Bio

Bio


Dr. Langlotz is responsible for the information technology that supports Stanford’s radiology practice, including 4.5 million imaging studies that require 0.5 petabytes of storage. His research laboratory investigates the use of deep neural networks and other machine learning technologies to help radiologists detect disease and eliminate diagnostic errors. His laboratory’s translational approach facilitates rapid evaluation and dissemination of the resulting algorithms.

He has led many recent national and international efforts to improve the quality of radiology communication, including the RadLex™ terminology standard, the RadLex™ Playbook of radiology exam codes, the RSNA report template library, and a technical standard for communication of radiology templates. He has published over 100 scholarly articles, and is author of the recent book “The Radiology Report: A Guide to Thoughtful Communication for Radiologists and Other Medical Professionals”.

Raised in St. Paul, Minnesota, Dr. Langlotz received his undergraduate degree in Human Biology, masters in Computer Science, MD in Medicine, and PhD in Medical Information Science, all from Stanford University. He is a founder and past president of the Radiology Alliance for Health Services Research, served as chair of the Society for Imaging Informatics in Medicine (SIIM), and as a board member of the American Medical Informatics Association and the Association of University Radiologists. He is a fellow of the American College of Medical Informatics and currently serves as president of the College of SIIM Fellows and as a board member of the Radiological Society of North America.

He is a recipient of the Lee B. Lusted Research Prize from the Society of Medical Decision Making and the Career Achievement Award from the Radiology Alliance for Health Services Research. He has founded three healthcare information technology companies, most recently Montage Healthcare Solutions, which was acquired by Nuance Communications in 2016.

Clinical Focus


  • Diagnostic Radiology

Academic Appointments


Administrative Appointments


  • Medical Informatics Director for Radiology, Stanford Health Care (2014 - Present)
  • Associate Chair for Information Systems, Department of Radiology (2014 - Present)

Honors & Awards


  • Lee B. Lusted Research Prize, Society for Medical Decision Making (1986)
  • GERRAF Career Development Award, Association of University Radiologists (1993)
  • Best Information Technology Company, New Jersey Technology Council (2001)
  • Fellow, American College of Medical Informatics (2008)
  • Fellow, Society for Imaging Informatics in Medicine (2010)
  • Career Achievement Award, Radiology Alliance for Health Services Research (2017)

Boards, Advisory Committees, Professional Organizations


  • Board of Directors, Radiological Society of North America (2016 - Present)
  • President, College of Imaging Informatics Fellows (2015 - Present)
  • Editorial Board, Pennsylvania Patient Safety Advisory (2008 - Present)
  • President, Society for Imaging Informatics in Medicine (2006 - 2008)
  • Board of Directors, Association for University Radiologists (2003 - 2010)
  • Founder and President, Radiology Alliance for Health Services Research (2002 - 2004)
  • Editorial Board, Journal of Biomedical Informatics (2000 - 2012)
  • Associate Editor (Biomedical Informatics), Academic Radiology (1997 - 2005)
  • Associate Editor (Health Policy and Practice), Radiology (1997 - 2000)
  • Board of Trustees, Society for Medical Decision Making (1996 - 1998)

Professional Education


  • AB, Stanford University, Human Biology (1981)
  • MS, Stanford University, Computer Science: Artificial Intelligence (1983)
  • MD, Stanford University, Medicine (1989)
  • Medical Education:Stanford University, Medical School Registrar (1989) CA
  • PhD, Stanford University, Medical Information Sciences (1989)
  • Internship:Hospital of the University of PennsylvaniaPA
  • Residency:Hospital of the University of Pennsylvania, Department of RadiologyPA
  • Board Certification: Diagnostic Radiology, American Board of Radiology (1994)

Patents


  • Curtis Langlotz. "United States Patent 6,366,683 Apparatus and Method for Recording Image Analysis Information", Radiological Society of North America, Apr 2, 2002

Research & Scholarship

Current Research and Scholarly Interests


My laboratory employs deep neural networks and other machine learning technologies to design algorithms that detect and classify disease on medical images. We also develop natural language processing methods that use narrative radiology reports to create large annotated image training sets for supervised machine learning experiments. The resulting systems provide real-time decision support for radiologists to improve accuracy and reduce errors. We are committed to enabling the clinical use of ideas conceived in the laboratory. When our results show potential, we evaluate their utility in the reading room or the clinic and disseminate them as open source or commercial software.

Teaching

2016-17 Courses


Graduate and Fellowship Programs


Publications

All Publications


  • Performance of a Machine Learning Classifier of Knee MRI Reports in Two Large Academic Radiology Practices: A Tool to Estimate Diagnostic Yield. AJR. American journal of roentgenology Hassanpour, S., Langlotz, C. P., Amrhein, T. J., Befera, N. T., Lungren, M. P. 2017: 1–4

    Abstract

    The purpose of this study is to evaluate the performance of a natural language processing (NLP) system in classifying a database of free-text knee MRI reports at two separate academic radiology practices.An NLP system that uses terms and patterns in manually classified narrative knee MRI reports was constructed. The NLP system was trained and tested on expert-classified knee MRI reports from two major health care organizations. Radiology reports were modeled in the training set as vectors, and a support vector machine framework was used to train the classifier. A separate test set from each organization was used to evaluate the performance of the system. We evaluated the performance of the system both within and across organizations. Standard evaluation metrics, such as accuracy, precision, recall, and F1 score (i.e., the weighted average of the precision and recall), and their respective 95% CIs were used to measure the efficacy of our classification system.The accuracy for radiology reports that belonged to the model's clinically significant concept classes after training data from the same institution was good, yielding an F1 score greater than 90% (95% CI, 84.6-97.3%). Performance of the classifier on cross-institutional application without institution-specific training data yielded F1 scores of 77.6% (95% CI, 69.5-85.7%) and 90.2% (95% CI, 84.5-95.9%) at the two organizations studied.The results show excellent accuracy by the NLP machine learning classifier in classifying free-text knee MRI reports, supporting the institution-independent reproducibility of knee MRI report classification. Furthermore, the machine learning classifier performed well on free-text knee MRI reports from another institution. These data support the feasibility of multiinstitutional classification of radiologic imaging text reports with a single machine learning classifier without requiring institution-specific training data.

    View details for DOI 10.2214/AJR.16.16128

    View details for PubMedID 28140627

  • JOURNAL CLUB: Predictors of Provider Response to Clinical Decision Support: Lessons Learned From the Medicare Imaging Demonstration. AJR. American journal of roentgenology Ip, I. K., Lacson, R., Hentel, K., Malhotra, S., Darer, J., Langlotz, C., Weiss, J., Raja, A. S., Khorasani, R. 2017; 208 (2): 351–57

    Abstract

    The efficacy of imaging clinical decision support (CDS) varies. Our objective was to identify CDS factors contributing to imaging order cancellation or modification.This pre-post study was performed across four institutions participating in the Medicare Imaging Demonstration. The intervention was CDS at order entry for selected outpatient imaging procedures. On the basis of the information entered, computerized alerts indicated to providers whether orders were not covered by guidelines, appropriate, of uncertain appropriateness, or inappropriate according to professional society guidelines. Ordering providers could override or accept CDS. We considered actionable alerts to be those that could generate an immediate order behavior change in the ordering physician (i.e., cancellation of inappropriate orders or modification of orders of uncertain appropriateness that had a recommended alternative). Chi-square and logistic regression identified predictors of order cancellation or modification after an alert.A total of 98,894 radiology orders were entered (83,114 after the intervention). Providers ignored 98.9%, modified 1.1%, and cancelled 0.03% of orders in response to alerts. Actionable alerts had a 10 fold higher rate of modification (8.1% vs 0.7%; p < 0.0001) or cancellation (0.2% vs 0.02%; p < 0.0001) orders compared with nonactionable alerts. Orders from institutions with preexisting imaging CDS had a sevenfold lower rate of cancellation or modification than was seen at sites with newly implemented CDS (1.4% vs 0.2%; p < 0.0001). In multivariate analysis, actionable alerts were 12 times more likely to result in order cancellation or modification. Orders at sites with preexisting CDS were 7.7 times less likely to be cancelled or modified (p < 0.0001).Using results from the Medicare Imaging Demonstration project, we identified potential factors that were associated with CDS effect on provider imaging ordering; these findings may have implications for future design of such computerized systems.

    View details for DOI 10.2214/AJR.16.16373

    View details for PubMedID 27897445

  • Implications of Direct Patient Online Access to Radiology Reports Through Patient Web Portals. Journal of the American College of Radiology : JACR Lee, C. I., Langlotz, C. P., Elmore, J. G. 2016; 13 (12 Pt B): 1608–14

    Abstract

    In an era of increasing health information transparency and informed decision making, more patients are being provided with direct online access to their medical records, including radiology reports, via web-based portals. Although radiologists' narrative reports have previously been the purview of referring physicians, patients are now reading these on their own. Many potential benefits may result from patients reviewing their radiology reports, including improvements in patients' own understanding of their health, promotion of shared decision making and patient-physician communication, and, ultimately, improvements in patient outcomes. However, there may also be negative consequences, including confusion and anxiety among patients and longer patient-physician interactions. The rapid adoption of this new technology has led to major questions regarding ethics and professionalism for radiologists, including the following: Who is the intended audience of radiology reports? How should content be presented or worded? How will open access influence radiologists' relationships with patients and referring physicians? What legal ramifications may arise from increased patient access? The authors describe the current practices and research findings associated with patient online access to medical records, including radiology reports, and discuss several implications of this growing trend for the radiology profession.

    View details for DOI 10.1016/j.jacr.2016.09.007

    View details for PubMedID 27888949

  • Information extraction from multi-institutional radiology reports ARTIFICIAL INTELLIGENCE IN MEDICINE Hassanpour, S., Langlotz, C. P. 2016; 66: 29-39

    Abstract

    The radiology report is the most important source of clinical imaging information. It documents critical information about the patient's health and the radiologist's interpretation of medical findings. It also communicates information to the referring physicians and records that information for future clinical and research use. Although efforts to structure some radiology report information through predefined templates are beginning to bear fruit, a large portion of radiology report information is entered in free text. The free text format is a major obstacle for rapid extraction and subsequent use of information by clinicians, researchers, and healthcare information systems. This difficulty is due to the ambiguity and subtlety of natural language, complexity of described images, and variations among different radiologists and healthcare organizations. As a result, radiology reports are used only once by the clinician who ordered the study and rarely are used again for research and data mining. In this work, machine learning techniques and a large multi-institutional radiology report repository are used to extract the semantics of the radiology report and overcome the barriers to the re-use of radiology report information in clinical research and other healthcare applications.We describe a machine learning system to annotate radiology reports and extract report contents according to an information model. This information model covers the majority of clinically significant contents in radiology reports and is applicable to a wide variety of radiology study types. Our automated approach uses discriminative sequence classifiers for named-entity recognition to extract and organize clinically significant terms and phrases consistent with the information model. We evaluated our information extraction system on 150 radiology reports from three major healthcare organizations and compared its results to a commonly used non-machine learning information extraction method. We also evaluated the generalizability of our approach across different organizations by training and testing our system on data from different organizations.Our results show the efficacy of our machine learning approach in extracting the information model's elements (10-fold cross-validation average performance: precision: 87%, recall: 84%, F1 score: 85%) and its superiority and generalizability compared to the common non-machine learning approach (p-value<0.05).Our machine learning information extraction approach provides an effective automatic method to annotate and extract clinically significant information from a large collection of free text radiology reports. This information extraction system can help clinicians better understand the radiology reports and prioritize their review process. In addition, the extracted information can be used by researchers to link radiology reports to information from other data sources such as electronic health records and the patient's genome. Extracted information also can facilitate disease surveillance, real-time clinical decision support for the radiologist, and content-based image retrieval.

    View details for DOI 10.1016/j.artmed.2015.09.007

    View details for Web of Science ID 000371368900003

    View details for PubMedID 26481140

  • Code Abdomen: An Assessment Coding Scheme for Abdominal Imaging Findings Possibly Representing Cancer. Journal of the American College of Radiology : JACR Zafar, H. M., Chadalavada, S. C., Kahn, C. E., Cook, T. S., Sloan, C. E., Lalevic, D., Langlotz, C. P., Schnall, M. D. 2015

    View details for DOI 10.1016/j.jacr.2015.04.005

    View details for PubMedID 26130223

  • Documentation of nonroutine communications of critical or significant radiology results: a multiyear experience at a tertiary hospital. Journal of the American College of Radiology Lakhani, P., Langlotz, C. P. 2010; 7 (10): 782-790

    Abstract

    The aim of this study was to determine the frequency of radiology reports that contain nonroutine communications of results and categorize the urgency of such communications.A rule-based text-query algorithm was applied to a database of 2.3 million radiology reports, which has an accuracy of 98% for classifying reports containing documentation of communications. The frequency of such communications by year, modality, and study type was then determined. Finally, 200 random reports selected by the algorithm were analyzed, and reports containing critical results were categorized according to ascending levels of urgency.Critical or noncritical results to health care providers were present in 5.09% of radiology reports (116,184 of 2,282,923). For common modalities, documentation of communications were most frequent in CT (14.34% [57,537 of 402,060]), followed by ultrasound (9.55% [17,814 of 186,626]), MRI (5.50% [13,697 of 248,833]), and chest radiography (1.57% [19,840 of 1,262,925]). From 1997 to 2005, there was an increase in reports containing such communications (3.04% in 1997, 6.82% in 2005). More reports contained nonroutine communications in single-view chest radiography (1.29% [5,533 of 428,377]) than frontal/lateral chest radiography (0.80% [1,815 of 226,837]), diagnostic mammography (9.42% [3,662 of 38,877]) than screening mammography (0.47% [289 of 61,114]), and head CT (26.21% [20,963 of 79,985]) than abdominal CT (15.05% [19,871 of 132,034]) or chest CT (5.33% [3,017 of 56,613]). All of these results were statistically significant (P < .00001). Of 200 random radiology reports indicating nonroutine communications, 155 (78%) had critical and 45 (22%) had noncritical results. Regarding level of urgency, 94 of 155 reports (60.6%) with critical results were categorized as high urgency, 31 (20.0%) as low urgency, 26 (16.8%) as medium urgency, and 4 (2.6%) as discrepant.From 1997 to 2005, there was a significant increase in documentation of nonroutine communications, which may be due to increasing compliance with ACR guidelines. Most reports with nonroutine communications contain critical findings.

    View details for DOI 10.1016/j.jacr.2010.05.025

    View details for PubMedID 20889108

  • ACR BI-RADS for breast imaging communication: a roadmap for the rest of radiology. Journal of the American College of Radiology Langlotz, C. P. 2009; 6 (12): 861-863

    View details for DOI 10.1016/j.jacr.2009.09.015

    View details for PubMedID 19945041

  • Structured Radiology Reporting: Are We There Yet? RADIOLOGY Langlotz, C. P. 2009; 253 (1): 23-25

    View details for DOI 10.1148/radiol.2531091088

    View details for Web of Science ID 000271275200005

    View details for PubMedID 19789252

  • Toward Best Practices in Radiology Reporting RADIOLOGY Kahn, C. E., Langlotz, C. P., Burnside, E. S., Carrino, J. A., Channin, D. S., Hovsepian, D. M., Rubin, D. L. 2009; 252 (3): 852-856

    Abstract

    The goals and current efforts of the Radiological Society of North America Radiology Reporting Committee are described. The committee's charter provides an opportunity to improve the organization, content, readability, and usefulness of the radiology report and to advance the efficiency and effectiveness of the reporting process.

    View details for DOI 10.1148/radiol.2523081992

    View details for Web of Science ID 000270809500028

    View details for PubMedID 19717755

  • The radiology report of the future: a summary of the 2007 Intersociety Conference. Journal of the American College of Radiology Dunnick, N. R., Langlotz, C. P. 2008; 5 (5): 626-629

    Abstract

    A radiology report is the official record documenting the contribution of a radiologist to a patient's care. The use of structured reports and a common lexicon will help referring physicians better understand the contents of reports. These same features in electronic health records will enable radiologists to mine reports for utilization management information as well as form the basis for clinical investigations.

    View details for DOI 10.1016/j.jacr.2007.12.015

    View details for PubMedID 18442766

  • From the chair: The top 10 myths about imaging informatics certification (January 2008-SIIM news) JOURNAL OF DIGITAL IMAGING Langlotz, C. 2008; 21 (1): 1-2

    View details for DOI 10.1007/s10278-007-9100-1

    View details for Web of Science ID 000253626200001

    View details for PubMedID 18213485

  • Fundamental measures of diagnostic examination performance: Usefulness for clinical decision making and research RADIOLOGY Langlotz, C. P. 2003; 228 (1): 3-9

    Abstract

    Measures of diagnostic accuracy, such as sensitivity, specificity, predictive values, and receiver operating characteristic curves, can often seem like abstract mathematic concepts that have a minimal relationship with clinical decision making or clinical research. The purpose of this article is to provide definitions and examples of these concepts that illustrate their usefulness in specific clinical decision-making tasks. In particular, nine principles are provided to guide the use of these concepts in daily radiology practice, in interpreting clinical literature, and in designing clinical research studies. An understanding of these principles and of the measures of diagnostic accuracy to which they apply is vital to the appropriate evaluation and use of diagnostic imaging examinations.

    View details for DOI 10.1148/radiol.2281011106

    View details for Web of Science ID 000183689700001

    View details for PubMedID 12832567

  • Incremental cost of department-wide implementation of a picture archiving and communication system and computed radiography RADIOLOGY Pratt, H. M., Langlotz, C. P., Feingold, E. R., Schwartz, J. S., Kundel, H. L. 1998; 206 (1): 245-252

    Abstract

    To determine the incremental cash flows associated with department-wide implementation of a picture archiving and communication system (PACS) and computed radiography (CR) at a large academic medical center.The authors determined all capital and operational costs associated with PACS implementation during an 8-year time horizon. Economic effects were identified, adjusted for time value, and used to calculate net present values (NPVs) for each section of the department of radiology and for the department as a whole.The chest-bone section used the most resources. Changes in cost assumptions for the chest-bone section had a dominant effect on the department-wide NPV. The base-case NPV (i.e., that determined by using the initial assumptions) was negative, indicating that additional net costs are incurred by the radiology department from PACS implementation. PACS and CR provide cost savings only when a 12-year hardware life span is assumed, when CR equipment is removed from the analysis, or when digitized long-term archives are compressed at a rate of 10:1.Full PACS-CR implementation would not provide cost savings for a large, subspecialized department. However, institutions that are committed to CR implementation (for whom CR implementation would represent a sunk cost) or institutions that are able to archive images by using image compression will experience cost savings from PACS.

    View details for Web of Science ID 000071093500042

    View details for PubMedID 9423679

  • A METHODOLOGY FOR GENERATING COMPUTER-BASED EXPLANATIONS OF DECISION-THEORETIC ADVICE MEDICAL DECISION MAKING Langlotz, C. P., Shortliffe, E. H., Fagan, L. M. 1988; 8 (4): 290-303

    Abstract

    Decision analysis is an appealing methodology with which to provide decision support to the practicing physician. However, its use in the clinical setting is impeded because computer-based explanations of decision-theoretic advice are difficult to generate without resorting to mathematical arguments. Nevertheless, human decision analysts generate useful and intuitive explanations based on decision trees. To facilitate the use of decision theory in a computer-based decision support system, the authors developed a computer program that uses symbolic reasoning techniques to generate nonquantitative explanations of the results of decision analyses. A combined approach has been implemented to explain the differences in expected utility among branches of a decision tree. First, the mathematical relationships inherent in the structure of the tree are used to find any asymmetries in tree structure or inequalities among analogous decision variables that are responsible for a difference in expected utility. Next, an explanation technique is selected and applied to the most significant variables, creating a symbolic expression that justifies the decision. Finally, the symbolic expression is converted to English-language text, thereby generating an explanation that justifies the desirability of the choice with the greater expected utility. The explanation does not refer to mathematical formulas, nor does it include probability or utility values. The results suggest that explanations produced by a combination of decision analysis and symbolic processing techniques may be more persuasive and acceptable to clinicians than those produced by either technique alone.

    View details for Web of Science ID A1988Q325300010

    View details for PubMedID 3185181

  • ADAPTING A CONSULTATION SYSTEM TO CRITIQUE USER PLANS INTERNATIONAL JOURNAL OF MAN-MACHINE STUDIES Langlotz, C. P., Shortliffe, E. H. 1983; 19 (5): 479-496
  • Characterization of Change and Significance for Clinical Findings in Radiology Reports Through Natural Language Processing. Journal of digital imaging Hassanpour, S., Bay, G., Langlotz, C. P. 2017

    Abstract

    We built a natural language processing (NLP) method to automatically extract clinical findings in radiology reports and characterize their level of change and significance according to a radiology-specific information model. We utilized a combination of machine learning and rule-based approaches for this purpose. Our method is unique in capturing different features and levels of abstractions at surface, entity, and discourse levels in text analysis. This combination has enabled us to recognize the underlying semantics of radiology report narratives for this task. We evaluated our method on radiology reports from four major healthcare organizations. Our evaluation showed the efficacy of our method in highlighting important changes (accuracy 99.2%, precision 96.3%, recall 93.5%, and F1 score 94.7%) and identifying significant observations (accuracy 75.8%, precision 75.2%, recall 75.7%, and F1 score 75.3%) to characterize radiology reports. This method can help clinicians quickly understand the key observations in radiology reports and facilitate clinical decision support, review prioritization, and disease surveillance.

    View details for DOI 10.1007/s10278-016-9931-8

    View details for PubMedID 28050714

  • "Chasing a Ghost": Factors that Influence Primary Care Physicians to Follow Up on Incidental Imaging Findings. Radiology Zafar, H. M., Bugos, E. K., Langlotz, C. P., Frasso, R. 2016; 281 (2): 567-573

    Abstract

    Purpose To explore provider and patient characteristics that influence how primary care providers (PCPs) communicate and manage incidental imaging findings. Materials and Methods This HIPAA-compliant study was approved by the institutional review board. Through semistructured interviews, researchers explored concerns and perspectives of 30 PCPs on receiving and acting on incidental imaging findings. Open-ended questions were designed to elicit a range of responses rather than quantifiable data. Thematic codes were developed and explicitly defined. Three research assistants independently coded all 30 deidentified transcripts and resolved discrepancies (κ = 0.85). Codes pertaining to PCP and patient characteristics were organized into an explanatory model. Results Some PCPs felt compelled but frustrated to pursue costly follow-up for incidental imaging findings of limited clinical importance. Other PCPs did not act on findings that were unfamiliar or occurred in an unusual clinical context when follow-up recommendations were not given; the challenges of researching the clinical importance of these findings or seeking specialist consultation led to inaction. Some PCPs reported using a uniform approach to communicate and manage incidental findings, while others adapted their approach to the patient and the finding. Sometimes PCP characteristics such as follow-up style superseded patient characteristics. At other times patient characteristics such as health literacy superseded PCP characteristics. Conclusion PCPs cited a variety of objective and subjective factors that influence how they communicate and manage incidental imaging findings. These results suggest that some patients may receive inappropriate follow-up of incidental imaging findings and present an opportunity for radiologists to help PCPs and patients to best use the information conveyed in imaging reports. (©) RSNA, 2016 Online supplemental material is available for this article.

    View details for PubMedID 27192458

  • Why Isn't There More High-fidelity Simulation Training in Diagnostic Radiology? Results of a Survey of Academic Radiologists ACADEMIC RADIOLOGY Cook, T. S., Hernandez, J., Scanlon, M., Langlotz, C., Li, C. L. 2016; 23 (7): 870-876

    Abstract

    Despite its increasing use in training other medical specialties, high-fidelity simulation to prepare diagnostic radiology residents for call remains an underused educational resource. To attempt to characterize the barriers toward adoption of this technology, we conducted a survey of academic radiologists and radiology trainees.An Institutional Review Board-approved survey was distributed to the Association of University Radiologists members via e-mail. Survey results were collected electronically, tabulated, and analyzed.A total of 68 survey responses representing 51 programs were received from program directors, department chairs, chief residents, and program administrators. The most common form of educational activity for resident call preparation was lectures. Faculty supervised "baby call" was also widely reported. Actual simulated call environments were quite rare with only three programs reporting this type of educational activity. Barriers to the use of simulation include lack of faculty time, lack of faculty expertise, and lack of perceived need.High-fidelity simulation can be used to mimic the high-stress, high-stakes independent call environment that the typical radiology resident encounters during the second year of training, and can provide objective data for program directors to assess the Accreditation Council of Graduate Medical Education milestones. We predict that this technology will begin to supplement traditional diagnostic radiology teaching methods and to improve patient care and safety in the next decade.

    View details for DOI 10.1016/j.acra.2016.03.008

    View details for Web of Science ID 000378444600014

    View details for PubMedID 27212606

  • Unsupervised Topic Modeling in a Large Free Text Radiology Report Repository JOURNAL OF DIGITAL IMAGING Hassanpour, S., Langlotz, C. P. 2016; 29 (1): 59-62

    Abstract

    Radiology report narrative contains a large amount of information about the patient's health and the radiologist's interpretation of medical findings. Most of this critical information is entered in free text format, even when structured radiology report templates are used. The radiology report narrative varies in use of terminology and language among different radiologists and organizations. The free text format and the subtlety and variations of natural language hinder the extraction of reusable information from radiology reports for decision support, quality improvement, and biomedical research. Therefore, as the first step to organize and extract the information content in a large multi-institutional free text radiology report repository, we have designed and developed an unsupervised machine learning approach to capture the main concepts in a radiology report repository and partition the reports based on their main foci. In this approach, radiology reports are modeled in a vector space and compared to each other through a cosine similarity measure. This similarity is used to cluster radiology reports and identify the repository's underlying topics. We applied our approach on a repository of 1,899,482 radiology reports from three major healthcare organizations. Our method identified 19 major radiology report topics in the repository and clustered the reports accordingly to these topics. Our results are verified by a domain expert radiologist and successfully explain the repository's primary topics and extract the corresponding reports. The results of our system provide a target-based corpus and framework for information extraction and retrieval systems for radiology reports.

    View details for DOI 10.1007/s10278-015-9823-3

    View details for Web of Science ID 000372263300009

    View details for PubMedID 26353748

  • Optimization of Radiology Reports for Intensive Care Unit Portable Chest Radiographs Perceptions and Preferences of Radiologists and ICU Practitioners JOURNAL OF THORACIC IMAGING Barbosa, E. J., Lynch, M. C., Langlotz, C. P., Gefter, W. B. 2016; 31 (1): 43-48
  • Predicting High Imaging Utilization Based on Initial Radiology Reports: A Feasibility Study of Machine Learning ACADEMIC RADIOLOGY Hassanpour, S., Langlotz, C. P. 2016; 23 (1): 84-89
  • Optimization of Radiology Reports for Intensive Care Unit Portable Chest Radiographs: Perceptions and Preferences of Radiologists and ICU Practitioners. Journal of thoracic imaging Mortani Barbosa, E. J., Lynch, M. C., Langlotz, C. P., Gefter, W. B. 2016; 31 (1): 43-48

    Abstract

    The aim of the study was to evaluate opinions and perceptions of radiologists and referring practitioners regarding reports of portable chest radiography (pCXR) obtained in the intensive care unit (ICU).A total of 1265 referring practitioners and 76 radiologists were invited to participate in 2 internet-based surveys, containing 15 and 17 multiple choice questions, respectively, similarly presented to both groups, utilizing a Likert scale or multiple choices. Results were compared using the Fisher exact test or χ test.One hundred ninety-two referring practitioners and 63 radiologists answered the surveys, resulting in response rates of 15% and 83%. The majority of radiologists and referring practitioners are satisfied with the quality of the reports; however, radiologists and referring practitioners disagree about the reports' clinical value and impact, the referring practitioners having a more positive view. Both groups overwhelmingly agree that pertinent clinical information is crucial for optimal image interpretation. The 2 groups differ in their preferences regarding report style and information content, with radiologists strongly supporting concise reports emphasizing temporal changes and major findings, whereas referring practitioners prefer more complete, itemized structured reports describing support devices in detail.The results substantiate the perceived clinical value of radiologist reports for pCXR, from the perspective of referring practitioners. Nonetheless, there is disagreement regarding report structure and content. Several issues were raised, offering opportunities for improvement, which may increase referring practitioners' satisfaction and positively impact patient outcomes. Any strategy to implement standardized structured reports for pCXR will have to satisfy referring practitioners' needs while optimizing radiologists' efficiency, will have to be widely accepted, and will have to fulfill the overarching goal of maximizing the value of pCXR reports.

    View details for DOI 10.1097/RTI.0000000000000165

    View details for PubMedID 26258599

  • Conversion of Radiology Reporting Templates to the MRRT Standard JOURNAL OF DIGITAL IMAGING Kahn, C. E., Genereaux, B., Langlotz, C. P. 2015; 28 (5): 528-536

    Abstract

    In 2013, the Integrating the Healthcare Enterprise (IHE) Radiology workgroup developed the Management of Radiology Report Templates (MRRT) profile, which defines both the format of radiology reporting templates using an extension of Hypertext Markup Language version 5 (HTML5), and the transportation mechanism to query, retrieve, and store these templates. Of 200 English-language report templates published by the Radiological Society of North America (RSNA), initially encoded as text and in an XML schema language, 168 have been converted successfully into MRRT using a combination of automated processes and manual editing; conversion of the remaining 32 templates is in progress. The automated conversion process applied Extensible Stylesheet Language Transformation (XSLT) scripts, an XML parsing engine, and a Java servlet. The templates were validated for proper HTML5 and MRRT syntax using web-based services. The MRRT templates allow radiologists to share best-practice templates across organizations and have been uploaded to the template library to supersede the prior XML-format templates. By using MRRT transactions and MRRT-format templates, radiologists will be able to directly import and apply templates from the RSNA Report Template Library in their own MRRT-compatible vendor systems. The availability of MRRT-format reporting templates will stimulate adoption of the MRRT standard and is expected to advance the sharing and use of templates to improve the quality of radiology reports.

    View details for DOI 10.1007/s10278-015-9787-3

    View details for Web of Science ID 000364522100003

    View details for PubMedID 25776768

  • True "Meaningful Use": Technology Meets Both Patient and Provider Needs AMERICAN JOURNAL OF MANAGED CARE Black, H., Gonzalez, R., Priolo, C., Schapira, M. M., Sonnad, S. S., Hanson, C. W., Langlotz, C. P., Howell, J. T., Apter, A. J. 2015; 21 (5): E329-E337
  • True "meaningful use": technology meets both patient and provider needs. American journal of managed care Black, H., Gonzalez, R., Priolo, C., Schapira, M. M., Sonnad, S. S., Hanson, C. W., Langlotz, C. P., Howell, J. T., Apter, A. J. 2015; 21 (5): e329-37

    Abstract

    Voluntary patient uptake and use of electronic health record (EHR) features have been low. It is unknown whether EHRs fully meet needs of providers or patients with chronic diseases.To explore in-depth user experiences, we conducted 6 focus groups: 3 of patients followed by 3 of providers discussing 2 key EHR components: the after-visit summary (AVS) and the patient portal (PP). Focus groups were audio-recorded, transcribed, and analyzed by 3 independent coders.Participants with moderate-to-severe asthma and prevalent comorbidities were recruited from 4 primary care and 2 asthma clinics serving low-income urban neighborhoods. Participants discussed their expectations and experience using the AVS and PP, and responded to prototype formats of these features. Additionally, one-on-one interviews were conducted with 10 patients without PP experience to assess their ability to use the system.The 21 patient and 13 provider perspectives differed regarding AVS features and use. Patients wanted a unified view of their medical issues and health management tools, while providers wanted to focus on recommendations from 1 visit at a time. Both groups advocated improving the AVS format and content. Lack of awareness and knowledge about the PP was patients' largest barrier, and was traced back to providers' lack of PP training.Our results underscore the importance of user-centered design when constructing the content and features of the EHR. As technology evolves, an ongoing understanding of patient and provider experiences will be critical to improve uptake, increase use, and ensure engagement, optimizing the potential of EHRs.

    View details for PubMedID 26167781

  • Assessment of Follow-up Completeness and Notification Preferences for Imaging Findings of Possible Cancer: What Happens After Radiologists Submit Their Reports? ACADEMIC RADIOLOGY Sloan, C. E., Chadalavada, S. C., Cook, T. S., Langlotz, C. P., Schnall, M. D., Zafar, H. M. 2014; 21 (12): 1579-1586

    Abstract

    To understand the reasons leading to potentially inappropriate management of imaging findings concerning for malignancy and identify optimal methods for communicating these findings to providers.We identified all abdominal imaging examinations with findings of possible cancer performed on six randomly selected days in August to December 2013. Electronic medical records (EMR) of one patient group were reviewed 3 months after the index examination to determine whether management was appropriate (completed follow-up or documented reason for no follow-up) or potentially inappropriate (no follow-up or no documented reason). Providers of a second patient group were contacted 5-6 days after imaging examinations to determine notification preferences.Among 43 patients in the first group, five (12%) received potentially inappropriate management. Reasons included patient loss to follow-up and provider failure to review imaging results, document known imaging findings, or communicate findings to providers outside the health system. Among 16 providers caring for patients in the second group, 33% were unaware of the findings, 75% preferred to be notified of abnormal findings via e-mail or EMR, 56% wanted an embedded hyperlink enabling immediate follow-up order entry, and only 25% had a system to monitor whether patients had completed ordered testing.One in eight patients did not receive potentially necessary follow-up care within 3 months of imaging findings of possible cancer. Automated notification of imaging findings and follow-up monitoring not only is desired by providers but can also address many of the reasons we found for inappropriate management.

    View details for DOI 10.1016/j.acra.2014.07.006

    View details for Web of Science ID 000344844400013

    View details for PubMedID 25179562

  • Ten Commandments for Effective Clinical Decision Support for Imaging: Enabling Evidence-Based Practice to Improve Quality and Reduce Waste AMERICAN JOURNAL OF ROENTGENOLOGY Khorasani, R., Hentel, K., Darer, J., Langlotz, C., Ip, I. K., Manaker, S., Cardella, J., Min, R., Seltzer, S. 2014; 203 (5): 945-951

    Abstract

    We describe best practices for effective imaging clinical decision support (CDS) derived from firsthand experience, extending the Ten Commandments for CDS published a decade ago. Our collective perspective is used to set expectations for providers, health systems, policy makers, payers, and health information technology developers.Highlighting unique attributes of effective imaging CDS will help radiologists to successfully lead and optimize the value of the substantial federal and local investments in health information technology in the United States.

    View details for DOI 10.2214/AJR.14.13134

    View details for Web of Science ID 000347415700030

    View details for PubMedID 25341131

  • Automated Extraction of Critical Test Values and Communications from Unstructured Radiology Reports: An Analysis of 9.3 Million Reports from 1990 to 2011 RADIOLOGY Lakhani, P., Kim, W., Langlotz, C. P. 2012; 265 (3): 809-818

    Abstract

    To determine the frequency of critical radiology results in 9.3 million radiology reports from our health system, to identify those containing documentation of communication by using automated text-classification algorithms, and to assess the impact of a policy requiring documentation of critical results communication.This HIPAA-compliant retrospective study received institutional review board approval. Text-mining algorithms that were previously validated to have mean accuracies of more than 90% for identifying certain critical results and documentation of communications were applied to a database of 9.3 million radiology reports. The frequency of critical results and documentation of communication were then determined from 1990 to 2011.There was an increase in documentation of communication for all critical results from 1990 to 2011. In 1990, 19.0% of reports with critical values had evidence of documentation of communication compared with 72.4% of reports in 2010. The linear trend for increasing documentation of communications began in 1997 and continued until 2011 (P < .001). From 1990 to 2011, documentation of communication was highest in acute scrotal torsion (70.6%) and ectopic pregnancy (65.4%) and lowest in unexplained free-intraperitoneal air (29.5%) and malpositioned tubes (30.4%). In 2010-2011, radiologists were least likely to document communication of results for malpositioned endotracheal and enteric tubes (2010, 58.56%; 2011, 57.50%) and unexplained free-intraperitoneal air (2010, 59.57%; 2011, 75.51%). They were most likely to document communication of results for ectopic pregnancy (2010, 94.12%; 2011, 93.48%) and acute appendicitis (2010, 86.87%; 2011, 84.31%).There was an increase in documentation of communication of critical results, which demonstrated a rising linear trend that began in 1997 and continued until 2011. The increasing trend began well before policy implementation, indicating that other factors such as heightened awareness among radiologists likely had a role.

    View details for DOI 10.1148/radiol.12112438

    View details for Web of Science ID 000311420300018

    View details for PubMedID 22952381

  • Clinical Decision Support for Imaging in the Era of the Patient Protection and Affordable Care Act JOURNAL OF THE AMERICAN COLLEGE OF RADIOLOGY Zafar, H. M., Mills, A. M., Khorasani, R., Langlotz, C. P. 2012; 9 (12): 907-918

    Abstract

    Imaging clinical decision support (CDS) systems provide evidence for or against imaging procedures ordered within a computerized physician order entry system at the time of the image order. Depending on the pertinent clinical history provided by the ordering clinician, CDS systems can optimize imaging by educating providers on appropriate image order entry and by alerting providers to the results of prior, potentially relevant imaging procedures, thereby reducing redundant imaging. The American Recovery and Reinvestment Act (ARRA) has expedited the adoption of computerized physician order entry and CDS systems in health care through the creation of financial incentives and penalties to promote the "meaningful use" of health IT. Meaningful use represents the latest logical next step in a long chain of legislation promoting the areas of appropriate imaging utilization, accurate reporting, and IT. It is uncertain if large-scale implementation of imaging CDS will lead to improved health care quality, as seen in smaller settings, or to improved patient outcomes. However, imaging CDS enables the correlation of existing imaging evidence with outcome measures, including morbidity, mortality, and short-term imaging-relevant management outcomes (eg, biopsy, chemotherapy). The purposes of this article are to review the legislative sequence relevant to imaging CDS and to give guidance to radiology practices focused on quality and financial performance improvement during this time of accelerating regulatory change.

    View details for DOI 10.1016/j.jacr.2012.09.014

    View details for Web of Science ID 000312629700016

    View details for PubMedID 23206649

  • Predictors of initial F-18-fluorodeoxyglucose-positron emission tomography indication among patients with colorectal cancer NUCLEAR MEDICINE COMMUNICATIONS Zafar, H. M., Kramer, S., Bonaccorsi, D., Langlotz, C. P., Armstrong, K. 2012; 33 (7): 739-746

    Abstract

    To evaluate the determinants of initial F-fluorodeoxyglucose (F-FDG)-PET indication following primary colorectal cancer diagnosis among patients who underwent surgery between January 2000 and December 2007 and who were observed at a single institution for at least 2 years after diagnosis.Of the 530 patients who underwent colorectal cancer resection, 113 patients received at least one F-FDG-PET following diagnosis. Outcome variables included indication and time of the first F-FDG-PET following diagnosis. Potential predictors included disease-level and patient-level characteristics. Univariate and multivariate regression analyses were performed.Patients diagnosed later in the study period and patients with higher-stage disease were more likely to receive their first F-FDG-PET for initial staging (P<0.001 and P=0.016, respectively). Patients with lower-stage disease were more likely to receive their initial F-FDG-PET for suspected recurrence on conventional imaging. When performed more than 2 years after diagnosis, F-FDG-PET was more likely to be ordered for suspected recurrence either on the basis of conventional imaging or on the basis of patient symptoms/tumor markers (P=0.003 and 0.031, respectively). F-FDG-PET demonstrated disease progression in at least 50% of patients referred for each indication (P=0.037).Higher utilization of F-FDG-PET may be appropriate among patients referred for a number of indications including: initial staging, particularly among those with higher-stage disease; suspected recurrence on conventional imaging among patients with lower-stage disease; and suspected recurrence more than 2 years after diagnosis. Further research is needed to verify these findings.

    View details for DOI 10.1097/MNM.0b013e328353b249

    View details for Web of Science ID 000305500600009

    View details for PubMedID 22531828

  • The Diagnostic and Economic Yield of Neuroimaging in Neuro-ophthalmology JOURNAL OF NEURO-OPHTHALMOLOGY Mehta, S., Loevner, L. A., Mikityansky, I., Langlotz, C., Ying, G., Tamhankar, M. A., Shindler, K. S., Volpe, N. J. 2012; 32 (2): 139-144

    Abstract

    Diagnostic studies such as computed tomography scans (CT) and magnetic resonance imaging (MRI) are ordered frequently in neuro-ophthalmic practice, although the diagnostic yield and cost-effectiveness of these tests have been studied for only a few conditions. We assessed the diagnostic and economic yield of CT and MRI across all patients evaluated in a neuro-ophthalmology practice.This retrospective review included all patients referred by the division of neuro-ophthalmology at the Scheie Eye Institute for CT, CT angiography, MRI, MRA, or magnetic resonance venography over a 12-month period. Abnormal imaging findings were categorized as significant (one that elicited changes in management) and/or relevant (one that related to the patient's neuro-ophthalmic complaint or examination findings). The diagnostic yield of the test ordered was analyzed according to the patient's chief complaint, neuro-ophthalmic examination findings, and indication for imaging. The total costs for each diagnostic group and costs per significant finding were calculated using the global Resource-Based Relative Value Units for each examination from the Centers for Medicare and Medicaid Services Web site.Two hundred eleven imaging studies in 157 patients were evaluated. 28.9% (95% confidence interval, 22.5%-36.2%) of imaging studies had significant abnormalities relevant to the neuro-ophthalmic complaint. Imaging obtained for evaluation of progressive optic nerve dysfunction and cranial nerve palsy had statistically significant higher diagnostic yield than studies performed for other reasons. Total cost of all imaging studies performed was $107,615.72. Cost per clinically significant and relevant finding was $1,764.19.In comparison to the diagnostic yield of neuroimaging studies in other specialties, CT and MRI of the brain requested by neuro-ophthalmologists provide significant and relevant data at a reasonable cost.

    View details for DOI 10.1097/WNO.0b013e31824e3753

    View details for Web of Science ID 000304790500010

    View details for PubMedID 22510684

  • Automated Detection of Critical Results in Radiology Reports JOURNAL OF DIGITAL IMAGING Lakhani, P., Kim, W., Langlotz, C. P. 2012; 25 (1): 30-36

    Abstract

    The goal of this study was to develop and validate text-mining algorithms to automatically identify radiology reports containing critical results including tension or increasing/new large pneumothorax, acute pulmonary embolism, acute cholecystitis, acute appendicitis, ectopic pregnancy, scrotal torsion, unexplained free intraperitoneal air, new or increasing intracranial hemorrhage, and malpositioned tubes and lines. The algorithms were developed using rule-based approaches and designed to search for common words and phrases in radiology reports that indicate critical results. Certain text-mining features were utilized such as wildcards, stemming, negation detection, proximity matching, and expanded searches with applicable synonyms. To further improve accuracy, the algorithms utilized modality and exam-specific queries, searched under the "Impression" field of the radiology report, and excluded reports with a low level of diagnostic certainty. Algorithm accuracy was determined using precision, recall, and F-measure using human review as the reference standard. The overall accuracy (F-measure) of the algorithms ranged from 81% to 100%, with a mean precision and recall of 96% and 91%, respectively. These algorithms can be applied to radiology report databases for quality assurance and accreditation, integrated with existing dashboards for display and monitoring, and ported to other institutions for their own use.

    View details for DOI 10.1007/s10278-011-9426-6

    View details for Web of Science ID 000304113400006

    View details for PubMedID 22038514

  • Extracting templates from radiology reports using sequence alignment INTERNATIONAL JOURNAL OF DATA MINING AND BIOINFORMATICS Wu, S., Langlotz, C. P., Lakhani, P., Ungar, L. H. 2012; 6 (6): 633-650

    Abstract

    Health care providers often dictate their reports by filling in slots in templates. These slots can be filled with a variety of different procedures, measurements, or findings. Many radiologists currently create their own personalised templates, costing time and leading to inconsistencies across physicians. We present a sequence alignment method Radiology Content Alignment (RADICAL) that uses dynamic programming to efficiently extract templates that are common across sets of reports, and give examples of the extracted templates and the contents of their slots.

    View details for DOI 10.1504/IJDMB.2012.050248

    View details for Web of Science ID 000311137000005

    View details for PubMedID 23356012

  • Informatics in Radiology An Information Model of the DICOM Standard RADIOGRAPHICS Kahn, C. E., Langlotz, C. P., Channin, D. S., Rubin, D. L. 2011; 31 (1): 295-U356

    Abstract

    The Digital Imaging and Communications in Medicine (DICOM) Standard is a key foundational technology for radiology. However, its complexity creates challenges for information system developers because the current DICOM specification requires human interpretation and is subject to nonstandard implementation. To address this problem, a formally sound and computationally accessible information model of the DICOM Standard was created. The DICOM Standard was modeled as an ontology, a machine-accessible and human-interpretable representation that may be viewed and manipulated by information-modeling tools. The DICOM Ontology includes a real-world model and a DICOM entity model. The real-world model describes patients, studies, images, and other features of medical imaging. The DICOM entity model describes connections between real-world entities and the classes that model the corresponding DICOM information entities. The DICOM Ontology was created to support the Cancer Biomedical Informatics Grid (caBIG) initiative, and it may be extended to encompass the entire DICOM Standard and serve as a foundation of medical imaging systems for research and patient care.

    View details for DOI 10.1148/rg.311105085

    View details for Web of Science ID 000286608900024

    View details for PubMedID 20980665

  • Automated Detection of Radiology Reports that Document Non-routine Communication of Critical or Significant Results JOURNAL OF DIGITAL IMAGING Lakhani, P., Langlotz, C. P. 2010; 23 (6): 647-657

    Abstract

    The purpose of this investigation is to develop an automated method to accurately detect radiology reports that indicate non-routine communication of critical or significant results. Such a classification system would be valuable for performance monitoring and accreditation. Using a database of 2.3 million free-text radiology reports, a rule-based query algorithm was developed after analyzing hundreds of radiology reports that indicated communication of critical or significant results to a healthcare provider. This algorithm consisted of words and phrases used by radiologists to indicate such communications combined with specific handcrafted rules. This algorithm was iteratively refined and retested on hundreds of reports until the precision and recall did not significantly change between iterations. The algorithm was then validated on the entire database of 2.3 million reports, excluding those reports used during the testing and refinement process. Human review was used as the reference standard. The accuracy of this algorithm was determined using precision, recall, and F measure. Confidence intervals were calculated using the adjusted Wald method. The developed algorithm for detecting critical result communication has a precision of 97.0% (95% CI, 93.5-98.8%), recall 98.2% (95% CI, 93.4-100%), and F measure of 97.6% (ß=1). Our query algorithm is accurate for identifying radiology reports that contain non-routine communication of critical or significant results. This algorithm can be applied to a radiology reports database for quality control purposes and help satisfy accreditation requirements.

    View details for DOI 10.1007/s10278-009-9237-1

    View details for Web of Science ID 000284163300001

    View details for PubMedID 19826871

  • Documentation of Nonroutine Communications of Critical or Significant Radiology Results: A Multiyear Experience at a Tertiary Hospital JOURNAL OF THE AMERICAN COLLEGE OF RADIOLOGY Lakhani, P., Langlotz, C. P. 2010; 7 (10): 782-790
  • Comparison of two methods to transmit clinical history information from referring providers to radiologists. Journal of the American College of Radiology Agarwal, R., Bleshman, M. H., Langlotz, C. P. 2009; 6 (11): 795-799

    Abstract

    At many institutions, clerical personnel manually enter clinical histories into radiology information systems during the process of scheduling examinations. For outpatients, radiologists use this information as their primary source of clinical histories. The purpose of this study was to determine the discrepancy rate between these manually recorded clinical histories and paper request slips, thereby assessing the accuracy of the clinical information used by radiologists at the time of interpretation.A total of 129 imaging request slips for CT scans were randomly selected from 7 days in February and March 2007. The clinical history on each request slip was compared with the clinical history manually entered into the radiology information system. Discrepancies between paper request slips and the electronic information available to radiologists were placed into 4 categories: 1) no discrepancy, 2) electronic or paper history incomplete, 3) disagreement between electronic and paper information, and 4) other. Incomplete or discrepant histories were further subcategorized on the basis of whether they were clinically significant.Thirty-eight percent of studies (49 of 129) had no discrepancies between the paper request slips and the manually entered electronic information. The remaining 62% of studies (80 of 129) had incomplete or discrepant clinical histories. Forty-nine percent of studies (63 of 129) had incomplete electronic or paper information. Greater than half of those incomplete histories (36 of 63) were clinically significant. Ten percent of cases (13 of 129) showed frank disagreements between paper and electronic information. Sixty-nine percent of these (9 of 13) were clinically significant. Three percent of studies (4 of 129) showed other discrepancies whose clinical significance could not be categorized.The manual entry of clinical information introduces a high rate of discrepancies, most of which are clinically significant. These discrepancies highlight the need for better communication between referring providers and radiologists.

    View details for DOI 10.1016/j.jacr.2009.06.012

    View details for PubMedID 19878887

  • Radiologist Use of and Perceived Need for Patient Data Access JOURNAL OF DIGITAL IMAGING Boonn, W. W., Langlotz, C. P. 2009; 22 (4): 357-362

    Abstract

    Given the increasing volume of radiological exams, the decreasing frequency of direct communication with the referring provider, and the distribution of patient data over many clinical systems, radiologists often do not have adequate clinical information at the time of interpretation. We have performed a survey of radiologists to determine the need and actual utilization of patient data at the time of image interpretation. Our findings demonstrate that most radiologists want more clinical information when interpreting images and that this information would impact their report, but they are discouraged by the time it takes to access this information. In addition, current mechanisms for monitoring necessary patient follow-up are inadequate.

    View details for DOI 10.1007/s10278-008-9115-2

    View details for Web of Science ID 000267824800003

    View details for PubMedID 18459002

  • The IR Radlex Project: An Interventional Radiology Lexicon-A Collaborative Project of the Radiological Society of North America and the Society of Interventional Radiology JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kundu, S., Itkin, M., Gervais, D. A., Krishnamurthy, V. N., Wallace, M. J., Cardella, J. F., Rubin, D. L., Langlotz, C. P. 2009; 20 (4): 433-435

    View details for DOI 10.1016/j.jvir.2008.10.022

    View details for Web of Science ID 000264958300001

    View details for PubMedID 19081735

  • Improving language models for radiology speech recognition JOURNAL OF BIOMEDICAL INFORMATICS Paulett, J. M., Langlotz, C. P. 2009; 42 (1): 53-58

    Abstract

    Speech recognition systems have become increasingly popular as a means to produce radiology reports, for reasons both of efficiency and of cost. However, the suboptimal recognition accuracy of these systems can affect the productivity of the radiologists creating the text reports. We analyzed a database of over two million de-identified radiology reports to determine the strongest determinants of word frequency. Our results showed that body site and imaging modality had a similar influence on the frequency of words and of three-word phrases as did the identity of the speaker. These findings suggest that the accuracy of speech recognition systems could be significantly enhanced by further tailoring their language models to body site and imaging modality, which are readily available at the time of report creation.

    View details for DOI 10.1016/j.jbi.2008.08.001

    View details for Web of Science ID 000263882700006

    View details for PubMedID 18761109

  • Extracting Templates from Radiology Reports using Sequence Alignment BIBMW: 2009 IEEE INTERNATIONAL CONFERENCE ON BIOINFORMATICS AND BIOMEDICINE WORKSHOP Wu, S., Langlotz, C. P., Lakhani, P., Ungar, L. H. 2009: 314-318
  • Structured Reporting: Patient Care Enhancement or Productivity Nightmare? RADIOLOGY Weiss, D. L., Langlotz, C. P. 2008; 249 (3): 739-747

    View details for DOI 10.1148/radiol.2493080988

    View details for Web of Science ID 000261139300003

    View details for PubMedID 19011178

  • RadLex: A new method for indexing online educational materials RADIOGRAPHICS Langlotz, C. P. 2006; 26 (6): 1595-1597

    View details for DOI 10.1148/rg.266065168

    View details for Web of Science ID 000241828200002

    View details for PubMedID 17102038

  • Mentoring the mentors: Aligning mentor and mentee expectations ACADEMIC RADIOLOGY Lee, J. M., Anzai, Y., Langlotz, C. P. 2006; 13 (5): 556-561

    Abstract

    The Radiology Alliance for Health Services Research sponsored a symposium at the 2005 Annual Meeting of the Association of University Radiologists, which focused on the issue of aligning mentor and mentee expectations to foster successful mentoring relationships. This article presents a summary of the informal discussion of the panelists' individual experiences, common themes, and insights gained from the panel participants.

    View details for DOI 10.1016/j.acra.2006.01.050

    View details for Web of Science ID 000237075400005

    View details for PubMedID 16627195

  • Development and validation of queries using structured query language (SQL) to determine the utilization of comparison imaging in radiology reports stored on PACS JOURNAL OF DIGITAL IMAGING Lakhani, P., Menschik, E. D., Goldszal, A. F., Murray, J. P., Weiner, M. G., Langlotz, C. P. 2006; 19 (1): 52-68

    Abstract

    The purpose of this research was to develop queries that quantify the utilization of comparison imaging in free-text radiology reports. The queries searched for common phrases that indicate whether comparison imaging was utilized, not available, or not mentioned. The queries were iteratively refined and tested on random samples of 100 reports with human review as a reference standard until the precision and recall of the queries did not improve significantly between iterations. Then, query accuracy was assessed on a new random sample of 200 reports. Overall accuracy of the queries was 95.6%. The queries were then applied to a database of 1.8 million reports. Comparisons were made to prior images in 38.69% of the reports (693,955/1,793,754), were unavailable in 18.79% (337,028/1,793,754), and were not mentioned in 42.52% (762,771/1,793,754). The results show that queries of text reports can achieve greater than 95% accuracy in determining the utilization of prior images.

    View details for DOI 10.1007/s10278-005-7667-y

    View details for Web of Science ID 000236218500006

    View details for PubMedID 16132483

  • A framework for improving radiology reporting. Journal of the American College of Radiology Sistrom, C. L., Langlotz, C. P. 2005; 2 (2): 159-167

    Abstract

    The interpretative reports rendered by radiologists are the only tangible manifestation of their expertise, training, and experience. These documents are very often the primary means by which radiologists provide patient care. Radiology reports are extremely variable in form, content, and quality. The authors propose a framework for conceptualizing the reporting process and how it might be improved. This consists of standard language, a structured format, and consistent content. These attributes will be realized by modifying the clinical reporting process, including the creation, storage, transmission, and review of interpretative documents. The authors also point out that changes in training and evaluation must be a part of the process, because they are complementary to purely technical solutions.

    View details for PubMedID 17411786

  • Using sonography to examine adult patients at an academic medical center: Have usage patterns changed with the expansion of managed care? AMERICAN JOURNAL OF ROENTGENOLOGY Liebeskind, M. E., Arger, P. H., Liebeskind, A., Maston, K., Langlotz, C. 2002; 179 (6): 1395-?

    Abstract

    This study was designed to determine whether significant changes have occurred in the utilization of sonography relative to more expensive cross-sectional imaging techniques in adult patients during a time of increasing reliance on managed care.Use of sonography was compared with use of CT and MR imaging of the abdomen, pelvis, and retroperitoneum in adult patients in 1993 and 1998 at an academic medical center. Clinicians who requested the greatest number of examinations in both years were surveyed to assess their perception of changes in their practice patterns during the interim.Between 1993 and 1998, the use of sonography relative to the other cross-sectional imaging modalities decreased from 56% to 43% (p < or = 0.001). During the same time, CT use increased from 30% to 41% (p < or = 0.001), and MR imaging use increased from 14% to 16% (p < or = 0.001). Survey responses indicated that potential cost saving was not a major factor in physicians' decisions to use sonography rather than other cross-sectional imaging modalities.Sonographic utilization decreased during a 5-year period in which managed care provided an increasingly large proportion of overall reimbursement. Cost did not appear to be a major factor in selection of diagnostic tests. Differences over time in refering clinicians' perception of the relative usefulness of sonography, CT, and MR imaging may have contributed to the change in usage patterns.

    View details for Web of Science ID 000179407900004

    View details for PubMedID 12438022

  • The effect of PACS on the time required for technologists to produce radiographic images in the emergency department radiology suite JOURNAL OF DIGITAL IMAGING Redfern, R. O., Langlotz, C. P., Abbuhl, S. B., Polansky, M., Horii, S. C., Kundel, H. L. 2002; 15 (3): 153-160

    Abstract

    The purpose of this study was to evaluate the effect of a switch to a filmless image management system on the time required for technologists to produce radiographic images in the emergency department (ED) after controlling for exam difficulty and a variable workload. Time and motion data were collected on patients who had radiographic images taken while being treated in the emergency department over the 3 1/2-year period from April 1997 to November 2000. Event times and demographic data were obtained from the radiology information system, from the hospital information system, from emergency department records, or by observation by research coordinators. Multiple least squares regression analysis identified several independent predictors of the time required for technologists to produce radiographic images. These variables included the level of technologist experience, the number of trauma-alert patient arrivals, and whether a filmless image management system was used (all P <.05). Our regression model explained 22% of the variability in technologist time (R2 Adjusted, 0.22; F = 24.01; P <.0001). The regression model predicted a time saving of 2 to 3 minutes per patient in the elapsed time from notification of a needed examination until image availability because of the implementation of PACS, a delay of 4 to 6 minutes per patient who were imaged by technologists who spent less than 10% of their work assignments within the ED, and a delay of 18 to 27 minutes in radiology workflow because of the arrival of a trauma alert patient. A filmless system decreased the amount of time required to produce radiographs. The arrival of a trauma alert patient delayed radiology workflow in the ED. Inexperienced technologists require 4 to 6 minutes of additional time per patient to complete the same amount of work accomplished by an experienced technologist.

    View details for DOI 10.1007/s10278-002-0024-5

    View details for Web of Science ID 000181622100006

    View details for PubMedID 12415466

  • Automatic structuring of radiology reports: Harbinger of a second information revolution in radiology RADIOLOGY Langlotz, C. P. 2002; 224 (1): 5-7

    View details for DOI 10.1148/radiol.2241020415

    View details for Web of Science ID 000176454700002

    View details for PubMedID 12091655

  • The completeness of existing lexicons for representing radiology report information. Journal of digital imaging Langlotz, C. P., Caldwell, S. A. 2002; 15: 201-205

    Abstract

    Although most medical lexicons contain up to 80% of clinical terms used in an ambulatory patient medical records archive, preliminary research suggests that they may be far less complete for radiology terms. We therefore compared the likelihood that several existing medical lexicons would contain terms found in a radiology report to the likelihood they would contain terms found in an ambulatory care medical record. We used three samples of imaging terms to assess the completeness of existing lexicons for medical imaging: (1) a random sample of imaging terms from the Unified Medical Language System Large Scale Vocabulary Test (UMLS-LSVT; n = 218), (2) terms actually used in the first 80 clinical knee magnetic resonance imaging reports generated by the routine clinical use of a structured reporting system (eDictation, Marlton, NJ; n = 76), and (3) terms listed in a glossary of thoracic imaging prepared by the Fleischner Society (n = 173). Using the UMLS Web-based Knowledge Source Server (http://umlsks.nlm.nih. gov/), we measured the rate at which terms in each of the above three sources were found in the UMLS and two of its major constituent terminologies: ICD-9-CM and SNOMED International. ICD-9-CM contained matches for 3%, 8%, and 11% of terms from the Fleischner Society Glossary, eDictation, and NLM-LSVT, respectively. SNOMED International contained matches for 32%, 46%, and 36% of terms from the Fleischner Society Glossary, eDictation, and NLM-LSVT, respectively. The UMLS contained matches for 36%, 50%, and 45% of terms from the Fleischner Society Glossary, eDictation, and NLM-LSVT, respectively. The assessed vocabularies were least likely to contain a term from the Fleischner Society Glossary and most likely to contain a term from the eDictation lexicon. The UMLS was the most complete, and ICD-9 was the least complete of the three systems evaluated. No lexicon achieved greater than 50% completeness for any test set of imaging terms. Our results show that no single lexicon is sufficiently complete to allow comprehensive indexing, search, and retrieval of radiology report information. These results confirm the few results available from the medical literature indicating that existing controlled vocabularies are insufficiently complete to represent the contents of radiology reports. A subjective analysis of these results may identify particular imaging sub-areas for which new terms should be developed.

    View details for PubMedID 12105728

  • Evidence-based radiology: A new approach to the practice of radiology RADIOLOGY Black, W. C., Jadad, A. R., Jarvik, J. G., Kazerooni, E. A., Langlotz, C. P., Lentle, B. C., Maceneaney, P. M., Malone, D. E., Nahmias, C., Reed, M. H., Salena, B. J., Shannon, S. I., Stolberg, H. O. 2001; 220 (3): 566-575

    Abstract

    In this review, the principles of evidence-based health care and their application to radiology are discussed. Evidence-based health care involves the more formal integration of the best research evidence with clinical expertise and explicit acknowledgment of patient values in clinical decision making, as compared with conventional practice. Recently, many health care disciplines have adopted the principles and practice of evidence-based health care. In radiology, including its diagnostic and interventional aspects, these developments have received limited attention. This review of evidence-based health care could, therefore, be useful to radiologists at any stage of their training or career, to encourage the practice of evidence-based radiology. The development of evidence-based health care is described, and evidence-based health care and evidence-based radiology are defined. The importance of evidence-based health care as a new approach to the practice of medicine and its importance for transdisciplinary collaboration are discussed. The skills required to practice evidence-based radiology are identified, and the roles of evidence-based radiology in radiologic practice, education, and research are discussed.

    View details for Web of Science ID 000170616700002

    View details for PubMedID 11526249

  • Acute appendicitis: Comparison of helical CT diagnosis - Focused technique with oral contrast material versus nonfocused technique with oral and intravenous contrast material RADIOLOGY Jacobs, J. E., Birnbaum, B. A., Macari, M., Megibow, A. J., Israel, G., Maki, D. D., Aguiar, A. M., Langlotz, C. P. 2001; 220 (3): 683-690

    Abstract

    To compare the diagnostic accuracy of focused helical computed tomography (CT) with orally administered contrast material with that of nonfocused helical CT with orally and intravenously administered contrast material.After receiving oral contrast material, 228 patients with clinically suspected appendicitis underwent focused appendiceal CT (5-mm section thickness, 15-cm coverage in the right lower quadrant). Immediately thereafter, helical CT of the entire abdomen and pelvis was performed following intravenous administration of contrast material (abdomen, 7-mm section thickness; pelvis, 5-mm section thickness). Studies were separated and independently interpreted by three observers who were blinded to patient names. Diagnoses were established by means of surgical and/or clinical follow-up findings.Fifty-one (22.4%) of 228 patients had acute appendicitis. Readers diagnosed appendicitis with 83.3%, 73.8%, and 71.4% sensitivity and 93.0%, 92.3%, and 97.9% specificity with focused nonenhanced appendiceal CT. Readers diagnosed appendicitis with 92.9%, 92.9%, and 88.1% sensitivity and 93.7%, 95.1%, and 96.5% specificity with nonfocused enhanced CT. Summary areas under the receiver operating characteristic curve estimates for focused nonenhanced and nonfocused enhanced CT were 0.916 and 0.964, respectively; the differences were statistically significant (P <.05) for two of three readers. All readers demonstrated higher sensitivities for detecting the inflamed appendix with nonfocused enhanced CT. Appendicitis was missed with focused CT in two patients whose inflamed appendix was not included in the imaging of the right lower quadrant. All readers were significantly more confident in diagnosing alternative conditions with nonfocused enhanced CT.Diagnostic accuracy of helical CT for acute appendicitis improved significantly with use of intravenous contrast material.

    View details for Web of Science ID 000170616700019

    View details for PubMedID 11526267

  • Visualization of areae gastricae on double-contrast upper gastrointestinal radiography: Relationship to age of patients AMERICAN JOURNAL OF ROENTGENOLOGY Charagundla, S. R., Levine, M. S., Langlotz, C. P., Rubesin, S. E., Laufer, I. 2001; 177 (1): 61-63

    Abstract

    The purpose of this study was to determine whether the frequency of visualization of areae gastricae on double-contrast upper gastrointestinal tract examinations is related to a patient's age.A total of 141 double-contrast upper gastrointestinal tract examinations with normal findings were reviewed for the presence or absence of areae gastricae on double-contrast images of the stomach. All images were evaluated by two radiologists who were blinded to the age of the patients. The data were then analyzed to determine if the frequency of visualization of areae gastricae on double-contrast studies was significantly related to the age of patients.The frequency of visualization of areae gastricae increased significantly with increasing age (p = 0.008). The youngest age group (20--29 years old) exhibited areae gastricae in only four (19%) of 21 cases, whereas the oldest age group (> or = 70 years old) exhibited areae gastricae in 19 (76%) of 25 cases. On average, the rate of visualization of areae gastricae on double-contrast studies increased by 9% per decade.Our data show that the frequency of visualization of areae gastricae on double-contrast upper gastrointestinal tract examinations increases significantly with increasing patient age. It is important for radiologists to be aware of the effect of aging on the delineation of areae gastricae on double-contrast studies.

    View details for Web of Science ID 000169457900012

    View details for PubMedID 11418398

  • Accuracy of MR imaging for staging prostate cancer: A meta-analysis to examine the effect of technologic change ACADEMIC RADIOLOGY Sonnad, S. S., Langlotz, C. P., Schwartz, J. S. 2001; 8 (2): 149-157

    Abstract

    The purpose of this study was to summarize the accuracy of magnetic resonance (MR) imaging for staging prostate cancer and to determine the effect of high magnetic field strength, use of the endorectal coil, use of fast spin-echo (SE) imaging, and study size on staging accuracy.A literature search and review yielded 27 studies comparing MR imaging to a pathologic standard in patients with clinically limited prostate cancer. Subgroup analyses examined magnetic field strength, use of an endorectal coil, use of fast SE imaging, publication date, and study size.A summary receiver operating characteristic curve for all studies had a maximum joint sensitivity and specificity of 74%. At a specificity of 80% on this curve, sensitivity was 69%. Subgroup analyses showed that fast SE imaging was statistically significantly more accurate than conventional SE techniques (P < .001). Unexpectedly, studies employing higher magnetic field strength and those employing an endorectal coil were less accurate.Seemingly small technologic advances may influence test accuracy. Early and small studies, however, may overstate accuracy because of publication bias, bias in small samples, or earlier studies being performed by the experts who developed the technology itself.

    View details for Web of Science ID 000168770500005

    View details for PubMedID 11227643

  • Economic consequences of diagnostic imaging for vocal cord paralysis ACADEMIC RADIOLOGY Liu, A. Y., Yousem, D. M., Chalian, A. A., Langlotz, C. P. 2001; 8 (2): 137-148

    Abstract

    The purpose of this retrospective study was to estimate the economic consequences of evaluating suspected vocal cord paralysis with magnetic resonance (MR) imaging and computed tomography (CT).Reports from MR imaging (n = 30) or CT (n = 19) studies of the neck in 49 patients were retrospectively reviewed for causes of vocal cord paralysis. The patients were divided into high-suspicion (n = 20) and low-suspicion (n = 29) groups, based on the presence or absence of a clinically detectable abnormality other than vocal cord immobility. Clinic and inpatient charts were examined to determine the work-up in all cases. The Medicare Resource-based Relative Value Scale was used to estimate the costs of most procedures.The high-clinical-suspicion group included nine true-positive, four false-positive, seven true-negative, and no false-negative cases. Further work-up was performed in seven true-positive, three false-positive, and one true-negative cases. The total cost of immediate diagnostic work-up in these 20 patients, including MR imaging and/or CT, was $20,737 ($2,304 per true-positive case). The low-suspicion group included two true-positive, nine false-positive, 18 true-negative, and no false-negative cases. Further work-up was performed in both true-positive, four false-positive, and two true-negative cases. The total cost of immediate diagnostic work-up in these 29 patients was $21,698, (mean, $748; $10,849 per true-positive case).The average cost of finding space-occupying lesions in patients with vocal cord paralysis is more than 4.5 times higher in patients without suspicious antecedent clinical findings than in those with such a history. The benefits of obtaining negative findings and of detecting a small number of space-occupying lesions should be weighed against the costs of such examinations and of additional work-up for false-positive findings.

    View details for Web of Science ID 000168770500004

    View details for PubMedID 11227642

  • Prostate Cancer: What is the future role for imaging? AMERICAN JOURNAL OF ROENTGENOLOGY Thornbury, J. R., Ornstein, D. K., Choyke, P. L., Langlotz, C. P., Weinreb, J. C. 2001; 176 (1): 17-22

    View details for Web of Science ID 000166074000003

    View details for PubMedID 11133530

  • Readings in clinical imaging research: A structured bibliography ACADEMIC RADIOLOGY Langlotz, C. P. 2000; 7 (10): 880-890

    View details for Web of Science ID 000089729500012

    View details for PubMedID 11048884

  • Accuracy of CT angiography versus pulmonary angiography in the diagnosis of acute pulmonary embolism: Evaluation of the literature with summary ROC curve analysis ACADEMIC RADIOLOGY Harvey, R. T., Gefter, W. B., Hrung, J. M., Langlotz, C. P. 2000; 7 (10): 786-797

    Abstract

    The authors performed this study to estimate, by using published data, the sensitivity and specificity of computed tomographic (CT) angiography in the evaluation of suspected acute pulmonary embolism (PE).Summary receiver operating characteristic (ROC) curve analysis was used to determine the sensitivity and specificity of CT angiography in the diagnosis of acute PE. Pulmonary angiography was used as the diagnostic standard of reference. The authors reviewed the results of 11 independent studies published in the English-language literature between January 1992 and June 1999.The sensitivity of CT angiography in the diagnosis or exclusion of PE in the central pulmonary arteries (to the level of the segmental pulmonary arteries) ranged from 0.74 to 0.81 on the basis of specificities of 0.89-0.91. The sensitivity of CT angiography in the diagnosis or exclusion of PE in all pulmonary arteries (to the level of the subsegmental pulmonary arteries) was 0.68 on the basis of a specificity of 0.91.On the basis of the studies in the current literature, most of which used 5.0-mm collimation and single-detector CT, CT angiography may be less accurate in the diagnosis of PE than previously reported. With improvements in data acquisition, particularly the use of thinner section collimation and multidetector CT, and in the increased use of workstations for data analysis, the accuracy and utility of CT angiography will require continued investigation.

    View details for Web of Science ID 000089729500002

    View details for PubMedID 11048876

  • Diagnosis of primary versus secondary achalasia: Reassessment of clinical and radiographic criteria AMERICAN JOURNAL OF ROENTGENOLOGY Woodfield, C. A., Levine, M. S., Rubesin, S. E., Langlotz, C. P., Laufer, I. 2000; 175 (3): 727-731

    Abstract

    Our purpose was to reassess the usefulness of barium studies and various clinical parameters for differentiating primary from secondary achalasia.Radiology files from 1989 through 1999 revealed 29 patients with primary achalasia and 10 with secondary achalasia (caused by carcinoma of the esophagus in three, of the gastric cardia in three, of the lung in three, and of the uterus in one) who met our study criteria. The radiographs were reviewed to determine the morphologic features of the narrowed distal esophageal segment and gastric cardia and fundus. Medical records were also reviewed to determine the clinical presentation; endoscopic, manometric, and surgical findings; and treatment.The mean patient age was 53 years in primary achalasia versus 69 years in secondary achalasia (p = 0.03). The mean duration of dysphagia was 4.5 years in primary achalasia versus 1.9 months in secondary achalasia (p <0.0001). The narrowed distal esophageal segment had a mean length of 1.9 cm in primary achalasia versus 4.4 cm in secondary achalasia (p < 0.0001), and the esophagus had a mean diameter of 6.2 cm in primary achalasia versus 4.1 cm in secondary achalasia (p <0.0001). The narrowed segment was eccentric or nodular or had abrupt proximal borders in only four of 10 patients with secondary achalasia, and evidence of tumor was present in the gastric fundus in only three.When findings of achalasia are present on barium studies, a narrowed distal esophageal segment longer than 3.5 cm with little or no proximal dilatation in a patient with recent onset of dysphagia should be considered highly suggestive of secondary achalasia, even in the absence of other suspicious radiographic findings.

    View details for Web of Science ID 000088910300025

    View details for PubMedID 10954457

  • The costs of CT procedures in an academic radiology department determined by an activity-based costing (ABC) method JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY Nisenbaum, H. L., Birnbaum, B. A., Myers, M. M., Grossman, R. I., Gefter, W. B., Langlotz, C. P. 2000; 24 (5): 813-823

    Abstract

    The purpose of this work was to determine the costs of computed tomography (CT) procedures in a large academic radiology department, including both professional (PC) and technical (TC) components, by analyzing actual resource consumption using an activity-based costing (ABC) method and comparing them with Medicare payments.Over a 12 month period from July 1, 1996, to June 30, 1997, 1,011 CT procedures, representing 16 Physicians' Current Procedural Terminology (CPT) codes and 98.3% of CT studies performed, were carefully observed by a research assistant trained in ABC methodology. Information collected during these time and motion studies included personnel/machine time and direct materials used. Actual resource units used during the different activities in each CT procedure were valued using appropriate cost drivers. Unit values for both direct and overhead costs were calculated: the cost of an individual procedure equaled the sum of component costs. Costs were compared with PC and TC payments according to the 1997 Medicare Fee Schedule.Total costs of CPT codes 70450 (CT Head unenhanced), 71260 (CT Chest enhanced), and 74160 (CT Abdomen enhanced), which represented 71.2% of CT studies performed, were $189.19, $273.53, and $343.20, respectively. For all 16 nonmodified CPT codes analyzed, Medicare's professional reimbursement was less than the professional cost, whereas its technical reimbursement exceeded respective cost in 14 of the 16 codes.In the setting and time period studied, Medicare underreimbursed professional costs while overreimbursing technical costs.

    View details for Web of Science ID 000089727900026

    View details for PubMedID 11045708

  • Enhancing the expressiveness of structured reporting systems JOURNAL OF DIGITAL IMAGING Langlotz, C. P. 2000; 13 (2): 49-53

    Abstract

    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.

    View details for Web of Science ID 000087339000013

    View details for PubMedID 10847362

  • A picture archival and communication system shortens delays in obtaining radiographic information in a medical intensive care unit CRITICAL CARE MEDICINE Redfern, R. O., Kundel, H. L., Polansky, M., Langlotz, C. P., Horii, S. C., Lanken, P. N. 2000; 28 (4): 1006-1013

    Abstract

    To assess whether variables such as unit occupancy and aggregate severity of illness that reflect increased work demands on physicians in medical intensive care units (MICU) are associated with increased delays in their obtaining information about nonroutine chest radiographic examinations. To determine whether the presence of a picture archiving and communication system (PACS) workstation in the MICU shortens those delays.A prospective cohort study stratified for presence or absence of PACS.MICU of a university hospital.A total of 118 patients admitted to the MICU who had nonroutine bedside chest radiographs.Multivariate analyses were conducted to determine how unit occupancy, patient acuity, the time of day the examination was taken, and the presence of a PACS workstation influenced the time from radiographic examination completion to the time when MICU physicians first obtained image information. In a multivariate analysis, patient acuity, unit occupancy, the aggregate level of severity of illness in the study cohort, whether the examination was taken at night or day, and the presence of a PACS workstation were significant predictors of the elapsed time from examination completion until review by MICU physicians. Without the PACS workstation, higher occupancy, higher aggregate severity of illness, and examinations taken during the day were associated with longer delays. Overall, the multivariate analysis showed a 24-min decrease in the elapsed time to obtain information during periods with the PACS workstation compared with periods without the workstation (p = .03).A PACS workstation significantly decreased the delays in obtaining image information that occurred with high unit occupancy and high aggregate severity of illness and may improve unit efficiency under conditions of high physician workload.

    View details for Web of Science ID 000086862800016

    View details for PubMedID 10809274

  • Enhancing the expressiveness and usability of structured image reporting systems JOURNAL OF THE AMERICAN MEDICAL INFORMATICS ASSOCIATION Langlotz, C. P., Meininger, L. 2000: 467-471

    Abstract

    We have implemented a structured reporting system for medical imaging that replaces dictation and transcription by allowing radiologists and other imaging professionals to select imaging findings from medical lexicons. The system uses an imaging-specific information model called a Description Set to organize selected terms in a relational database. The system's expressiveness for reporting is enhanced by its ability to codify uncertainty about imaging observations and to represent explicit causal and associational relationships among imaging findings. The system promptly and automatically generates a text report that referring physicians are accustomed to receiving. Because the image report information is stored in a fully coded fashion, it can be used to provide real-time decision support to radiologists, to transmit coded imaging data to electronic patient record systems, to measure and improve radiologists' performance, and to index images by content.

    View details for Web of Science ID 000170207500096

    View details for PubMedID 11079927

  • Cost-effectiveness of MR imaging and core-needle biopsy in the preoperative work-up of suspicious breast lesions RADIOLOGY Hrung, J. M., Langlotz, C. P., Orel, S. G., Fox, K. R., Schnall, M. D., Schwartz, J. S. 1999; 213 (1): 39-49

    Abstract

    To assess the clinical and economic consequences of the use of preoperative breast magnetic resonance (MR) imaging and core-needle biopsy (CNB) to avert excisional biopsy (EXB).A decision-analytic Markov model was constructed to compare MR imaging, CNB, and EXB without preoperative testing in a woman with a suspicious breast lesion. Stage-specific cancer prevalence, tumor recurrence, progression rates, and MR imaging and CNB sensitivity and specificity were obtained from the literature. Cost estimates were obtained from the literature and from the Medicare fee schedule.EXB without preoperative testing was associated with the greatest quality-adjusted life expectancy, followed by MR imaging and CNB; life expectancies were 17.409, 17.405, and 17.398 years, respectively. EXB resulted in the greatest lifetime treatment cost ($31,438), followed by MR imaging ($29,072) and CNB ($28,573). Results were robust over a wide range of cancer prevalence, stage distribution, tumor progression rates, and procedure and treatment costs. Incremental cost-effectiveness ratios showed that preoperative testing was cost-effective, but the choice between MR imaging and CNB was highly dependent on the accuracy of each test and to patient preferences.Preoperative testing of most suspicious breast lesions was cost-effective. More precise estimates of MR imaging and CNB test performance characteristics are needed. Until those are available, patient preferences should inform individual decisions regarding preoperative testing.

    View details for Web of Science ID 000082771900010

    View details for PubMedID 10540638

  • Accuracy of MR imaging in the work-up of suspicious breast lesions: A diagnostic meta-analysis ACADEMIC RADIOLOGY Hrung, J. M., Sonnad, S. S., Schwartz, J. S., Langlotz, C. P. 1999; 6 (7): 387-397

    Abstract

    The authors performed a systematic, critical review of the literature on magnetic resonance (MR) imaging for primary breast cancer detection in patients with suspicious breast lesions, analyzed MR test performance in the articles meeting study criteria, and used this information to examine the cost-effectiveness of preoperative MR imaging.A structured, predefined MEDLINE search was conducted to identify potentially relevant, peer-reviewed, English-language references from January 1996 through August 1997 on the diagnostic accuracy of breast MR imaging. This information was supplemented by manually searching bibliographies of the retrieved articles for additional potentially relevant references. All studies were independently abstracted by two reviewers using a prospectively designed worksheet. Abstraction results were analyzed with the summary receiver operating characteristic (ROC) method.Of 41 identified studies, 16 met the inclusion criteria. These studies reported sensitivities ranging from 63% to 100% and specificities ranging from 21% to 100%. Maximum joint sensitivity and specificity of the summary ROC curve was 89% (95% confidence interval [CI]: 82%, 93%). At a sensitivity of 95%, specificity was 67%. When test performance values were applied to a previous cost-effectiveness analysis, the cost-effectiveness of preoperative MR imaging relative to that of excisional biopsy was confirmed, but its cost-effectiveness relative to that of needle core biopsy varied widely.For MR imaging to be a cost-effective alternative to excisional biopsy for diagnosis of suspicious breast lesions, its diagnostic test performance must be equal to or better than the best results in recently published studies.

    View details for Web of Science ID 000086033200003

    View details for PubMedID 10410164

  • Gastrointestinal imaging: A systems analysis comparing digital and conventional techniques AMERICAN JOURNAL OF ROENTGENOLOGY Chawla, S., Levine, M. S., Laufer, I., Gingold, E. L., Kelly, T. J., Langlotz, C. P. 1999; 172 (5): 1279-1284

    Abstract

    The purpose of this study was to compare digital and conventional methods of gastrointestinal imaging based on the cost of image storage and estimated overall costs, radiation exposure to the patient, and duration of the examination.Our study sample consisted of 128 patients who underwent conventional gastrointestinal studies (64 double-contrast upper gastrointestinal examinations and 64 double-contrast barium enemas) and 139 patients who underwent digital gastrointestinal studies (66 double-contrast upper gastrointestinal examinations and 73 double-contrast barium enemas). The number of images and films for each study was recorded, and the mean cost of image storage and the estimated overall costs for digital versus conventional studies were calculated. Both the duration of fluoroscopy and the time from start to completion of the study were obtained from our radiology information system. From these data, we calculated mean radiation exposure to the patient and the duration of the examination. Finally, referring physicians completed a questionnaire about their level of satisfaction with paper prints generated from digital gastrointestinal studies.When digital studies were compared with conventional studies, the mean cost of image storage decreased by 45% and the estimated overall 10-year costs decreased by 8%. The mean number of spot images increased by 8% for upper gastrointestinal examinations and by 25% for barium enema examinations, whereas the mean duration of fluoroscopy decreased by 4% and by 10%, respectively. As a result, radiation exposure to patients increased by only 2%, a difference that did not approach statistical significance. Finally, the mean duration of examinations decreased by 24% for upper gastrointestinal examinations and by 33% for barium enemas. Approximately 85% of the physicians who completed the questionnaires indicated that they reviewed the paper prints generated from digital studies and that they would like to continue receiving them.Digital gastrointestinal imaging systems are associated with higher initial costs than conventional systems, but the long-term costs of these digital imaging systems are slightly less because of the lower cost of image storage, and radiation exposure to patients is comparable. The shorter duration of digital examinations is a potential benefit of this technology, allowing improved patient throughput. Finally, referring physicians have a high level of satisfaction with paper prints generated from digital imaging.

    View details for Web of Science ID 000079919700020

    View details for PubMedID 10227502

  • Assessment of a bolus-traching technique in helical renal CT to optimize nephrographic phase imaging RADIOLOGY Birnbaum, B. A., Jacobs, J. E., Langlotz, C. P., Ramchandani, P. 1999; 211 (1): 87-94

    Abstract

    To evaluate a bolus-tracking technique in helical computed tomography (CT) for identifying the onset of the nephrographic phase and to determine the effect of varying the volume and injection rate of contrast material on nephrographic phase onset.Seventy-five patients underwent bolus tracking of contrast material followed by helical renal CT. In 50 patients, 150 mL of 60% iodinated contrast material (iohexol or iothalamate meglumine) was injected at either 2 mL/sec (25 patients [group 1]) or 3 mL/sec (25 patients [group 2]). In 25 patients who had previously undergone nephrectomy, 100 mL of 60% iodinated contrast material was injected at 3 mL/sec (group 3). Nephrographic phase onset was determined by visually assessing the transition to a homogeneous nephrogram during a monitoring scan series starting 40 seconds after injection.Nephrographic phase onset ranged from 60 to 136 seconds (mean, 89 seconds +/- 17 [+/- SD]). Statistically significant differences in mean onset times were observed among groups 1 (103 seconds +/- 12), 2 (91 seconds +/- 16), and 3 (75 seconds +/- 9) (P < .001). Multiple regression analysis showed patient age, contrast material volume, and injection rate to be independent predictors of nephrographic phase onset. Contrast material volume, patient age, and patient weight were independent predictors of the degree of renal enhancement.Nephrographic phase onset is highly dependent on methods of contrast material administration and patient characteristics.

    View details for Web of Science ID 000079323200013

    View details for PubMedID 10189457

  • Overcoming barriers to outcomes research on imaging: lessons from an abstract decision model. Academic radiology Langlotz, C. P. 1999; 6: S29-34

    View details for PubMedID 9891164

  • A critical synopsis of the diagnostic and screening radiology outcomes literature. Academic radiology Blackmore, C. C., Black, W. C., Jarvik, J. G., Langlotz, C. P. 1999; 6: S8-18

    Abstract

    In summary, the radiology outcomes research literature is both extensive and broad. The methodologic quality, however, is quite variable. Overall, this quality could be improved by intervention in two areas: methodologic dissemination and development. The number of researchers investigating radiology-related outcomes is high, and presently there are over 20 journals devoted exclusively to radiology research. Even with a relatively narrow definition of "outcomes," we identified over 200 radiology outcomes studies, most from the past few years. However, the methodologic quality of most of these articles was relatively low, with important design flaws and biases. Nonetheless, a substantial number of radiology publications do employ state-of-the-art research methods and innovative approaches to methodologic challenges. The quality of radiology outcomes research overall would benefit tremendously from dissemination of such research methods. Instruction in outcomes research methods is accessible to radiologists. For example, there have been several recent articles and series of articles on outcomes research methods in JAMA, including guidelines for the performance and reporting of cost-effectiveness analyses (38-40) and for developing clinical prediction rules (57). Within radiology, several recent articles have appeared on, among other things, cost-effectiveness analysis (34,59,60), assessing quality of life (43), screening for disease (53), and defining the study population (61). The research compendium compiled for the GERRAF (General Electric-Association of University Radiologists Radiology Research Academic Fellowships) program remains a comprehensive methodologic source for many of the issues in radiology outcomes research, and outcomes research methods courses are offered every year at the Society for Health Services Research in Radiology and Society for Medical Decision Making meetings, as well as at the meeting of the Radiological Society of North America. Even so, awareness of the need for such research techniques remains limited. Dissemination of sound research methods is limited at least in part by the current incentives in radiology research. At many institutions, the number of research publications produced, rather than their quality, determines promotion or academic success. Unfortunately, more rigorous study designs often require more time and resources. Further, because peer reviewers are often as uninformed about research methods as the bulk of those who are submitting manuscripts, it may actually be more difficult to publish articles with more advanced methodologic designs. The standard in radiology is the uncontrolled case series, and deviation from the standard may make acceptance for publication more difficult. On a more optimistic note, recent publication of a number of methodology articles suggests that at least some journals are promoting improved research in methodology (43,53,59-61). We hope that time will be available for manuscript reviewers to learn to understand the strengths and weaknesses of various research approaches. If more rigorous study designs were required for publication, radiology outcomes research would probably improve drastically. Nevertheless, the current peer-review system does not effectively promote sound research design. The other great incentive in research is funding. Clearly, if advanced research design is required for funding, then there is incentive for improvement in research quality. Traditionally, National Cancer Institute and other National Institutes of Health and public sector funding has been predicated on a high level of research sophistication. Undoubtedly, availability of grants for diagnostic and screening imaging clinical trials and other research will go far to improve radiology research methods. The other traditional source of research funding is industry.

    View details for PubMedID 9891161

  • Correlation of lesion appearance and histologic findings for the nodes of a breast MR imaging interpretation model RADIOGRAPHICS Nunes, L. W., Schnall, M. D., Orel, S. G., Hochman, M. G., Langlotz, C. P., Reynolds, C. A., Torosian, M. H. 1999; 19 (1): 79-92

    Abstract

    An interpretation model for evaluating magnetic resonance (MR) images of the breast was constructed that allowed differentiation of benign from malignant palpable or mammographically visible abnormalities. Architectural features define each node of the model. Investigation was subsequently made of the histologic findings in individuals within each node and of the frequency with which each histologic finding manifested as a particular architectural feature to determine whether nodal location and specific histologic findings are mutually predictive. The strongest associations were found between fibrocystic change and smooth masses, fibroadenoma and lobulated masses with nonenhancing internal septations, invasive ductal carcinoma (with or without ductal carcinoma in situ [DCIS]) and enhancing irregular or spiculated masses, invasive tubular carcinoma or radial scar and spiculated masses, medullary or colloid carcinoma and enhancing lobulated masses, invasive lobular carcinoma and the absence of a focal mass, DCIS and ductal enhancement, and DCIS (with or without invasive ductal carcinoma) and regional enhancement. Nodal location and histologic findings proved to be mutually predictive within the model; that is, the nodal location of MR imaging features within the model can be used to predict histologic findings and vice versa.

    View details for Web of Science ID 000078106700010

    View details for PubMedID 9925393

  • Use sf endorectal MR imaging to predict prostate carcinoma recurrence after radical prostatectomy RADIOLOGY Manzone, T. A., Malkowicz, S. B., Tomaszewski, J. E., Schnall, M. D., Langlotz, C. P. 1998; 209 (2): 537-542

    Abstract

    To determine the ability of endorectal magnetic resonance (MR) imaging to help predict postprostatectomy disease recurrence and, thereby, patient outcome.The authors evaluated 116 patients referred for prostate MR imaging during 1991 and 1992 who subsequently underwent radical prostatectomy and for whom follow-up data through 1996 could be obtained. The MR reports, clinic charts, and pathology reports were reviewed. Disease recurrence was established by means of detectable levels of serum prostate-specific antigen (PSA) after surgery.Thirty-four patients (29%) had postoperative disease recurrence. Patients with recurrence had higher preoperative PSA values (P < .0001). These patients also more frequently had positive surgical margins (P = .0005), transcapsular tumor spread (P < .0001), seminal vesicle involvement (P = .0012), and tumors of advanced stage (P < .0001) and high grade (P = .0058). Of 13 patients whose MR examinations showed definite extracapsular disease, eight (62%) had disease recurrence. The recurrence rate when MR imaging indicated limited disease (24%) was similar to that when MR imaging showed possible microscopic extension (27%). An MR finding of definite extracapsular disease was 24% sensitive and 94% specific for the prediction of disease recurrence.MR imaging findings of definite extracapsular spread of disease helped predict prostate tumor recurrence with high specificity, although with low sensitivity.

    View details for Web of Science ID 000076618000039

    View details for PubMedID 9807586

  • Contrast media reactions and extravasation: Relationship to intravenous injection rates RADIOLOGY Jacobs, J. E., Birnbaum, B. A., Langlotz, C. P. 1998; 209 (2): 411-416

    Abstract

    To evaluate the belief that the frequencies of contrast material extravasation and minor, nonidiosyncratic contrast material reactions correlate with intravenous injection rates.Complications of 6,660 consecutive injections of contrast material for computed tomography were prospectively recorded. Ionic (n = 4,851) or nonionic (n = 1,809) contrast material was injected at 0.5-4.0 mL/sec. The injection rate was 1.9 mL/sec or less in group 1 (n = 2,899), 2.0-2.9 mL/sec in group 2 (n = 2,475), and 3.0-4.0 mL/sec in group 3 (n = 1,286).The extravasation rate (0.6%) did not differ significantly between the groups. The reaction rate (8.4%) also did not differ significantly between the groups. The rate of minor reactions (8.0%) was higher with ionic (9.9%) than nonionic (2.9%) contrast material (relative risk = 3.4). The rate of major reactions (0.4%) did not vary significantly with type of contrast material. The rate of nausea or vomiting (3.8%) did not differ significantly between the groups but was higher with ionic (4.9%) than nonionic (1.1%) contrast material (relative risk = 4.5). The rate of severe warmth (2.1%) was significantly higher in group 3 (2.8%) than group 1 (2.0%) or 2 (1.8%).No correlations exist between injection rate and extravasation rate or overall reaction rate.

    View details for Web of Science ID 000076618000021

    View details for PubMedID 9807567

  • Meta-analysis of diagnostic procedures: A brief overview ACADEMIC RADIOLOGY Langlotz, C. P., Sonnad, S. S. 1998; 5: S269-S273

    View details for Web of Science ID 000075665200008

    View details for PubMedID 9750829

  • MR identification of white matter abnormalities in multiple sclerosis: A comparison between 1.5 T and 4 T AMERICAN JOURNAL OF NEURORADIOLOGY Keiper, M. D., Grossman, R. I., Hirsch, J. A., Bolinger, L., Ott, I. L., Mannon, L. J., Langlotz, C. P., Kolson, D. L. 1998; 19 (8): 1489-1493

    Abstract

    Although MR spectroscopy and functional MR imaging of the brain have been successful at 4 T, conventional fast spin-echo imaging of the brain at 4 T has not been adequately evaluated. The purpose of this study was to compare the detection of white matter abnormalities in multiple sclerosis (MS) at 1.5 T and 4 T.Fifteen patients with clinically definite MS were imaged at both 1.5 T and 4 T within a 1-week period. Comparison was made between fast spin-echo long-TR images at both field strengths. Pulse sequences were tailored to maximize resolution and signal-to-noise ratio in clinically relevant imaging times (< 7 min). Four interpreters independently reviewed the images obtained at both field strengths in separate sessions and evaluated them for lesion identification, size, characterization, and subjective resolution. Differences in interpretations at 1.5 T and 4 T were subsequently recorded.Images obtained at 4 T showed a mean of 88 more lesions as compared with images obtained at 1.5 T. All the lesions measured less than 5 mm and were typically aligned along perivascular spaces. Twenty-five consensually identified lesions on 4-T images were not seen at all on 1.5-T images. Moreover, 4-T images showed 56 additional consensually identified lesions, which were indistinct and seen only in retrospect on 1.5-T images. These lesions were frequently (n = 48) identified in large confluent areas of white matter signal intensity abnormality at 1.5 T. All observers also agreed that 4-T images subjectively enhanced the perception of normal perivascular spaces and small perivascular lesions.MR imaging at 4 T can depict white matter abnormalities in MS patients not detectable at 1.5 T through higher resolution with comparable signal-to-noise ratio and imaging times.

    View details for Web of Science ID 000076039600024

    View details for PubMedID 9763383

  • Patient preference for magnetic resonance versus conventional angiography - Assessment methods and implications for cost-effectiveness analysis: An overview INVESTIGATIVE RADIOLOGY Swan, J. S., Langlotz, C. P. 1998; 33 (9): 553-559

    View details for Web of Science ID 000075842800011

    View details for PubMedID 9766040

  • Diagnostic criteria for fatty infiltration of the liver on contrast-enhanced helical CT AMERICAN JOURNAL OF ROENTGENOLOGY Jacobs, J. E., Birnbaum, B. A., Shapiro, M. A., Langlotz, C. P., Slosman, F., Rubesin, S. E., Horii, S. C. 1998; 171 (3): 659-664

    Abstract

    The purpose of the study was to develop quantitative and qualitative criteria for diagnosing fatty liver on contrast-enhanced helical CT.Differential liver-spleen attenuation was evaluated between 80 and 120 sec after injection in 76 patients who underwent contrast-enhanced helical CT. Unenhanced CT images had earlier established fatty liver when the liver minus spleen attenuation difference was less than or equal to -10 H (n = 18). Four observers who had not seen the unenhanced images used contrast-enhanced CT images to assess the presence of fatty liver on a five-point Likert scale, the presence of geographic areas spared from fatty infiltration, and the relative liver-spleen attenuation. The diagnostic accuracies of various imaging criteria were compared using McNemar's chi-square test (for sensitivity and specificity) and analysis of receiver operating characteristic curves.Sensitivity, specificity, and receiver operating characteristic curve areas for observers' qualitative judgments were 54%, 95%, and .91, respectively; for quantitative differential liver-spleen attenuation (80-100 sec; -20.5 H discriminatory value), the values were 86%, 87%, and .94, respectively; and for quantitative differential liver-spleen attenuation (101-120 sec; -18.5 H discriminatory value), the values were 93%, 93%, and .98, respectively. Differential liver-spleen attenuation was time-dependent; overlap was noted between healthy subjects and patients with fatty liver. Qualitatively, geographic sparing was highly specific (94%) for fatty liver, whereas liver attenuation greater than or equal to spleen attenuation excluded fatty liver in all but one case.Although quantitative and qualitative criteria for diagnosing fatty liver on helical CT can be determined, they are protocol-specific. Limited unenhanced hepatic CT remains the optimal technique for detection of fatty infiltration of the liver.

    View details for Web of Science ID 000075496700026

    View details for PubMedID 9725292

  • Reperfusion edema after thromboendarterectomy: Radiographic patterns of disease JOURNAL OF THORACIC IMAGING Miller, W. T., Osiason, A. W., Langlotz, C. P., Palevsky, H. I. 1998; 13 (3): 178-183

    Abstract

    In patients with chronic pulmonary embolism, pulmonary thromboendarterectomy may result in a unique form of noncardiogenic pulmonary edema termed reperfusion edema. This report reviews the authors' experience after pulmonary thromboendarterectomy with particular emphasis on the radiographic manifestations of reperfusion edema. The clinical and radiographic record of 25 patients who underwent pulmonary thromboendarterectomy at the University of Pennsylvania from 1985 through 1995 were reviewed. The zonal distribution of radiographic opacity, time to maximal opacity, and the time to clearance of reperfusion edema were determined. The relationship of these radiographic manifestations to clinical severity of disease and clinical outcome was examined. Reperfusion edema, characterized by patchy bilateral perihilar alveolar opacities, occurred in all but one patient. There is a lower lung zone predominance of opacities, but in individual cases, striking unilateral or haphazard arrangements of opacities may be seen. In this small sample of patients, no association between preoperative pulmonary arterial pressures and radiographic appearance or clinical outcome was found. However, severity of radiographic opacities, as measured by the extent of involved lung, correlated with disease severity, as measured by time to extubation and time to discharge. Pneumonia, defined as a radiographic opacity that evolves discordantly with the reperfusion edema opacities, occurred in 20% of cases. Reperfusion edema is a common consequence of pulmonary thromboendarterectomy. The severity of radiographic manifestations and clinical severity of disease are related. This characteristically appears as perihilar alveolar opacities.

    View details for Web of Science ID 000074500700003

    View details for PubMedID 9671419

  • Extracranial atherosclerotic carotid artery disease: Evaluation of non-breath-hold three-dimensional gadolinium-enhanced MR angiography AMERICAN JOURNAL OF ROENTGENOLOGY Slosman, F., Stolpen, A. H., Lexa, F. J., Schnall, M. D., Langlotz, C. P., Carpenter, J. P., Goldberg, H. I. 1998; 170 (2): 489-495

    Abstract

    The purpose of this study was to compare the diagnostic information provided by a combination of two-dimensional and three-dimensional (3D) time-of-flight (TOF) techniques with that provided by non-breath-hold 3D spoiled gradient-echo gadolinium-enhanced MR angiography.Fifty patients suspected of having extracranial atherosclerotic carotid artery disease were examined with all three imaging techniques using a 1.5-T MR imaging system. Three observers independently and retrospectively measured the degree of stenosis according to the North American Symptomatic Carotid Endarterectomy trial criteria. The observers were unaware of the results of other MR imaging pulse sequences and digital subtraction angiography. The standard of reference was established by digital subtraction angiography. Results were evaluated with receiver operating characteristic curve analysis. The degree of interobserver agreement was determined using pairwise kappa statistics.The grading of carotid artery stenosis as measured by the area under the receiver operating characteristic curve was less accurate with non-breath-hold 3D gadolinium-enhanced MR angiography than with TOF imaging. Interobserver variability was greater for non-breath-hold 3D gadolinium-enhanced MR angiography than for TOF techniques.Routine evaluation of carotid artery stenosis at the level of the bifurcation using non-breath-hold 3D gadolinium-enhanced MR angiography is less accurate than is TOF imaging and is therefore not recommended. The weakness of this technique may be due to problems in timing the injection of gadolinium and the masking of the carotid bifurcation by the venous jugular system.

    View details for Web of Science ID 000071619500049

    View details for PubMedID 9456971

  • Prototype controls for a plain radiography workstation MEDICAL IMAGING 1998 - PACS DESIGN AND EVALUATION: ENGINEERING AND CLINICAL ISSUES Horii, S. C., Grevera, G., Feingold, E., Kundel, H., Mezrich, R., Nodine, C., Langlotz, C. P., Redfern, R., Muck, J., Phelan, M., Scoleri, S. 1998; 3339: 87-91
  • Factors influencing the adoption of digital imaging systems MEDICAL IMAGING 1998 - PACS DESIGN AND EVALUATION: ENGINEERING AND CLINICAL ISSUES Langlotz, C. P., Pratt, H. M., Feingold, E. R., Horii, S. C., Kundel, H. L. 1998; 3339: 421-428
  • Assessing the impact of a radiology information management system in the emergency department MEDICAL IMAGING 1998 - PACS DESIGN AND EVALUATION: ENGINEERING AND CLINICAL ISSUES Redfern, R., Langlotz, C. P., Lowe, R. A., Horii, S. C., Abbuhl, S. B., Kundel, H. L. 1998; 3339: 414-420
  • Clinical and economic impact of incidental thyroid lesions found with CT and MR AMERICAN JOURNAL OF NEURORADIOLOGY Yousem, D. M., Huang, T., Loevner, L. A., Langlotz, C. P. 1997; 18 (8): 1423-1428

    Abstract

    To estimate the prevalence and the clinical and economic consequences of management strategies for thyroid lesions detected incidentally on cross-sectional imaging of the head and neck.Two hundred consecutive CT scans and 200 consecutive MR images of the neck performed over a 1-year period in patients being examined for other purposes were reviewed retrospectively to determine the prevalence of unexpected thyroid lesions. After excluding patients with prior thyroidectomies, known thyroid disease, and inadequate examinations, 231 imaging studies were analyzed.Incidental thyroid lesions were originally reported in 14 (6%) of the 231 patients, but an additional 22 (9.5%) were found on retrospective review for a total of nearly 16% (36 of 231). Six of the 36 patients received further workup, consisting of nuclear medicine scintigraphy (n = 3), sonography (n = 3), thyroid function tests (n = 5), fine-needle aspiration (n = 4), and thyroid lobectomy (n = 1). Final diagnoses, obtained in four of the six patients, included three multinodular goiters and one follicular adenoma. Two patients, one with nondiagnostic findings at fine-needle aspiration and a second with normal thyroid function test results, are being followed up. The mean cost of the workup and treatment per examined patient was $1158.Incidental thyroid lesions are frequently present and often overlooked on cross-sectional images of the neck in patients being examined for other reasons. The cost of pursuing a workup of these lesions and their high prevalence in the population raise questions regarding appropriate management strategies.

    View details for Web of Science ID A1997XV50000005

    View details for PubMedID 9296181

  • Prostate imaging may not be necessary in nonpalpable carcinoma of the prostate UROLOGY WERNERWASIK, M., Whittington, R., Malkowicz, S. B., Corn, B. W., Arger, P., REISINGER, S., Langlotz, C., Alexander, A., Damico, A. V., Hyslop, T., Gomella, L., BROWNSTEIN, K., WEIN, A. J. 1997; 50 (3): 385-389

    Abstract

    Stage T1c carcinoma of the prostate is defined as a nonpalpable carcinoma (NPC-P) that is not visible by imaging and is identified by needle biopsy performed because of elevated prostate-specific antigen (PSA) concentrations. The purpose of this study was to define the incidence of normal findings on transrectal ultrasound (TRUS) and/or endorectal coil magnetic resonance imaging (EMRI) among patients with NPC-P, as well as to investigate the value of differentiating patients with Stage T1c disease from all other patients with NPC-P.The records of 2211 patients diagnosed with prostate carcinoma between 1988 and 1995 were reviewed to identify 291 men with NPC-P. TRUS and EMRI reports were analyzed with regard to the presence and laterality of hypoechoic nodules or low-signal areas reported on T2-weighted images, respectively. Ninety percent of patients (n = 262) had at least six prostate biopsies, 185 patients (64%) underwent both TRUS and EMRI, 224 (77%) had TRUS, and 251 (86%) had an EMRI study.Results were considered normal in 101 (47%) of 214 patients undergoing TRUS, in 58 (23%) of 249 undergoing EMRI, and in 22 (12%) of 185 undergoing both TRUS and EMRI. For the side of the prostate with positive biopsy results, correlation with imaging abnormalities was better for EMRI than for TRUS (39% versus 24%). There was no significant difference in mean PSA value, distribution of Gleason score, or unilateral versus bilateral positive biopsy results among patients with normal versus abnormal findings on both TRUS and EMRI.(1) Only 12% of men with NPC-P have no TRUS or EMRI abnormalities, fulfilling the criteria for Stage T1c prostate carcinoma. (2) Those patients with Stage T1c disease do not differ from patients with NPC-P up-staged by TRUS or EMRI, with regard to pretreatment PSA levels, Gleason scores, and the probability of having bilateral rather than unilateral positive biopsy results. (3) The value of classifying patients with NPC-P into Stage T1c versus higher stages of prostate carcinoma on the basis of imaging should be questioned.

    View details for Web of Science ID A1997XW20100012

    View details for PubMedID 9301702

  • Diagnostic performance characteristics of architectural features revealed by high spatial-resolution MR imaging of the breast AMERICAN JOURNAL OF ROENTGENOLOGY Nunes, L. W., Schnall, M. D., Siegelman, E. S., Langlotz, C. P., Orel, S. G., Sullivan, D., Muenz, L. A., Reynolds, C. A., Torosian, M. H. 1997; 169 (2): 409-415

    Abstract

    Our objective was twofold: to determine which architectural features revealed by high spatial-resolution MR imaging of the breast contribute to diagnostic accuracy and to evaluate the diagnostic performance characteristics of those architectural features.Eligible patients with suspicious mammographic or palpable findings or both underwent MR imaging. Ninety-three patients whose MR images revealed lesions that corresponded to the mammographically visible or palpable findings were included in the study. Patients were examined with sagittal T1-weighted spin-echo MR imaging, fat-saturated T2-weighted fast spin-echo MR imaging, and dynamically enhanced fat-saturated fast gradient-echo MR imaging. All patients underwent subsequent excisional biopsy or cyst aspiration. Lesions were identified initially by an experienced radiologist who was aware of the patient's clinical or mammographic information. Two radiologists who were unaware of the patients' histories and who had less experience in MR imaging of the breast then independently evaluated each lesion for the architectural-features and predicted each lesion's potential for malignancy.Architectural features that were highly predictive of benign disease included smooth or lobulated borders (97-100%), the absence of mass enhancement (100%), and enhancement that was less than the enhancement of surrounding breast fibroglandular tissue (93-100%). Nonenhancing internal septations were specific for the diagnosis of fibroadenoma. Architectural features that were highly predictive of malignant disease included spiculated borders (76-88%) and peripheral rim enhancement in the presence of central lesion enhancement (79-92%).Architectural features revealed by high spatial-resolution MR imaging of the breast can help distinguish benign from malignant disease.

    View details for Web of Science ID A1997XM75800019

    View details for PubMedID 9242744

  • Endo-rectal coil magnetic resonance imaging in clinically localized prostate cancer: Is it accurate? JOURNAL OF UROLOGY Tempany, C. M., Langlotz, C. P. 1997; 157 (4): 1371-1372

    View details for Web of Science ID A1997WN12900068

    View details for PubMedID 9120955

  • Breast MB imaging: Interpretation model RADIOLOGY Nunes, L. W., Schnall, M. D., Orel, S. G., Hochman, M. G., Langlotz, C. P., Reynolds, C. A., Torosian, M. H. 1997; 202 (3): 833-841

    Abstract

    To develop an interpretation model based on architectural features of suspicious breast findings on magnetic resonance (MR) images.One hundred ninety-two patients with mammographically visible or palpable findings underwent T1- and fat-saturated T2-weighted spin-echo and contrast agent-enhanced fat-saturated gradient-echo MR imaging. Patients underwent subsequent excisional biopsy for histopathologic confirmation. An interpretation model was constructed by using 98 cases and was tested prospectively and expanded by using 94 different cases. Sensitivity, specificity, predictive values, and receiver operating characteristic curves were computed for all models.Individual features with high predictive values were MR visibility, enhancement degree and pattern, focal mass border characteristics, and focal mass internal septations. Feature combinations with high negative predictive values for malignancy were absence of an MR-visible abnormality, focal masses with smooth borders, lobulated or irregular masses with nonenhancing internal septations, and focal masses with no (or minimal) enhancement. The validated- and revised-model performance characteristics were, respectively, as follows: sensitivity, 100% and 96%; specificity, 69% and 79%; positive predictive value, 75% and 76%; negative predictive value, 100% and 97%; and overall accuracy, 83% and 86%.An interpretation model that incorporates breast MR architectural features can achieve high sensitivity and improve specificity for diagnosing breast cancer.

    View details for Web of Science ID A1997WJ45600044

    View details for PubMedID 9051042

  • Barium enema and colonoscopy: Appropriateness of utilization in a Medicaid population ABDOMINAL IMAGING Levine, M. S., Sor, S., Yin, D., Langlotz, C. P., Bachwich, D. 1997; 22 (1): 41-44

    Abstract

    To assess the appropriateness of utilization patterns for the barium enema and colonoscopy in a Medicaid population.From 1987 to 1991, a Medicaid managed-care database in Philadelphia revealed claims for a total of 2357 outpatient barium enemas and 896 outpatient colonoscopic examinations. The database was reviewed to determine the primary diagnostic (ICD-9-CM) codes assigned to patients who underwent these procedures. These codes were used as a proxy for indications. Each of the diagnostic codes for barium enema and colonoscopy was then classified either as appropriate, inappropriate, equivocal, or miscoded based on current guidelines in the medical literature.A total of 1962 claims (83%) for barium enema were classified as appropriate, 126 (5%) as inappropriate, 84 (4%) as equivocal, and 185 (8%) as miscoded, whereas 645 claims (72%) for colonoscopy were classified as appropriate, 176 (20%) as inappropriate, 65 (7%) as equivocal, and 10 (1%) as miscoded. Thus, significantly more colonoscopic examinations were rated as inappropriate (p < 0.001).Our study suggests that more stringent criteria need to be used by physicians in ordering diagnostic examinations of the colon, particularly colonoscopy. Further investigation of the appropriateness of these procedures and the development and dissemination of guidelines seems warranted.

    View details for Web of Science ID A1997VZ65600009

    View details for PubMedID 9000352

  • PACS workstation usage and patient outcome surrogates. PACS DESIGN AND EVALUATION: ENGINEERING AND CLINICAL ISSUES - MEDICAL IMAGING 1997 Redfern, R. O., Kundel, H. L., Seshadri, S. B., Langlotz, C., Horii, S. C., Nodine, C., Lanken, P. N., Polansky, M., Brikman, I., Bozzo, M. 1997; 3035: 424-430
  • Incremental cost of a department-wide PACS/CR implementation PACS DESIGN AND EVALUATION: ENGINEERING AND CLINICAL ISSUES - MEDICAL IMAGING 1997 Pratt, H. M., Langlotz, C. P., Feingold, E. R., Schwartz, J. S., Kundel, H. L. 1997; 3035: 413-423
  • What do we need to advance PACS workstations: A critical review with suggestions PACS DESIGN AND EVALUATION: ENGINEERING AND CLINICAL ISSUES - MEDICAL IMAGING 1997 Horii, S. C., Kundel, H. L., Feingold, E., Grevera, G., Nodine, C. F., Langlotz, C. P., Mezrich, R., Redfern, R., Muck, J. 1997; 3035: 6-14
  • Benefits and costs of MR imaging of prostate cancer. Magnetic resonance imaging clinics of North America Langlotz, C. P. 1996; 4 (3): 533-544

    Abstract

    This article answers several important questions about the ultimate clinical usefulness of prostate MR imaging. How accurate is prostate MR imaging? What are the optimal methods for performance and interpretation of the study, considering the tradeoffs between false-positive and false-negative results? Is endorectal-coil imaging a cost-effective part of the prostate examination? And, which men are likely to benefit the most from an endorectal prostate examination?

    View details for PubMedID 8873018

  • Clinical assessment of MR of the brain in nonsurgical inpatients AMERICAN JOURNAL OF NEURORADIOLOGY Hirsch, J. A., Langlotz, C. P., Lee, J., Tanio, C. P., Grossman, R. I., Schulman, K. A. 1996; 17 (7): 1245-1253

    Abstract

    To evaluate the effect of MR imaging of the brain on four domains of patient care: diagnosis, diagnostic workup, therapy, and prognosis.Pre- and post-MR written questionnaires and oral interviews were administered to the referring clinicians of 103 medical and neurologic inpatients at a tertiary care institution. Additional information was obtained from radiologic reports and records.The study population had a diverse array of signs and symptoms and of presumptive clinical diagnoses, reflecting the breadth of disease seen at our institution. The vast majority of physicians (89%) reported that MR imaging added significant diagnostic information, playing an important role in guiding diagnostic workup (24%), planning treatment (34%), and estimating prognosis (47%). MR imaging was significantly more likely to decrease than to increase confidence in the presumptive clinical diagnosis. Thus, MR imaging may be most useful in the setting of diagnostic uncertainty.Our results show that MR imaging of the brain has important effects on each of the four domains of care for medical inpatients.

    View details for Web of Science ID A1996VC32900008

    View details for PubMedID 8871707

  • Technology assessment methods for radiology systems RADIOLOGIC CLINICS OF NORTH AMERICA Langlotz, C. P., Seshadri, S. 1996; 34 (3): 667-?

    Abstract

    This article discusses the strengths and weaknesses of technology assessment methods for the evaluation of novel and complex radiology systems, including picture archiving and communication systems (PACS), computed radiography (CR), teleradiology, and other new models for the delivery of radiology services. Using examples from PACS and CR, we review early economic assessments of PACS from the radiology department. We then broaden our perspective to discuss the analytic criteria that can be used to evaluate economic analyses of PACS as the health care delivery system shifts toward managed care. We close with a proposal for optimizing the integration of information technology into the clinical environment through ongoing target data collection during the implementation of new radiology systems.

    View details for Web of Science ID A1996UN66400013

    View details for PubMedID 8657877

  • Cost-effectiveness of endorectal magnetic resonance imaging for the staging of prostate cancer ACADEMIC RADIOLOGY Langlotz, C. P., Schnall, M. D., Malkowicz, S. B., Schwartz, J. S. 1996; 3: S24-S27

    View details for Web of Science ID A1996UE51900011

    View details for PubMedID 8796502

  • Prospective study of PACS: Information flow and clinical action in a medical intensive care unit RADIOLOGY Kundel, H. L., Seshadri, S. B., Langlotz, C. P., Lanken, P. N., Horii, S. C., Nodine, C. F., Polansky, M., Feingold, E., Brikman, I., Bozzo, M., Redfern, R. 1996; 199 (1): 143-149

    Abstract

    To prospectively compare efficiency and outcome of a standard film-only system with those of a digital picture archiving and communication system (PACS).The film-only system, which used either analog film or computed radiography (CR) hard copy, was compared with a PACS, which used CR images displayed on a multiviewer in the radiology department and a workstation in the medical intensive care unit. A random sample of nonroutine, bedside chest radiographs was studied.Within 20 minutes of completion of radiography, 246 of 328 (75%) of the images were available at the workstations; it took 1.8 hours for 238 of 317 (75%) of the images to be displayed on the multiviewer. When the workstation was used, the staff did not access the image information earlier, but clinical actions were initiated more promptly in response to imaging findings. Consultation with radiologists decreased from 507 of 561 (90%) images with hard copies to 70 of 249 (28%) with the workstation.Use of a PACS improves the delivery of chest images, facilitates the initiation of clinical actions, and decreases input by radiologists.

    View details for Web of Science ID A1996UB58400025

    View details for PubMedID 8633138

  • An image workstation in a medical intensive care unit changes viewing patterns and timing of image based clinical actions in routine portable chest radiographs. PACS DESIGN AND EVALUATION: ENGINEERING AND CLINICAL ISSUES - MEDICAL IMAGING 1996 Redfern, R., Kundel, H. L., Polansky, M., Langlotz, C., Lanken, P. N., Brikman, I., Horii, S., Bozzo, M., Feingold, E., Nodine, C. F. 1996; 2711: 298-306
  • Workflow in a neuroradiology reading room using multiviewers PACS DESIGN AND EVALUATION: ENGINEERING AND CLINICAL ISSUES - MEDICAL IMAGING 1996 Kundel, H. L., Redfern, R., Langlotz, C., Grossman, R., Brikman, I., Horii, S. C., Feingold, E., Nodine, C. F. 1996; 2711: 232-235
  • PACS workstation functions: Usage differences between radiologists and MICU physicians PACS DESIGN AND EVALUATION: ENGINEERING AND CLINICAL ISSUES - MEDICAL IMAGING 1996 Horii, S., Feingold, E., Kundel, H., Nodine, C., Langlotz, C., Redfern, R., Grevera, G., Brikman, I., Muck, J. 1996; 2711: 266-271
  • The effect of PACS/CR on cost of care and length of stay in a medical intensive care unit PACS DESIGN AND EVALUATION: ENGINEERING AND CLINICAL ISSUES - MEDICAL IMAGING 1996 Langlotz, C. P., Kundel, H. L., Brikman, I., Pratt, H. M., Redfern, R. R., Horii, S. C., Schwartz, J. S. 1996; 2711: 272-280
  • EVALUATING HEALTH-SERVICES - THE IMPORTANCE OF PATIENTS PREFERENCES AND QUALITY-OF-LIFE AMERICAN JOURNAL OF ROENTGENOLOGY Yin, D. P., Forman, H. P., Langlotz, C. P. 1995; 165 (6): 1323-1328

    Abstract

    With limited resources available, we all would like to allocate health care dollars to do the most good. Clinical research tells us what outcomes to expect (in many cases) from the introduction of a health care program, a test, or a therapy. Even primitive cost analysis can assess the cost of such programs. The ability to place a value on health states is vital when assessing how patient outcomes influence the relative cost-effectiveness of medical procedures, therapies, and programs. Without a means to measure the value of a particular health state, one is left to compare apples with oranges and oranges with vacuum cleaners. In fact, comparisons of fruit and home appliances is relatively easy, because one can readily apply monetary values to apples, oranges, and vacuum cleaners and compare dollar amounts. How can one do the same for the outcomes of medical procedures and diagnostic tests? This is the challenge for health services and outcomes researchers throughout the world and, more urgently, the focus of policy makers, governments, and health insurers. The purpose of this paper is to describe quality-adjusted life-years (QALYs), a method that has successfully measured the outcomes of disparate health programs. We will introduce the QALY method, summarize the various methods of measuring and classifying health states, describe three methods that have been used to measure patients' preferences (utilities) for health states, and discuss the limitations of utility assessment and some controversies that result from the measurement and use of utilities and concerning health-related quality of life. Readers who are interested in general topics of radiology technology assessment and cost-effectiveness analysis should consult other review articles [1-4].

    View details for Web of Science ID A1995TF76800001

    View details for PubMedID 7484556

  • COLON-CANCER - MORPHOLOGY DETECTED WITH BARIUM ENEMA EXAMINATION VERSUS HISTOPATHOLOGIC STAGE RADIOLOGY McCarthy, P. A., Rubesin, S. E., Levine, M. S., Langlotz, C. P., Laufer, I., Furth, E. E., Herlinger, H. 1995; 197 (3): 683-687

    Abstract

    To determine the relationship between the morphology of colon carcinomas detected with barium enema examination and the cancer stage.Clinical, radiographic, endoscopic, surgical, and histopathologic findings were retrospectively reviewed in 152 patients with colon cancer detected with barium enema examination during a 2-year period.Eighty-six patients (57%) had lesions in the rectum and sigmoid and descending colon, and 66 (43%) patients had lesions more proximally in the colon. Lesions on the right side of the colon were less likely to cause symptoms than those on the left side. Eighty-one patients (53%) had annular or semiannular lesions, 57 (38%) had polypoid lesions, and 14 (9%) had plaquelike or carpet lesions. Six patients (4%) had Dukes stage A lesions; 84 (55%), Dukes stage B lesions; 42 (28%), Dukes stage C lesions; and 20 (13%), Dukes stage D lesions.Annular or semiannular carcinomas had higher rates of serosal invasion and lymph node metastasis than polypoid carcinomas, but the rates of liver metastases were comparable.

    View details for Web of Science ID A1995TG33300023

    View details for PubMedID 7480739

  • A METHODOLOGY FOR THE ECONOMIC-ASSESSMENT OF PICTURE ARCHIVING AND COMMUNICATION-SYSTEMS JOURNAL OF DIGITAL IMAGING Langlotz, C. P., EVENSHOSHAN, O., SESHADRI, S. S., Brikman, I., Kishore, S., Kundel, H. L., Schwartz, J. S. 1995; 8 (2): 95-102

    Abstract

    Most economic studies of picture archiving and communication systems (PACS) to date, including our own, have focused on the perspectives of the radiology department and its direct costs. However, many researchers have suggested additional cost savings that may accrue to the medical center as a whole through increased operational capacity, fewer lost images, rapid simultaneous access to images, and other decreases in resource utilization. We describe here an economic analysis framework we have developed to estimate these potential additional savings. Our framework is comprised of two parallel measurement methods. The first method estimates the cost of care actually delivered through online capture of charge entries from the hospital's billing computer and from the clinical practices' billing database. Multiple regression analyses will be used to model cost of care, length of stay, and other estimates of resource utilization. The second method is the observational measurement of actual resource utilization, such as technologist time, frequency and duration of film searches, and equipment utilization rates. The costs associated with changes in resource use will be estimated using wage rates and other standard economic methods. Our working hypothesis is that after controlling for the underlying clinical and demographic differences among patients, patients imaged using a PACS will have shorter lengths of stay, shorter exam performance times, and decreased costs of care. We expect the results of our analysis to explain and resolve some of the conflicting views of the cost-effectiveness of PACS.

    View details for Web of Science ID A1995QY34300006

    View details for PubMedID 7612707

  • STAGING OF PROSTATIC-CANCER - ACCURACY OF MR-IMAGING RADIOLOGY Langlotz, C., Schnall, M., Pollack, H. 1995; 194 (3): 645-646

    View details for Web of Science ID A1995QG91800004

    View details for PubMedID 7862957

  • COST-EFFECTIVENESS OF MR-ANGIOGRAPHY IN CASES OF LIMB-THREATENING PERIPHERAL VASCULAR-DISEASE RADIOLOGY Yin, D. P., Baum, R. A., Carpenter, J. P., Langlotz, C. P., Pentecost, M. J. 1995; 194 (3): 757-764

    Abstract

    To evaluate the cost-effectiveness of magnetic resonance (MR) angiography in the preoperative planning of treatment in patients with limb-threatening peripheral vascular disease (PVD).A decision model was developed to study the effects of MR angiography on the outcome and cost of treatment. The authors calculated the incremental cost per quality-adjusted life-years gained (ie, cost-effectiveness ratio) when conventional angiography was replaced or supplemented with MR angiography. Previously reported data regarding the accuracies of MR and conventional angiography were used in the analysis.The cost-effectiveness ratio of MR angiography ranged from negative (cost-reducing) values to $78,000. For the base case in which the sensitivity and specificity of MR angiography for the evaluation of inflow vessels were 92% and 88% and those of conventional angiography were 97% and 97%, respectively, the cost-effectiveness ratio was $25,895.MR angiography may be a cost-effective alternative to conventional angiography in patients with limb-threatening PVD if its accuracy for the inflow evaluation reaches certain thresholds. Further prospective investigation is warranted.

    View details for Web of Science ID A1995QG91800023

    View details for PubMedID 7862975

  • CD4 T-LYMPHOCYTE COUNT AND THE RADIOGRAPHIC PRESENTATION OF PULMONARY TUBERCULOSIS - A STUDY OF THE RELATIONSHIP BETWEEN THESE FACTORS IN PATIENTS WITH HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION CHEST Keiper, M. D., Beumont, M., Elshami, A., Langlotz, C. P., Miller, W. T. 1995; 107 (1): 74-80

    Abstract

    Pulmonary infection and tumor in the AIDS population has a variable clinical and radiographic presentation. The association between the radiographic presentation of pulmonary tuberculosis and CD4 T lymphocyte count in the HIV-infected patient is investigated in order to provide an empirical approach for early diagnosis, treatment, and isolation of infected subjects.A retrospective analysis of chest radiographs, CD4 T lymphocyte counts, and clinical history of 35 subjects from 3 urban hospitals was performed. All subjects were HIV-seropositive and had culture-proven pulmonary tuberculosis. Radiographs were evaluated for the presence of either a pattern characteristic of post-primary tuberculosis (typical pattern) or a pattern uncharacteristic of post-primary infection (atypical pattern).Twenty-one of 26 subjects with a CD4 T lymphocyte count less than 0.20 x 10(9) cells/L, whereas only 1 of 9 subjects with a CD4 T lymphocyte count of 0.20 x 10(9) cells/L or more presented with an atypical pattern of pulmonary tuberculosis (p < 0.001). The mean CD4 T lymphocyte counts of those subjects presenting with atypical versus typical radiographic pattern of post-primary pulmonary tuberculosis were 0.069 x 10(9) cells/L (n = 22) and 0.323 x 10(9) cells/L (n = 13), respectively (p < 0.01). Twenty-one of the 22 subjects with an atypical radiographic pattern of pulmonary tuberculosis were significantly immunosuppressed (CD4 < 0.20 x 10(9) cells/L). Atypical radiographic pattern included diffuse and lower lobar opacities, pleural effusion, mediastinal adenopathy, interstitial nodules, and a normal chest radiograph.AIDS patients presenting with CD4 count less than 0.20 x 10(9) cells/L and an atypical radiographic pattern for pulmonary tuberculosis are at risk for tuberculous infection requiring appropriate treatment and isolation until the diagnosis of pulmonary tuberculosis has been excluded.

    View details for Web of Science ID A1995QC15800018

    View details for PubMedID 7813316

  • PROSPECTIVE COMPARISON OF THE USAGE OF CONVENTIONAL FILM AND PACS BASED COMPUTED RADIOGRAPHY FOR PORTABLE CHEST X-RAY IMAGING IN A MEDICAL INTENSIVE CARE UNIT PACS DESIGN AND EVALUATION: ENGINEERING AND CLINICAL ISSUES Kundel, H. L., SESHADRI, S. S., Langlotz, C. P., Lanken, P. N., Horii, S., Polansky, M., Kishore, S., FINEGOLD, E., Brikman, I., Bozzo, M., Redfern, R. 1995; 2435: 302-309
  • INTENSIVE CARE UNIT WORKSTATION USAGE - DIGITIZED FILM VERSUS PHOSPHOR PLATE IMAGING PACS DESIGN AND EVALUATION: ENGINEERING AND CLINICAL ISSUES Horii, S., Kishore, S., Feingold, E., Stevens, J. F., Seshadri, S., Langlotz, C., Kundel, H., Bozzo, M., Redfern, R., Brikman, I. 1995; 2435: 286-293
  • THE INCREMENTAL COST OF PACS IN A MEDICAL INTENSIVE CARE UNIT PACS DESIGN AND EVALUATION: ENGINEERING AND CLINICAL ISSUES Langlotz, C. P., Cleff, B., EVENSHOSHAN, O., Bozzo, M., Redfern, R., SESHADRI, S. S., Horii, S., Kundel, H. L. 1995; 2435: 294-301
  • CATEGORIZATION OF ACROMIAL SHAPE - INTEROBSERVER VARIABILITY WITH MR-IMAGING AND CONVENTIONAL RADIOGRAPHY AMERICAN JOURNAL OF ROENTGENOLOGY Haygood, T. M., Langlotz, C. P., Kneeland, J. B., Iannotti, J. P., Williams, G. R., Dalinka, M. K. 1994; 162 (6): 1377-1382

    Abstract

    Our purpose was to determine interobserver variability in the interpretation of the shape of the acromion on sagittal oblique MR images and conventional radiographs. The shape of the acromion was defined according to a previously described classification scheme.We reviewed 26 sets of sagittal oblique MR images and corresponding conventional Y- or outlet-view radiographs of the shoulder. The shape of the acromion was graded for each study independently by four reviewers. Interobserver agreement was measured by using the kappa statistic. Analysis of variance and the chi 2-test were used for univariate analysis.The acromion was interpreted most often as being curved. The observers scored 9% of MR images and 28% of conventional radiographs as nondiagnostic (p < .001) (41% of transscapular Y views and 3% of supraspinatus outlet views were also considered nondiagnostic [p < .0001]). Kappa values were .23 for MR images and .43 for conventional radiographs. Variability in interpretation between techniques when controlled for observer was not statistically significant.Although sagittal oblique MR images were significantly more likely than conventional radiographs to be considered diagnostic by observers, interobserver agreement for MR examinations was poor. There was moderate agreement with conventional radiographs. This calls into question the usefulness of the previous system of interpretation and suggests that it might be more applicable with conventional radiographs than with MR images.

    View details for Web of Science ID A1994NN22800024

    View details for PubMedID 8192003

  • EVALUATION OF PACS IN A MEDICAL INTENSIVE-CARE UNIT - THE EFFECT OF COMPUTED RADIOGRAPHY PACS: DESIGN AND EVALUATION Kundel, H. L., SESHADRI, S. S., Shile, P. E., Polansky, M., Langlotz, C., Lanken, P. N., Horii, S. C., Grossman, R. I., Purcell, J. A., Kishore, S., Brikman, I., BOZZO, M. T., Redfern, R. 1994; 2165: 481-487
  • A METHODOLOGY FOR THE ECONOMIC-ASSESSMENT OF PACS PACS: DESIGN AND EVALUATION Langlotz, C. P., EVENSHOSHAN, O., SESHADRI, S. S., Brikman, I., Kishore, S., Kundel, H. L., Schwartz, J. S. 1994; 2165: 584-592
  • THE FEASIBILITY OF AXIOMATICALLY-BASED EXPERT SYSTEMS COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE Langlotz, C. P. 1989; 30 (2-3): 85-95

    Abstract

    We distinguish axiomatically-based expert systems, whose design and implementation are guided by one or more axiomatically-based theories of decision-making (e.g., decision theory, Bayesian probability theory, maximum entropy theory), from traditional expert systems. An analysis of the knowledge acquisition and computational needs of axiomatically-based expert systems is presented. An explicit quantitative comparison is made between the actual knowledge acquisition effort required to build an existing expert system, and the effort that would be required to build an analogous axiomatically-based advice system. The costs and benefits of the axiomatic approach are discussed. The analysis suggests that the small additional cost of knowledge acquisition for the axiomatic approach are outweighed by the long-term benefits this approach provides.

    View details for Web of Science ID A1989CA90600003

    View details for PubMedID 2684496

  • LOGICAL AND DECISION-THEORETIC METHODS FOR PLANNING UNDER UNCERTAINTY AI MAGAZINE Langlotz, C. P., Shortliffe, E. H. 1989; 10 (1): 39-47
  • A THERAPY PLANNING ARCHITECTURE THAT COMBINES DECISION-THEORY AND ARTIFICIAL-INTELLIGENCE TECHNIQUES COMPUTERS AND BIOMEDICAL RESEARCH Langlotz, C. P., Fagan, L. M., Tu, S. W., Sikic, B. I., Shortliffe, E. H. 1987; 20 (3): 279-303

    Abstract

    Through our experience with the ONCOCIN cancer therapy consultation system, we have identified a set of medical planning problems to which no single existing computer-based reasoning technique readily applies. In response to the need for automated assistance with this class of problems, we have devised a computer program called ONYX that combines decision-theoretic and artificial intelligence approaches to planning. We discuss our rationale for devising a new planning architecture and describe in detail how that architecture is implemented. The program's planning process consists of three steps: (i) the use of rules derived from therapy planning strategies to generate a small set of plausible plans, (ii) the use of knowledge about the structure and behavior of the human body to create simulations that predict possible consequences of each plan for the patient, and (iii) the use of decision theory to rank the plans according to how well the results of each simulation meet the treatment goals. This architecture explicitly manages the uncertainty inherent in many planning tasks, introduces a possible mechanism for the dissemination of decision-theoretic therapy advice, and potentially increases the number of problem solving domains in which expert system techniques can be effectively applied.

    View details for Web of Science ID A1987H761400006

    View details for PubMedID 3301187