130 results on '"Levin, David"'
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2. Contributors
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Alper, Hal S., primary, Bayer, Edward A., additional, Biddy, Mary J., additional, Bomble, Yannick J., additional, Brown, Steven D., additional, Brunecky, Roman, additional, Carpita, Nicholas C., additional, Davis, Ryan E., additional, Haan, R. den, additional, Donohoe, Bryon S., additional, Dugard, Christopher K., additional, Ehsaan, Muhammad, additional, Guss, Adam M., additional, Himmel, Michael E., additional, Hobdey, Sarah E., additional, Islam, Rumana, additional, Johnson, David K., additional, Kovács, Katalin, additional, Kruer-Zerhusen, Nathan, additional, Kuit, Wouter, additional, la Grange, D.C., additional, Lal, Sadhana, additional, Lee, Sun-Mi, additional, Levin, David B., additional, Liao, James C., additional, Lin, Xiaoxia N., additional, McCann, Maureen C., additional, Minton, Nigel P., additional, Minty, Jeremy J., additional, Mittal, Ashutosh, additional, Moens, Luc, additional, Moraïs, Sarah, additional, Munir, Riffat, additional, Olstad, Jessica, additional, Penning, Bryan W., additional, Pilath, Heidi, additional, Ramachandran, Umesh, additional, Rose, S.H., additional, Sander, Kyle B., additional, Scarlata, Christopher J., additional, Schellenberg, John, additional, Schwarz, Katrin, additional, Singh, Arjun, additional, Sparling, Richard, additional, Takasumi, Jennifer L., additional, Tan, Eric C.D., additional, Tao, Ling, additional, Tucker, Melvin P., additional, van Zyl, W.H., additional, Verbeke, Tobin J., additional, Vinzant, Todd B., additional, Wackett, Lawrence P., additional, Wang, Wei, additional, Wei, Hui, additional, Wilmot, Carrie M., additional, Wilson, David B., additional, Winzer, Klaus, additional, Wolfrum, Edward J., additional, Wu, Chia-Wei, additional, Xu, Qi, additional, Yang, Shihui, additional, Yarbrough, John M., additional, Young, Eric M., additional, Zhang, Min, additional, and Zhang, Ying, additional
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- 2015
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3. Chapter 2 The N‐Acetylglucosamine‐PI Transfer Reaction, the GlcNAc‐PI Transferase Complex, and Its Regulation
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Levin, David E., primary and Stamper, Ronald J., additional
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- 2009
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4. Completion of base excision repair by mammalian DNA ligases
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Tomkinson, Alan E, primary, Chen, Ling, additional, Dong, Zhiwan, additional, Leppard, John B, additional, Levin, David S, additional, Mackey, Zachary B, additional, and Motycka, Teresa A, additional
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- 2001
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5. Mpk1
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Levin, David E., primary
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- 1995
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6. Bck1
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Levin, David E., primary
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- 1995
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7. SpKin 1
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Levin, David E., primary
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- 1995
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8. Kin 1/2
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Levin, David E., primary
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- 1995
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9. ScPKC
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Levin, David E., primary
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- 1995
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10. Stationary and Non-Stationary Binary Subdivision Schemes
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Dyn, Nira, primary and Levin, David, additional
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- 1992
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11. Derivation of gauge invariance from high-energy unitarity bounds on the S matrix
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Cornwall, John M., primary, Levin, David N., additional, and Tiktopoulos, George, additional
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- 1991
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12. Means to improve the utilization of canola meal by broiler chickens: new low-fiber canola and the use of exogenous enzymes
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Nyachoti, Martin (Animal Science) Crow, Gary (Animal Science) Levin, David (Biosystems Engineering) / Parsons, Carl (University of Illinois), Slominski, Bogdan (Animal Science), Rad-Spice, Maya, Nyachoti, Martin (Animal Science) Crow, Gary (Animal Science) Levin, David (Biosystems Engineering) / Parsons, Carl (University of Illinois), Slominski, Bogdan (Animal Science), and Rad-Spice, Maya
- Abstract
Means of improving the quality of CM for poultry, including breeding for low-fiber canola and the use of exogenous enzymes, have been proposed. The objectives of the current study were: (1) To evaluate the chemical and nutritive composition of new yellow-seeded B. napus and B. juncea canola, (2) To investigate the effect of canola type and enzyme supplementation on AMEn and SID of amino acids, and growth performance of broiler chickens, (3) To explore the new carbohydrase enzymes for their ability to depolymerize NSP of CM in vitro, and (4) To evaluate the effect of new enzyme combinations in vivo with broiler chickens. In comparison with the conventional meal, yellow-seeded B. napus and B. juncea contained more crude protein, more sucrose, and less dietary fiber. The AMEn and SID amino acid values for yellow-seeded B. napus, B. juncea canola, and the conventional black-seeded B. napus were 1865, 2092 and 1902 kcal/kg DM, and 82.5, 83.2, and 81.8%, respectively. Enzyme addition resulted in a more pronounced effect on the AMEn content of B. juncea meal. When birds were fed diets containing 15% CM, BWG averaged 2.32, 2.30, 2.19, and 2.31 kg for the SBM-based Control, black and yellow B. napus, and B. juncea meals, respectively. A lower (P<0.05) BWG was observed in birds fed a diet containing 30% of B. juncea meal. In another experiment, enzyme supplementation improved FCR in chicks fed B. juncea meal. In the in vitro enzyme incubation studies, enzyme preparations galactanase/pectinase and cellulase/xylanase showed NSP degradation of more than 40%, and were subsequently used in the broiler chicken experiments. A lower BWG and higher intestinal viscosity were observed in birds fed the enzyme-supplemented diet containing 30% of B. juncea meal. High digesta viscosity could be attributed to the release of water-soluble NSP due to the low dietary enzyme concentration and/or unfavorable gut conditions. No differences in growth performance were observed in broiler chickens fe
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- 2017
13. [29] Detection of oxidative mutagens with a new Salmonella tester strain (TA102)
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Levin, David E., primary, Hollstein, Monica, additional, Christman, Michael F., additional, and Ames, Bruce N., additional
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- 1984
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14. Investigations of Single Cell Oils (SCOs): an analysis of growth and lipid biosynthesis in oleaginous microbes for biodiesel production
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Cicek, Nazim (Biosystems Engineering) Court, Deborah (Microbiology) French, W. Todd (Chemical Engineering) Mississippi State University, Levin, David, B. (Biosystems Engineering), Sestric, Ryan, Cicek, Nazim (Biosystems Engineering) Court, Deborah (Microbiology) French, W. Todd (Chemical Engineering) Mississippi State University, Levin, David, B. (Biosystems Engineering), and Sestric, Ryan
- Abstract
Biodiesel production from the triglycerides of Single Cell Organisms (SCO) has been researched for many years, and could supplement the transportation fuel market. Several improvements to the understanding of microbial physiology have led to increased lipid yields and reduction in costs of biodiesel production. Microalgae and oleaginous yeasts have been at the forefront of research for SCO production, and lipid biosynthesis is stimulated by nutrient limitation in both. The microalga Chlamydomonas reinhardtii BAFJ5, a mutant strain blocked for starch granule synthesis was grown heterotrophically and mixotrophically in both nutrient limited and rich media. The lipid production in heterotrophic growth was similar to mixotrophically grown cells. Following this, an extensive screen of known and uncharacterized oleaginous yeast assessed the lipid profiles and biomass concentrations of 69 strains. The strain Yarrowia lipolytica was chosen for further characterization, demonstrating its ability to metabolize biodiesel derived ‘waste’ glycerol and the effect it has on lipid synthesis. Pure and waste glycerol were both acceptable carbon substrates for biomass production, and no deleterious effects to the cell were seen. Finally, the proteome of Y. lipolytica was examined, which showed glycolysis, the tricarboxylic cycle, and lipid biosynthesis had similar regulation at the protein level under nitrogen-limited and nitrogen-sufficient conditions.
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- 2013
15. A meta-analysis reveals that operational parameters influence levels of antibiotic resistance genes during anaerobic digestion of animal manures.
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Flores-Orozco D, Levin D, Kumar A, Sparling R, and Cicek N
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- Anaerobiosis, Animals, Cattle, Drug Resistance, Microbial genetics, Genes, Bacterial, Swine, Anti-Bacterial Agents pharmacology, Manure
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Anaerobic digestion (AD) has shown the potential to reduce the numbers and types of antibiotic-resistance genes (ARG) present in animal manures. However, the variability of the results has limited the ability to draw solid conclusions. To address this issue, we performed a series of meta-analyses to evaluate how AD of pig, cattle, and dairy manures affects ARG levels and how different parameters, such as temperature, pH, digestion times, and the addition of other substances (e.g., solids, antibiotics) influence ARG changes. Twenty studies with enough details on changes in ARG levels during the AD process were identified and used for the meta-analyses. The results suggested that AD could significantly reduce ARG levels regardless of the conditions of the process. Also, thermophilic AD was more effective than mesophilic AD at reducing ARGs, although this difference was only significant for pig manures. The results also suggested that long digestion times (>50 days) yielded better ARG reduction rates, and that the addition of solids from an external source (co-digestion) negatively affected the efficiency of ARG reduction. In general, the results suggested that ARG changes during AD could be linked to the abundance and activity of hydrolytic communities., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)
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- 2022
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16. Influence of the World Wars on vital sign monitoring technology.
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Sud S, Steinberg BE, Levin D, and Siddiqui A
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- Capnography history, Capnography instrumentation, History, 20th Century, Humans, Monitoring, Physiologic methods, Oximetry history, Oximetry instrumentation, Radiometry instrumentation, Capnography methods, Monitoring, Physiologic history, Oximetry methods, Radiometry methods, Vital Signs physiology, World War I, World War II
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Competing Interests: Declarations of interest The authors declare that they have no conflict of interest.
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- 2021
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17. Emphysematous Lung Lesions Caused by Perivascular and Alveolar-Septal Deposition of Amyloid Light-Chain Amyloidosis.
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Martin MJ, Pennington KM, Skalski JH, Yi ES, Levin DL, Durani U, and Ryu JH
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- Aged, Biomarkers blood, Biopsy, Female, Humans, Immunoglobulin G blood, Immunoglobulin Light-chain Amyloidosis diagnostic imaging, Lung Diseases diagnostic imaging, Pulmonary Emphysema diagnostic imaging, Tomography, X-Ray Computed, Immunoglobulin Light-chain Amyloidosis complications, Lung Diseases complications, Pulmonary Emphysema etiology
- Abstract
Pulmonary amyloidosis, whether isolated or seen as part of systemic amyloidosis, has a variety of radiographic manifestations. Known parenchymal lung findings include reticulonodular opacities, diffuse interstitial infiltrates, or cystic lesions. Here, we present a case of systemic amyloid light-chain (AL) amyloidosis presenting with severe exertional dyspnea and emphysematous lung lesions on chest CT, a finding described only once before. Although factors that influence the pattern of pulmonary amyloid deposition remain unclear, CT image findings typically reflect the histopathologic patterns of deposition. In this case, we hypothesize that the emphysematous changes in the lower lung zones are likely a manifestation of severe alveolar-septal involvement. This case suggests that radiographic findings of pulmonary amyloidosis are not limited to the more common findings of reticular opacities or interstitial infiltrates. Emphysematous changes are possible, and clinicians should maintain a broad differential when seen in the setting of dyspnea., (Copyright © 2021 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)
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- 2021
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18. Radiology in the Era of Value-Based Healthcare: A Multi Society Expert Statement From the ACR, CAR, ESR, IS3R, RANZCR, and RSNA.
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Brady AP, Bello JA, Derchi LE, Fuchsjäger M, Goergen S, Krestin GP, Lee EJY, Levin DC, Pressacco J, Rao VM, Slavotinek J, Visser JJ, Walker REA, and Brink JA
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- Australia, Canada, Delivery of Health Care, Europe, Humans, Societies, Medical, Radiology
- Abstract
Background: The Value-Based Healthcare (VBH) concept is designed to improve individual healthcare outcomes without increasing expenditure, and is increasingly being used to determine resourcing of and reimbursement for medical services. Radiology is a major contributor to patient and societal healthcare at many levels. Despite this, some VBH models do not acknowledge radiology's central role; this may have future negative consequences for resource allocation., Methods, Findings and Interpretation: This multi-society paper, representing the views of Radiology Societies in Europe, the USA, Canada, Australia, and New Zealand, describes the place of radiology in VBH models and the health-care value contributions of radiology. Potential steps to objectify and quantify the value contributed by radiology to healthcare are outlined., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
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19. Trends in the Use of Percutaneous Versus Open Surgical Breast Biopsy: An Update.
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Teberian I, Kaufman T, Shames J, Rao VM, Liao L, and Levin DC
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- Biopsy, Needle, Fee-for-Service Plans, Image-Guided Biopsy, United States, Breast diagnostic imaging, Breast surgery, Current Procedural Terminology
- Abstract
Purpose: Despite the emergence of core-needle (percutaneous) biopsy as the standard of breast care, open surgical breast biopsies continue to be performed with variable frequency. The aim of this study was to compare trends in the use of percutaneous and open surgical breast biopsies and the relative roles of radiologists and surgeons in performing them., Methods: The nationwide Medicare Part B Physician/Supplier Procedure Summary Master Files for 2004 to 2016 were reviewed, and trends were studied in the total volume of breast biopsies performed in the Medicare fee-for-service population and in volumes of imaging-guided percutaneous biopsies (IGPBs) and open surgical biopsies. Using Medicare's physician specialty codes, the numbers of procedures performed by different specialties were determined. Trends in the type of imaging used for IGPBs were analyzed using the relevant Current Procedural Terminology codes, introduced in 2014., Results: Between 2004 and 2016, utilization of IGPBs increased from 124,423 to 187,914 (+51%), whereas the use of open surgical breast biopsies declined from to 6,605 to 2,373 (-64%). IGPBs performed by radiologists increased from 89,493 to 160,485 (+79%), and IGPBs by surgeons declined from 30,264 to 24,703 (-18%). Among IGPBs from 2014 to 2016, ultrasound-guided and MRI-guided percutaneous biopsies increased, whereas stereotactic biopsies declined., Conclusions: There is a steady upward trend in the utilization of imaging-guided breast biopsies, and a majority are performed by radiologists. Ultrasound is the primary guidance technique used in percutaneous breast biopsies., (Copyright © 2020 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
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- 2020
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20. Recent Trends in Medicare Reimbursements to Nonradiologist Physicians for In-Office MRI and CT.
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Kamel SI, Parker L, Rao V, and Levin DC
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- Health Services Research, Humans, United States, Magnetic Resonance Imaging economics, Medicare Part B economics, Office Visits economics, Practice Patterns, Physicians' economics, Reimbursement Mechanisms, Tomography, X-Ray Computed economics
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Purpose: Previous studies demonstrated rapid growth in payments to nonradiologist providers (NRPs) for MRI and CT in their private offices. In this study, we re-examine the trends in these payments., Methods: The nationwide Medicare Part B master files from 2004 to 2016 were accessed. They provide payment data for all Current Procedural Terminology codes. Codes for MRI and CT were selected. Global and technical component claims were counted. Medicare specialty codes identified payments made to NRPs and radiologists, and place-of-service codes identified payments directed to their private offices., Results: Medicare MRI payments to NRPs peaked in 2006 at $247.7 million. As a result of the Deficit Reduction Act, there was a sharp drop to $189.5 million in 2007, eventually declining to $101.6 million by 2016 (-59% from peak in 2006). The NRP specialty groups with the highest payments for MRI ownership include orthopedists, neurologists, primary care physicians, and hospital-based specialists (pathology, physiatry, and hospitalists). Medicare CT payments to NRPs peaked in 2008 at $284.1 million and declined to $94.7 million in 2016 (-67% from peak). Cardiologists, primary care physicians, internal medicine specialists, urologists, and medical oncologists accounted for the most payments made to NRPs. Dollars paid to radiologists for private office MRI and CT dropped substantially since they peaked in 2006., Conclusions: NRP private offices (and radiology offices also) experienced massive decreases in Medicare payments for MRI and CT since peaking in 2006 and 2008, respectively. These trends suggest the financial viability of private office practice may be in jeopardy. However, certain recent policy changes could promote a resurgence., (Copyright © 2019 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
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- 2020
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21. A novel thermostable GH5 β-xylosidase from Thermogemmatispora sp. T81.
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Tomazini A, Higasi P, Manzine LR, Stott M, Sparling R, Levin DB, and Polikarpov I
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- Enzyme Stability, Hydrogen-Ion Concentration, Xylosidases chemistry, Xylosidases genetics, Chloroflexi enzymology, Temperature, Xylosidases metabolism
- Abstract
A glycoside hydrolase family 5 (GH5) subfamily 22 gene, designated T81Xyl5_22A, was identified in the genome of the aerobic thermophilic bacterium, Thermogemmatispora sp. T81 (locus A4R35_07040). The gene was cloned and heterologously expressed in Escherichia coli and the gene product characterized biochemically. The recombinant enzyme had an optimal catalytic activity at pH5.0 and 65 °C, and was active against beechwood xylan and rye arabinoxylan. It yielded only xylose molecules as products of beechwood xylan hydrolysis, indicating that it is a GH5 family β-d-xylosidase. Using 4-nitrophenyl β-d-xylopyranoside (pNPX) as a substrate, the K
M , Vmax, kcat and kcat /KM kinetic parameters were determined as 0.25 ± 0.03 mM, 889.47 ± 28.54 U/mg, 39.20 s-1 and 156.8 mM-1 s-1 , respectively. Small-angle X-ray scattering (SAXS) data enabled reconstruction of the enzyme's low-resolution molecular envelope and revealed that it formed dimers in solution. As far as we are aware, this is the first description of a thermostable bacterial GH5 family β-d-xylosidase., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2019
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22. Recent Trends Suggest Possible Inappropriate Utilization of Myocardial Perfusion Imaging.
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Kamel SI, Intenzo CM, Parker L, Rao V, and Levin DC
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- Aged, Current Procedural Terminology, Fee-for-Service Plans, Health Services Research, Humans, Medicare, Medicare Part B, United States, Myocardial Perfusion Imaging trends, Practice Patterns, Physicians' trends, Utilization Review
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Purpose: The aim of this study was to analyze the utilization of elective stress nuclear myocardial perfusion imaging (MPI) in the Medicare population., Methods: Nationwide Medicare Part B fee-for-service databases for 2004 to 2016 were reviewed. Current Procedural Terminology codes for stress MPI were selected: standard planar and single-photon emission computed tomography (STD) and PET. Utilization rates per 1,000 Medicare beneficiaries were calculated. Elective examinations were identified using place-of-service codes for private offices and hospital outpatient departments (HOPDs). Medicare physician specialty codes identified the performing physician. Because Medicare Part B databases are complete population counts, sample statistics were not required., Results: Elective STD MPI utilization peaked in 2006 at 74 studies/1,000 and had declined by 36% by 2016. Cardiologists' share of STD MPI grew from 79% to 87% between 2004 and 2016. Cardiologists perform STD MPI primarily in private offices, where utilization peaked in 2008 and then demonstrated an absolute decline of 28 studies/1,000 by 2016. During this same time period, cardiologists' use of STD MPI in HOPDs demonstrated an absolute increase of 8.1 studies/1,000. From 2004 to 2016, STD MPI use by radiologists declined by 58%. Elective PET MPI maintained an upward trend, reflecting increasing use by cardiologists in private offices., Conclusions: Elective STD MPI use is declining, but cardiologists are performing an increasing share in outpatient settings. The drop in private office STD MPI among cardiologists was far greater than the corresponding increase in its use in HOPDs, suggesting that many studies previously performed in private offices were unindicated. Self-referred PET MPI utilization has rapidly grown in cardiology private offices., (Copyright © 2019 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
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23. Hydrocarbonoclastic Ascomycetes to enhance co-composting of total petroleum hydrocarbon (TPH) contaminated dredged sediments and lignocellulosic matrices.
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Becarelli S, Chicca I, Siracusa G, La China S, Gentini A, Lorenzi R, Munz G, Petroni G, Levin DB, and Di Gregorio S
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- Ascomycota isolation & purification, Composting, RNA, Ribosomal, 16S genetics, RNA, Ribosomal, 16S metabolism, Ascomycota metabolism, Geologic Sediments chemistry, Hydrocarbons metabolism, Petroleum metabolism
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Four new Ascomycete fungi capable of degrading diesel oil were isolated from sediments of a river estuary mainly contaminated by shipyard fuels or diesel oil. The isolates were identified as species of Lambertella, Penicillium, Clonostachys, and Mucor. The fungal candidates degraded and adsorbed the diesel oil in suspension cultures. The Lambertella sp. isolate displayed the highest percentages of oxidation of diesel oil and was characterised by the capacity to utilise the latter as a sole carbon source. This isolate showed extracellular laccase and Mn-peroxidase activities in the presence of diesel oil. It was tested for capacity to accelerate the process of decontamination of total petroleum hydrocarbon contaminated sediments, co-composted with lignocellulosic residues and was able to promote the degradation of 47.6% of the TPH contamination (54,074 ± 321 mg TPH/Kg of sediment) after two months of incubation. The response of the bacterial community during the degradation process was analysed by 16S rRNA gene meta-barcoding., (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Published
- 2019
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24. High-Deductible Health Plans and the Challenges They Pose to Radiologists.
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Levin DC, Rao VM, Hiatt MD, and Colarossi M
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- Access to Information, Disclosure, Economics, Hospital, Health Care Costs, Humans, United States, Deductibles and Coinsurance, Diagnostic Imaging economics, Radiologists economics
- Abstract
Patients with high-deductible health plans will increasingly be motivated to contact their hospitals or various websites to try to obtain information about the costs of expensive services like advanced imaging. Unfortunately, they will not find price transparency but rather confusion and opaqueness. Hospital personnel and commercial websites often unwittingly provide erroneous pricing information. The reasons for this are explained. Detailed examples of the erroneous information are provided. State-mandated websites may be somewhat of an improvement, but their methodology seems to vary from state to state, and they too can be confusing. All this obviously creates problems for patients, who are left not knowing what their true costs will be. The situation also creates problems for radiologists and their hospitals. Because of misunderstandings that can occur during the information-gathering phase, the pricing information shown for many hospital facilities may be greatly inflated, placing them at a competitive disadvantage. Certain strategic solutions to the problems are available, and these are discussed., (Copyright © 2018 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
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25. Coronary CT Angiography: Reversal of Earlier Utilization Trends.
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Levin DC, Parker L, Halpern EJ, and Rao VM
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- Current Procedural Terminology, Fee-for-Service Plans, Humans, United States, Computed Tomography Angiography statistics & numerical data, Coronary Angiography statistics & numerical data, Medicare Part B, Practice Patterns, Physicians' statistics & numerical data, Utilization Review
- Abstract
Purpose: To assess recent trends in utilization of coronary CT angiography (CCTA), based upon place of service and provider specialty., Materials and Methods: The nationwide Medicare Part B master files for 2006 through 2016 were the data source. Current Procedural Terminology, version 4 codes for CCTA were selected. The files provided procedure volume for each code. Utilization rates per 100,000 Medicare fee-for-service enrollees were then calculated. Medicare's place-of-service codes were used to identify CCTAs performed in private offices, hospital outpatient departments (HOPDs), emergency departments (EDs), and inpatient settings. Physician specialty codes were used to identify CCTAs interpreted by radiologists, cardiologists, and all other physicians as a group. Medicare practice share was defined as the percent of total Medicare utilization that was billed by each specialty., Results: The total utilization rate of CCTA in the Medicare population rose sharply from 2006 to 2007, peaking at 210.3 per 100,000 enrollees in 2007. Radiologists' CCTA practice share in 2007 was 32%, compared with 60% for cardiologists. The overall utilization rate then declined to a nadir of 107.1 per 100,000 enrollees in 2013, but subsequently increased to 131.0 by 2016. By that year, radiologists' share of CCTA practice had risen to 58%, compared with 38% for cardiologists. HOPD utilization increased sharply since 2010, primarily among radiologists. In EDs and inpatient settings, greater utilization has also occurred recently, primarily among radiologists. By contrast, private office utilization has dropped sharply since 2007., Conclusion: After years of declining utilization, the utilization rate of CCTA is now increasing, predominantly among radiologists., (Copyright © 2018 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
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26. Combined pulmonary fibrosis and emphysema as a clinicoradiologic entity: Characterization of presenting lung fibrosis and implications for survival.
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Alsumrain M, De Giacomi F, Nasim F, Koo CW, Bartholmai BJ, Levin DL, and Moua T
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- Aged, Female, Humans, Lung Diseases, Interstitial diagnostic imaging, Lung Diseases, Interstitial mortality, Male, Middle Aged, Prevalence, Pulmonary Emphysema diagnostic imaging, Pulmonary Emphysema mortality, Pulmonary Fibrosis diagnostic imaging, Pulmonary Fibrosis mortality, Survival Analysis, Lung Diseases, Interstitial epidemiology, Pulmonary Emphysema epidemiology, Pulmonary Fibrosis epidemiology
- Abstract
Background: The prevalence of classifiable and unclassifiable causes of lung fibrosis and its implications for survival are mostly unknown in combined pulmonary fibrosis and emphysema (CPFE)., Materials and Methods: Patients with >10% involvement of both emphysema and lung fibrosis seen over 11 years at our institution were reviewed independently by expert radiologists for fibrotic and emphysematous findings and overall fibrotic CT pattern. Underlying interstitial lung disease (ILD) diagnoses and baseline demographic and clinical characteristics were collated and assessed for predictors of comparative survival., Results: In this retrospective cohort, 179 CPFE patients were identified and categorized as 58 usual interstitial pneumonia/idiopathic pulmonary fibrosis (UIP/IPF) (32%), 42 secondary ILD (23%), and 79 unclassifiable ILD (44%). The most prevalent (47%) radiologic pattern was 'unclassifiable', followed by 'consistent' and 'possible' UIP pattern in 38%. Adjusted predictors of mortality for the cohort as a whole included age (HR 1.03[1.01-1.06], P = 0.002), percent predicted diffusing capacity for carbon monoxide (unit HR 0.97 [0.96-0.99], P = 0.001), honeycombing (HR 1.58 [1.02-2.43], P = 0.04), and right ventricular dysfunction (HR 2.28 [1.39-3.97], P = 0.002). Survival was similar between CPFE with secondary ILD and CPFE with UIP/IPF, while CPFE with unclassifiable ILD had better comparative survival (Log rank = 0.026)., Conclusions: Our findings suggest only about a third of CPFE patients represent suspected UIP/IPF; the majority were clinically and radiologically unclassifiable ILD whose survival was comparatively better. Identifiable or secondary causes of lung fibrosis in CPFE occurred in about a fifth of presenting patients., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2019
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27. Deep learning and the evaluation of pulmonary fibrosis.
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Levin DL
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- Cohort Studies, Humans, Tomography, X-Ray Computed, Deep Learning, Pulmonary Fibrosis
- Published
- 2018
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28. National Trends in the Utilization of Skeletal Radiography From 2003 to 2015.
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Mizrahi DJ, Parker L, Zoga AM, and Levin DC
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- Fee-for-Service Plans, Female, Humans, Male, Medicare Part B, Radiology trends, United States, Bone and Bones diagnostic imaging, Medicare trends, Practice Patterns, Physicians' trends, Utilization Review
- Abstract
Purpose: Examine recent trends in the use of skeletal radiography and assess the roles of various nonradiologic specialties in the interpretations., Methods: Medicare Part B fee-for-service claims data files from 2003 to 2015 were analyzed for all Current Procedural Terminology, version 4 (CPT-4) procedure codes related to skeletal radiography. The files provide examination volume, and we calculated utilization rates per 1,000 Medicare beneficiaries. Medicare's physician specialty codes were used to determine the specialties of the providers. Total utilization rate trends were analyzed, as well as those for radiologists and nonradiologists. We determined which nonradiologist specialties were the highest users of skeletal radiography. Medicare place-of-service codes were used to identify the locations where the services were provided., Results: The total utilization rate per 1,000 of skeletal radiography within the Medicare population increased 9.5% from 2003 to 2015. The utilization rate for radiologists increased 5.5% from 2003 to 2015 versus 11.1% for nonradiologists as a group. Among nonradiologist specialties in all health care settings over the study period, orthopedic surgeons increased 10.6%, chiropractors and podiatrists together increased 14.4%, nonphysician providers (primarily nurse practitioners and physician assistants) increased 441%, and primary care physicians' rate decreased 33.5%. Although radiologists do almost all skeletal radiography interpretation in hospital settings, nonradiologists do the majority in private offices. There has been strong growth in skeletal radiography in emergency departments, but a substantial drop in inpatient settings., Conclusions: The utilization of skeletal radiography has increased more rapidly among nonradiologists than among radiologists. This raises concerns about self-referral and quality., (Copyright © 2017 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
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29. The Percent Share of All Medicare Payments to Physicians That Is Attributable to Noninvasive Diagnostic Imaging.
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Levin DC, Parker L, and Rao VM
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- Fee Schedules, Humans, United States, Diagnostic Imaging economics, Insurance, Health, Reimbursement economics, Medicare economics
- Abstract
Purpose: To ascertain the proportion of all Medicare payments to physicians under the Medicare Physician Fee Schedule (PFS) that is attributable to noninvasive diagnostic imaging (NDI)., Materials and Methods: The Medicare Part B Physician/Supplier Procedure Summary Master Files for 2003 to 2015 were the data source. Total approved payments to physicians for all medical services were determined each year. We then selected all procedure codes for NDI and determined aggregate approved payments to physicians for those codes. Also, Medicare's provider specialty codes were used to define payments to four provider categories: radiologists, cardiologists, all other physicians, and independent diagnostic testing facilities together with multispecialty groups (in this category, the specialty of the actual provider cannot be determined)., Results: Total Medicare-approved payments for all physician services under the PFS increased progressively from $92.73 billion in 2003 to $132.85 billion in 2015. In 2003, the share of those payments attributable to NDI was 9.5%, increasing to a peak of 10.8% in 2006, but then progressively declining to 6.0% in 2015. All four provider categories saw the same trend pattern-a peak in 2006 but then decline thereafter. By 2015, the shares of total PFS payments to physicians that were attributable to NDI were as follows: radiologists 3.2%, cardiologists 1.2%, all other physicians 1.2%, independent diagnostic testing facilities or multispecialty groups 0.4%., Conclusion: The proportion of Medicare PFS spending on physician services that is attributable to NDI has been declining in recent years and is now quite small., (Copyright © 2018 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
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30. Comparative Trends in Utilization of MRI and Ultrasound to Evaluate Nonspine Joint Disease 2003 to 2015.
- Author
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Kanesa-Thasan RM, Nazarian LN, Parker L, Rao VM, and Levin DC
- Subjects
- Humans, Medicare Part B, United States, Utilization Review, Joint Diseases diagnostic imaging, Magnetic Resonance Imaging trends, Practice Patterns, Physicians' trends, Ultrasonography trends
- Abstract
Purpose: MRI and ultrasound (US) are effective diagnostic tools to evaluate extremities. In this study, we analyze utilization trends in musculoskeletal (MSK) US and MRI from 2003 to 2015 within the Medicare population., Methods: Our data sources were the Medicare Part B Physician/Supplier Procedure Summary Master Files for 2003 to 2015. They cover all Medicare fee-for-service enrollees (37.5 million in 2015). Current Procedural Terminology codes for nonvascular, nonspine joint MRI and extremity US were selected and volumes within these codes were determined. Medicare's physician specialty codes were used to identify provider specialty. We accounted for the 2011 code change that created both complete and limited US examinations., Results: Total Medicare joint MRI volume increased from 738,509 in 2003 to 1,131,503 in 2015 (+53%), although there was little change after 2007. Radiologist MRI share in 2015 was 93%, followed by orthopedic surgeons at 5%. Total MSK US volume grew from 96,235 in 2003 to 429,695 in 2015 (+347%). Radiologists' market share of US decreased from 65% in 2003 to 37% in 2015, with nonradiologists now representing a majority of ultrasound examinations. Multiple nonradiology subspecialties also exceed radiology in volume of complete ultrasounds., Conclusion: The potential negative impact of MSK US on MSK MRI volume is likely overestimated because MRI volume has remained stable. MSK ultrasound is increasingly utilized outside radiology. If radiologists want to maintain their market share as MSK imaging leaders, more emphasis should be placed on increasing their involvement and expertise in MSK US., (Copyright © 2017 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
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31. Reducing Inappropriate Use of Diagnostic Imaging Through the Choosing Wisely Initiative.
- Author
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Levin DC and Rao VM
- Subjects
- Cost Savings, Evidence-Based Medicine, Humans, Societies, Medical, United States, Decision Making, Diagnostic Imaging statistics & numerical data, Unnecessary Procedures
- Published
- 2017
- Full Text
- View/download PDF
32. The Recent Losses in Medicare Imaging Revenues Experienced by Radiologists, Cardiologists, and Other Physicians.
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Levin DC, Parker L, and Rao VM
- Subjects
- Economics, Medical, Fee Schedules, Humans, Medicare Part B legislation & jurisprudence, Medicare Part B trends, Medicine, United States, Cardiologists economics, Medicare Part B economics, Radiologists economics, Radiology economics
- Abstract
Purpose: The aim of this study was to assess recent trends in Medicare reimbursements to radiologists, cardiologists, and other physicians for noninvasive diagnostic imaging (NDI)., Methods: The Medicare Part B databases for 2002 to 2015 were the data source. These files provide total allowed payments for all NDI Current Procedural Terminology codes under the Medicare Physician Fee Schedule. Medicare specialty codes were used to identify payments to radiologists, cardiologists, and all other specialists. In additional to total reimbursements, those made for global, technical component, and professional component claims were studied., Results: Total reimbursements to physicians for NDI under the Medicare Physician Fee Schedule peaked at $11.936 billion in 2006. Over the ensuing years, the Deficit Reduction Act and other cuts reduced them by 33% to $8.005 billion in 2015. Reimbursements to radiologists peaked at $5.300 billion in 2006 but dropped to $4.269 billion by 2015 (-19.5%). NDI reimbursements to cardiologists dropped from $2.998 billion in 2006 to $1.653 billion by 2015 (-44.9%). Most other specialties also saw decreases over the study period. An important reason for the large decline for cardiologists was their dependence on global reimbursement, which saw a 50.5% drop from 2006 to 2015. Radiologists' global payments also dropped sharply (40.4%), but radiologists themselves were somewhat protected by receiving a much larger proportion of their reimbursement for the professional component, which was not nearly as affected by Medicare payment reductions., Conclusions: The Deficit Reduction Act and other NDI payment cuts that followed have created huge savings for the Medicare program but have led to sharp reductions in payments received by radiologists, cardiologists, and other physicians for those services., (Copyright © 2017 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
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33. Recent Trends in Imaging Use in Hospital Settings: Implications for Future Planning.
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Levin DC, Parker L, and Rao VM
- Subjects
- Current Procedural Terminology, Databases, Factual, Forecasting, Humans, Medicare Part B, United States, Diagnostic Imaging statistics & numerical data, Practice Patterns, Physicians' statistics & numerical data, Utilization Review
- Abstract
Purpose: To compare trends in utilization rates of imaging in the three hospital-based settings where imaging is conducted., Methods: The nationwide Medicare Part B databases for 2004-2014 were used. All discretionary noninvasive diagnostic imaging (NDI) CPT codes were selected and grouped by modality. Procedure volumes of each code were available from the databases and converted to utilization rates per 1,000 Medicare enrollees. Medicare's place-of-service codes were used to identify imaging examinations done in hospital inpatients, hospital outpatient departments (HOPDs), and emergency departments (EDs). Trends were observed over the life of the study., Results: Trendlines were strongly affected by code bundling in echocardiography in 2009, nuclear imaging in 2010, and CT in 2011. However, even aside from these artifactual effects, important trends could be discerned. Inpatient imaging utilization rates of all modalities are trending downward. In HOPDs, the utilization rate of conventional radiographic examinations (CREs) is declining but rates of CT, MRI, echocardiography, and noncardiac ultrasound (US) are increasing. In EDs, utilization rates of CREs, CT, and US are increasing. In the 3 years after 2011, when no further code bundling occurred, the total inpatient NDI utilization rate dropped 15%, whereas the rate in EDs increased 12% and that in HOPDs increased 1%., Conclusions: The trends in utilization of NDI in the three hospital-based settings where imaging occurs are distinctly different. Radiologists and others who are involved in deciding what kinds of equipment to purchase and where to locate it should be cognizant of these trends in making their decisions., (Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
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- View/download PDF
34. Utilization Trends in Noncardiac Thoracic Imaging, 2002-2014.
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Kamel SI, Levin DC, Parker L, and Rao VM
- Subjects
- Current Procedural Terminology, Databases, Factual, Diagnostic Imaging economics, Humans, Medicare Part B economics, Practice Patterns, Physicians' economics, United States, Diagnostic Imaging statistics & numerical data, Practice Patterns, Physicians' trends, Thorax diagnostic imaging, Utilization Review
- Abstract
Purpose: To analyze recent trends in utilization of the various noncardiac thoracic imaging modalities in the Medicare population., Methods: The Medicare Part B databases for 2002 through 2014 were reviewed. All CPT codes pertaining to noninvasive imaging of the thorax were selected and grouped into seven categories: x-ray, CT, computed tomographic angiography (CTA), nuclear scans (noncardiac), MRI, MR angiography, and ultrasound. Yearly utilization rates per 1,000 Medicare beneficiaries were calculated. Medicare physician specialty codes were used to determine how many studies were performed by radiologists versus nonradiologist physicians., Results: The total utilization rate of all chest imaging peaked at 1,090 per 1,000 in 2005, then progressively declined to 913 by 2014 (-16%). In 2002, radiologists' share of thoracic imaging was 87% and increased to 91% by 2014. Among all providers, the total utilization rate of chest CT rose sharply, peaked at 100 in 2007, and has remained steady at around 89-91 in more recent years. The CTA utilization rate rose progressively from 2 in 2002 to 23 in 2014. Utilization rates of nuclear chest imaging decreased steadily after 2002. Chest x-ray rates reached a peak of 976 in 2005 but then declined to 790 in 2014; this change was largely responsible for the decline in total thoracic imaging., Conclusion: Overall thoracic imaging utilization rates have declined in recent years, despite an increase in use of CT and CTA. The decline largely resulted from a decrease in use of chest x-rays., (Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
35. The Effect of the Controversial US Preventive Services Task Force Recommendations on the Use of Screening Mammography.
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Sharpe RE Jr, Levin DC, Parker L, and Rao VM
- Subjects
- Adult, Aged, Aged, 80 and over, Female, Guideline Adherence statistics & numerical data, Humans, Middle Aged, Prevalence, Risk Factors, United States epidemiology, Breast Neoplasms diagnostic imaging, Breast Neoplasms epidemiology, Early Detection of Cancer standards, Early Detection of Cancer statistics & numerical data, Mammography standards, Mammography statistics & numerical data, Utilization Review
- Abstract
Purpose: The 2009 release of updated US Preventive Services Task Force (USPSTF) recommendations on screening mammography differed sharply from those of the American Cancer Society, the ACR, and the American College of Obstetricians and Gynecologists. The aim of this study was to ascertain the effect of these recommendations on the utilization of screening mammography in the Medicare population., Methods: The Medicare Part B Physician/Supplier Procedure Summary Master Files from 2005 through 2010 were used to determine the annual utilization rate of screening mammography from 2005 to 2010. A utilization trend line was plotted for those years., Results: The utilization rate of screening mammography per 1,000 women in the Medicare population was 311.6 in 2005 and increased gradually each year to 322.9 in 2009 (a compound annual growth rate of 0.9%). However, after the USPSTF recommendations were issued in late 2009, this rate decreased abruptly to 309.1 (-4.3%) in 2010., Conclusions: The abrupt decrease in the utilization of screening mammography in 2010 was in sharp contrast to the previous slow annual increases in its utilization from 2005 to 2009. Because there are no other factors to explain a decrease of this magnitude, it would seem that the USPSTF recommendations and the ensuing publicity resulted in a decrease in the utilization of screening mammography in the Medicare population in the first year after issuance of the new recommendations., (Copyright © 2013 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
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36. Marketing a Radiology Practice.
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Levin DC, Rao VM, Flanders AE, Sundaram B, and Colarossi M
- Subjects
- Humans, Marketing of Health Services economics, Practice Management, Medical economics, Radiology economics, Marketing of Health Services organization & administration, Practice Management, Medical organization & administration, Radiology organization & administration
- Abstract
In addition to being a profession, the practice of radiology is a business, and marketing is an important part of that business. There are many facets to marketing a radiology practice. The authors present a number of ideas on how to go about doing this. Some marketing methods can be directed to both patients and referring physicians. Others should be directed just to patients, while still others should be directed just to referring physicians. Aside from marketing, many of them provide value to both target audiences., (Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
37. Factors That Will Determine Future Utilization Trends in Diagnostic Imaging.
- Author
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Levin DC and Rao VM
- Subjects
- Delivery of Health Care economics, Delivery of Health Care statistics & numerical data, Diagnostic Imaging economics, Insurance, Health economics, United States, Delivery of Health Care trends, Diagnostic Imaging statistics & numerical data, Diagnostic Imaging trends, Forecasting, Insurance, Health statistics & numerical data, Insurance, Health trends
- Abstract
Radiologists are facing uncertain times, and in this kind of environment, strategic planning is important but difficult. In particular, it is hard to know whether future imaging volume will increase, decrease, or stay approximately the same. In this article, the authors discuss a variety of factors that will influence imaging use in the coming years. Some factors will tend to increase imaging use, whereas others will tend to curtail it. Some of these factors will affect individual groups differently, depending on their locations and the circumstances of their practices. Radiologists would be well advised to become aware of and consider these factors as they go about their planning processes., (Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
- Full Text
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38. Recent Trends in Imaging for Suspected Coronary Artery Disease: What Is the Best Approach?
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Levin DC, Parker L, Halpern EJ, and Rao VM
- Subjects
- Coronary Artery Disease epidemiology, Humans, Practice Patterns, Physicians' statistics & numerical data, Practice Patterns, Physicians' trends, Prevalence, Reproducibility of Results, Sensitivity and Specificity, United States epidemiology, Utilization Review, Cardiologists statistics & numerical data, Computed Tomography Angiography statistics & numerical data, Coronary Angiography statistics & numerical data, Coronary Artery Disease diagnostic imaging, Echocardiography, Stress statistics & numerical data, Myocardial Perfusion Imaging statistics & numerical data
- Abstract
Purpose: The aim of this study was to ascertain recent trends in noninvasive imaging utilization for suspected coronary artery disease., Methods: The Medicare Part B databases for 2001 to 2013 were reviewed. Current Procedural Terminology primary codes for radionuclide myocardial perfusion imaging (MPI), stress echocardiography (SE), and coronary CT angiography (CCTA) were selected. Physician specialty codes were used to designate providers as radiologists, cardiologists, and all others as a group. Procedure volumes were tabulated, and utilization rates per 1,000 Medicare beneficiaries were calculated over the period of study., Results: Total MPI utilization rates per 1,000 rose rapidly from 63.4 in 2001 to a peak of 88.0 in 2006 but declined every year thereafter, dropping to 61.9 in 2013. SE rates generally held steady around 12 to 13 from 2001 to 2010 but then began to decline, reaching 10.8 in 2013. Cardiologists predominate in both MPI and SE. CCTA rates were far lower. They peaked at 2.1 in 2007, but then dropped before leveling off at 1.07 in both 2012 and 2013. Radiologists and cardiologists have approximately equal roles in this procedure., Conclusions: Both MPI and SE seem to be declining in use in recent years. This is likely due to unfavorable reimbursement trends caused by code bundling and resulting in the closure of many private cardiology offices. CCTA use is far lower than the two other types of imaging and has also declined in recent years. This is puzzling, as it is a new and promising procedure that has some advantages over MPI and SE. In 2013, 58 times as many MPI studies as CCTA studies were performed., (Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
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39. Vascular Ultrasound and Noninvasive Physiological Testing for Peripheral Arterial Disease: Are These Tests Being Overused?
- Author
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Levin DC, Gardiner GA Jr, Parker L, and Rao VM
- Subjects
- Humans, Practice Patterns, Physicians' statistics & numerical data, Prevalence, United States epidemiology, Utilization Review, Diagnostic Techniques, Cardiovascular statistics & numerical data, Medical Overuse statistics & numerical data, Medicare statistics & numerical data, Peripheral Arterial Disease diagnosis, Peripheral Arterial Disease epidemiology, Ultrasonography, Doppler, Duplex statistics & numerical data
- Abstract
Purpose: To examine recent trends in the use of duplex ultrasound and noninvasive physiologic tests (NPTs) for determining the presence of peripheral arterial disease (PAD)., Methods: Medicare Part B databases for 2001-2013 were used. The two Current Procedural Terminology, version four codes for duplex ultrasound of lower-extremity arteries, and the three codes for NPTs of extremity arteries were selected. Procedure volumes of both types of examinations were determined, and utilization rates per 100,000 beneficiaries were calculated. Medicare specialty codes were used to determine what proportions were performed by the major specialty groups involved in these examinations: surgeons, cardiologists, radiologists, and primary care physicians (PCPs)., Results: Between 2001 and 2010 (the peak year), the total utilization rates per 100,000 of duplex ultrasound and NPTs increased by 94% and 84%, respectively. During the ensuing three years, small declines occurred in both. In 2013, utilization rates of both types of tests were far higher than they had been in 2001 (88% higher for duplex ultrasound; 63% higher for NPTs). From 2001 to 2013, use of duplex ultrasound increased 235% among cardiologists, 90% among surgeons, 76% among radiologists, and 53% among PCPs. Utilization rates of NPTs among surgeons were already high in 2001 and increased an additional 23% by 2013. The NPT utilization rates increased 180% among PCPs, 179% among cardiologists, and 61% among radiologists., Conclusions: During a period when little growth occurred in the incidence of PAD, sharp growth occurred in testing for the disease., (Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
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40. Vertebral Augmentation After Recent Randomized Controlled Trials: A New Rise in Kyphoplasty Volumes.
- Author
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Cox M, Levin DC, Parker L, Morrison W, Long S, and Rao VM
- Subjects
- Humans, Medicare Part B, Randomized Controlled Trials as Topic, United States, Vertebroplasty statistics & numerical data, Kyphoplasty statistics & numerical data, Practice Patterns, Physicians' statistics & numerical data
- Abstract
Purpose: In 2009, the results of two randomized controlled trials refuting the effectiveness of vertebroplasty compared with sham procedures were published in a leading journal. The purpose of the present study was to evaluate the impact of these randomized trials on subsequent volume and utilization rates of vertebral augmentation (VA) in the United States., Methods: Using nationwide Medicare Part B databases, Current Procedural Terminology, version 4, codes for thoracic and lumbar vertebroplasty and kyphoplasty were studied from 2006 to 2013 (codes 22520 to 22525). The total volumes of procedures were determined and utilization rates were calculated. Volumes and rates by provider specialty were also studied., Results: The total volume of VA procedures peaked in 2008 at 101,807 and thereafter fell steadily to 80,940 in 2013. The utilization rates per 100,000 beneficiaries also showed a similar trend. Radiologists performed the largest number of VA procedures in 2013 (33,618 procedures [42%]), followed by orthopedic surgeons (19,886 procedures [25%]). After 2009, vertebroplasty volumes decreased sharply. Kyphoplasty volumes increased in 2011, after an initial decrease in 2010. The divergent trend in the volumes of the two procedures persisted through 2013., Conclusions: After the publication of the two trials' results in 2009, vertebroplasty volumes and rates decreased sharply. However, there is an emerging trend toward performing more kyphoplasty procedures, mitigating the decrease in total volume of VA procedures. Radiologists have the strongest role in performing these procedures among all medical specialties., (Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
- Full Text
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41. Trends in Use of Percutaneous Versus Open Surgical Drainage of Abdominal Abscesses.
- Author
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Levin DC, Eschelman D, Parker L, and Rao VM
- Subjects
- Abdominal Abscess diagnostic imaging, Aged, Aged, 80 and over, Cohort Studies, Cost-Benefit Analysis, Databases, Factual, Drainage trends, Female, Humans, Laparotomy adverse effects, Male, Minimally Invasive Surgical Procedures economics, Minimally Invasive Surgical Procedures methods, Radiography, Interventional economics, Radiography, Interventional methods, Retrospective Studies, Risk Assessment, Skin, Suction methods, Suction trends, Treatment Outcome, United States, Abdominal Abscess surgery, Drainage methods, Laparotomy methods, Medicare economics
- Abstract
Purpose: To compare recent trends in the use of percutaneous and surgical approaches to treating abdominal abscesses in a large population., Methods: The nationwide Medicare Physician/Supplier Procedure Summary Master Files for 2001 through 2013 were searched. Current Procedural Terminology-4 codes were selected for the four types of abdominal abscesses that had distinct codes for both open surgical and percutaneous drainage-appendiceal, peritoneal, subphrenic, and liver. Medicare specialty codes were used to determine if the procedures were performed by radiologists or other nonradiologist physicians. Trends in use of the two approaches were compared., Results: In 2001, a total of 14,068 abdominal abscesses were drained percutaneously. This volume increased progressively every year thereafter, reaching 28,486 in 2013 (+102%). Open surgical drainage volume was 8,146 in 2001, decreasing progressively to 6,397 in 2013 (-21%). In 2001, 63% of all abdominal abscesses had been drained percutaneously; by 2013, this figure had risen to 82%. In 2001, radiologists had performed 90% of all percutaneous abdominal abscess drainages; this percentage share increased to 97% in 2013. Of all abdominal abscesses treated in 2013 in Medicare patients, 79% were treated by radiologists., Conclusions: Use of percutaneous drainage of abdominal abscesses has steadily increased, whereas use of open surgical drainage has declined. The vast majority of these abscesses are now treated percutaneously. Radiologists are a strong majority of those performing the procedures. Although this database does not provide information on outcomes, percutaneous drainage is another good example of radiology-related value., (Copyright © 2015 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
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42. Relative Roles of Radiologists and Other Physicians in Percutaneous Endovascular Neurointerventions.
- Author
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Cox M, Levin DC, Parker L, and Rao VM
- Subjects
- Practice Patterns, Physicians' statistics & numerical data, United States, Cerebrovascular Disorders surgery, Endovascular Procedures statistics & numerical data, Neurosurgical Procedures statistics & numerical data, Physician's Role, Radiography, Interventional statistics & numerical data, Radiology, Interventional statistics & numerical data
- Abstract
Purpose: Cerebral catheter angiography and endovascular neurointerventions (ENIs) were developed and refined by early pioneers in neuroradiology. Recently, with developments in the safety and efficacy of ENIs, other physician specialists have expressed strong interest in performing these procedures. Our purpose was to compare volume and utilization of ENIs, among the various specialties, from 2000 to 2013., Methods: Data from the Medicare Part B Physician/Supplier Procedure Summary Master Files for 2000 to 2013 were used to study ENI volume and utilization rates, by radiologists, neurosurgeons, neurologists, vascular surgeons, cardiologists, and other physicians., Results: From 2000 to 2013, the volume of intracranial ENIs increased: overall, from 2,439 to 7,424; for radiologists, from 1,956 to 3,993; and for neurosurgeons, from 237 to 2,900. Although cardiologists did not perform many intracranial ENIs in these years, they performed most of the carotid artery stenting procedures (4,097, which is 51% of the total 8,201 performed in 2013)., Conclusions: Radiologists continue to maintain a strong presence in the field of neurointerventional radiology, particularly in percutaneous intracranial interventions, performing 51% of all intracranial procedures in 2013, down from 80% in 2000. However, neurosurgeons have made substantial inroads into ENI procedures, with their volume increasing from 10% to 33%, from 2000 to 2013. The overall volume of ENIs rose steadily from 2000 to 2013., (Copyright © 2015 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
43. The Shift in Outpatient Advanced Imaging From Private Offices to Hospital Facilities.
- Author
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Patel BP, Levin DC, Parker L, and Rao VM
- Subjects
- Diagnostic Imaging trends, Private Practice trends, Radiology Department, Hospital statistics & numerical data, United States, Utilization Review, Ambulatory Care statistics & numerical data, Ambulatory Care trends, Diagnostic Imaging statistics & numerical data, Outpatient Clinics, Hospital statistics & numerical data, Outpatient Clinics, Hospital trends, Private Practice statistics & numerical data
- Abstract
Purpose: To study recent outpatient imaging trends in private offices and hospital outpatient departments (HOPDs), to determine if shifting between the two has occurred. Concern is currently focused on whether reduced reimbursements and other factors might lead to a shift to higher-cost HOPDs., Methods: The nationwide Medicare Physician/Supplier Procedure Summary Master Files for 2001 to 2013 were studied. All Current Procedural Terminology codes for MRI, echocardiography, nuclear medicine, ultrasound, and CT were selected, and procedure utilization rates per 1,000 Medicare beneficiaries were determined for each year. Medicare location codes identified the settings where the scans were performed., Results: Total utilization rates, per 1,000 beneficiaries, of all these examination types in private offices, grew from 478 in 2001, to 874 in 2008 (+83%), and then declined to 503 in 2011 (-42%), primarily as a result of code bundling. No further bundling occurred in 2012 or 2013, but the decline continued in those years, to 462. In HOPDs, the total rate rose from 416 in 2001, to 523 in 2008 (+26%), followed by similar bundling-related declines, to 418 (-20%) in 2011. But in 2012 and 2013, in contrast to private office trends, the HOPD rate increased to 447. The ratio of private office to HOPD advanced imaging was 1.67 in 2008, declining to 1.03 in 2013. In addition, individual modality shifts away from offices and into HOPDs were quite apparent., Conclusions: In recent years, a shift has occurred in utilization of all advanced imaging modalities, from private offices to HOPDs. This change could portend a loss of access for patients and an increase in costs., (Copyright © 2015 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
44. Have CT and MR Angiography Replaced Catheter Angiography in Diagnosing Peripheral Arterial Disease?
- Author
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Patel MC, Levin DC, Parker L, and Rao VM
- Subjects
- Health Services Research, Humans, Medicare, United States, Utilization Review, Angiography statistics & numerical data, Catheterization, Peripheral statistics & numerical data, Magnetic Resonance Angiography statistics & numerical data, Peripheral Vascular Diseases diagnosis, Tomography, X-Ray Computed statistics & numerical data
- Abstract
Purpose: To determine whether MR angiography (MRA) and CT angiography (CTA) have replaced diagnostic catheter angiography (DCA) in diagnosing peripheral arterial disease., Methods: Medicare Part B databases for 2002-2013 were reviewed. Current Procedural Terminology codes for extremity MRA, CTA, and DCA were selected. Physician specialty codes were used to classify providers as radiologists, cardiologists, or surgeons. Utilization rates per 100,000 Medicare beneficiaries were calculated., Results: Among all specialties, the combined utilization rate of all 3 types of angiography increased from 917 per 100,000 in 2002 to 1,261 in 2006 (+38%), after which it remained stable until 2010, and then declined to 1,010 in 2013. The overall rate of MRA and CTA together increased from 89 in 2002 to 440 in 2006 (+394%), after which it leveled off, and then gradually decreased to 331 in 2013. In 2013, 33% of the total procedures were MRA or CTA, up from 10% in 2002. Radiologists performed >85% of MRA and CTA examinations. Among radiologists, the DCA utilization rate decreased by 75% from 2002 to 2013, whereas among cardiologists and surgeons together, the overall DCA utilization rate increased by 64% from 2002 to 2010 before dropping somewhat in 2011., Conclusions: Among radiologists, MRA and CTA have replaced DCA in diagnosing peripheral arterial disease. Although overall utilization of DCA has remained steady, it has risen sharply among cardiologists and surgeons, while dropping sharply among radiologists. Given the increased utilization of DCA among cardiologists and surgeons despite noninvasive alternatives, self-referral continues to be of concern in the setting of increasing health care costs., (Copyright © 2015 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2015
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45. Quantitative proteomic analysis of the cellulolytic system of Clostridium termitidis CT1112 reveals distinct protein expression profiles upon growth on α-cellulose and cellobiose.
- Author
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Munir RI, Spicer V, Shamshurin D, Krokhin OV, Wilkins J, Ramachandran U, Sparling R, and Levin DB
- Subjects
- Cellobiose chemistry, Cellulose chemistry, Proteomics, Bacterial Proteins biosynthesis, Cellobiose pharmacology, Cellulose pharmacology, Clostridium growth & development, Gene Expression Regulation drug effects
- Abstract
Clostridium termitidis CT1112 is an anaerobic, mesophilic, cellulolytic bacterium with potential applications in consolidated bioprocessing of lignocellulosic biomass. To understand how C. termitidis degrades lignocellulose, iTRAQ-based 2D HPLC-MS/MS proteomics was used to measure protein expression in cell lysates and extracellular (secretome) fractions of C. termitidis grown on α-cellulose and cellobiose at both exponential and stationary growth phases. Exoglucanases (GH48, GH9), endoglucanases (GH5, GH8, GH9), hemicellulases including xylanases (GH8, GH10, GH11, GH30) and mannanase (GH26) as well as extracellular adhesion proteins and cellulosome associated proteins, exhibited higher expression on cellulose-grown cells. The expression of these proteins increased with a decrease in growth rate. Non-cellulosomal proteins however did not change significantly between substrate conditions, although there were a few exceptions. Collectively, these would contribute to hydrolysis of lignocellulosic material for uptake through ABC sugar transport proteins. On cellobiose, chitinases (GH18) were expressed abundantly. Although a large number of proteins were shared between the fractions analyzed, some proteins were detected exclusively in the cellular fraction, while others were detected in the secretome. This study reports for the first time on the cellulolytic machinery employed by C. termitidis to hydrolyze cellulosic substrate and provides an understanding of how this microbe deconstructs biomass., Biological Significance: The genome of C. termitidis CT1112 contains genes for a wide variety of carbohydrate active enzymes. Based on bioinformatics analyses, many of these genes appear to encode cellulosome-associated proteins, while others may be secreted extracellularly. To understand how C. termitidis degrades and depolymerizes cellulosic substrates, cells were grown on simple and complex carbohydrates, and quantitative 4-plex iTRAQ-based 2D HPLC-MS/MS proteomics was applied to measure protein expression levels in biological replicates of both cell lysates and extracellular protein (secretome) fractions, at exponential and stationary phases of growth. The resulting data have provided insight into the range of substrates that may be hydrolyzed by C. termitidis, and may be useful in determining potential industrial applications of C. termitidis in biomass to bioenergy production via consolidated bioprocessing., (Copyright © 2015 Elsevier B.V. All rights reserved.)
- Published
- 2015
- Full Text
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46. Trends in outpatient MRI seem to reflect recent reimbursement cuts.
- Author
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Levin DC, Rao VM, and Parker L
- Subjects
- Ambulatory Care statistics & numerical data, Cost Control economics, Cost Control trends, Insurance, Health, Reimbursement statistics & numerical data, Insurance, Health, Reimbursement trends, Medicare trends, Outpatient Clinics, Hospital statistics & numerical data, Practice Patterns, Physicians' economics, Practice Patterns, Physicians' statistics & numerical data, Practice Patterns, Physicians' trends, Private Practice economics, Private Practice statistics & numerical data, Private Practice trends, Radiology economics, Radiology statistics & numerical data, Radiology trends, United States, Utilization Review, Ambulatory Care economics, Insurance, Health, Reimbursement economics, Magnetic Resonance Imaging economics, Magnetic Resonance Imaging statistics & numerical data, Medicare economics, Outpatient Clinics, Hospital economics
- Abstract
Purpose: To determine whether recent reimbursement cuts have resulted in a shift of outpatient MRI from private offices to hospital outpatient departments (HOPDs); and to study office MRI utilization trends among radiologists and other specialists., Methods: The Medicare Part B Physician/Supplier Procedure Summary Master Files were used. MRI codes were aggregated, and total MRI volumes from 2002 to 2012 were studied. Medicare place-of-service codes were used to identify studies performed in private offices and HOPDs and create trend lines. Specialty codes were used to categorize private office MRI users as radiologists, orthopedic surgeons, other physicians, and independent diagnostic testing facilities., Results: Medicare office and HOPD utilization of MRI (all specialties) rose rapidly from 2002 to 2006, reaching 2,727,807 in offices and 2,355,641 in HOPDs. Thereafter, office volume steadily declined, whereas HOPD volume steadily increased. By 2012, more studies were done in HOPDs than in offices. Over the entire period from 2002 and 2012, office MRI volume among radiologists increased 27%, compared with 216% among orthopedic surgeons and 124% among other physicians., Conclusions: Although the majority of Medicare outpatient MRI studies had previously been performed in private offices, recent years brought a shift, with more now being performed in HOPDs. This change will increase costs to payers, because reimbursements to HOPDs are generally higher than those to offices. Although radiologists perform the majority of MRI exams that are conducted in private offices, the rate of growth for such exams from 2002 to 2012 was considerably higher among orthopedic surgeons and other physicians than among radiologists., (Copyright © 2015 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
47. Continued growth in emergency department imaging is bucking the overall trends.
- Author
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Levin DC, Rao VM, Parker L, and Frangos AJ
- Subjects
- Diagnostic Imaging economics, Emergency Service, Hospital economics, Humans, United States, Diagnostic Imaging statistics & numerical data, Emergency Service, Hospital statistics & numerical data, Medicare Part B
- Abstract
Purpose: The aim of this study was to examine recent trends in imaging utilization in emergency departments (EDs) in the Medicare population., Methods: The 2002 to 2012 Medicare Part B databases were used. Imaging studies were categorized by modality. Medicare's place-of-service codes identified those studies performed in ED patients. Specialty codes identified the specialties of the interpreting physicians. Utilization rates per 1,000 Medicare beneficiaries were calculated. Trends were assessed in plain radiography (XR), CT, noncardiac ultrasound, MRI, and nuclear medicine., Results: XR and CT were the most widely used modalities in ED patients. From 2002 to 2012, the XR utilization rate per 1,000 increased from 248.7 to 320.0 (+29%), and CT increased from 57.2 to 147.9 (+159%). Utilization rates of the other modalities were much lower. Ultrasound increased from 9.5 to 21.0 (+121%), while MRI increased from 1.4 to 5.1 (+264%). Growth in these 4 modalities was continuous and did not show the flattening that has characterized the utilization trends in other places of service. Nuclear medicine use was very low and remained essentially flat. During the study period, CT accrued 91 new examinations per 1,000, followed by XR at 71 and ultrasound at 11.5. The vast majority of examinations were interpreted by radiologists., Conclusions: Despite the cessation of overall utilization growth of the various modalities in recent years, ED utilization rates continued to increase. The greatest increases, in terms of accrued new examinations per 1,000, were seen in CT and XR. This suggests that radiologists and ED physicians need to work together to better manage imaging utilization., (Copyright © 2014 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
48. Are combined CT scans of the thorax being overused?
- Author
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Levin DC, Parker L, Halpern EJ, and Rao VM
- Subjects
- Contrast Media, Humans, Medicare, United States, Practice Patterns, Physicians' trends, Radiography, Thoracic statistics & numerical data, Tomography, X-Ray Computed statistics & numerical data, Unnecessary Procedures statistics & numerical data
- Abstract
Purpose: A news article in June 2011 reported that Medicare claims showed considerable overuse of "double" CT scans of the thorax (ie, combined scans without contrast followed by with contrast) at a number of hospitals. Most radiologists agree that they should be done only on rare occasions. The aim of this study was to determine what proportion of all thoracic CT scans are combined scans in the Medicare population., Methods: The data sources were the Medicare Part B Physician/Supplier Procedure Summary Master Files for 2001 to 2011. The 3 Current Procedural Terminology codes for thoracic CT (with contrast, without contrast, and without plus with contrast) were selected. Utilization rates per 1,000 beneficiaries and the percentage that were combined scans were calculated., Results: The utilization rate of combined scans increased from 2001 through 2006, remained steady in 2007, but then decreased sharply thereafter. The compound annual rate of change from 2007 to 2011 was -10.4%. From 2001 through 2006, combined thoracic CT scans constituted 6.0% to 6.1% of all thoracic CT scans. However, from 2006 to 2011, this percentage progressively declined, reaching a low of 4.2% in 2011., Conclusions: Despite the 2011 news report, only a very small percentage of thoracic CT scans nationwide are done both without and with contrast. Moreover, that percentage dropped by almost one-third from 2006 to 2011, suggesting that the practice is declining. The figure of 4.2% can be used as a benchmark against which to judge radiology facilities in the future., (Copyright © 2014 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
49. The diversion of outpatient echocardiography from private offices to higher cost hospital facilities: an unanticipated effect of code bundling.
- Author
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Levin DC, Parker L, Halpern EJ, and Rao VM
- Subjects
- Humans, Medicare economics, Physicians' Offices economics, Practice Patterns, Physicians' economics, United States, Ambulatory Care economics, Clinical Coding, Echocardiography, Doppler economics, Patient Care Bundles economics, Radiology Department, Hospital economics
- Abstract
Purpose: In 2009, the add-on codes for spectral Doppler and color flow Doppler echocardiography were bundled into the code for primary transthoracic echocardiography. The relative value units for the new single code were substantially lower than the previous sum for the 3 codes. The purpose of this study was to see how this affected the distribution of outpatient echocardiographic studies between cardiology offices and hospital outpatient departments (HOPDs)., Methods: The 2005 to 2011 Medicare databases were used. All echocardiography Current Procedural Terminology codes were selected. Specialty codes identified those done by cardiologists (who do most echocardiographic studies). Place-of-service codes identified those done in offices and HOPDs. Procedure volumes and utilization rates per 1,000 were determined each year before and after bundling occurred in 2009., Results: Cardiologists' office echocardiography utilization rate rose from 219.5 per 1,000 in 2005 to 257.1 in 2008 (+17%), then dropped to 100.0 in 2009 (-61%) because of bundling. Their HOPD echocardiography rate rose from 72.2 in 2005 to 76.5 in 2008 (+6%), then dropped to 35.0 in 2009 (-54%). From 2009 to 2011, cardiologists' office echocardiography rate dropped again from 100.0 to 88.8 (-11%), while their HOPD rate increased from 35.0 to 46.1 (+32%)., Conclusions: Echocardiography code bundling produced the expected sharp drop in outpatient claims from cardiologists in 2009. But after bundling, office echocardiography rates continued to drop, while HOPD rates increased. It seems that in this instance, code bundling led to the closure of many cardiology offices and a resultant shift of echocardiography from that lower cost setting to the higher cost HOPD setting., (Copyright © 2014 American College of Radiology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
50. Reflections on principles of good leadership.
- Author
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Levin DC
- Subjects
- Motivation, Organizational Culture, United States, Health Facility Administration methods, Leadership, Models, Organizational, Professional Competence, Radiology organization & administration, Radiology Department, Hospital organization & administration, Staff Development
- Published
- 2014
- Full Text
- View/download PDF
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