Biomedical Imaging in Modern Medicine

Specific features of biomedical imaging in modern medicine are discussed. Particular emphasis is placed on aspects of practical application. Modern trends in radiation diagnosis are associated with digital engineering. Digital medical imaging is widely used in various areas of modern medicine. The demand for imported digital imaging apparatuses is considered. Diagnostic information and corresponding software require unification and standardization.     

Biomedical applications of photoacoustic imaging with exogenous contrast agents

Photoacoustic imaging is a biomedical imaging modality that provides functional information, and, with the help of exogenous contrast agents, cellular and molecular signatures of tissue. In this article, we review the biomedical applications of photoacoustic imaging assisted with exogenous contrast agents. Dyes, noble metal nanoparticles, and other constructs are contrast agents which absorb strongly in the near-infrared band of the optical spectrum and generate strong photoacoustic response. These contrast agents, which can be specifically targeted to molecules or cells, have been coupled with photoacoustic imaging for preclinical and clinical applications ranging from detection of cancer cells, sentinel lymph nodes, and micrometastasis to angiogenesis to characterization of atherosclerotic plaques. Multi-functional agents have also been developed, which can carry drugs or simultaneously provide contrast in multiple imaging modalities. Furthermore, contrast agents were used to guide and monitor the therapeutic procedures. Overall, photoacoustic imaging shows significant promise in its ability to assist in diagnosis, therapy planning, and monitoring of treatment outcome for cancer, cardiovascular disease, and other pathologies.     

Biomedical imaging research opportunities workshop IV: a white paper

The Fourth Biomedical Imaging Research Opportunities Workshop (BIROW IV) was held on February 24-25, 2006, in North Bethesda, MD. The workshop focused on opportunities for research and development in four areas of imaging: imaging of rodent models; imaging in drug development; imaging of chronic metabolic disease: diabetes; and image guided intervention in the fourth dimension-time. These topics were examined by four keynote speakers in plenary sessions and then discussed in breakout sessions devoted to identifying research opportunities and challenges in the individual topics. This paper synthesizes these discussions into a strategy for future research directions in biomedical imaging.     

Quantitative Imaging Biomarker Ontology (QIBO) for Knowledge Representation of Biomedical Imaging Biomarkers

A widening array of novel imaging biomarkers is being developed using ever more powerful clinical and preclinical imaging modalities. These biomarkers have demonstrated effectiveness in quantifying biological processes as they occur in vivo and in the early prediction of therapeutic outcomes. However, quantitative imaging biomarker data and knowledge are not standardized, representing a critical barrier to accumulating medical knowledge based on quantitative imaging data. We use an ontology to represent, integrate, and harmonize heterogeneous knowledge across the domain of imaging biomarkers. This advances the goal of developing applications to (1) improve precision and recall of storage and retrieval of quantitative imaging-related data using standardized terminology; (2) streamline the discovery and development of novel imaging biomarkers by normalizing knowledge across heterogeneous resources; (3) effectively annotate imaging experiments thus aiding comprehension, re-use, and reproducibility; and (4) provide validation frameworks through rigorous specification as a basis for testable hypotheses and compliance tests. We have developed the Quantitative Imaging Biomarker Ontology (QIBO), which currently consists of 488 terms spanning the following upper classes: experimental subject, biological intervention, imaging agent, imaging instrument, image post-processing algorithm, biological target, indicated biology, and biomarker application. We have demonstrated that QIBO can be used to annotate imaging experiments with standardized terms in the ontology and to generate hypotheses for novel imaging biomarker–disease associations. Our results established the utility of QIBO in enabling integrated analysis of quantitative imaging data.     

Biomedical Imaging Research Opportunities Workshop III: A White Paper

The third Biomedical Imaging Research Opportunities Workshop (BIROW III) was held on March 11–12, 2005, in Bethesda, MD. The workshop addressed four areas of imaging that present opportunities for research and development: Multimodality Image-Guided Therapy, Imaging Informatics, Imaging Cell Trafficking, and Technology Improvement and Commercialization. The first three areas were individually addressed in their own plenary sessions, followed by audience discussions that explored research opportunities and challenges. This paper synthesizes these discussions into a strategy for future research directions in biomedical imaging.     

Biomedical image visualization research using the Visible Human Datasets

The practice of medicine and conduct of research in major segments of the biologic sciences have always relied on visualizations to study the relationship of anatomic structure to biologic function. Traditionally, these visualizations have either been direct, via vivisection and postmortem examination, or have required extensive mental reconstruction. The revolutionary capabilities of 3-D and 4-D medical imaging modalities, together with computer reconstruction and rendering of multidimensional medical and histological volume image data, obviate the need for physical dissection or abstract assembly. The availability of the Visible Human Datasets from the National Library of Medicine, coupled with the development of advanced computer algorithms to accurately and rapidly process, segment, register, measure, and display high resolution 3-D images, has provided a rich opportunity to help advance these important new imaging, visualization, and analysis methodologies from scientific theory to clinical practice.     

Managing Biomedical Image Metadata for Search and Retrieval of Similar Images

Radiology images are generally disconnected from the metadata describing their contents, such as imaging observations (“semantic” metadata), which are usually described in text reports that are not directly linked to the images. We developed a system, the Biomedical Image Metadata Manager (BIMM) to (1) address the problem of managing biomedical image metadata and (2) facilitate the retrieval of similar images using semantic feature metadata. Our approach allows radiologists, researchers, and students to take advantage of the vast and growing repositories of medical image data by explicitly linking images to their associated metadata in a relational database that is globally accessible through a Web application. BIMM receives input in the form of standard-based metadata files using Web service and parses and stores the metadata in a relational database allowing efficient data query and maintenance capabilities. Upon querying BIMM for images, 2D regions of interest (ROIs) stored as metadata are automatically rendered onto preview images included in search results. The system’s “match observations” function retrieves images with similar ROIs based on specific semantic features describing imaging observation characteristics (IOCs). We demonstrate that the system, using IOCs alone, can accurately retrieve images with diagnoses matching the query images, and we evaluate its performance on a set of annotated liver lesion images. BIMM has several potential applications, e.g., computer-aided detection and diagnosis, content-based image retrieval, automating medical analysis protocols, and gathering population statistics like disease prevalences. The system provides a framework for decision support systems, potentially improving their diagnostic accuracy and selection of appropriate therapies.     

微粒子成像测速在生物医学工程领域的研究进展

血液是生物体内重要组成部分,肩负着物质输送和传递的任务。血流微环境影响着心血管发育、红细胞聚集及血液黏度、癌症转移和动脉粥样硬化等生理病理过程,在药物输送、细胞分选、人工器官设计和生物体运动等研究领域,流场环境也起到重要作用,这使得微流场的测量和定量分析变得尤为重要。微粒子成像测速(micro-particle imaging velocimetry, Micro-PIV)将传统的粒子成像测速和显微技术结合起来,通过对高速相机在不同时刻拍摄的两组图像进行互相关分析,能够计算得到微流场环境的速度场。与其他速度测量方法相比,Micro-PIV技术具有较高的时间分辨率和空间分辨率。本文介绍Micro-PIV系统的主要组成及相关原理和分析方法,并总结其近年来在生物医学工程领域的研究进展,对Micro-PIV的不足和应用前景展望进行探讨。     

金纳米材料的可控制备、组装及在生物医学上的应用

金纳米材料具有独特的光、电、热、催化等物理与化学性质,生物相容性好,是构筑新型复合功能材料的重要组元,在生物传感、细胞及活体成像、癌细胞的光热治疗、靶向载药、光化学催化等领域展现出了广阔的应用前景。我们结合本课题组前期研究中遇到的问题和积累的经验,从金纳米材料的可控制备、组装及其在生物医学上的应用等方面的最新研究进展进行了全面综述,分析了其中存在的不足,展望了金纳米材料的发展趋势。     

The National Institute of Biomedical Imaging and Bioengineering: History, Status, and Potential Impact

This paper describes the history, current status, and objectives and potential impact of the new National Institute of Biomedical Imaging and Bioengineering (NIBIB). Three of the authors (Hendee, Chien, and Maynard) have been involved over several years in the effort to raise the identity of biomedical imaging and bioengineering at the National Institutes of Health. The fourth author (Dean) is the Acting Director of the newly formed NIBIB. These individuals have an extensive collective knowledge of the events that led to formation of the NIBIB, and are intimately involved in shaping its objectives and implementation strategy. This special report provides a historical record of activities leading to establishment of the NIBIB, and an accounting of present and potential advances in biomedical engineering and imaging that will be facilitated and enhanced by NIBIB. The National Institute of Biomedical Imaging and Bioengineering represents a coming of age of biomedical engineering and imaging, and offers great potential to expand the research frontiers of these disciplines to unparalleled heights. © 2002 Biomedical Engineering Society. PAC2002: 8762+n, 8759-e, 0178+p, 0165+g, 8761-c     

Special Report: Biomedical Imaging Research Opportunities Workshop IV. A Summary of Findings and Recommendations

The fourth Biomedical Imaging Research Opportunities Workshop (BIROW IV) was held in February, 2006 in Bethesda, Maryland. The workshop explored four promising areas of imaging research: Imaging of rodent models; Imaging in drug development; Imaging of chronic metabolic disease – diabetes; and Image-guided intervention in the 4th dimension – time. These explorations uncovered multiple research opportunities that have the potential of enhancing the discovery of new knowledge, providing more efficient pathways for drug development, yielding improvements in the management of chronic metabolic diseases such as diabetes mellitus, and guiding medical interventions such as surgery, radiation oncology, and ablation therapy. Research challenges were identified in each of these areas of opportunity that must be resolved through scientific exploration and technology development. The meeting concluded with the observation that research in biomedical imaging offers the potential of improving patient care in many ways, and the promise of exciting and rewarding careers to young research aspirants.Authors of the report-back sessions from which this summary has been prepared are Filip Banovac MD, Paul L. Carson PhD, Ralph A. DeFronzo MD, William C. Eckelman PhD, Gary D. Fullerton PhD, Steven M. Larson MD, Gordon McLennan MD, Michael J. Welch PhD.     

A Biomedical Microphysiometer

We report on a micromachined silicon chip that is capable of providing a high-throughput functional assay based on calorimetry. A prototype twin microcalorimeter based on the Seebeck effect has been fabricated by using IC technology process steps in combination with micromachined postprocessing techniques. A biocompatible liquid rubber membrane supports two identical 0.5×2 cm² measurement chambers, situated at the cold and hot junction sites of a thermopile. The thermopile consists of 666 aluminum/p+-polysilicon thermocouples. The chambers can house up to 10⁶ eukaryotic cells cultured to confluence. The advantage of the device over microcalorimeters on the market, is the integration of the measurement channels on chip, rendering microvolume reaction vessels, ranging from 10 to 600 µl, in the closest possible contact with the thermopile sensor (no springs are needed). Power and temperature sensitivity of the sensor are 23 V/W and 130 mV/K, respectively. The small thermal inertia of the microchannels results in the short response time of 70 s, when filled with 50% of water.Biological experiments were done with cultured kidney cells of Xenopus laevis (A6). The thermal equilibration time of the device is 45 minutes. Stimulation of transport mechanisms by reducing bath osmolality by 50% increased metabolism by 20%. Our results show that it is feasible to apply this large-area, small-volume whole-cell biosensor for drug discovery, where the binding assays that are commonly used to provide high-throughput need to be complemented with a functional assay.Solutions are brought onto the sensor by a simple pipette, making the use of an industrial microtiterplate dispenser feasible on a nx96-array of the microcalorimeter biosensor. Such an array of biosensors has been designed based on a new set of requirements as set forth by people in the field.     

基于时域光声信号的谱分析技术及其在生物医学领域的应用

基于时域光声信号的谱分析技术是一种能够提供生物组织结构和功能信息的非侵入式检测技术,其结合了光学模态的高对比度和超声模态在深层组织中的高分辨率两重特性,可对不同波长光激发下的目标生物组织的光声信号数据集进行处理分析。相较于传统光谱检测,该技术不易受被测对象形状、形态的限制和光散射的影响,使其对较深层组织的检测仍具有较高灵敏度。相较于光声成像,该技术无需引入图像重建算法且专注于实现定量分析。综述时域光声信号的谱分析技术在生物组织、生物体液、生物呼出气体检测中的应用,介绍相关研究所采用的改进实验系统或不同信号处理方法,阐述该技术的研究进展与发展方向。     

Biomedical informatics training at Stanford in the 21st century

The Stanford Biomedical Informatics training program began with a focus on clinical informatics, and has now evolved into a general program of biomedical informatics training, including clinical informatics, bioinformatics and imaging informatics. The program offers PhD, MS, distance MS, certificate programs, and is now affiliated with an undergraduate major in biomedical computation. Current dynamics include (1) increased activity in informatics within other training programs in biology and the information sciences (2) increased desire among informatics students to gain laboratory experience, (3) increased demand for computational collaboration among biomedical researchers, and (4) interaction with the newly formed Department of Bioengineering at Stanford University. The core focus on research training-the development and application of novel informatics methods for biomedical research-keeps the program centered in the midst of this period of growth and diversification.     

Focus on: Washington Hospital Center, Biomedical Engineering Department

The Biomedical Engineering Department of the Washington Hospital Center provides clinical engineering services to an urban 907-bed, tertiary care teaching hospital and a variety of associated healthcare facilities. With an annual budget of over $3,000,000, the 24-person department provides cradle-to-grave support for a host of sophisticated medical devices and imaging systems such as lasers, CT scanners, and linear accelerators as well as traditional patient care instrumentation. Hallmarks of the department include its commitment to customer service and patient care, close collaboration with clinicians and quality assurance teams throughout the hospital system, proactive involvement in all phases of the technology management process, and shared leadership in safety standards with the hospital's risk management group. Through this interactive process, the department has assisted the Center not only in the acquisition of 11,000 active devices with a value of more than $64 million, but also in becoming one of the leading providers of high technology healthcare in the Washington, DC metropolitan area.     

Focus on: Westchester County Medical Center Division of Biomedical Engineering

The Division of Biomedical Engineering (DBME), a vital element in the structure of any medical center, provides complete biomedical equipment services at Westchester County Medical Center (WCMC), through a Biomedical Instrumentation Program. Under this program, the DBME assumes direct responsibility for all diagnostic imaging equipment in radiology, radiation medicine and nuclear medicine; and patient care, surgical life support (respiratory care) equipment in critical care units, operating rooms, G.I. (gastro-intestinal) suites, renal center, burn center, emergency rooms, as well as clinical laboratories. In addition, the DBME provides academic and internship programs, research, design, database support, technology planning, and device inspection or evaluation. The DBME is "looking into the future" for a gradual migration of state-of-the-art technology into healthcare.     

生物医用金属材料的腐蚀

总结了生物医用金属材料的腐蚀问题,讨论了金属材料在生理环境中的腐蚀机理及其释放腐蚀产物引起的局部组织反应和全身系统反应,阐述了生物医用金属材料腐蚀研究的发展方向和解决现在问题的对策。     

医用传感器的发展

传感器技术的发展随着信息技术的发展日新月异，而医用传感器技术也在近些年取得了巨大进展，逐渐向智能化、微型化、多参数、可遥控和无创检测等方向发展。现就医用传感器的技术现状和未来发展方向加以综述。     

Biomedical amplifiers using integrated circuits

Amplifiers suitable for biomedical applications must usually have a high common-mode rejection and a high differential input resistance. Although several integrated-circuit operational amplifiers possess these qualities, it has hitherto been difficult to obtain satisfactory performance with respect to these properties in practical circuits. An unusual method of applying feedback which enables the high values appearing in manufacturers specifications to be fully realised is described and the circuit details of a simple amplifier having a common-mode rejection ratio of 80 dB and an input resistance of 7·5 MΩ are given.