N A Obuchowski

Summary

Affiliation: Cleveland Clinic Foundation
Country: USA

Publications

  1. ncbi request reprint Screening with multisection CT: unmasking the benefit
    Nancy A Obuchowski
    Radiology 237:401-3. 2005
  2. ncbi request reprint Estimating sample size for a randomized clinical trial of lung cancer screening
    Nancy A Obuchowski
    Department of Quantitative Health Sciences Wb4, Division of Radiology, Cleveland Clinic, 9500 Euclid Ave, Cleveland, OH 44195, USA
    Contemp Clin Trials 29:466-77. 2008
  3. ncbi request reprint Multireader, multicase receiver operating characteristic analysis: an empirical comparison of five methods
    Nancy A Obuchowski
    Departments of Biostatistics and Epidemiology, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
    Acad Radiol 11:980-95. 2004
  4. ncbi request reprint How many observers are needed in clinical studies of medical imaging?
    Nancy A Obuchowski
    Department of Biostatistics and Epidemiology, Desk Wb4, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195, USA
    AJR Am J Roentgenol 182:867-9. 2004
  5. ncbi request reprint Special Topics III: bias
    Nancy A Obuchowski
    Departments of Biostatistics and Epidemiology and Radiology Wb4, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195, USA
    Radiology 229:617-21. 2003
  6. ncbi request reprint Receiver operating characteristic curves and their use in radiology
    Nancy A Obuchowski
    Department of Biostatistics and Epidemiology Wb4, Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195, USA
    Radiology 229:3-8. 2003
  7. ncbi request reprint ROC curves in clinical chemistry: uses, misuses, and possible solutions
    Nancy A Obuchowski
    Department of Biostatistics, Division of Radiology Wb4, The Cleveland Clinic Foundation, Cleveland, OH 44195 5196, USA
    Clin Chem 50:1118-25. 2004
  8. ncbi request reprint Estimating and comparing diagnostic tests' accuracy when the gold standard is not binary
    Nancy A Obuchowski
    Department of Quantitative Health Sciences Wb4, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195, USA
    Acad Radiol 12:1198-204. 2005
  9. ncbi request reprint Total body screening: predicting actionable findings
    Nancy Obuchowski
    Division of Radiology, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA
    Acad Radiol 13:480-5. 2006
  10. doi request reprint What's the control in studies measuring the effect of computer-aided detection (CAD) on observer performance?
    Nancy A Obuchowski
    Quantitative Health Sciences, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA
    Acad Radiol 17:761-7. 2010

Detail Information

Publications54

  1. ncbi request reprint Screening with multisection CT: unmasking the benefit
    Nancy A Obuchowski
    Radiology 237:401-3. 2005
  2. ncbi request reprint Estimating sample size for a randomized clinical trial of lung cancer screening
    Nancy A Obuchowski
    Department of Quantitative Health Sciences Wb4, Division of Radiology, Cleveland Clinic, 9500 Euclid Ave, Cleveland, OH 44195, USA
    Contemp Clin Trials 29:466-77. 2008
    ....
  3. ncbi request reprint Multireader, multicase receiver operating characteristic analysis: an empirical comparison of five methods
    Nancy A Obuchowski
    Departments of Biostatistics and Epidemiology, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
    Acad Radiol 11:980-95. 2004
    ..The objective of this article is to increase awareness of these methods and determine if their results are concordant for published datasets...
  4. ncbi request reprint How many observers are needed in clinical studies of medical imaging?
    Nancy A Obuchowski
    Department of Biostatistics and Epidemiology, Desk Wb4, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195, USA
    AJR Am J Roentgenol 182:867-9. 2004
  5. ncbi request reprint Special Topics III: bias
    Nancy A Obuchowski
    Departments of Biostatistics and Epidemiology and Radiology Wb4, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195, USA
    Radiology 229:617-21. 2003
    ..Potential implications of various biases are discussed, and practical approaches to eliminating or minimizing them are presented...
  6. ncbi request reprint Receiver operating characteristic curves and their use in radiology
    Nancy A Obuchowski
    Department of Biostatistics and Epidemiology Wb4, Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195, USA
    Radiology 229:3-8. 2003
    ..Two examples of ROC curve application in radiologic research are presented...
  7. ncbi request reprint ROC curves in clinical chemistry: uses, misuses, and possible solutions
    Nancy A Obuchowski
    Department of Biostatistics, Division of Radiology Wb4, The Cleveland Clinic Foundation, Cleveland, OH 44195 5196, USA
    Clin Chem 50:1118-25. 2004
    ..Our aims were to observe how the accuracy of clinical laboratory diagnostic tests is assessed, compared, and reported in the literature; to identify common problems with the use of ROC curves; and to offer some possible solutions...
  8. ncbi request reprint Estimating and comparing diagnostic tests' accuracy when the gold standard is not binary
    Nancy A Obuchowski
    Department of Quantitative Health Sciences Wb4, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195, USA
    Acad Radiol 12:1198-204. 2005
    ..The objective of this article is to describe nonparametric estimators of diagnostic test accuracy when the gold standard is continuous, ordinal, and nominal scale...
  9. ncbi request reprint Total body screening: predicting actionable findings
    Nancy Obuchowski
    Division of Radiology, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA
    Acad Radiol 13:480-5. 2006
    ..Even the appropriate target for screening has not been addressed. In this study, we determined the variables from a subject's demographic and medical and family history that are predictive of actionable findings on total body screening...
  10. doi request reprint What's the control in studies measuring the effect of computer-aided detection (CAD) on observer performance?
    Nancy A Obuchowski
    Quantitative Health Sciences, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA
    Acad Radiol 17:761-7. 2010
    ..The crossover design is considered the most valid. The sequential design takes less time and is less expensive but may be biased. We conducted a study to investigate the differences between these two designs...
  11. ncbi request reprint Assessing physicians' accuracy in diagnosing paediatric patients with acute abdominal pain: measuring accuracy for multiple diseases
    N A Obuchowski
    Department of Biostatistics and Epidemiology Wb4, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195 5196, USA
    Stat Med 20:3261-78. 2001
    ..The new data collection format and summary measure were used in a paediatric acute abdominal pain study; data from this study are used to illustrate the methods...
  12. ncbi request reprint Assessment of the efficacy of noninvasive screening for patients with asymptomatic neck bruits
    N A Obuchowski
    Department of Biostatistics and Epidemiology, Cleveland Clinic Foundation, Ohio 44195, USA
    Stroke 28:1330-9. 1997
    ..The purpose of this study was to evaluate the effectiveness of various test strategies for screening and diagnosing carotid artery disease...
  13. ncbi request reprint Sample size calculations in studies of test accuracy
    N A Obuchowski
    Department of Biostatistics and Epidemiology, Cleveland Clinic Foundation, OH 44195 5196, USA
    Stat Methods Med Res 7:371-92. 1998
    ..Four real examples illustrate the concepts involved in sample size determination. Lastly, various study design issues are discussed, such as sampling methods, choices in format for the test results, and the issue of replicated readings...
  14. ncbi request reprint On the comparison of correlated proportions for clustered data
    N A Obuchowski
    Department of Biostatistics and Epidemiology, Cleveland Clinic Foundation, Ohio 44195 5196, USA
    Stat Med 17:1495-507. 1998
    ..The proposed method is a good alternative to Eliasziw and Donner's test when, in practice, little is known about the correlation pattern of the data...
  15. ncbi request reprint Can electronic medical images replace hard-copy film? Defining and testing the equivalence of diagnostic tests
    N A Obuchowski
    Department of Biostatistics and Epidemiology Wb4 and the Division of Radiology, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, Ohio 44195 5196, USA
    Stat Med 20:2845-63. 2001
    ..Data from a mammography screening study is used to illustrate the proposed methods and compare them with results from more conventional methods of assessing equivalence and inter-procedure agreement...
  16. ncbi request reprint Quantitative detection of outlet strut separations in Björk-Shiley convexo-concave mitral valves
    K A Powell
    Department of Biomedical Engineering, Cleveland Clinic Foundation, OH 44195, USA
    Circulation 94:3251-6. 1996
    ..The goal of the present study was to develop an objective postprocessing technique to evaluate outlet strut leg integrity quantitatively in these cineradiographic images...
  17. ncbi request reprint Cholecystokinin-stimulated peak lipase concentration in duodenal drainage fluid: a new pancreatic function test
    Darwin L Conwell
    The Pancreas Clinic, Section of Endoscopy and Pancreaticobiliary Diseases, Cleveland Clinic Foundation, Ohio, USA
    Am J Gastroenterol 97:1392-7. 2002
    ..The aim of this study was to test the efficacy of a new CCK-stimulated pancreatic function test measuring peak lipase concentration...
  18. ncbi request reprint The "differential diagnosis" for multiple diseases: comparison with the binary-truth state experiment in two empirical studies
    N A Obuchowski
    Department of Biostatistics and Epidemiology, The Cleveland Clinic Foundation, OH 44195, USA
    Acad Radiol 8:947-54. 2001
    ..The differential diagnosis format is useful for estimating accuracy when there are multiple possible diagnoses...
  19. ncbi request reprint Creating an international comprehensive web-based curriculum in pediatric radiology
    Janet R Reid
    The Children s Hospital at the Cleveland Clinic, 9500 Euclid Avenue, Hb6, Cleveland, OH 44195, USA
    AJR Am J Roentgenol 182:797-801. 2004
    ....
  20. ncbi request reprint An endoscopic pancreatic function test with cholecystokinin-octapeptide for the diagnosis of chronic pancreatitis
    Darwin L Conwell
    Department of Gastroenterology and Hepatology, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
    Clin Gastroenterol Hepatol 1:189-94. 2003
    ..We have developed a function test that can be modified to a purely endoscopic collection method (ePFT). The aim of this study was to compare the endoscopic and traditional Dreiling tube collection methods...
  21. doi request reprint Probability of reduced renal function after contrast-enhanced CT: a model based on serum creatinine level, patient age, and estimated glomerular filtration rate
    Brian R Herts
    Imaging Institute, Cleveland Clinic, 9500 Euclid Ave, Desk Hb6, Cleveland, OH 44195, USA
    AJR Am J Roentgenol 193:494-500. 2009
    ....
  22. ncbi request reprint Whole-body CT screening for cancer and coronary disease: does it pass the test?
    Michael T Modic
    Division of Radiology, The Cleveland Clinic Foundation, OH 44195, USA
    Cleve Clin J Med 71:47-56. 2004
    ....
  23. ncbi request reprint Vertebral augmentation and the limits of interpreting complications reported in the food and drug administration manufacturer and user facility device experience database
    Isador H Lieberman
    Department of Orthopaedic Surgery, The Cleveland Clinic Foundation, Cleveland, OH 44195, USA
    J Vasc Interv Radiol 15:1193-6. 2004
  24. ncbi request reprint Lung cancer screening: is it time for a change in policy?
    Peter Mazzone
    Department of Pulmonary, Allergy, and Critical Care Medicine, Cleveland Clinic, Cleveland, OH 44195, USA
    Cleve Clin J Med 74:441-8. 2007
    ..These questions warrant further study prior to accepting CT screening as the standard of care. Hopefully, much of this knowledge will be gained when the results of ongoing controlled studies are available...
  25. ncbi request reprint Do segmented reconstruction algorithms for cardiac multi-slice computed tomography improve image quality?
    Sandra S Halliburton
    Section of Cardiovascular Imaging, Division of Radiology, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
    Herz 28:20-31. 2003
    ..To evaluate segmented reconstruction algorithms for spiral multi-slice computed tomography (MSCT) that use data from two cardiac cycles to improve temporal resolution (tau) for imaging of the heart...
  26. ncbi request reprint Evaluation of left ventricular dysfunction using multiphasic reconstructions of coronary multi-slice computed tomography data in patients with chronic ischemic heart disease: validation against cine magnetic resonance imaging
    Sandra S Halliburton
    Section of Cardiovascular Imaging, Division of Radiology Cleveland Clinic Foundation, Cleveland, OH 44195, USA
    Int J Cardiovasc Imaging 19:73-83. 2003
    ..The purpose of this work was to determine if multiphasic reconstructions of the same data used for the assessment of CAD could also be used for global functional evaluation of the left ventricle (LV)...
  27. ncbi request reprint Automatic segmentation of mammographic density
    R Sivaramakrishna
    Department of Biomedical Engineering, Lerner Research Institute, Cleveland, OH, USA
    Acad Radiol 8:250-6. 2001
    ..This algorithm could be useful in providing clinically accurate estimates of breast density...
  28. ncbi request reprint An endoscopic pancreatic function test with synthetic porcine secretin for the evaluation of chronic abdominal pain and suspected chronic pancreatitis
    Darwin L Conwell
    The Pancreas Clinic, Department of Gastroenterology, Section, Cleveland Clinic Foundation, Cleveland, Ohio, USA
    Gastrointest Endosc 57:37-40. 2003
    ..This study examined the utility of a simple, newly developed, purely endoscopic pancreatic function test with synthetic porcine secretin...
  29. doi request reprint Effects of diagnostic information, per se, on patient outcomes in acute radiculopathy and low back pain
    L M Ash
    Division of Radiology, Cleveland Clinic Foundation, Cleveland, Ohio, USA
    AJNR Am J Neuroradiol 29:1098-103. 2008
    ..If this rationale is valid, one would expect to see a measurable effect from diagnostic information, per se...
  30. doi request reprint Does the presence of focal normal marrow fat signal within a tumor on MRI exclude malignancy? An analysis of 184 histologically proven tumors of the pelvic and appendicular skeleton
    C S Simpfendorfer
    Department of Radiology, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
    Skeletal Radiol 37:797-804. 2008
    ..The aim of this study was to determine if the presence of focal normal bone marrow fat signal within a tumor on magnetic resonance imaging excludes malignancy...
  31. ncbi request reprint Spiral CT scanning technique in the detection of aspiration of LEGO foreign bodies
    K E Applegate
    Department of Radiology, Cleveland Clinic Foundation, 11 106 Euclid Avenue, Cleveland, OH 44196, USA
    Pediatr Radiol 31:836-40. 2001
    ..Materials and..
  32. ncbi request reprint Noninvasive assessment of cardiac mechanics and clinical outcome after partial left ventriculectomy
    Randolph M Setser
    Department of Radiology, The Cleveland Clinic Foundation, OH, USA
    Ann Thorac Surg 76:1576-85; discussion 1585-6. 2003
    ..Little is known about its effects on myocardial mechanics and their relation to clinical outcome...
  33. ncbi request reprint Analysis of changes in attenuation of proven renal cysts on different scanning phases of triphasic MDCT
    Eugene P Chung
    Department of Radiology Hb6, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195, USA
    AJR Am J Roentgenol 182:405-10. 2004
    ..The purpose of this study is to document changes in attenuation values on triphasic MDCT of histologically or surgically proven cystic renal lesions...
  34. ncbi request reprint Enhancement characteristics of papillary renal neoplasms revealed on triphasic helical CT of the kidneys
    Brian R Herts
    Department of Radiology H66, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195, USA
    AJR Am J Roentgenol 178:367-72. 2002
    ..The purpose of this study was to determine whether renal tumor enhancement or heterogeneity on triphasic helical CT scans is predictive of the papillary cell subtype or nuclear grade of renal cell carcinoma...
  35. ncbi request reprint The predictive value of helical computed tomography for collecting-system entry during nephron-sparing surgery
    Ithaar H Derweesh
    Section of Abdominal Imaging, Department of Diagnostic Radiology, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
    BJU Int 98:963-8. 2006
    ....
  36. ncbi request reprint Computer-aided detection of colorectal polyps: can it improve sensitivity of less-experienced readers? Preliminary findings
    Mark E Baker
    Department of Radiology, The Cleveland Clinic Foundation, 9500 Euclid Ave, Hb6, Cleveland, OH 44195, USA
    Radiology 245:140-9. 2007
    ....
  37. ncbi request reprint Total-body screening: preliminary results of a pilot randomized controlled trial
    Nancy A Obuchowski
    Division of Radiology, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
    J Am Coll Radiol 4:604-11. 2007
    ..The authors performed a pilot randomized controlled trial of total-body screening to assess the feasibility of a full-scale study...
  38. ncbi request reprint The effect of misclassification in screening trials: a simulation study
    Nancy A Obuchowski
    Department of Quantitative Health Sciences, Cleveland Clinic, OH 44195, USA
    Contemp Clin Trials 29:125-35. 2008
    ..Misclassification of study endpoints in randomized clinical trials of screening tests has been well documented, yet its effect on study power, type I error rate, and risk ratio estimate have not been studied in depth...
  39. doi request reprint Identifying outpatients with renal insufficiency before contrast-enhanced CT by using estimated glomerular filtration rates versus serum creatinine levels
    Brian R Herts
    Division of Radiology, Cleveland Clinic, 9500 Euclid Ave, Cleveland, OH 44195, USA
    Radiology 248:106-13. 2008
    ....
  40. doi request reprint Statistics and methodology
    Nancy A Obuchowski
    Department of Quantitative Health Sciences, Lerner Research Institute and Imaging Institute, Cleveland Clinic, 9500 Euclid Ave, Cleveland, OH 44195, USA
    Skeletal Radiol 37:393-6. 2008
  41. ncbi request reprint New methodological tools for multiple-reader ROC studies
    Nancy A Obuchowski
    Radiology 243:10-2. 2007
  42. ncbi request reprint A comparison of the Dorfman-Berbaum-Metz and Obuchowski-Rockette methods for receiver operating characteristic (ROC) data
    Stephen L Hillis
    Center for Research in the Implementation of Innovative Strategies in Practice, Iowa City VA Medical Center, Iowa City, IA, USA
    Stat Med 24:1579-607. 2005
    ..The methods are compared using data from a factorial study with two modalities, five readers, and 114 patients...
  43. ncbi request reprint Determining sample size for ROC studies: what is reasonable for the expected difference in tests' ROC areas?
    Nancy A Obuchowski
    Acad Radiol 10:1327-8. 2003
  44. ncbi request reprint Acute low back pain and radiculopathy: MR imaging findings and their prognostic role and effect on outcome
    Michael T Modic
    Division of Radiology, Spine Center, Cleveland Clinic Foundation, Cleveland, Ohio, 44195, USA
    Radiology 237:597-604. 2005
    ..To prospectively determine in patients with acute low back pain (LBP) or radiculopathy, the magnetic resonance (MR) imaging findings, prognostic role of these findings, and effect of diagnostic information on outcome...
  45. ncbi request reprint An ROC-type measure of diagnostic accuracy when the gold standard is continuous-scale
    Nancy A Obuchowski
    Department of Quantitative Health Sciences Wb4, and the Division of Radiology, The Cleveland Clinic Foundation, 9500 Euclid Avenue, OH 44195 5196, USA
    Stat Med 25:481-93. 2006
    ..e. CI coverage, type I error rate, power) of the proposed methods with several alternatives. An example is presented where the accuracies of two quick blood tests for measuring serum iron concentrations are estimated and compared...
  46. ncbi request reprint Confidence bounds when the estimated ROC area is 1.01
    Nancy A Obuchowski
    Department of Biostatistics and Epidemiology The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland OH, 44195, USA
    Acad Radiol 9:526-30. 2002
    ..The purpose of this study was to develop tables for determining the approximate 95% lower confidence bound when the estimated ROC area is 1.0...
  47. ncbi request reprint Clinical evaluation of diagnostic tests
    Susan Weinstein
    Department of Radiology, University of Pennsylvania Medical Center, Medical Center, Philadelphia, PA 19104, USA
    AJR Am J Roentgenol 184:14-9. 2005
  48. ncbi request reprint Calcium scoring: criteria for evaluating its effectiveness
    Nancy A Obuchowski
    Department of Biostatistics and Epidemiology, Cleveland Clinic Foundation, Cleveland, OH, USA
    Semin Ultrasound CT MR 24:39-44. 2003
    ..We discuss how these criteria can be used to estimate NNS and NSH. Although this work focuses on coronary calcification screening, reference is made as well to other areas, such as lung and colon cancer screening...
  49. ncbi request reprint One less bias to worry about
    Nancy A Obuchowski
    Radiology 232:302. 2004
  50. ncbi request reprint ROC analysis
    Nancy A Obuchowski
    Department of Biostatistics and Epidemiology, Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH, USA
    AJR Am J Roentgenol 184:364-72. 2005
  51. ncbi request reprint Assessment of suspected breast cancer by MRI: a prospective clinical trial using a combined kinetic and morphologic analysis
    Jonathan I Wiener
    Department of Radiology, Boca Raton Community Hospital, 800 Meadows Rd, Boca Raton, FL 33486, USA
    AJR Am J Roentgenol 184:878-86. 2005
    ....
  52. ncbi request reprint Multivariate statistical methods
    Nancy A Obuchowski
    Department of Quantitative Health Sciences, Rm Wb4, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195, USA
    AJR Am J Roentgenol 185:299-309. 2005
  53. ncbi request reprint Incidence of advanced symptomatic disease as primary endpoint in screening and prevention trials
    Nancy A Obuchowski
    Department of Quantitative Health Sciences, Wb4, The Cleveland Clinic, 9500 Euclid Ave, Cleveland, OH 44195, USA
    AJR Am J Roentgenol 189:19-23. 2007
    ..This endpoint is sensitive to the benefit of screening, correlates with patients' quality of life and societal costs, and can dramatically reduce the sample size and follow-up requirements of RCTs...
  54. ncbi request reprint Colonic abnormalities on CT in adult hospitalized patients with Clostridium difficile colitis: prevalence and significance of findings
    Lorraine Ash
    Division of Radiology Hb 6, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195, USA
    AJR Am J Roentgenol 186:1393-400. 2006
    ....