Nancy A. Obuchowski,  PhD

Nancy A. Obuchowski, PhD

Vice Chairman

(Joint appointment with Department of Diagnostic Radiology in the Imaging Institute)

Lerner Research Institute, 9500 Euclid Avenue, Cleveland, Ohio 44195
Location: JJN3-296
Email: obuchon@ccf.org
Phone: (216) 445-9549
Fax: (216) 444-9307

 


Dr. Obuchowski’s primary focus is collaborative and methodologic research into the assessment of screening and diagnostic tests. She has been analyzing imaging data (diagnostic, screening, and quantitative biomarker data) and developing new study designs and methods of analysis for over 25 years. Dr. Obuchowski has authored or co-authored 200 journal papers in the imaging literature, as well as three books. She has served as co-director of metrology workshops on quantitative imaging biomarkers, editor of a special series on quantitative imaging for Statistical Methods in Medical Research, and co-director of RSNA’s clinical trials methodology workshops; she is on the steering committee of the NCI Clinical Imaging network and the Quantitative Imaging Biomarker Alliance, as well as numerous Data Safety and Monitoring Committees. Dr. Obuchowski is a fellow of the American Statistical Association.

Dr. Obuchowski’s PhD dissertation addressed the analysis of a common study design in radiology – a multi-reader Receiver Operating Characteristic (ROC) study- where the goal is to compare the accuracy of two or more diagnostic tests. The tests require interpretation by a trained reader, and, naturally, readers have different cognitive and visual abilities. She developed a method of comparing the accuracies of tests, while incorporating the variability of readers and the correlations in the data introduced by the study design; she also addressed how to compute sample size for these studies. These methods are used in many clinical trials for comparing imaging modalities, as well as assessing the effect of computer-aided detection and artificial intelligence (AI) algorithms in medical imaging.

At the Cleveland Clinic Dr. Obuchowski see lots of studies with clustered data - two breasts, four thyroid glands, multiple lesions in the same patient. Multiple observations from the same patient cannot be treated as independent because of the correlation that exists between the observations from the same patient. Dr. Obuchowski extended a simple idea for clustered binary data to single-reader and multi-reader ROC analysis. This method is used widely in radiology research.

New, less invasive or less expensive tests are constantly being developed to replace conventional imaging methods. For these situations, since the new test is less risky, it can have a little less accuracy than the old test and still be more efficacious. Dr. Obuchowski developed a statistical method to test for equivalence, using different criteria for equivalence. Similarly, she has developed new statistical methods that test for interchangeability of new tests with conventional tests

Sometimes the diagnostic test needs to do more than detect a disease - sometimes correctly locating the lesion(s) is critical to the management of the patient. Dr. Obuchowski developed a method for analyzing data that takes both detection and localization of multiple lesions into account. The new statistical method accounts for the correlations between multiple lesions and between multiple false detections, whereas other methods assumed independence. Dr. Obuchowski has worked on extending ROC analysis to the detection of multiple different diseases, as well as staging disease.

Most recently, Dr. Obuchowski has focused on statistical methods for assessing the technical performance of quantitative imaging biomarkers (QIBs). QIBs are disease characteristics that can be automatically derived from a patient’s medical image. These biomarkers are useful for assessing changes in patients’ disease, both in clinical practice and clinical trials. Dr. Obuchowski has worked with the Quantitative Imaging Biomarker Alliance to develop appropriate metrics and study designs to assess these powerful new endpoints.

In other words ...

Dr. Obuchowski works with radiologists to help them develop and test new ways to image patients.  Conventional imaging methods are sometimes not accurate enough, take too much time, or are too costly. As researchers develop new imaging methods, the new methods must be tested and compared with the old methods.  Dr. Obuchowski plans research studies to test new methods, then she analyzes the results from the study to determine how the new methods performed.  Dr. Obuchowski has developed novel research methods, including more efficient study designs and more powerful methods for analyzing the study results.


Jones MH; MOON Knee Group, Spindler KP, Andrish JT, Cox CL, Dunn WR, Duryea J, Duong

            CL, Flanigan DC, Fleming BC, Huston LJ, Kaeding CC, Matava MJ, Obuchowski NA,

            Oksendahl HL, Parker RD, Scaramuzza EA, Smith MV, Winalski CS, Wright RW,

            Reinke EK. Differences in the lateral compartment joint space after anterior cruciate

            ligament reconstruction: data from the MOON onsite cohort. Am J Sports Med. 2018 Jan

            1.

Alaia EF, Benedick A, Obuchowski NA, Polster JM, Beltran LS, Schils J, Garwood E, Burke

            CJ, Chang IJ, Gyftopoulos S, Subhas N. Comparison of a fast 5-min knee MRI protocol

            with a standard knee MRI protocol: a multi-institutional multi-reader study. Skeletal

            Radiol. 2018; 47:107-116.

Yokoo T, Serai SD, Pirasteh A, Bashir MR, Hamilton G, Hernando D, Hu HH, Hetterich H,

            Kühn JP, Kukuk GM, Loomba R, Middleton MS, Obuchowski NA, Song JS, Tang A,

            Wu X, Reeder SB, Sirlin CB; RSNA-QIBA PDFF Biomarker Committee. Linearity, bias,

            and precision of hepatic proton density fat fraction measurements by using MR imaging:

 a meta-analysis.  Radiology. 2018; 286: 486-498.

Sheahan M, Ma X, Paik D, Obuchowski NA, St Pierre S, Newman WP 3rd, Rae G, Perlman ES,

            Rosol M, Keith JC Jr, Buckler AJ. Atherosclerotic plaque tissue: noninvasive quantitative

            assessment of characteristics with software-aided measurements from conventional CT

            angiography.  Radiology 2018; 286: 622-631.

Obuchowski NA, Bullen JA. Receiver Operating Characteristic (ROC) curves: review of

            methods with applications in diagnostic medicine. Physics in Medicine and Biology

            2018: 63:

Obuchowski NA, Mozley DP, Matthews D, Buckler A, Bullen J, and Jackson E. Statistical

            Considerations for Planning Clinical Trials with Quantitative Imaging Biomarkers.

            JNCI; 2018 Dec 31. Epub 2018.

Shukla-Dave A, Obuchowski NA, Chenevert TL, et al. Quantitative imaging biomarkers

 alliance (QIBA) recommendations for improved precision of DWI and DCE‐MRI

 derived biomarkers in multicenter oncology trials.  J Magn Reson Imaging 2018 Nov 19.

 Epub 2018.

Kwon DH, Obuchowski NA, Marwick TH, Menon V, Griffin B, Flamm SD, Hachamovitch R.

             Jeopardized myocardium defined by late gadolinium enhancement magnetic resonance

             imaging predicts survival in patients with ischemic cardiomyopathy: impact of

             revascularization. J Magn Reson Imaging 2018 Nov 19. Epub 2018.

Wunderle KA, Chung MK, Rayadurgam S, Miller MA, Obuchowski NA, Lindsay BD.

Occupational and patient radiation doses in a modern cardiac electrophysiology

laboratory. J Interv Card Electrophysiol 2018 Oct 2. Epub 2018.

Robins M, Kalpathy-Cramer J, Obuchowski NA, Buckler A, Athelogou M, Jarecha R, Petrick N,

            Pezeshk A, Sahiner B, Samei E. Evaluation of Simulated Lesions as Surrogates to Clinical

            Lesions for Thoracic CT Volumetry: The Results of an International Challenge. Academic

            Radiology2018 Sep 12. Epub 2018.

Alvin MD, Lubelski D, Alam R, Williams S, Obuchowski NA, Steinmetz MP, Wang JC, Melillo

            AJ, Pahwa A, Benzel EC, Modic MT, Quencer R, Mroz TE. Spine Surgeon Treatment

            Variability: The Impact on Costs. Global Spine J 2018 Aug 15; 8: 498-506.

Mantripragada VP, Bova WA, Boehm C, Piuzzi NS, Obuchowski NA, Midura RJ, Muschler

GF. Progenitor cells from different zones of human cartilage and their correlation with

histopathological osteoarthritis progression. J Orthop Res 2018; 36: 1728-1738.

Mantripragada VP, Piuzzi NS, Zachos T, Obuchowski NA, Muschler GF, Midura RJ. High

             occurrence of osteoarthritic histopathological features unaccounted for by traditional

            scoring systems in lateral femoral condyles from total knee arthroplasty patients with varus

             alignment. Acta Orthop 2018; 89: 197-203.

Bhatt KM, Tandon YK, Graham R, Lau CT, Lempel JK, Azok JT, Mazzone PJ, Schneider E,

Obuchowski NA, Bolen MA. Electromagnetic navigational bronchoscopy versus CT-

guided percutaneous sampling of peripheral indeterminate pulmonary nodules: a cohort

study. Radiology 2018; 286: 1052-1061.

Obuchowski NA. Interpreting Change in Quantitative Imaging Biomarkers. Acad Radiol 2018;

            25: 372-379.

SubhasN, PursykoCP, Polster JM, Obuchowski NA, Primak AN, Dong FF, and Herts BR. Dose

 Reduction With Dedicated CT Metal Artifact Reduction Algorithm: CT Phantom Study.

 Am J Roentgenol 2018; 210: 593-600.

Jones MH, Spindler KP, Andrish JT, Cox CL, Dunn WR, Duryea J, Duong CL, Flanigan DC,

             Fleming BC, Huston LJ, Kaeding CC, Matava MJ, Obuchowski NA, Oksendahl HJ,

             Parker RD, Scaramuzza EA, Smith MV, Winalski CS, Wright RW, Reinke EK.

             Differences in the Lateral Compartment Joint Space Width After Anterior Cruciate

            Ligament Reconstruction: Data From the MOON Onsite Cohort.  Am J Sports Med 2018;

            46: 876-882.

Mikkilineni  H, Delzell PB, Andrish J, Bullen J, Obuchowski NA, Subhas N, Polster JM, Schils

            JP. Ultrasound evaluation of infrapatellar fat pad impingement: An exploratory prospective

             study.  Knee 2018; 25: 279-285.

Sheahan M, Ma X, Paik D, Obuchowski NA, St. Pierre S, Newman WP, Rae G, Perlman ES,

Rosol M, Keith JC, Buckler AJ. Atherosclerotic plaque tissue: noninvasive quantitative assessment of characteristics with software-aided measurements from conventional CT angiography. Radiology 2018; 286: 622-631.

Yokoo T, Serai SD, Pirasteh A, Bshir MR, Hamilton G, Hernando D, Hu HH, Hetterich H, Kuhn

 JP, Kukuk GM, Loomba R, Middleton MS, Obuchowski NA, Song JS, Tang A, Wu X,

 Reeder SB, Sirlin CB. Linearity, bias, and precision of hepatic proton density fat fraction

measurements by using MR Imaging: a meta-analysis.  Radiology 2018; 286: 486-498.

Bandos AI, Obuchowski NA. Evaluation of diagnostic accuracy in free-response detection-

            localization tasks using ROC tools. Stat Methods Med Res 2018 Jan 1. Epub 2018 Jan 1.


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