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Your search keyword '"Robert A. Halvorsen"' showing total 3 results
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3 results on '"Robert A. Halvorsen"'

1. Comparison of MDCT protocols in trauma patients with suspected splenic injury: superior results with protocol that includes arterial and portal venous phase imaging

Author

Raymond Melikian, Stephanie Goldberg, Brian James Strife, and Robert A. Halvorsen

Subjects
Medical physics. Medical radiology. Nuclear medicine, R895-920
Abstract

PURPOSE:We aimed to determine which intravenous contrast-enhanced multidetector computed tomography (MDCT) protocol produced the most accurate results for the detection of splenic vascular injury in hemodynamically stable patients who had sustained blunt abdominal trauma. METHODS:We retrospectively reviewed 88 patients from 2003 to 2011 who sustained blunt splenic trauma and underwent contrast-enhanced MDCT and subsequent angiography. Results of MDCT scans utilizing single phase (portal venous only, n=8), dual phase (arterial + portal venous or portal venous + delayed, n=42), or triple phase (arterial + portal venous + delayed, n=38) were compared with results of subsequent splenic angiograms for the detection of splenic vascular injury.RESULTS:Dual phase imaging was more sensitive and accurate than single phase imaging (P = 0.016 and P = 0.029, respectively). When the subsets of dual phase imaging were compared, arterial + portal venous phase imaging was more sensitive and accurate than portal venous + delayed phase imaging (P = 0.005 and P = 0.002, respectively). Triple phase imaging was more accurate (P = 0.015) than dual phase; however, when compared with the dual phase subset of arterial + portal venous, there was no statistical difference in either sensitivity or accuracy.CONCLUSION:Our results support the use of dual phase contrast-enhanced MDCT, which includes the arterial phase, in patients with suspected splenic injury and question the utility of obtaining a delayed sequence.

Published
2016
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2. Optimizing column-to-column retention time alignment in high-speed gas chromatography by combining retention time locking and correlation optimized warping

Author

Robert C. Halvorsen, Timothy J. Trinklein, Cable G. Warren, Riley D. Rogan, and Robert E. Synovec

Subjects
Analytical Chemistry
Abstract

We examine and then optimize alignment of chromatograms collected on nominally identical columns using retention time locking (RTL), an instrumental alignment tool, and software-based alignment using correlation optimized warping (COW). For this purpose, three samples are constructed by spiking two sets of analytes into a base test mixture. The three samples are analyzed by high-speed gas chromatography with four nominally identical columns and identical separation conditions. The data is first analyzed without alignment, then using COW alone, then RTL alone, and finally with RTL followed by COW to correct the severe column-to-column misalignment. Principal component analysis (PCA) is used to investigate how well each alignment method clustered the chromatograms into the three sample classes via a scores plot without being compromised by the specific column(s) used. The degree-of-class separation (DCS) is used as a classification metric, measured as the Euclidian distance between the centroids of two clusters in PC space in the scores plot, normalized by their pooled variance. With no alignment, the average DCS between sample classes (DCS

Published
2023
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3. Contributors

Author

Jalil Afnan, Jeffrey A. Alexander, Lauren F. Alexander, Surabhi Bajpai, Mark E. Baker, Stephen R. Baker, Aparna Balachandran, Dennis M. Balfe, Emil J. Balthazar, Stuart A. Barnard, Ahmed Ba-Ssalamah, Genevieve L. Bennett, Senta Berggruen, Jonathan W. Berlin, George S. Bissett, Roi M. Bittane, Michael A. Blake, Peyman Borghei, Kevin P. Boyd, Warren M. Brandwein, David H. Bruining, James L. Buck, Carina L. Butler, Selim R. Butros, Laura R. Carucci, Wei-Chou Chang, Raj R. Chinnappan, Byung Ihn Choi, Peter L. Cooperberg, Abraham H. Dachman, Alexander Ding, Carolyn K. Donaldson, Ronald L. Eisenberg, Sukru Mehmet Erturk, Thomas A. Farrell, Kate A. Feinstein, Sandra K. Fernbach, Hector Ferral, Florian J. Fintelmann, Elliot K. Fishman, Joel G. Fletcher, Kathryn J. Fowler, Aletta A. Frazier, Ann S. Fulcher, Helena Gabriel, Ana Maria Gaca, Kirema Garcia-Reyes, Gabriela Gayer, Gary G. Ghahremani, Seth N. Glick, Margaret D. Gore, Richard M. Gore, Sofia Gourtsoyianni, Nicholas C. Gourtsoyiannis, Jared R. Green, Gianfranco Gualdi, Rajan T. Gupta, Ravi Guttikonda, Robert A. Halvorsen, Nancy A. Hammond, Mukesh G. Harisinghani, Sandeep S. Hedgire, Frederick L. Hoff, Caroline L. Hollingsworth, Karen M. Horton, Steven Y. Huang, James E. Huprich, Aleksandar M. Ivanovic, Jill E. Jacobs, Bruce R. Javors, Bronwyn Jones, Naveen Kalra, Avinash Kambadakone, Mariam M. Kappil, Ana L. Keppke, David H. Kim, Stanley Taeson Kim, Douglas R. Kitchin, Michael L. Kochman, Dow-Mu Koh, J. Satheesh Krishna, Naveen Kulkarni, John C. Lappas, Igor Laufer, Fred T. Lee, Jr, Jeong Min Lee, Marc S. Levine, Angela D. Levy, Jennifer E. Lim-Dunham, Mark D. Little, Russell N. Low, Dean D.T. Maglinte, Abdullah Mahmutoglu, Maria A. Manning, Charles S. Marn, Gabriele Masselli, Shaunagh McDermott, Alec J. Megibow, Uday K. Mehta, Vincent M. Mellnick, Christine O. Menias, Joseph Meranda, James M. Messmer, Arthur B. Meyers, Morton A. Meyers, Frank H. Miller, Tara Morgan, Koenraad J. Mortele, Peter R. Mueller, Brian P. Mullan, Vamsi Narra, Albert A. Nemcek, Jr, Geraldine Mogavero Newmark, Jennifer L. Nicholas, Paul Nikolaidis, David J. Ott, Joseph Owen, Orhan S. Ozkan, Nickolas Papanikolaou, Mikin V. Patel, Pritesh Patel, Erik K. Paulson, Christine M. Peterson, Perry J. Pickhardt, Aliya Qayyum, David N. Rabin, Siva P. Raman, Peter M. Rodgers, Pablo R. Ros, Stephen E. Rubesin, Tara Sagebiel, Dushyant V. Sahani, Sanjay Saini, Martha Cotsen Saker, Riad Salem, Kumar Sandrasegaran, Rupan Sanyal, Christopher D. Scheirey, Francis J. Scholz, Adeel R. Seyal, Martin J. Shelly, Linda C. Sherbahn, Ali Shirkhoda, Ana Catarina Silva, Paul M. Silverman, Stuart G. Silverman, Robert I. Silvers, Ajay K. Singh, Jovitas Skucas, Gail S. Smith, Sat Somers, Anthony W. Stanson, Allison L. Summers, Richard A. Szucs, Mark Talamonti, Andrew J. Taylor, Darshit J. Thakrar, Kiran H. Thakrar, Yee Liang Thian, Ruedi F. Thoeni, Stephen Thomas, William Moreau Thompson, Temel Tirkes, Mary Ann Turner, Jennifer W. Uyeda, Fauzia Q. Vandermeer, Robert L. Vogelzang, Patrick M. Vos, Natasha Wehrli, Daniel R. Wenzke, Ellen L. Wolf, Jade J. Wong-You-Cheong, Cecil G. Wood, Michael A. Woods, Vahid Yaghmai, and Benjamin M. Yeh

Published
2015
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