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Feasibility and clinical value of "intelligent" compression and digital storage of transthoracic echocardiograms in day-to-day practice.

BACKGROUND: The aim of this study was to assess the clinical concordance of expert cardiologists' interpretation of echocardiographic studies recorded on Super-VHS videotape or stored in magneto-optical disk, as well as the feasibility and clinical value of intelligent compression and digital storage of echocardiographic data as cine-loops and still-frames for interpretation of transthoracic echocardiographic images in clinical practice. METHODS: All clinical cardiologists experienced in echocardiography in our department (n = 10) reported on a standardized worksheet checklist the echocardiographic data of 7 consecutive patients (140 reports), and recorded them on videotape or magneto-optical disks to compare the interpretation of videotaped studies, acquired in the usual way, with clinically compressed studies stored to magneto-optical disks using a standard (Italian Society of Echocardiography) image acquisition protocol. RESULTS: The time interval between analog and digital study readings was 50 +/- 15 days. Except for tricuspid valve regurgitation grading (k = 0.28) and for left ventricular global hypokinesia (k = 0.32), the intraobserver agreement in the interpretation of the 3290 cardiovascular morphological and functional findings found on analog and digitally stored images was good (k value ranging from 0.66 to 1.00). The wall motion score index was 1.56 +/- 0.53 when interpreting analog studies, and 1.52 +/- 0.54 on digital studies (p = 0.35). Conversely, the interobserver variability of the wall motion score index (Gini index ranging from 0 to 0.80) was significantly lower when interpreting studies stored digitally than when analog ones were examined (0.48 +/- 0.021 and 0.52 +/- 0.023 respectively, p = 0.006). In comparison to videotape recordings, digital storage of echocardiographic studies significantly shortened the time to image access for study review (327 +/- 62 and 30 +/- 4 s, respectively, p < 0.0001) and the reading time (600 +/- 300 and 540 +/- 300 s respectively, p = 0.034), rendered study accessibility easier (difficult or good: 73 vs 43% of observers, fast or optimal: 27 vs 57% of observers respectively, p = 0.0011) and improved the recorded image quality perception (poor: 25 vs 10% of observers, sufficient or good: 75 vs 90% of observers respectively, p = 0.022), without loss of study completeness (insufficient: 18 vs 17% of observers, adequate or complete: 82 vs 83% of observers, respectively; p = NS). Finally, from September 1, 1999, digital storage has become routine practice for patients admitted to our Department. By December 31, 1999, 411 echo studies had been stored: 7 +/- 3 cine-loop/study, 32 +/- 18 frames/cine-loop, and 3 +/- 2 still-frames/study. The average amount of memory needed for storage was 18.6 +/- 11.9 MB/study. CONCLUSIONS: Clinical compression of echocardiographic studies seems to be an accurate summary of the complete examination recorded to videotape for the assessment of patients admitted in the coronary care unit. In addition, digitally stored studies allow a significant improvement in the interobserver reproducibility of wall motion score assessment.

Analog-Digital Conversion↗

Uses and limitations of microcomputers for epidemiological research in occupational health.

The rapid improvements in microcomputer systems have contributed to ease of performance of epidemiological research in occupational health. Computers now available can aid in all stages of research- from the early stages of literature review to data collection, analysis and presentation. Optical storage devices now allow large occupational health data bases to be stored on a single compact disc, with the information accessible by microcomputer. Hand-held computers and optical scanners allow paperless collection of field data. Epidemiological analysis and data presentation is easily done with software packages, some of which are in the public domain. However, there are limitations in the use of computers for any epidemiological research. Investment of time is required to learn the use of a computer. Care needs to be taken to ensure accurate data entry, and correct choice has to be made of methods for subsequent statistical analysis. Microcomputers are valuable as labour saving devices, but cannot replace proper planning, execution and appropriate data analysis in epidemiological research in occupational health.

Health Services Research↗

Present status and performance of PACS at Kyoto University Hospital.

A pilot PACS project, named KIDS, has been running in Kyoto University Hospital. The purpose of the system is to establish a small PACS that includes all digital imaging modalities and to evaluate it. The project has been continued from the first phase (KIDS-1) to the second phase (KIDS-2). In the first phase, a small-scale PACS was developed. In the second phase, the expansion of coverage of modalities and completion of the image database was intended. At present, the database contains image data of 16264 patients amounting to 150 Gbytes. Simulation of the retrieval process to the database shows that 154.3 s per patient is required for retrieving his/her entire image data. This calculated value is close to the actual time.

Computer Communication Networks↗

Insect infestation of stored oats in Florida and field evaluation of a device for counting insects electronically.

Automated methods of monitoring stored grain for insect pests will contribute to early detection and aid in management of pest problems. An insect population infesting stored oats at a seed processing plant in north-central Florida was studied to test a device for counting insects electronically (Electronic Grain Probe Insect Counter, EGPIC), and to characterize the storage environment. The device counts insects as they fall through an infrared beam incorporated into a modified grain probe (pitfall) trap and transmits the counts to a computer for accumulation and storage. Eight traps were inserted into the surface of the grain bulk, and the insects trapped were identified and counted manually at weekly intervals. Grain temperature and moisture content also were recorded for each trap location. Manual and automatic counts were compared to estimate error in the EGPIC system. Both over- and undercounting occurred, and errors ranged from -79.4 to 82.4%. The mean absolute value of error (+/- SE) was 31.7% (+/- 4.3). At least 31 species, or higher taxa, were detected, but the psocid Liposcelis entomophila (Enderlein) and the foreign grain beetle, Ahasverus advena (Waltl), accounted for 88% of the captured insects. Species diversity, phenology, and spatial distribution are presented, as well as temporal and spatial distribution of grain temperature and moisture content. The data sets generated will find application in population modeling and development of integrated pest management systems for stored grain.

Animals↗

Computer-monitored radionuclide tracking of three-dimensional mandibular movements. Part I: theoretical approach.

A new technique for the three-dimensional recording of a person's mandibular movement is described. A small and harmless radioactive source is fixed on the patient's skin at the point of interest or sealed in a tooth cavity. Using the proper collimation, the motion of the point source is recorded via a gamma camera and minicomputer. Long-term storage on a magnetic device offers playback, slow motion facilities, and data analysis through the use of sophisticated computer languages. Simultaneous recordings using two cameras, or postsynchronization of two different views of an experiment, enable the three-dimensional restitution of mandibular movements. Superimposition of a grid of radioactive spots spaced at measured intervals during the recording permits a straightforward calibration of the patient's motion. Multiple sources in a single experiment may be recorded to describe the displacement of several points of interest. This method, derived from nuclear medicine techniques, offers a powerful tool of general interest for the tracking of dynamic events in many fields of dentistry such as temporomandibular joint dysfunction and prosthetic restorative techniques. Further considerations on our experimental settings and results will be published in part II.

Analog-Digital Conversion↗

Neuropoiesis: proposal for a connectionistic neurobiology.

Given current assumptions about the biology of neural organization, some connectionists believe that it may not be possible to accurately model the brain's neural architecture. We have identified five restrictive neurobiological dogmas that we believe have limited the exploration of more fundamental correlations between computational and biological neural networks. We postulate that: 1) the dendritic tree serves as a synapse storage device rather than a simple summation device; 2) connection strength between neurons depends on the number and location of synapses of similar weight, not on synapses of variable weights; 3) axonal sprouting occurs regularly in adult organisms; 4) the postsynaptic genome directly controls the presynaptic cell via mRNA, rather than indirectly by the expression of NCAMs, reverse neurotransmitters, etc.; 5) dendritic spines serve a trophic function by controlling development of new sprouts via a process we term retroduction. We entertain an alternative formulation of a computational neural element that is fully consistent with modern neuroscience research. We then show how our model neuron can learn under Hebbian conditions, and extend the model to explain non-Hebbian, one-trial learning. This work is significant because by stretching the theoretical boundaries of modern neuroscience, we show how connectionists can potentially create new, more biologically-based neural elements which, when, interconnected into networks, exhibit not only properties of existing backpropagation networks, but other physiological properties as well.

Adult↗

Sorting efficiency.

Computers and the tasks they perform are becoming increasingly important in medicine. It behooves medical personnel to become familiar with some computer functions so that they may be in a better position to demand and evaluate a given implementation. One very basic computer task is sorting information. Some general principles of computing efficiency are discussed, as well as the standard "O" notation. A simple sort, bubblesort, is discussed and analyzed. A second elementary sort, insertionsort, is considered in relation to its more sophisticated descendant, shellsort. The most efficient in-memory sort, quicksort (and its various descendants), is likewise examined, and the advantages and disadvantages of each variant are discussed in some detail, as well as methods that may enhance speed and resource utilization. Finally, mergesort, which is used in sorting large files resident in mass-storage devices, is discussed, along with its particular advantages.

Algorithms↗

Universal interface for exchange of medical images via magneto-optical discs.

Digital images are the ever-growing basis of modern medical imaging and treatment. Despite the advent of the DICOM 3.0 standard for medical image communication it still requires cumbersome efforts to export images from imaging modalities to other computer systems. This is true especially for smaller institutions, which often have limited resources for standardized image transfer. To gain access even to these data we developed an exchange interface on the basis of magneto-optical discs (MO-discs), as they are usually available in most of the imaging modalities in use today. Unfortunately images on MO-discs are usually stored in formats specific for each manufacturer. Therefore special routines to access the data on MO-discs had to be developed for each company or even each scanner. Over 10,000 CT and MRI images including their header information from different General Electric and Siemens scanners were extracted successfully from MO-discs. The interface proved to be reliable and easy to handle by technicians. Support of additional manufacturers and of the DICOM 3.0 standard are work in progress.

Computer Communication Networks↗

Development and evaluation of oral reporting system for PACS.

Experimental workstations for oral reporting and synchronized image filing have been developed and evaluated by radiologists and referring physicians. The file media is a 5.25-inch rewritable magneto-optical disk of 600-Mb capacity whose file format is in accordance with the IS&C specification. The results of evaluation tell that this system is superior to other existing methods of the same kind such as transcribing, dictating, handwriting, typewriting and key selections. The most significant advantage of the system is that images and their interpretation are never separated. The first practical application to the teaching file and the teaching conference is contemplated in the Osaka University Hospital. This system is a complete digital system in terms of images, voices and demographic data, so that on-line transmission, off-line communication or filing to any database will be easily realized in a PACS environment. We are developing an integrated system of a speech recognizer connected to this digitized oral system.

Education, Medical↗

A proposal of an off-line PACS based on a personal database.

Problems with picture archiving and communication systems (PACS) are focused and an off-line PACS of practical value is proposed in this paper. This system is based on the personal database where each patient has his/her own recording medium. This medium files all medical information as well as images of value, and is carried with a patient through hospital. Advantages over the conventional or on-line PACS communicating through a network are discussed and a possibility of practical use is analysed showing a prototype system. The biggest advantage of this system is quick and easy access to the images of concern and a small amount of cost for initial investment. It is also pointed out that the format of the data recording on the disk has to be standardized so that this system could be used for a medical care system over a wide area.

Computer Systems↗

Integrated information and image management systems for the 90s.

The rising number of implementations of PACS (Picture Archiving and Communications Systems) subsystems, specialized information systems (radiology, laboratory, pharmacy, and other ancillary departments), and increased interest in the role of optical storage systems hospitalwide, creates an environment that demands the integration of each of these systems if the hospital is to operate at maximum profitability levels. This has been recognized by several groups who have proposed standards for communication between vendors and systems, and their efforts, combined with the support of the hospitals, will hopefully allow the promise of a fully electronic hospital to become a reality. While the concept of a totally integrated fully electronic hospital has been with us for over a decade, only recently have medical vendors attempted to evolve from a conceptual phase to one of workable, cost-effective systems. Few will debate the fact that the fully integrated information and image management system is still several years away, yet many hospitals have recognized the importance of planning for use of the component technology available today. This planning stage is critical and, combined with the phased implementation of the existing technologies, it can provide significant advantages in the overall acceptance of this future technology. This paper addresses the role of the standards organizations in making this integration a reality, how conceptually a fully integrated information and image management system will work, new technologies and their potential uses in the hospital, and both the advantages the technology can bring in solving existing problems and hurdles that still need to be overcome.

Computer Communication Networks↗

Regional medical information network using optical memory cards and integrated services for digital network.

Since 1986, we have been developing a regional health and welfare system using optical memory cards. We have expanded the system and performed model experiments and evaluations this time. There are approximately 3000 card-holders and 23 card-reader terminals in use. They cover 50 percent of the medical facilities in the city of Isehara. Two medical clinics within neighboring cities have joined our project. Standard Deviation Index (SDI) has been introduced to standardize the numeric results of examinations. The terminals are connected with Integrated Services for Digital Network (ISDN) allowing remote access to the optical memory cards. This enhanced connectivity has allowed greater cooperation in delivering quality medical services.

Aged↗

Analog and digital computer theory.

Analog signals abound in the natural world. With appropriate transducers these signals can be converted to continuous voltages and can be displayed, transmitted, stored, or copied. They can be processed by analog computers, the simplest of which is an audio amplifier. With analog signals, however, there can be errors because of signals loss, interference, and noise. Binary digital signals permit only two values, either 0 ('off' or 'low') or 1 ('on' or 'high'). These signals are much less susceptible to transmission problems. Binary signals are commonly organized into 8-bit groups which can represent 256 different numbers or meanings. These data can be transmitted in either serial or parallel fashion at high rates of speed. Analog-to-digital converters permit analog signals to be transformed to digital signals. A computer consists of the memory, the processor, and the input/output devices. Memory includes the fastest registers, the very fast core memory, the peripheral storage devices such as diskettes and disks, and the very slow peripheral devices such as magnetic tape. The processor can only load and store numbers in memory, add two numbers, test a number, and provide input and output. The program counter indicates the next computer instruction to be performed. Input/output devices allow communication with the outside world and may assume many forms. A computer by itself can do nothing. A program or series of instructions is required. The most simplistic program language is assembler or machine language. Most programming is done in more sophisticated languages, however.(ABSTRACT TRUNCATED AT 250 WORDS)

Analog-Digital Conversion↗

CD-ROM source data uploaded to the operating and storage devices of an IBM 3090 mainframe through a PC terminal.

A powerful method of processing MEDLINE and CINAHL source data uploaded to the IBM 3090 mainframe computer through an IBM/PC is described. Data are first downloaded from the CD-ROM's PC devices to floppy disks. These disks then are uploaded to the mainframe computer through an IBM/PC equipped with WordPerfect text editor and computer network connection (SONNGATE). Before downloading, keywords specifying the information to be accessed are typed at the FIND prompt of the CD-ROM station. The resulting abstracts are downloaded into a file called DOWNLOAD.DOC. The floppy disks containing the information are simply carried to an IBM/PC which has a terminal emulation (TELNET) connection to the university-wide computer network (SONNET) at the Ohio State University Academic Computing Services (OSU ACS). The WordPerfect (5.1) processes and saves the text into DOS format. Using the File Transfer Protocol (FTP, 130,000 bytes/s) of SONNET, the entire text containing the information obtained through the MEDLINE and CINAHL search is transferred to the remote mainframe computer for further processing. At this point, abstracts in the specified area are ready for immediate access and multiple retrieval by any PC having network switch or dial-in connection after the USER ID, PASSWORD and ACCOUNT NUMBER are specified by the user. The system provides the user an on-line, very powerful and quick method of searching for words specifying: diseases, agents, experimental methods, animals, authors, and journals in the research area downloaded. The user can also copy the TItles, AUthors and SOurce with optional parts of abstracts into papers under edition. This arrangement serves the special demands of a research laboratory by handling MEDLINE and CINAHL source data resulting after a search is performed with keywords specified for ongoing projects. Since the Ohio State University has a centrally founded mainframe system, the data upload, storage and mainframe operations are free.

CD-ROM↗

Migration from hierarchal storage management to ASM storage server: a case study.

The Department of Radiology at the University of Utah Hospitals and Clinics had to make a change from its current hierarchical storage management (HSM) system. The HSM software is the heart of any near-line data storage system and any change in this software affects all near-line and on-line data storage. In this case, over a terabyte of data had been migrated in more than 2 million files. The traditional method of reading in the old data and then writing it out to the new system was calculated to take more than 60 years. Here, we will examine the reasons for making such a radical change in the HSM used. We will also discuss why ASM (the new HSM software) was selected, and the performance improvements seen. A second, less difficult transition was made a few months later, of upgrading to a newer faster tape technology. The two types of tapes were incompatible, but the storage software and robotics used allowed for a peaceful coexistence during the transition. The transition from HSM to ASM was not a trivial task. It required a reasonable implementation/migration plan, which involved finding the correct resources and thinking outside the norm for solutions. All sites that have any amount of data stored in near-line devices will face similar conversions. This presentation should help in the event that a data conversion plan is not already in place.

Computer Systems↗