From data to knowledge through concept-oriented terminologies: experience with the Medical Entities Dictionary.
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Knowledge representation involves enumeration of conceptual symbols and arrangement of these symbols into some meaningful structure. Medical knowledge representation has traditionally focused more on the structure than the symbols. Several significant efforts are under way, at local, national, and international levels, to address the representation of the symbols though the creation of high-quality terminologies that are themselves knowledge based. This paper reviews these efforts, including the Medical Entities Dictionary (MED) in use at Columbia University and the New York Presbyterian Hospital. A decade's experience with the MED is summarized to serve as a proof-of-concept that knowledge-based terminologies can support the use of coded patient data for a variety of knowledge-based activities, including the improved understanding of patient data, the access of information sources relevant to specific patient care problems, the application of expert systems directly to the care of patients, and the discovery of new medical knowledge. The terminological knowledge in the MED has also been used successfully to support clinical application development and maintenance, including that of the MED itself. On the basis of this experience, current efforts to create standard knowledge-based terminologies appear to be justified. (+info)
Enhancing the expressiveness of structured reporting systems.
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The overall goal of this research is to build a structured reporting system that reduces the cost, delays, and inconvenience associated with conventional dictation and speech recognition systems. We have implemented such a structured reporting system for radiology that replaces current dictation and transcription processes by allowing radiologists and other imaging professionals to select imaging findings from a medical lexicon. The system uses an imaging-specific information model, called a "description set,' to organize selected terms in a relational database. Unique features of the knowledge representation that enhance its expressiveness include its ability to codify uncertainty about an imaging observation and to represent explicitly the logical relationships among imaging findings. In addition, the system does not require the user to fill in "blanks' in a static text template. Instead, it allows entry of terms in arbitrary order and uses automated text-generation techniques to create a text report that referring physicians are accustomed to receiving. In parallel, the system also produces a multimedia report that the referring physician can use as a quick reference. Unlike the results of conventional dictation or speech recognition, each finding is coded in a relational database for later information processing. Thus, the structured report database can be used to index images by content, to provide real-time decision support, to enhance radiologists' performance, to conduct exploratory clinical research, and to transmit imaging report data to computer-based patient record systems. (+info)
Common object request broker architecture (CORBA)-based security services for the virtual radiology environment.
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The US Army Great Plains Regional Medical Command (GPRMC) has a requirement to conform to Department of Defense (DoD) and Army security policies for the Virtual Radiology Environment (VRE) Project. Within the DoD, security policy is defined as the set of laws, rules, and practices that regulate how an organization manages, protects, and distributes sensitive information. Security policy in the DoD is described by the Trusted Computer System Evaluation Criteria (TCSEC), Army Regulation (AR) 380-19, Defense Information Infrastructure Common Operating Environment (DII COE), Military Health Services System Automated Information Systems Security Policy Manual, and National Computer Security Center-TG-005, "Trusted Network Interpretation." These documents were used to develop a security policy that defines information protection requirements that are made with respect to those laws, rules, and practices that are required to protect the information stored and processed in the VRE Project. The goal of the security policy is to provide for a C2-level of information protection while also satisfying the functional needs of the GPRMC's user community. This report summarizes the security policy for the VRE and defines the CORBA security services that satisfy the policy. In the VRE, the information to be protected is embedded into three major information components: (1) Patient information consists of Digital Imaging and Communications in Medicine (DICOM)-formatted fields. The patient information resides in the digital imaging network picture archiving and communication system (DIN-PACS) networks in the database archive systems and includes (a) patient demographics; (b) patient images from x-ray, computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound (US); and (c) prior patient images and related patient history. (2) Meta-Manager information to be protected consists of several data objects. This information is distributed to the Meta-Manager nodes and includes (a) radiologist schedules; (b) modality worklists; (c) routed case information; (d) DIN-PACS and Composite Health Care system (CHCS) messages, and Meta-Manager administrative and security information; and (e) patient case information. (3) Access control and communications security is required in the VRE to control who uses the VRE and Meta-Manager facilities and to secure the messages between VRE components. The CORBA Security Service Specification version 1.5 is designed to allow up to TCSEC's B2-level security for distributed objects. The CORBA Security Service Specification defines the functionality of several security features: identification and authentication, authorization and access control, security auditing, communication security, nonrepudiation, and security administration. This report describes the enhanced security features for the VRE and their implementation using commercial CORBA Security Service software products. (+info)
Advanced applications of MRI in human brain science.
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Magnetic resonance imaging of the brain is now generally indispensable to state of art clinical medicine. Robust, high resolution imaging systems are currently available worldwide. The availability of MRI has, in little more than a decade, revolutionized the certainty and efficiency of clinical diagnosis and management. As a dividend of this revolution, clinicians and radiologists who are expert in the many and varied applications of MRI methods are able to relate this expertise to a confident mastery of the topographic anatomy of the brain as revealed in magnetic resonance images. Whereas the yield to clinical objectives has been massive, the clinician as yet draws upon a relatively limited sampling of the potential informational harvest from this technology which in theory could further enrich both clinical concerns and those of fundamental neuroscience. Here we will review early explorations into these other offerings with the expectation that the coming decade will see them established comfortably with current uses. We will also consider potential offerings of the extended applications of brain MRI to the characterization and insights into biological origins of certain obscure developmental disorders. (+info)
Remote access to anatomical information: an integration between semantic knowledge and visual data.
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A novel internet-based application is presented which provides access to anatomy knowledge through symbolic modality expressed by keywords taken from controlled or non-controlled terminology. The system is based on a database where anatomical concepts have been organized into a hierarchical framework. Along with term queries that allow retrieving concepts containing or exactly matching the used keyword, the system also provides semantic access to anatomical information. Queries can be setup, which retrieve concepts relying to a particular meaning and sharing a particular relationship. Moreover, the application has the capability to refine the search of the terms by querying the UMLS knowledge server. Anatomical image data have been integrated by using Visible Human Dataset. A set of these images has been indexed according to our anatomical classification and is used inside the application. The system has been implemented through Java client-server technology and works within standard Internet browsers. (+info)
Models to predict cardiovascular risk: comparison of CART, multilayer perceptron and logistic regression.
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The estimate of a multivariate risk is now required in guidelines for cardiovascular prevention. Limitations of existing statistical risk models lead to explore machine-learning methods. This study evaluates the implementation and performance of a decision tree (CART) and a multilayer perceptron (MLP) to predict cardiovascular risk from real data. The study population was randomly splitted in a learning set (n = 10,296) and a test set (n = 5,148). CART and the MLP were implemented at their best performance on the learning set and applied on the test set and compared to a logistic model. Implementation, explicative and discriminative performance criteria are considered, based on ROC analysis. Areas under ROC curves and their 95% confidence interval are 0.78 (0.75-0.81), 0.78 (0.75-0.80) and 0.76 (0.73-0.79) respectively for logistic regression, MLP and CART. Given their implementation and explicative characteristics, these methods can complement existing statistical models and contribute to the interpretation of risk. (+info)
An ontological approach for the development of shareable guidelines.
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Computer-based clinical guidelines and protocols are being increasingly applied in diverse areas. Although there is still little standardization to facilitate sharing, various parties are engaged in the development of shareable guideline representation formalisms and corresponding decision support systems. This paper mentions some of these developed representations, discusses their pros en cons, and demonstrates and discusses a new approach, which combines common elements from earlier-developed formalisms with new ones to improve the reusability and shareability of developed guidelines. An ontological representation is presented that formalizes guidelines in terms of domain-specific knowledge and employed generic strategies that use this domain-specific knowledge in order to solve particular guideline tasks. Furthermore, a framework is described that supports this representation and three examples are shown of guidelines of various granularity and complexity that were developed by means of this approach. (+info)
Comparison of two knowledge bases on the detection of drug-drug interactions.
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This paper describes a drug ordering decision support system that helps with the prevention of adverse drug events by detecting drug-drug interactions in drug orders. The architecture of the system was devised in order to facilitate its use attached to physician order entry systems. The described model focuses in issues related to knowledge base maintenance and integration with external systems. Finally, a retrospective study was performed. Two knowledge bases, developed by different academic centers, were used to detect drug-drug interactions in a dataset with 37,237 drug prescriptions. The study concludes that the proposed knowledge base architecture enables content from other knowledge sources to be easily transferred and adapted to its structure. The study also suggests a method that can be used on the evaluation and refinement of the content of drug knowledge bases. (+info)