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Computed tomography is the essential examination in patients with severe manifestations of neurological disorders. We discuss emergency situations involving the central nervous system due to vascular and infections lesions. Trauma and acute complications of brain tumours, usually seen within a neurosurgical context, are not discussed here.
A description is given of a computer-based system for electrocardiogram and vectorcardiogram analysis. Its main purpose is to provide a basic research and study tool of the variability occurring in electrocardiographic activity when the observation time is of the order of 30 min. System/operator interaction is designed to allow the user to validate or correct the identifications executed by the program. Special attention is given to graphic representation techniques suitable for synthesizing a great many numerical results. Data acquisition and analysis are performed by two different PDP 11 systems. The acquisition programs are written in ASSEMBLER, the analysis programs are in FORTRAN. Intermediate files are structured by a data compression technique. At present the program is oriented to study normal subjects. A new version to study bundle-branch blocks is now available.
A computer-based quantitative angiography system for the acquisition and analysis of ventriculographic data has been developed. In addition to the apparatus normally required for angiography and left ventricular pressure recording, a digitizing tablet, PDP 11/20 mini computer, and TV monitor with a hard-copy device is employed. Four modes of operation are currently in use: data acquisition, analysis, mini cine, and data tape editor. Data acquisition facilitates forming a magnetic tape record of the digitized pressure, timing, and event identification, together with anywhere from 4 to 100 digitilized LV contours. A number of error checks and feedbacks are incorporated to provide some measure of quality control. In the event an error is written onto the magnetic tape record, the data tape editor can be used to review the record and correct most errors. Analysis of the generated data tape consists of several options which include: pump function, muscle function, pressure derived indices of contractility and systolic time intervals, and contour pattern recognition which is still under development. If the complete analysis option is chosen, a summary of the analysis, referred to as the quick-sight list, is also presented. The so called mini cine option employs a separate and independent acquisition-analysis program. This requires only the end-diastolic (with a segment of wall) and end-systolic contours (without pressure data) to extract the most essential parameters (EDV, EF, CI, HR, and wall mass). As a result of the relative straightforward processing and inherent simplicity, the mini cine option is most frequently used. This system has done much to reduce the time required for analysis of angiographic data, while at the same time maintaining and even improving the quality of the results. Other less tangible benefits include: the possibility to build a readily accessible library of patient data files facilitating a posteriori studies, precise and uniform definition of the rules to input and analyze data, and finally providing a useful step towards fully automatic ventriculographic processing.
In the Centre of Diabetes and Metabolic Disorders of Berlin, G.D.R., a computer-aided care system has been used since 1974, aiming at relieving physicians and medical staff from routine tasks and rendering possible epidemiological research on an unselected diabetes population of a defined area. The basis of the system is the data bank on diabetics (DB), where at present data from approximately 55,000 patients are stored. DB is used as a diabetes register of Berlin. On the basis of standardised criteria of diagnosis and therapy of diabetes mellitus in our dispensary care system, DB facilitates representative epidemiological analyses of the diabetic population, e.g. prevalence, incidence, duration of diabetes, and modes of treatment. The availability of general data on the population or the selection of specified groups of patients serves the management of the care system. Also, it supports the computer-aided recall of type II diabetics, treated either with diet alone or with diet and oral drugs. In this way, the standardised evaluation of treatment strategies in large populations of diabetics is possible on the basis of uniform metabolic criteria (blood glucose plus urinary glucose). The system consists of a main computer in the data processing unit and of personal computers in the diabetes centre which can be used either individually or as terminals to the main computer. During 14 years of experience, the computer-aided out-patient care of type II diabetics has proved efficient in a big-city area with a large population.
Computed tomography (CT), including biphasic contrast material-enhanced helical dynamic scanning and three-dimensional CT angiography, is useful in evaluating acquired abnormalities of the portal venous system. At contrast-enhanced CT, portal venous thrombus usually manifests as low-attenuation intraluminal lesions combined with enlargement of the affected portal vein. Cavernous transformation, a masslike network of intertwined veins that provides an alternative pathway for a stenosed or occluded portal vein, is depicted as multiple, periportal vascular structures. At helical dynamic CT, arterioportal shunts manifest as early enhancement of the affected portal vein, transient hyperperfusion abnormalities with lobar or segmental distribution, or transient wedge-shaped enhancement peripheral to the tumor. In patients with portosplenic venous invasion by malignant neoplasms, peripancreatic or perigastric veins may dilate if they function as hepatopetal collateral veins. In patients with portal hypertension, a variety of hepatofugal collateral pathways can develop, including esophageal, paraesophageal, coronary gastric, inferior phrenic, paraumbilical, abdominal wall, splenorenal, gastrorenal, retrocaval, and mesocaval collateral pathways. An understanding of the varied CT appearances of acquired abnormalities of the portal venous system will allow more definitive diagnosis and help avoid false diagnosis of disease.
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Recommended methods to test the performance of computed radiography (CR) digital radiographic systems have been recently developed by the AAPM Task Group No. 10. Included are tests for dark noise, uniformity, exposure response, laser beam function, spatial resolution, low-contrast resolution, spatial accuracy, erasure thoroughness, and throughput. The recommendations may be used for acceptance testing of new CR devices as well as routine performance evaluation checks of devices in clinical use. The purpose of this short communication is to provide a tabular summary of the tests recommended by the AAPM Task Group, delineate the technical aspects of the tests, suggest quantitative measures of the performance results, and recommend uniform quantitative criteria for the satisfactory performance of CR devices. The applicability of the acceptance criteria is verified by tests performed on CR systems in clinical use at five different institutions. This paper further clarifies the recommendations with respect to the beam filtration to be used for exposure calibration of the system, and the calibration of automatic exposure control systems.
A multiple computer system and implantable biotelemetry permit on-line monitoring of physiological data while observational data is collected on social group living unrestrained monkey infants in studies of the physiological correlates of behavior. Experimental data may be collected for up to 40 days on each experimental animal, with statistical data presented as the experiment progresses. Data are used to describe normal baseline and various experimentally induced changes in biological and behavioral variables.
Modern technology offers new opportunities for the storage and manipulation of hospital information. A computer-based system for urology and nephrology has been designed and developed in this centre. It uses a program that allows the analysis of unrestricted non-codified texts and the operation by hospital staff who have had no more than minimal computer training. The potential of such a system is outlined and a comparison is made with other existing systems. Future prospects and potential lines of development are presented.
A system based on a personal computer has been developed which provides a relatively inexpensive way to equip an electron microscopy laboratory for quantitative elemental analyses of cryosectioned biological samples. This system demonstrates the feasibility of making an X-ray analyser from a personal computer, together with commercially available hardware and software components. Hardware and software have been assembled to drive the beam in a scanning electron microscope, collect and analyse X-ray spectra, and save, retrieve, and analyse data. Our software provides a menu-controlled user interface to direct spectra acquisition and analysis. Spot analyses, video images, and quantitative elemental images may be obtained and results transferred in ASCII format to other computers. Wet weight, as well as dry weight, concentrations are calculated, if measurements were made of areas of the hydrated sample before it was freeze-dried. Grey-level copies of video and quantitative elemental images may be made on a laser printer.
An interactive computer graphic system has been developed for 3-D reconstruction of stained serial sections. The system has been used for 3-D reconstruction of portions of mouse lung containing melanoma nodules. A stereoscopic color picture of a wire model of the reconstructed object is produced. The volume, surface area, and sphericity index of structures such as tumor nodules can be computed.
One hundred consecutive cases of primary rhinoplasty were planned with a computer imaging system. All the preoperative and one-year postoperative profile pictures were discussed with the patients. Not one patient complained that the planned result was not achieved, and all patients considered the postoperative picture identical to the planned preoperative screen picture. To analyze the results better, a comparison between computer screen and postoperative profile lines was made. Two orthographic negatives were made: one of the picture from the computer screen, the other from the slide one year after rhinoplasty. The negatives are of the same proportions, i.e., the distance between eye and mouth is the same. The negatives were converted into line drawings using a photographic process called solarization. The two resulting lines were superimposed to produce the final picture. The differences in position of other features of the face are due to different positions of mouth, head, hair, and expression or slide changes in the camera angle. Using a computer to plan rhinoplasty allows the surgeon to eliminate patients with unrealistic expectations, to analyze the patients' wishes better, and to plan the operation more accurately.
OBJECTIVES: Surveillance of surgical site infections (SSIs) is effective in reducing the rates of these complications, but it is extremely time-consuming and, consequently, underused. We determined the sensitivity and specificity of a computer-assisted surveillance system, compared with a conventional method involving review of medical records, and the time saved with the computer-assisted system. METHOD: A prospective study was conducted from January 1 to December 31, 2001. With the computer-assisted method, screening for SSIs relied on identification in the laboratory database of positive results of microbiological tests of surgical-site specimens; confirmation was obtained via computer-generated questionnaires completed by the surgeon in charge of the patient. In the conventional method, SSIs were identified by exhaustive chart review. The time spent on surveillance was recorded for both methods. SETTING: A 25-bed gastrointestinal surgery unit in a tertiary care hospital. PATIENTS: A total of 766 consecutive patients who underwent gastrointestinal surgery. RESULTS: The sensitivity of the computer-assisted method was 84.3% (95% confidence interval, 0.66-0.94); the specificity was 99.9%. For the 807 surgical procedures in the study, 197 had an SSI identified by culture of a surgical-site specimen. After elimination of 63 duplicate cultures with positive results, 134 questionnaires were sent to the surgeons, who confirmed 27 SSIs. The conventional method identified 32 SSIs. The computer-assisted method required 60% less time than the conventional method (90 hours vs 223 hours). CONCLUSION: Surveillance for SSIs using computer-assisted, laboratory-based screening and case confirmation by surgeons is as efficient as and far less time-consuming than the conventional method of chart review. This method permits routine surveillance for SSIs with reliable accuracy.
CONTEXT: Adverse drug events (ADEs) are the most common type of iatrogenic injury occurring in hospitalized patients. Errors leading to ADEs are often due to restricted availability of information at the time of physician order writing. OBJECTIVES: To develop, implement, and evaluate a computer alert system designed to correct errors that might lead to ADEs and to detect ADEs before maximum injury occurs. DESIGN: Prospective case series. SETTING: A 650-bed community teaching hospital in Phoenix, Ariz. PATIENTS: Consecutive sample of 9306 nonobstetrical adult patients admitted during the last 6 months of 1997. INTERVENTIONS: Thirty-seven drug-specific ADEs were targeted. Our hospital information system was programmed to generate alerts in clinical situations with increased risk for ADE-related injury. A clinical system was developed to ensure physician notification of alerts. MAIN OUTCOME MEASURES: A true-positive alert was defined as one in which the physician wrote orders consistent with the alert recommendation after alert notification. RESULTS: During the 6-month study period, the alert system fired 1116 times and 596 were true-positive alerts (positive predictive value of 53%). The alerts identified opportunities to prevent patient injury secondary to ADEs at a rate of 64 per 1000 admissions. A total of 265 (44%) of the 596 true-positive alerts were unrecognized by the physician prior to alert notification. CONCLUSIONS: Clinicians can use hospital information systems to detect opportunities to prevent patient injury secondary to a broad range of ADEs.
This report describes a computer filing and retrieval system for patient records of uterine cervix cancer which contain a secondary status after first treatment necessitated by residual primary tumor, recurrence after 6 months or more, and metastasis. In 2 working sheets are entered registration number and birth-data, first therapy method, secondary status, topographic locations of recurrence and metastasis, policy and outcome at 5 years after secondary treatment. This information was entered in the computer filing system. The records of 549 patients who were treated between 1961 and 1976, were loaded in to the disk file and magnetic tape of our computer. The 5-year cumulative survival rate of the total cases was 11.7% (1.4% standard error); it was 26.9% (S.E. = 4.4%) for patients that had undergone primary surgery. We found that the longer the interval between first therapy and recurrence, the better was the 5-year survival after secondary treatment (mainly radiotherapy). We conclude that long-term follow-up study is important in patients with uterine cervix cancer, because our 28 cases with recurrence (10% of total cases), were found more than 4-years after the first therapy.
We report a method for computer enhancement of color vision tests. In our graphics system 256 colors are selected from a much larger range and displayed on a screen divided into 768 x 288 pixels. Eight-bit digital-to-analogue converters drive a high quality monitor with separate inputs to the red, green, and blue amplifiers and calibrated gun chromaticities. The graphics are controlled by a PASCAL program written for a personal computer, which calculates the values of the red, green, and blue signals and specifies them in Commité Internationale d'Eclairage X, Y, and Z fundamentals, so changes in chrominance occur without changes in luminance. The system for measuring color contrast thresholds with gratings is more than adequate in normal observers. In patients with mild retinal damage in whom other tests of visual function are normal, this method of testing color vision shows specific increases in contrast thresholds along tritan color-confusion lines. By the time the Hardy-Rand-Rittler and Farnsworth-Munsell 100-hue tests disclose abnormalities, gross defects in color contrast threshold can be seen with our system.
An electronic interface, imagamma, has been designed in order to link analog gamma cameras to IBM personal computers (PCs). The performance of the interface was assessed for a camera-computer system composed by a GE Maxicamera II-400T gamma camera and an IBM PC, which has a DX 80486 processor, 8 Mb RAM and a suitable acquisition and processing software. Quality control tests for gamma camera-computer systems, established by the International Atomic Energy Agency in the IAEA-TECDOC-602 for < >, were performed. The main performance characteristics of the gamma camera: intrinsic flood field uniformity, intrinsic spatial resolution and spatial linearity were tested as well as the system time performance for dynamic and gated studies. The results obtained for the camera-computer system performance parameters show a good stability. Those results concerning the dynamic characteristics of the interface are between the limits of acceptability, established for each test by the IAEA standards. We conclude that the imagamma interface has suitable performance characteristics to link analog gamma cameras to PC based computer systems in order to be used with clinical application purposes.
OBJECTIVE: For fetal monitoring and assessment of high risk mother and fetus at regional hospitals, we developed a new computer network system. METHODS: The system incorporates a notebook-type personal computer (PC-9801nv) at regional hospital for communication in with 3 servers (IBM5580-YOC) connected via 2 Ethernet LANs to 2 host computers (IBM3080, IBM3174) and 5 workstations (IBM5521 V2b), and transmits the compressed data by telephone. When the data arrive, the doctor in perinatal center can immediately display and interpret the data on his workstation and give appropriate advice to the doctor at the regional hospital. RESULTS: The rate of reliable data transmission was 100%. Each 1 hour recording session and characteristic perinatal information was transmitted in less than 2 minutes. Regional medical institutions can easily access the center, and thereby can receive both simplified automatic diagnosis by fetal cardiotocography and pregnancy-risk evaluation. CONCLUSIONS: Because this system uses telephone circuits, it can be accessed from all regions of the country. Thus, our system is useful for perinatal management of high risk mother and fetus.