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MO-FF-A4-01: Evaluation of Background Trend Correction Technique in Breast Tomosynthesis Quantitation

Medical Physics 2009年第6PART21期36卷 2713-2713页

作者： C Shafer J Lo E Samei Carl E. Ravin Advanced Imaging Laboratories Duke University Medical Center Durham NC Department of Biomedical Engineering Duke University Durham NC Department of Radiology Medical Physics Graduate Program Duke University Medical Center Durham NC

Purpose: The main shortcoming of breast tomosynthesis (tomo) imaging when compared to CT is poor resolution in the depth direction and the associated difficulty in quantifying tissue density. This study will assess the quantitative potential of breast tomo using a clinical prototype and relatively simple reconstruction and the proposed background trend correction scheme. Tomo quantitation would allow improved characterization of lesions as well as proper image processing of tomo images (analogous to that of mammography). Method and Materials: Studies were based on a Siemens prototype breast tomo system with a 45° total angular span. First, Monte Carlo simulations were conducted using geometry to mimic the aforementioned prototype and voxelized breast tissue-equivalent phantoms embedded with eleven small cuboid lesions of varying density. The material surrounding the lesions was either fat or glandular equivalent plastic. From the simulations, the effects of scatter, lesion depth, and background material density were studied. Empirical studies were then conducted with the prototype system and tissue-equivalent phantoms similar to those of the simulations to allow investigation of the effects of lesion depth and background material density. All image reconstruction was performed using filtered backprojection incorporating a filter designed to emulate some grayscale characteristics of iterative reconstruction. Results: Resulting images displayed a visible difference in lesion brightness for both empirical and simulated experiments. After applying our background trend correction technique, the lesion voxel values varied linearly with glandular fraction (all R 2 ⩾ 0.90) under all simulated and empirical conditions. Significant differences were encountered only for different background materials (in all scatter-included paradigms). Conclusions: These high R 2 values suggest that breast tomo image voxel values corrected by our outlined methods are highly positively correla

关键词： Medical imaging Digital tomosynthesis mammography Monte Carlo methods Brightness Image reconstruction Mammography Image processing Computed tomography Medical image reconstruction

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Controlled drug delivery of an anti-inflammatory protein

Controlled drug delivery of an anti-inflammatory protein

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8th World Biomaterials Congress 2008, WBC 2008

作者： Kennedy, Karen L. Lucas, Alexandra R. Wan, Wankei Biomedical Engineering Graduate Program University of Western Ontario London ON Canada Department of Chemical and Biochemical Engineering University of Western Ontario London ON Canada Department of Medicine University of Florida Gainesville FL United States

Release of the viral protein from PVA decreased with each increasing thermal cycle. These release properties will aid in future studies to tailor the release of the viral protein for the appropriate time and dosage le... 详细信息

ISBN: (纸本)9781615670802

关键词： Controlled drug delivery

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Evaluating the Quality of Human Embryos with a Measurement of Oxygen Consumption by Scanning Electrochemical Microscopy

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Journal of Mammalian Ova Research 2008年第1期25卷 2-7页

作者： Utsunomiya, Takafumi Goto, Kaori Nasu, Megumi Kumasako, Yoko Araki, Yasuhisa Nasu, Masaki Itoh-Sasaki, Takahiro Abe, Hiroyuki St-Luke Clinic Oita City Oita 870-0947 5 Tsumori Tomioka Japan The Institute for ARMT Gunma 371-0101 Japan Innovation of New Biomedical Engineering Center Tohoku University Sendai 980-8754 Japan Graduate Program of Human Sensing and Functional Sensor Engineering Graduate School of Science and Engineering Yamagata University Yonezawa 92-8510 Japan

Morphological evaluation has been widely used to evaluate embryo quality because it is non-invasive and useful in predicting pregnancy rate. However, morphological evaluations are subjective and categorization standards often vary between investigators. The respiration rate of embryos is a useful parameter for evaluating embryo quality. The scanning electrochemical microscopy (SECM) measuring system provides a non-invasive, simple, accurate, and consistent measurement of the respiration activity of human embryos. After morphological evaluation by Veeck's method, oxygen consumption by individual human embryos was quantified by SECM. Fundamentally, the maturation of mitochondria correlated with an increase in oxygen consumption during the development of embryos. The development of mitochondria may be an important factor in embryo quality, because mitochondria provide ATP for embryonic development by metabolism of nutrients in the cytoplasm. The respiration rates on the day 3 after in vitro fertilization (IVF) were measured and significant differences in oxygen consumption were registered even among embryos with the same morphological classification. There were no significant differences between the mean rates of oxygen consumption at each cleavage stage, however, there was considerable variation in respiration rate within embryos of the same morphological grade. The safety of SECM is assured as the embryos which were examined by SECM for oxygen consumption showed the same development levels as the control group. These results support the hypothesis that measuring embryonic respiration provides additional and valuable information about embryo quality. © 2008, JAPANESE SOCIETY OF OVA RESEARCH. All rights reserved.

关键词： Embryo quality Non-invasive evaluation Oxygen consumption

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Virtual reality-enhanced ultrasound guidance for atrial ablation: In vitro epicardial study

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11th International Conference on Medical Image Computing and Computer-Assisted Intervention, MICCAI 2008

作者： Linte, Cristian A. Wiles, Andrew Moore, John Wedlake, Chris Peters, Terry M. Imaging Research Laboratories Robarts Research Institute London ON Canada Biomedical Engineering Graduate Program University of Western Ontario London ON Canada Department of Medical Biophysics University of Western Ontario London ON Canada

ISBN: (纸本)3540859896

In an effort to reduce morbidity of cardiac interventions, minimizing invasiveness inevitably leads to limited visual access to the surgical targets. To address these limitations, we provide the surgeons with a robust visualization environment that integrates interventional ultrasound imaging augmented with pre-operative anatomical models and virtual surgical instruments within a virtual reality environment. Here we present an in vitro study on a cardiac phantom that mimics an ablation therapy procedure, which allows us to assess the feasibility of our surgical system in comparison to traditional intra-operative ultrasound imaging. Following surgical target identification via an electro-anatomical model, the "ablation procedure" is performed blindly. A 2.8 mm RMS targeting error is achieved using our novel surgical system. This level of accuracy is adequate from both a clinical and engineering perspective, under the inherent procedure requirements and limitations of the system. © 2008 Springer Berlin Heidelberg.

关键词： Ablation

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Association between periodontitis and anti-cardiolipin antibodies in Buerger disease

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Journal of Clinical Periodontology 2009年第10期36卷 830-835页

作者： Chen, Yi-Wen Nagasawa, Toshiyuki Wara-Aswapati, Nawarat Ushida, Yuka Wang, Dongqing Takeuchi, Yasuo Kobayashi, Hiroaki Umeda, Makoto Inoue, Yoshinori Iwai, Takehisa Ishikawa, Isao Izumi, Yuichi Department of Hard Tissue Engineering Graduate School Tokyo Medical and Dental University Tokyo Japan National Taiwan University Hospital National Taiwan University Taipei Taiwan Department of Periodontology Faculty of Dentistry Khon Kaen University Khon Kaen Thailand Department of Periodontics and Oral Medicine Beijing Stomatological Hospital Capital Medical University Beijing China Department of Vascular and Applied Surgery Graduate School Tokyo Medical and Dental University Tokyo Japan Tsukuba Vascular Center Buerger Disease Research Institute Ibaragi Japan Institute of Advanced Biomedical Engineering and Science Tokyo Women's Medical University Tokyo Japan Global Center of Excellence Program International Research Center for Molecular Science in Tooth and Bone Diseases Tokyo Medical and Dental University Tokyo Japan Department of Periodontology and Endodontology Health Science University of Hokkaido Ishikari-gun Hokkaido 061-0293 1757 Kanazawa Tobetsu-cho Japan

Aim: Anti-cardiolipin (CL) antibodies can be induced in Buerger disease (BD), an inflammatory occlusive disorder affecting peripheral blood vessels, in response to bacteria bearing homology to the TLRVYK peptide of a phospholipid-binding plasma protein β-2-glycoprotein I. TLRVYK homologies are present in Porphyromonas gingivalis (TLRIYT) and Treponema denticola (TLALYK). This study investigated the association between periodontal infection and anti-CL antibodies in BD patients. Material and Methods: Periodontal conditions were examined in 19 BD patients and 25 systemically healthy control subjects. All subjects were heavy smokers. Serum anti-CL, anti-TLRVYK, anti-TLRIYT, and anti-TLALYK antibodies were assessed using the enzyme-linked immunosorbent assay. Results: BD patients had a significantly higher prevalence of periodontitis, more severe periodontal destruction and increased titres of serum anti-CL, anti-TLRVYK, anti-TLRIYT, and anti-TLALYK antibodies compared with healthy subjects. The levels of anti-CL antibodies positively correlated with those of the three anti-peptide antibodies. Anti-CL antibody titres were significantly associated with the percentage of sites with clinical attachment level ≥4 mm in BD patients. Conclusion: Elevated anti-CL antibody levels were associated with periodontal destruction in BD patients. Periodontopathic bacteria may serve as exogenous antigens that stimulate the anti-CL antibody production through molecular mimicry between the bacterial peptides and a host plasma protein. © 2009 John Wiley & Sons A/S.

关键词： β-2-glycoprotein I Anti-cardiolipin antibody Buerger disease Molecular mimicry Periodontitis

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Bioactive nanofibers for tissue engineering applications

Bioactive nanofibers for tissue engineering applications

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Fiber Society 2008 Fall Meeting and Technical Conference

作者： Haley, Jason Wan, Wankei Boughner, Derek Biomedical Engineering Graduate Program University of Western Ontario LondonON Canada Department of Chemical and Biochemical Engineering University of Western Ontario LondonON Canada Robarts Research Institute University of Western Ontario LondonON Canada Department of Medical Biophysics University of Western Ontario LondonON Canada

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Comparison of 2D scintimammography and 3D dedicated breast SPECT using a compressible breast phantom and lesions of varying size and tracer uptake

Comparison of 2D scintimammography and 3D dedicated breast S...

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IEEE Symposium on Nuclear Science (NSS/MIC)

作者： Spencer J. Cutler Kristy L. Perez Priti Madhav Martin P. Tornai Biomedical Engineering and Radiology Departments Duke University Durham NC USA Medical Physics Graduate Program and Radiology Department Duke University Durham NC USA Medical Physics Graduate Program Biomedical Engineering and Radiology Departments Duke University Durham NC USA

This study aims to qualitatively and quantitatively compare 2D planar scintimammography imaging of the breast under various degrees of compression with uncompressed, dedicated 3D SPECT using dedicated acquisition trajectories. A 700mL compressible anthropomorphic breast phantom containing small lesions was developed to compare 2D and 3D breast imaging. Thin walled, deformable lesions ranging from 40 to 500uL volume suspended on a thin plastic sheet in the phantom were used to mimic breast lesions undergoing different degrees of compression. Using a 16×20cm 2 CZT-based gamma camera, 99m Tc-scintimammography was performed for 10min imaging times for compression thicknesses of 6 and 12cm (fully uncompressed) using a single mediolateral view. Dedicated breast SPECT was then performed for 10min using the uncompressed breast acquired with a simple tilted rotation, and a complex 3D acquisition trajectory. Experimental variables include: (1) background torso contamination; (2) (in)homogeneous breast composition; and (3) low count (clinically relevant) and high count (low noise) images. The radioactivity lesion:background concentration ratio was varied from 12:1 down to 3:1. A comparison between the two modalities was made in a limited observer study with independent observers evaluating reconstructed images for the smallest detectable lesion and total number of lesions. Image quality, based on lesion SNRs and contrasts were also evaluated. SPECT images appear to yield observation of smaller and more simulated lesions than those seen in scintimammography, additionally with more than twice the SNR and contrast. Due to greater positioning flexibility of the SPECT system gantry, under a wide range of measurement conditions, statistically significantly (p≪0.05) more lesions, smaller lesion sizes, and (3D) lesion locations were detected with dedicated breast SPECT than with compressed breast scintimammography.

关键词： Breast Imaging phantoms Lesions Optical imaging Anthropomorphism Thin wall structures Plastics Cameras Torso Contamination

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Biomineral/agarose composite gels as grafting materials for bone regeneration in animal model

Biomineral/agarose composite gels as grafting materials for ...

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8th World Biomaterials Congress 2008, WBC 2008

作者： Suzawa, Yoshika Funaki, Takafumi Iwai, Soichi Yura, Yoshiaki Watanabe, Junji Nakano, Takayoshi Umakoshi, Yukichi Akashi, Mitsuru Graduate School of Dentistry Osaka University Osaka Japan Graduate School of Engineering Osaka University Osaka Japan BioMedical Technology Hybrid Ltd. Kagoshima Japan Osaka Industrial Promotion Organization Osaka Japan 21st Century COE Program center for Integrated Cell and Tissue Regulation Osaka University Japan

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Study on the immobilization of Ni-NTA and NTA on PMMA substrate base

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Key engineering Materials 2008年 381-382卷 357-360页

作者： Chong, W.S. Kim, G.B. Hong, C.U. Department of Biomedical Engineering Graduate School Chonbuk National University Duckjin-Dong Jeonju Jeonbuk 561-756 Korea Republic of Education Program for 21st Century Chonbuk National University Research Institute of Clinical Medicine Duckjin-Dong Jeonju Jeonbuk 561-756 Korea Republic of Division of Bionics and Bioinformatics Collage of Engineering Chonbuk National University Duckjin-Dong Jeonju Jeonbuk 561-756 Korea Republic of

In this study, we attempts to develop a sensing method to detect mismatched DNA in order to diagnose cancer. The sensing method will be developed to use for early diagnosis of cancer. Thus, protein immobilization was applied on the surface of the sensor in order to facilitate the detection of mismatched DNA. This method was designed to achieve the Ni-His-Tag to selectively bond with MutS, which has a covalent bond with the His-Tag, by using Ni-NTA. This method is troublesome because it involves a number of repeated composition processes. This method need gold surface to immobilize NTA (nitrotriamino acid). But this process is very complicated and expensive cost. Therefore, we try to immobilize NTA using PMMA (poly methyl methacrylate) polymer in this research to improve this method. In this study revealed that we could directly immobilize the NTA to the PMMA substrate not used Gold substrate. Also, we could directly immobilize the MutS to the NTA using the EDC solution. In addition, we can expect that the mismatched DNA can be detected from the results.

关键词： Proteins

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Co-registration of a needle-positioning device with a volumetric x-ray micro-computed tomography scanner for image-guided preclinical interventions

Co-registration of a needle-positioning device with a volume...

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IEEE International Symposium on biomedical Imaging

作者： Adam C. Waspe David W. Holdsworth James C. Lacefield Aaron Fenster Biomedical Engineering Graduate Program and Imaging Research Laboratories Robarts Research Institute University of Western Ontario London ONT Canada

An apparatus and method are developed for integration of a needle- positioning robot with volumetric micro-computed tomography image guidance for interventions in small animals. Accurate registration is critical for integration as it enables targets identified in the image to be mapped to physical coordinates inside the animal. Registration is accomplished by injecting barium sulfate into needle tracks created in a tissue-mimicking phantom. Registration accuracy is therefore affected by the positioning error of the robot and is assessed by measuring the point-to-line target registration error (TRE). Centroid points along cross-sectional slices of the track are determined using region growing segmentation followed by application of a center-of-mass algorithm. The centerline points are registered to needle trajectories in robot coordinates by applying an iterative closest point algorithm between points and lines. Implementation of this procedure with four fiducial needle tracks produced a point-to-line TRE of 194 plusmn 18 mum.

关键词： X-ray imaging Tomography Robot kinematics Needles Animals Target tracking Barium Imaging phantoms Position measurement Iterative algorithms

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