the sampling and aliasing consequences of employing a quarter-detector-offset (QDO) in helical computed tomography (CT) are analyzed. QDO is often used in conventional CT to reduce in-plane aliasing by eliminating data redundancies to improve radial sampling. In helical CT, these same redundancies are exploited to improve longitudinal sampling and so it might seem ill-advised to emp...

本文分析了在螺旋计算机断层扫描（CT）中使用四分之一探测器偏移（QDO）的采样和混叠后果。QDO通常用于传统CT，通过消除数据冗余来减少平面内混叠，从而改善径向采样。在螺旋CT中，这些相同的冗余被利用来改善纵向采样，因此似乎不建议使用...

Most methods for structure-function analysis of the brain in medical images are usually based on voxel-wise statistical tests performed on registered magnetic resonance (MR) images across subjects. A major drawback of such methods is the inability to accurately locate regions that manifest nonlinear associations with clinical variables. In this paper, we propose Bayesian morphological analysis met...

大多数基于医学图像中脑结构功能分析的方法通常是在注册的磁共振（MR）图像上跨受试者进行基于体素的统计分析。这类方法的一个主要缺点是难以准确定位与临床变量呈非线性关联的区域。在本文中，我们提出了一种贝叶斯形态学分析方法，旨在克服这一局限性。

We propose a method for concept-based medical image retrieval that is a superset of existing semantic-based image retrieval methods. We conceive of a concept as an incremental and interactive formalization of the user's conception of an object in an image. The premise is that such a concept is closely related to a user's specific preferences and subjectivity and, thus, allows to deal with the comp...

我们提出了一种基于概念的医学图像检索方法，它是现有基于语义的图像检索方法的超集。我们将概念视为用户对图像中物体概念的增量式和交互式形式化。其前提是，这样的概念与用户的特定偏好和主观性密切相关，因此能够处理...

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。

Provides a listing of current committee members and society officers.

提供当前委员会成员和学会官员列表。

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

请有意投稿的作者提交新的、未发表的手稿，以便纳入本次征稿通知中描述的即将举行的活动。

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本页或这些页面故意留空。

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

介绍本期期刊的目录。