检索结果-内蒙古大学图书馆

Sub-milliSievert (sub-mSv) CT colonography: a prospective comparison of image quality and polyp conspicuity at reduced-dose versus standard-dose imaging

引用

EUROPEAN RADIOLOGY 2015年第7期25卷 2089-2102页

作者： Lubner, Meghan G. Pooler, B. Dustin Kitchin, Douglas R. Tang, Jie Li, Ke Kim, David H. del Rio, Alejandro Munoz Chen, Guang-Hong Pickhardt, Perry J. Univ Wisconsin Sch Med & Publ Hlth Dept Radiol Madison WI 53792 USA Univ Wisconsin Sch Med & Publ Hlth Med Phys Madison WI 53792 USA

To prospectively compare reduced-dose (RD) CT colonography (CTC) with standard-dose (SD) imaging using several reconstruction algorithms. Following SD supine CTC, 40 patients (mean age, 57.3 years;17 M/23 F;mean BMI, 27.2) underwent an additional RD supine examination (targeted dose reduction, 70-90 %). DLP, CTDIvol, effective dose, and SSDE were compared. Several reconstruction algorithms were applied to RD series. SD-FBP served as reference standard. Objective image noise, subjective image quality and polyp conspicuity were assessed. Mean CTDIvol and effective dose for RD series was 0.89 mGy (median 0.65) and 0.6 mSv (median 0.44), compared with 3.8 mGy (median 3.1) and 2.8 mSv (median 2.3) for SD series, respectively. Mean dose reduction was 78 %. Mean image noise was significantly reduced on RD-PICCS (24.3 +/- 19HU) and RD-MBIR (19 +/- 18HU) compared with RD-FBP (90 +/- 33), RD-ASIR (72 +/- 27) and SD-FBP (47 +/- 14 HU). 2D image quality score was higher with RD-PICCS, RD-MBIR, and SD-FBP (2.7 +/- 0.4/2.8 +/- 0.4/2.9 +/- 0.6) compared with RD-FBP (1.5 +/- 0.4) and RD-ASIR (1.8 +/- 0.44). A similar trend was seen with 3D image quality scores. Polyp conspicuity scores were similar between SD-FBP/RD-PICCS/RD-MBIR (3.5 +/- 0.6/3.2 +/- 0.8/3.3 +/- 0.6). Sub-milliSievert CTC performed with iterative reconstruction techniques demonstrate decreased image quality compared to SD, but improved image quality compared to RD images reconstructed with FBP. aEuro cent CT colonography dose can be substantially lowered using advanced iterative reconstruction techniques. aEuro cent Iterative reconstruction techniques (MBIR/PICCS) reduce image noise and improve image quality. aEuro cent The PICCS/MBIR-reconstructed, reduced-dose series shows decreased 2D/3D image quality compared to the standard-dose series. aEuro cent Polyp conspicuity was similar on standard-dose images compared to reduced-dose images reconstructed with MBIR/PICCS.

关键词： Computed Tomographic Colonography Radiation Dosage Multidetector Computed Tomography Colonic Neoplasms computer-assisted image processing

来源：评论

学校读者我要写书评

暂无评论

Reducing the semantic gap in content-based image retrieval in mammography with relevance feedback and inclusion of expert knowledge

引用

INTERNATIONAL JOURNAL OF computer assisted RADIOLOGY AND SURGERY 2008年第1-2期3卷 123-130页

作者： de Azevedo-Marques, Paulo Mazzoncini Rosa, Natalia Abdala Machado Traina, Agma Juci Traina, Caetano, Jr. Kinoshita, Sergio Koodi Rangayyan, Rangaraj Mandayam Univ Sao Paulo Fac Med Ribeirao Preto Dept Internal Med Image Sci & Med Phys Ctr BR-14048900 Ribeirao Preto SP Brazil Univ Sao Paulo Inst Math & Comp Sci BR-13560970 Sao Carlos SP Brazil Univ Calgary Schulich Sch Engn Dept Elect & Comp Engn Calgary AB T2N 1N4 Canada

Object We investigate the use of relevance feedback (RFb) and the inclusion of expert knowledge to reduce the semantic gap in content-based image retrieval (CBIR) of mammograms. Materials and methods Tests were conducted with radiologists, in which their judgment of the relevance of the retrieved images was used with techniques of query-point movement to incorporate RFb. The measures of similarity of images used for CBIR were based upon textural characteristics and the distribution of density of fibroglandular tissue in the breast. The features used include statistics of the gray-level histogram, texture features based upon the gray-level co-occurrence matrix, moment-based features, measures computed in the Radon domain, and granulometric measures. Queries for CBIR with RFb were executed by three radiologists. The performance of CBIR was measured in terms of precision of retrieval and a measure of relevance-weighted precision (RWP) of retrieval. Results The results indicate improvement due to RFb of up to 62% in precision and 39% in RWP. Conclusion The gain in performance of CBIR with RFb depended upon the BI-RADS breast density index of the query mammographic image, with greater improvement in cases of mammograms with higher density.

关键词： computer-assisted radiographic image interpretation computer-assisted image processing Automated pattern recognition Information retrieval

来源：评论

学校读者我要写书评

暂无评论

Statistical image reconstruction for inconsistent CT projection data

引用

METHODS OF INFORMATION IN MEDICINE 2007年第3期46卷 261-269页

作者： Oehler, M. Buzug, T. M. Univ Lubeck Inst Med Engn D-23538 Lubeck Germany

Objectives: The filtered backprojection is not able to cope with metal-induced inconsistencies in the Radon space which leads to artifacts in reconstructed CF images. A new algorithm is presented that reduces the drawbacks of existing artifact reduction strategies. Methods. Inconsistent projection data are bridged by directed interpolation. These projections are reconstructed using a weighted maximum likelihood algorithm (lambda-MLEM). The correlation coefficient between images of a torso phantom marked with steel markers reconstructed with lambda-MLEM and images of the some torso slice without markers quantifies the quality achieved. For clinical data, entropy maximization is presented to obtain appropriate weightings. Results. Different interpolation strategies have been applied. The quality of reconstruction sensitively depends on the complexity of interpolation. A directional interpolation gives best results. However, the quality of the images can be further improved by an appropriate weighing within eta-MLEM. This has been demonstrated with data from a torso phantom, a jaw with amalgam fillings and a hip prosthesis. Conclusions: eta-MLEM image reconstruction using data from directional Radon space interpolation is a new approach for metal artifact reduction. The weighting in this statistical approach is used to reduce the influence of residual inconsistencies in a way that optimal artifact suppression is obtained by optimizing a compromise between residual inconsistencies and void data. The image quality is superior compared with other artifact reduction strategies.

关键词： transmission computed tomography artifacts computer-assisted image processing image reconstruction

来源：评论

学校读者我要写书评

暂无评论

Optimization of exposure in panoramic radiography while maintaining image quality using adaptive filtering

引用

ACTA ODONTOLOGICA SCANDINAVICA 2016年第3期74卷 229-235页

作者： Svenson, Bjorn Larsson, Lars Bath, Magnus Postgrad Dent Educ Ctr Dept Oral Radiol SE-70111 Orebro Sweden Univ Orebro Fac Med & Hlth Sch Hlth & Med Sci SE-70182 Orebro Sweden Skaraborg Hosp Skovde Dept Radiol Skovde Sweden Sahlgrens Univ Hosp Dept Med Phys & Biomed Engn Gothenburg Sweden Univ Gothenburg Dept Radiat Phys Inst Clin Sci Sahlgrenska Acad Gothenburg Sweden

Objective The purpose of the present study was to investigate the potential of using advanced external adaptive image processing for maintaining image quality while reducing exposure in dental panoramic storage phosphor plate (SPP) radiography. Materials and methods Thirty-seven SPP radiographs of a skull phantom were acquired using a Scanora panoramic X-ray machine with various tube load, tube voltage, SPP sensitivity and filtration settings. The radiographs were processed using General Operator Processor (GOP) technology. Fifteen dentists, all within the dental radiology field, compared the structural image quality of each radiograph with a reference image on a 5-point rating scale in a visual grading characteristics (VGC) study. The reference image was acquired with the acquisition parameters commonly used in daily operation (70 kVp, 150 mAs and sensitivity class 200) and processed using the standard process parameters supplied by the modality vendor. Results All GOP-processed images with similar (or higher) dose as the reference image resulted in higher image quality than the reference. All GOP-processed images with similar image quality as the reference image were acquired at a lower dose than the reference. This indicates that the external image processing improved the image quality compared with the standard processing. Regarding acquisition parameters, no strong dependency of the image quality on the radiation quality was seen and the image quality was mainly affected by the dose. Conclusions The present study indicates that advanced external adaptive image processing may be beneficial in panoramic radiography for increasing the image quality of SPP radiographs or for reducing the exposure while maintaining image quality.

关键词： computer-assisted image processing panoramic radiography radiation dosages

来源：评论

学校读者我要写书评

暂无评论

image-based biomarkers for solid tumor quantification

引用

EUROPEAN RADIOLOGY 2019年第10期29卷 5431-5440页

作者： Savadjiev, Peter Chong, Jaron Dohan, Anthony Agnus, Vincent Forghani, Reza Reinhold, Caroline Gallix, Benoit McGill Univ Dept Diagnost Radiol Montreal PQ Canada McGill Univ Ctr Hlth Dept Diagnost Radiol 1001 Decarie Blvd Montreal PQ H4A 3J1 Canada Univ Diderot Paris 7 Hop Lariboisiere AP HP Dept Body & Intervent Imaging 2 Rue Ambroise Pare F-75475 Paris 10 France INSERM U965 2 Rue Ambroise Pare F-75475 Paris 10 France Inst Chirurg Guidee Image IHU Strasbourg 1 Pl Hop F-67091 Strasbourg France Jewish Gen Hosp Dept Radiol 3755 Chemin Cote St Catherine Montreal PQ H3T 1E2 Canada

The last few decades have witnessed tremendous technological developments in image-based biomarkers for tumor quantification and characterization. Initially limited to manual one- and two-dimensional size measurements, image biomarkers have evolved to harness developments not only in image acquisition technology but also in image processing and analysis algorithms. At the same time, clinical validation remains a major challenge for the vast majority of these novel techniques, and there is still a major gap between the latest technological developments and image biomarkers used in everyday clinical practice. Currently, the imaging biomarker field is attracting increasing attention not only because of the tremendous interest in cutting-edge therapeutic developments and personalized medicine but also because of the recent progress in the application of artificial intelligence (AI) algorithms to large-scale datasets. Thus, the goal of the present article is to review the current state of the art for image biomarkers and their use for characterization and predictive quantification of solid tumors. Beginning with an overview of validated imaging biomarkers in current clinical practice, we proceed to a review of AI-based methods for tumor characterization, such as radiomics-based approaches and deep learning. Key Points center dot Recent years have seen tremendous technological developments in image-based biomarkers for tumor quantification and characterization. center dot image-based biomarkers can be used on an ongoing basis, in a non-invasive (or mildly invasive) way, to monitor the development and progression of the disease or its response to therapy. center dot We review the current state of the art for image biomarkers, as well as the recent developments in artificial intelligence (AI) algorithms for image processing and analysis.

关键词： Diagnostic imaging Biomarkers Artificial intelligence (AI) computer-assisted image processing computer-assisted image interpretation

来源：评论

学校读者我要写书评

暂无评论

image analysis of benign and malignant neck masses

引用

ANNALS OF OTOLOGY RHINOLOGY AND LARYNGOLOGY 1998年第8期107卷 689-696页

作者： Plant, RL Eastern Virginia Med Sch Dept Otolaryngol Head & Neck Surg Norfolk VA 23507 USA

Current techniques for differentiating benign and malignant neck masses in computed tomography scans rely on basic features such as size and image density. Advances in digital imaging have led to development of sophisticated computerized image processing tools. Four different image processing algorithms were used to compare 10 patients with neck masses positive for squamous cell carcinoma and 11 patients with benign neck nodes. Statistically significant differences were seen between the malignant and benign masses for edge analysis and Fourier analysis. Significant differences were also seen in several texture parameters, although these results were considered less reliable. There were no differences between the two groups when compared by histogram analysis. It is concluded that both edge analysis and Fourier analysis can provide additional information to distinguish benign and malignant neck masses.

关键词： computer-assisted image processing head and neck neoplasms

来源：评论

学校读者我要写书评

暂无评论

Enabling user-guided segmentation and tracking of surface-labeled cells in time-lapse image sets of living tissues

引用

CYTOMETRY PART A 2012年第5期81A卷 409-418页

作者： Mashburn, David N. Lynch, Holley E. Ma, Xiaoyan Hutson, M. Shane Vanderbilt Univ Dept Phys & Astron Nashville TN 37235 USA Vanderbilt Univ Dept Biol Sci Nashville TN 37235 USA Vanderbilt Univ Vanderbilt Inst Integrat Biosyst Res & Educ Nashville TN 37235 USA

To study the process of morphogenesis, one often needs to collect and segment time-lapse images of living tissues to accurately track changing cellular morphology. This task typically involves segmenting and tracking tens to hundreds of individual cells over hundreds of image frames, a scale that would certainly benefit from automated routines;however, any automated routine would need to reliably handle a large number of sporadic, and yet typical problems (e.g., illumination inconsistency, photobleaching, rapid cell motions, and drift of focus or of cells moving through the imaging plane). Here, we present a segmentation and cell tracking approach based on the premise that users know their data bestinterpreting and using image features that are not accounted for in any a priori algorithm design. We have developed a program, SeedWater Segmenter, that combines a parameter-less and fast automated watershed algorithm with a suite of manual intervention tools that enables users with little to no specialized knowledge of image processing to efficiently segment images with near-perfect accuracy based on simple user interactions. (c) 2012 International Society for Advancement of Cytometry

关键词： image segmentation computer-assisted image processing tissue analysis confocal microscopy Drosophila embryogenesis

来源：评论

学校读者我要写书评

暂无评论

Making renal stones change size-impact of CT image post processing and reader variability

引用

EUROPEAN RADIOLOGY 2011年第10期21卷 2218-2225页

作者： Liden, Mats Andersson, Torbjoern Geijer, Hayenkan Univ Orebro Sch Hlth & Med Sci S-70182 Orebro Sweden Univ Orebro Rontgenkliniken Dept Radiol S-70185 Orebro Sweden

Objectives The objectives of this study were to quantify the impact of image post-processing parameters on the apparent renal stone size, and to quantify the intra- and inter-reader variability in renal stone size estimation. Methods Fifty CT datasets including a renal or ureteral stone were included retrospectively during a prospective inclusion period. Each of the CT datasets was post-processed in different ways regarding slice thickness, slice increment and window setting. In the first part of the study a single reader repeated size estimations for the renal stones using different post-processing parameters. In the intra-reader variability experiment one reader reported size estimations for the same images with a one-week interval. The inter-reader variability data were obtained from 11 readers reporting size estimations for the same renal stones. Results The apparent stone size differed according to image post-processing parameters with the largest mean differences seen with regard to the window settings experiment (1.5 mm, p < 0.001) and slice thickness (0.8 mm, p < 0.001). Changes in parameters introduced a bias and a pseudo-random variability. The inter-reader variability was considerably larger than the intra-reader variability. Conclusion Our results indicate a need for the standardisation of making measurements on CT images.

关键词： X-ray computed tomography computer-assisted image processing Ureteral calculi Kidney calculi Reproducibility of results

来源：评论

学校读者我要写书评

暂无评论

Trans-rectal ultrasound visibility of prostate lesions identified by magnetic resonance imaging increases accuracy of image-fusion targeted biopsies

引用

WORLD JOURNAL OF UROLOGY 2015年第11期33卷 1669-1676页

作者： Ukimura, Osamu Marien, Arnaud Palmer, Suzanne Villers, Arnauld Aron, Manju Abreu, Andre Luis de Castro Leslie, Scott Shoji, Sunao Matsugasumi, Toru Gross, Mitchell Dasgupta, Prokar Gill, Inderbir S. Univ So Calif Keck Sch Med USC Inst Urol Los Angeles CA 90089 USA Univ So Calif Keck Sch Med Dept Radiol Los Angeles CA 90089 USA Univ So Calif Keck Sch Med Dept Pathol Los Angeles CA 90089 USA Kings Coll London Dept Urol London England

To compare the diagnostic yield of targeted prostate biopsy using image-fusion of multi-parametric magnetic resonance (mp-MR) with real-time trans-rectal ultrasound (TRUS) for clinically significant lesions that are suspicious only on mp-MR versus lesions that are suspicious on both mp-MR and TRUS. Pre-biopsy MRI and TRUS were each scaled on a 3-point score: highly suspicious, likely, and unlikely for clinically significant cancer (sPCa). Using an MR-TRUS elastic image-fusion system (Koelis), a 127 consecutive patients with a suspicious clinically significant index lesion on pre-biopsy mp-MR underwent systematic biopsies and MR/US-fusion targeted biopsies (01/2010-09/2013). Biopsy histological outcomes were retrospectively compared with MR suspicion level and TRUS-visibility of the MR-suspicious lesion. sPCa was defined as biopsy Gleason score a parts per thousand yen7 and/or maximum cancer core length a parts per thousand yen5 mm. Targeted biopsies outperformed systematic biopsies in overall cancer detection rate (61 vs. 41 %;p = 0.007), sPCa detection rate (43 vs. 23 %;p = 0.0013), cancer core length (7.5 vs. 3.9 mm;p = 0.0002), and cancer rate per core (56 vs. 12 %;p < 0.0001), respectively. Highly suspicious lesions on mp-MR correlated with higher positive biopsy rate (p < 0.0001), higher Gleason score (p = 0.018), and greater cancer core length (p < 0.0001). Highly suspicious lesions on TRUS in corresponding to MR-suspicious lesion had a higher biopsy yield (p < 0.0001) and higher sPCa detection rate (p < 0.0001). Since majority of MR-suspicious lesions were also suspicious on TRUS, TRUS-visibility allowed selection of the specific MR-visible lesion which should be targeted from among the multiple TRUS suspicious lesions in each prostate. MR-TRUS fusion-image-guided biopsies outperformed systematic biopsies. TRUS-visibility of a MR-suspicious lesion facilitates image-guided biopsies, resulting in higher detection of significant cancer.

关键词： Prostate neoplasms Magnetic resonance imaging image-guided biopsy Ultrasonography computer-assisted image processing

来源：评论

学校读者我要写书评

暂无评论

Integrated teaching of anatomy and radiology using three-dimensional image post-processing

引用

EUROPEAN RADIOLOGY 2009年第12期19卷 2870-2877页

作者： Rengier, Fabian Doll, Sara von Tengg-Kobligk, Hendrik Kirsch, Joachim Kauczor, Hans-Ulrich Giesel, Frederik L. German Canc Res Ctr Dept Radiol Imaging & Radiooncol E010 D-69120 Heidelberg Germany German Canc Res Ctr Heidelberg Dkfz Dept Radiol D-69120 Heidelberg Germany Univ Heidelberg Hosp Dept Diagnost & Intervent Radiol D-69120 Heidelberg Germany Univ Heidelberg Inst Anat & Cell Biol D-69120 Heidelberg Germany Univ Heidelberg Hosp Dept Nucl Med D-69120 Heidelberg Germany

This article presents a new way of teaching by integrating both anatomy and radiology using three-dimensional image post-processing tools. One preclinical and one clinical module were developed for integrated teaching of anatomy and radiology. Potential benefits were assessed by anonymous evaluation among the 176 participating students. The students highly appreciated the new approach, especially the high degree of interactivity with the post-processing software and the possibility to correlate the real dissection with the virtual dissection. Students agreed that three-dimensional imaging and post-processing improved their understanding of difficult anatomical topics and topographical relations. We consider the new approach to provide great additional benefits for participating students regarding preparation for everyday clinical practice. In particular, it imparts familiarity with imaging and image post-processing techniques and may improve anatomical understanding, radiological diagnostic skills and three-dimensional appreciation.

关键词： Undergraduate medical education Radiology Anatomy computer-assisted image processing Teaching

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：