Showing papers on "Imaging technology published in 1991"

Digital X-ray imaging

Abstract: Digital radiography is progressively replacing conventional (film-based) radiographic techniques promising consistently high levels of image quality, more effective use of radiation and more efficient work practices. At the same time its introduction poses new challenges to those physical scientists who design radiological imaging systems and those who provide scientific/technical support to a clinical radiology service Scientific aspects of those digital X-ray imaging systems which are proving most successful are described. Physical measurement techniques developed to evaluate the imaging performance and radiation dose efficiency of clinical digital radiography systems are outlined. Directions in which digital X-ray imaging technology may evolve in the 1990s are discussed.

Imaging: Fine Arts

Abstract: Imaging in the fine arts shares many problems and characteristics with imaging in other domains. But almost by definition the fine arts are especially concerned with the preservation and quality of images. In this article we focus on those issues that take on a particular character in the fine arts—issues that are likely to be less crucial in other domains, such as medicine or document scanning. We look at general image quality issues including image capture, resolution, and display, and then turn our attention to the uses of imaging technology for conservation and preservation purposes. Next, we examine the implications of the distribution of digital fine arts images outside their normal environment—libraries, museums, and educational institutions. Finally, we briefly summarize published resources for imaging in the fine arts. © 1991 John Wiley & Sons, Inc.

Computer applications in radiology.

Abstract: Computer applications in radiology are evolving rapidly, tied to incremental improvements in hardware, software, and methods In computer hardware, the emergence of dramatically improved graphic and computational performance for engineering workstations enables their use for visualization Major changes in networking, storage, and display technology play a major role in influencing applications The use of three-dimensional digitizers to perform localization of real three-dimensional points in conjunction with images and the rendering of objects using rapid prototyping methods, such as stereolithography, were recently reported Major software advances have taken place through the availability of applications packages that are operated with menu-driven or point-and-click user interfaces, data flow languages, or complete turnkey applications Imaging methods including CT, MR imaging, digital radiography, biomagnetism, and optical range sensing, which take advantage of advanced computer technology, are new this year Image processing for multimodality fusion or image registration, visualization, reconstruction, and quantification of images, have been reported at a wide variety of conferences and in key publications New computer methods to fabricate custom orthopaedic implants, and to improve imaging technology assessment were introduced

Images in rheumatology (IR): a multimedia program for medical education

Abstract: Traditional instruction in undergraduate medical education has stressed textbook-based courses, lab exercises, and formal lectures augmented by a variety of audio/visuals. Projection of 35mm slides remains the dominant display medium. In recent years, image databases stored on videodisc have become important adjuncts to standard curricula in the preclinical sciences. However, in the case of clinical and postgraduate medical education, there is still a paucity of computer-based instructional programs, especially those using high-resolution images. A program developed at the Washington, D.C. Veterans Affairs Medical Center called Images in Rheumatology (IR) was designed to fill this gap in clinical instruction for the rheumatic diseases. The purpose of IR is to provide students, trainees and attending physicians with basic information and representative clinical and x-ray images for the medical specialty of rheumatology. IR is a prototype for designing similar instructional programs in the other internal medicine subspecialties. By using IR, we can take a teaching slide and x-ray collection of another subspecialty and develop a similar instructional program. Images and Medicine Medicine is necessarily an image-intensive discipline. Health professionals are continuously confronted with patients who have specific and visible clinical lesions. A physician is regularly called upon to interpret x-rays or pathologic specimens and to decide whether they are suggestive of, or pathognomonic for, a particular disease. Thus, having a fundamental knowledge base of disease-associated images is crucial to the diagnostic process. Of the recent advances in medical technology that have impacted diagnostic medicine, imaging technology is preeminent. Consider the crucial role that has been established for such high-technology tools as computed tomography (CT), magnetic resonance imaging (MRI), and ultrasonography; each provides a unique image of the inner body, areas heretofore only accessible to the surgeon or pathologist. Thus, the technological advances in medical science compel the health professional to acquire an ever expanding knowledge base of images. Initial Program Development Our initial sojourn into the realm of multimedia computing and image display was undertaken using IBM's Link Way program. It offered a convenient way of producing hypertext screens, and provided us with a means of importing images and linking them with sound bites. Working with a mouse, the user could display an image by clicking over highlighted text words that had embedded triggers. Instructional material (text) was displayed on one monitor, while a second monitor was used for the image. While the original program was well received, we had additional goals: a program that would not only use a single monitor, but also could display higher-resolution images, use special custom-color palettes and incorporate 16-bit digitized sound. IBM's Audio Visual Connection (AVC) software fit the bill, and it is in this environment that the current version of IR was developed. Hardware Used The development hardware used to implement the AVC software is designed primarily for the IBM Micro Channel environment. This includes the Audio Capture and Playback Adapter, the Video Capture Adapter/A and the M-Motion Video Adapter/A. However, the run-time version of the software (that fraction of the overall development package that allows the authored program to be used by others) is not limited to Micro Channel machines and can also be used on computers with the common IBM AT (ISA) bus. A high-resolution RGB frame-grabber camera was used to digitize (capture) all of the images used in IR. Standard 35mm slides were placed on a lightbox and were captured using a macro lens. In a similar fashion, x-rays were also digitized, but a wide angle lens was used. …

Imaging of the temporomandibular joint.

Abstract: Imaging of the temporomandibular joint recently has been characterized by a shift in emphasis from plain films, arthrography, and computed tomography toward magnetic resonance imaging. The past year represents the continuation of the era of refinement in magnetic resonance technology not immediately obvious as an advantage for temporomandibular joint imaging but nonetheless, of potential significant impact. A few examples of relatively "quiet" developments include: 1) new alloys for lighter weight permanent magnets with reduced operating costs; 2) gradient coil technology for more rapid image acquisition leading to the possibility of true cine magnetic resonance; and 3) smaller, more powerful computers for more rapid data processing. The implications are for comprehensive anatomic and physiologic assessments of the joint along with increased patient throughput and reduced costs. This review surveys the recent literature on the techniques and selection of imaging modalities, new observations regarding the pathophysiology of temporomandibular joint diseases afforded by advances in imaging technology, and my opinions regarding future directions in imaging technology based on my own experience and a review of the current literature.

NIH Supported PACS Related Research

Abstract: The diagnostic imaging research program at the National Cancer Institute took a leading role in the development and utilization of electronics and other imaging technology. Research in areas of digital electronic communication technology, picture archiving and communication systems (PACS), image acquisition and sorting, and image enhancement has been actively pursued by our program. The following three research centers were established to bring electronic imaging technology to clinics and to advance early cancer diagnosis.

A High Speed and Low Cost Data and Image Processing System using DSP TMS320C25 and an IBM-PC

Abstract: As one of the important tools of NDE, imaging technology provides fast, intuitive, and reliable diagnostic information for various research and industrial NDE applications. While as digital computer and electronic technologies bloom, a large number of advanced imaging systems as well as digital image processing algorithms have been successfully developed in the last two decades. These devices and algorithms have been adapted for NDE applications. A high quality NDE image obtained by an imaging system provides the visible information of the material structure. However, qualities of NDE images are often limited by some factors such as noise and unsharpness, incomplete data and information loss, sensitivities of the sensors and capability of the devices [1, 2, 3]. Many image processing methods can be applied to increase reliability of the images and to analyze the images. These methods includes image transform, reconstruction, enhancement, restoration, and feature extraction. The references of these methods can be readily found in many textbooks and research journals and we try not to do an exhaustive list in here. To have a quick review of different image processing techniques, one may find useful a recent review paper by Demoment [4] and the textbook written by Gonzalez and Wintz [5].