Volume 33, Issue 12

Attenuation correction is an essential requirement for quantification of positron emission tomography (PET) data. In PET/CT acquisition systems, attenuation maps are derived from computed tomography (CT) images. However, in hybrid PET/MR scanners, magnetic resonance imaging (MRI) images do not directly provide a patient-specific attenuation map. The aim of the proposed work is to improve attenuation correction for PET/MR scanners by generating synthetic CTs and attenuation maps. The synthetic images are generated through a multi-atlas information propagation scheme, locally matching the MRI-derived patient's morphology to a database of MRI/CT pairs, using a local image similarity measure. Results show significant improvements in CT synthesis and PET reconstruction accuracy when compared to a segmentation method using an ultrashort-echo-time MRI sequence and to a simplified atlas-based method.

衰减校正是正电子发射断层扫描（PET）数据定量分析的基本要求。在PET/CT采集系统中，衰减图来源于计算机断层扫描（CT）图像。然而，在混合PET/MR扫描仪中，磁共振成像（MRI）图像不能直接提供患者特定的衰减图。本研究旨在通过生成合成CT和衰减图来改进PET/MR扫描仪的衰减校正。合成图像通过多图谱信息传播方案生成，该方案使用局部图像相似性度量，将MRI衍生的患者形态与MRI/CT对数据库进行局部匹配。结果显示，与使用超短回波时间MRI序列的分割方法和简化的基于图谱的方法相比，在CT合成和PET重建精度方面有显著改善。

Low-dose computed tomography (LDCT) images are often severely degraded by amplified mottle noise and streak artifacts. These artifacts are often hard to suppress without introducing tissue blurring effects. In this paper, we propose to process LDCT images using a novel image-domain algorithm called “artifact suppressed dictionary learning (ASDL).” In this ASDL method, orientation and scale informa...

低剂量计算机断层扫描（LDCT）图像通常因放大的斑点噪声和条状伪影而严重退化。这些伪影往往难以抑制而不引入组织模糊效应。在本文中，我们提出使用一种称为“伪影抑制字典学习（ASDL）”的新型图像域算法来处理LDCT图像。在这种ASDL方法中，方向和尺度信息...

Magnetic resonance (MR) fingerprinting is a technique for acquiring and processing MR data that simultaneously provides quantitative maps of different tissue parameters through a pattern recognition algorithm. A predefined dictionary models the possible signal evolutions simulated using the Bloch equations with different combinations of various MR parameters and pattern recognition is completed by...

磁共振指纹识别是一种用于采集和处理MR数据的技术，通过模式识别算法同时提供不同组织参数的定量图。预定义的字典模拟了使用布洛赫方程对不同MR参数组合模拟的可能信号演变，模式识别通过...

In this study, we propose a novel pathological lung segmentation method that takes into account neighbor prior constraints and a novel pathology recognition system. Our proposed framework has two stages; during stage one, we adapted the fuzzy connectedness (FC) image segmentation algorithm to perform initial lung parenchyma extraction. In parallel, we estimate the lung volume using rib-cage inform...

在本研究中，我们提出了一种新颖的病理性肺部分割方法，该方法考虑了邻域先验约束和一个新的病理识别系统。我们提出的框架分为两个阶段；在第一阶段，我们采用模糊连通性（FC）图像分割算法进行初始肺实质提取。同时，我们利用肋骨笼信息估计肺体积...

In ophthalmology, it is now common practice to record every surgical procedure and to archive the resulting videos for documentation purposes. In this paper, we present a solution to automatically segment and categorize surgical tasks in real-time during the surgery, using the video recording. The goal would be to communicate information to the surgeon in due time, such as recommendations to the l...

在眼科学中，现在常规记录每个手术过程并归档所产生的视频以供文档记录。本文提出了一种解决方案，利用视频记录在手术过程中实时自动分割和分类手术任务。目标是及时向外科医生传达信息，例如对...的建议

Tissue image grading is one of the most important steps in prostate cancer diagnosis, where the pathologist relies on the gland structure to assign a Gleason grade to the tissue image. In this grading scheme, the discrimination between grade 3 and grade 4 is the most difficult, and receives the most attention from researchers. In this study, we propose a novel method (called nuclei-based method) t...

组织图像分级是前列腺癌诊断中最重要的步骤之一，病理学家依靠腺体结构为组织图像分配Gleason分级。在这一分级方案中，3级和4级之间的区分最为困难，也最受研究人员关注。在本研究中，我们提出了一种新方法（称为基于细胞核的方法）...

A model-based reconstruction technique for accelerated T2 mapping with improved accuracy is proposed using undersampled Cartesian spin-echo magnetic resonance imaging (MRI) data. The technique employs an advanced signal model for T2 relaxation that accounts for contributions from indirect echoes in a train of multiple spin echoes. An iterative solution of the nonlinear inverse reconstruction probl...

提出了一种基于模型的重建技术，利用欠采样笛卡尔自旋回波磁共振成像（MRI）数据，实现加速且精度更高的T2映射。该技术采用先进的T2弛豫信号模型，考虑了多自旋回波序列中间接回波的贡献。通过非线性逆重建问题的迭代求解...

Diffuse optical tomography (DOT) is a noninvasive technique which measures hemodynamic changes in the tissue with near infrared light, which has been increasingly used to study brain functions. Due to the nature of light propagation in the tissue, the reconstruction problem is severely ill-posed. For linearized DOT problems, sparsity regularization has achieved promising results over conventional ...

漫射光学断层扫描（DOT）是一种使用近红外光测量组织中血流动力学变化的非侵入性技术，越来越多地被用于研究脑功能。由于光在组织中传播的性质，重建问题严重病态。对于线性化的DOT问题，稀疏正则化相较于传统方法取得了有希望的结果...

When segmenting intraretinal layers from multiple optical coherence tomography (OCT) images forming a mosaic or a set of repeated scans, it is attractive to exploit the additional information from the overlapping areas rather than discarding it as redundant, especially in low contrast and noisy images. However, it is currently not clear how to effectively combine the multiple information sources a...

当从构成马赛克或一组重复扫描的多幅光学相干断层扫描（OCT）图像中分割视网膜内层时，利用重叠区域中的额外信息而不是将其作为冗余丢弃是有吸引力的，尤其是在低对比度和噪声图像中。然而，目前尚不清楚如何有效地结合多个信息源...

The Sussex MK4 electrical impedance mammography system is especially designed for 3-D breast screening. It aims to diagnose breast cancer at an early stage when it is most treatable. Planar electrodes are employed in this system. The challenge with planar electrodes is the inaccuracy and poor sensitivity in the vertical direction for 3-D imaging. An enhanced image reconstruction algorithm using a ...

苏塞克斯MK4电阻抗乳腺成像系统专为三维乳腺筛查设计，旨在乳腺癌早期、最可治疗阶段进行诊断。该系统采用平面电极，但平面电极在垂直方向上存在成像不准确和灵敏度差的问题。本文介绍了一种改进的图像重建算法，使用...

In pinhole single photon emission computed tomography (SPECT), multi-pinhole collimators can increase sensitivity but may lead to projection overlap, or multiplexing, which can cause image artifacts. In this work, we explore whether a stacked-detector configuration with a germanium and a silicon detector, used with 123I (27-32, 159 keV), where little multiplexing occurs in the Si projections, can ...

在针孔单光子发射计算机断层扫描（SPECT）中，多针孔准直器可以提高灵敏度，但可能导致投影重叠或多重成像，从而引起图像伪影。本研究探索了使用锗和硅探测器的堆叠探测器配置与123I（27-32、159 keV）结合使用，其中硅投影中发生较少的重叠，是否可以...

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

提供现任工作人员、委员会成员及学会官员的名录。

This index covers all technical items - papers, correspondence, reviews, etc. - that appeared in this periodical during the year, and items from previous years that were commented upon or corrected in this year. Departments and other items may also be covered if they have been judged to have archival value. The Author Index contains the primary entry for each item, listed under the first author's ...

本索引涵盖了本年度该期刊上发表的所有技术性文章——论文、通信、评论等，以及往年发表但在本年度被评论或更正的文章。其他部门或项目如果被认为具有档案价值也可能被收录。作者索引包含每个条目的主要条目，列在第一作者名下...

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

展示本期期刊的封面/目录。

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本页或这些页面故意留空。

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

为希望投稿的潜在作者提供说明和指南。