Volume 19, Issue 2

One of the major drawbacks of magnetic resonance imaging (MRI) has been the lack of a standard and quantifiable interpretation of image intensities. Unlike in other modalities, such as X-ray computerized tomography, MR images taken for the same patient on the same scanner at different times may appear different from each other due to a variety of scanner-dependent variations and, therefore, the absolute intensity values do not have a fixed meaning. The authors have devised a two-step method wherein all images (independent of patients and the specific brand of the MR scanner used) can be transformed in such a may that for the same protocol and body region, in the transformed images similar intensities will have similar tissue meaning. Standardized images can be displayed with fixed windows without the need of per-case adjustment. More importantly, extraction of quantitative information about healthy organs or about abnormalities can be considerably simplified. This paper introduces and compares new variants of this standardizing method that can help to overcome some of the problems with the original method.

磁共振成像的主要缺点之一是缺乏对图像强度的标准和可量化解释。与其他模态（如X射线计算机断层扫描）不同，同一患者在同一扫描仪上不同时间拍摄的MR图像可能因多种扫描仪相关变化而彼此不同，因此，上述问题...

Ultrasonic measurements of human carotid and femoral artery walls are conventionally obtained by manually tracing interfaces between tissue layers. The drawbacks of this method are the interobserver variability and inefficiency. Here, the authors present a new automated method which reduces these problems. By applying a multiscale dynamic programming (DP) algorithm, approximate vessel wall positio...

超声测量人类颈动脉和股动脉壁的传统方法是通过手动追踪组织层之间的界面。这种方法的缺点是观察者间差异和效率低下。本文作者提出了一种新的自动化方法，减少了这些问题。通过应用多尺度动态规划算法，近似血管壁位置...

The authors have evaluated eight different similarity measures used for rigid body registration of serial magnetic resonance (MR) brain scans. To assess their accuracy the authors used 33 clinical three-dimensional (3-D) serial MR images, with deformable extradural tissue excluded by manual segmentation and simulated 3-D MR images with added intensity distortion. For each measure the authors deter...

作者评估了用于刚性体配准连续磁共振脑扫描的八种不同相似性度量。为了评估其准确性，作者使用了33组临床三维连续MR图像，通过手动分割排除可变形硬膜外组织，并添加了强度失真的模拟三维MR图像。对于每种度量，作者确定了...

Clusters of microcalcifications in mammograms are an important early sign of breast cancer. This paper presents a computer-aided diagnosis (CAD) system for the automatic detection of clustered microcalcifications in digitized mammograms. The proposed system consists of two main steps. First, potential microcalcification pixels in the mammograms are segmented out by using mixed features consisting ...

乳腺X线片中的微钙化簇是乳腺癌的重要早期征象。本文提出了一种计算机辅助诊断（CAD）系统，用于自动检测数字化乳腺X线片中的簇状微钙化。该系统包括两个主要步骤：首先，利用混合特征对乳腺X线片中的潜在微钙化像素进行分割；其次，...

Echo-planar imaging (EPI) is a fast nuclear magnetic resonance imaging (MRI) method. Unfortunately, local magnetic field inhomogeneities induced mainly by the subject's presence cause significant geometrical distortion, predominantly along the phase-encoding direction, which must be undone to allow for meaningful further processing. So far, this aspect has been too often neglected. In this paper, ...

回波平面成像（EPI）是一种快速的核磁共振成像（MRI）方法。不幸的是，主要由受试者存在引起的局部磁场不均匀性会导致显著的几何畸变，主要沿相位编码方向，必须进行校正才能进行有意义的进一步处理。到目前为止，这一方面常常被忽视。在本文中，……

This paper describes a method for the automated anatomical labeling of the bronchial branch extracted from a three-dimensional (3-D) chest X-ray CT image and its application to a virtual bronchoscopy system (VBS). Automated anatomical labeling is necessary for implementing an advanced computer-aided diagnosis system of 3-D medical images. This method performs the anatomical labeling of the bronchi...

本文描述了一种从三维胸部X射线CT图像中提取的支气管分支的自动解剖标记方法及其在虚拟支气管镜系统中的应用。自动解剖标记对于实现三维医学图像的先进计算机辅助诊断系统是必要的。该方法对支气管进行解剖标记...

A graphical user interface (GUI) has been developed which enables interactive feedback and control to the real-time diminishing variance algorithm (DVA). This interactivity allows the user to set scan parameters, view scan statistics, and view image updates during the course of the scan. In addition, the DVA has been extended to simultaneously reduce motion artifacts in three dimensions using thre...

已开发了一个图形用户界面（GUI），能够实现实时降方差算法（DVA）的交互式反馈和控制。这种交互性允许用户在扫描过程中设置扫描参数、查看扫描统计信息和图像更新。此外，DVA已扩展为使用三个维度同时减少运动伪影。