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Michal CA. Low-cost low-field NMR and MRI: Instrumentation and applications. J Magn Reson 2020; 319:106800. [PMID: 33036708 PMCID: PMC7538153 DOI: 10.1016/j.jmr.2020.106800] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/25/2020] [Accepted: 07/26/2020] [Indexed: 05/29/2023]
Abstract
While NMR and MRI are often thought of as expensive techniques requiring large institutional investment, opportunities for low-cost, low-field NMR and MRI abound. We discuss a number of approaches to performing magnetic resonance experiments with inexpensive, easy to find or build components, aimed at applications in industry, education, and research. Opportunities that aim to make NMR accessible to a broad community are highlighted. We describe and demonstrate some projects from our laboratory, including a new prototype instrument for measurements at frequencies up to ∼200 kHz and demonstrate its application to the study of the rapidly advancing technique known as inhomogeneous magnetization transfer imaging, a promising method for characterizing myelin in vivo.
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Affiliation(s)
- Carl A Michal
- Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada.
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2
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Lee J, Ramirez MS, Walker CM, Chen Y, Yi S, Sandulache VC, Lai SY, Bankson JA. High-throughput hyperpolarized (13)C metabolic investigations using a multi-channel acquisition system. J Magn Reson 2015; 260:20-27. [PMID: 26397217 PMCID: PMC4628838 DOI: 10.1016/j.jmr.2015.08.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 08/27/2015] [Accepted: 08/29/2015] [Indexed: 06/05/2023]
Abstract
Magnetic resonance imaging and spectroscopy of hyperpolarized (HP) compounds such as [1-(13)C]-pyruvate have shown tremendous potential for offering new insight into disease and response to therapy. New applications of this technology in clinical research and care will require extensive validation in cells and animal models, a process that may be limited by the high cost and modest throughput associated with dynamic nuclear polarization. Relatively wide spectral separation between [1-(13)C]-pyruvate and its chemical endpoints in vivo are conducive to simultaneous multi-sample measurements, even in the presence of a suboptimal global shim. Multi-channel acquisitions could conserve costs and accelerate experiments by allowing acquisition from multiple independent samples following a single dissolution. Unfortunately, many existing preclinical MRI systems are equipped with only a single channel for broadband acquisitions. In this work, we examine the feasibility of this concept using a broadband multi-channel digital receiver extension and detector arrays that allow concurrent measurement of dynamic spectroscopic data from ex vivo enzyme phantoms, in vitro anaplastic thyroid carcinoma cells, and in vivo in tumor-bearing mice. Throughput and the cost of consumables were improved by up to a factor of four. These preliminary results demonstrate the potential for efficient multi-sample studies employing hyperpolarized agents.
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Affiliation(s)
- Jaehyuk Lee
- Department of Imaging Physics, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA
| | - Marc S Ramirez
- Department of Imaging Physics, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA
| | - Christopher M Walker
- Department of Imaging Physics, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA
| | - Yunyun Chen
- Department of Head & Neck Surgery, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA
| | - Stacey Yi
- Department of Imaging Physics, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA
| | - Vlad C Sandulache
- Department of Otolaryngology, Baylor College of Medicine, Houston, TX, USA
| | - Stephen Y Lai
- Department of Head & Neck Surgery, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA
| | - James A Bankson
- Department of Imaging Physics, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA.
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3
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Matsuki Y, Nakamura S, Fukui S, Suematsu H, Fujiwara T. Closed-cycle cold helium magic-angle spinning for sensitivity-enhanced multi-dimensional solid-state NMR. J Magn Reson 2015; 259:76-81. [PMID: 26302269 DOI: 10.1016/j.jmr.2015.08.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 08/04/2015] [Indexed: 05/21/2023]
Abstract
Magic-angle spinning (MAS) NMR is a powerful tool for studying molecular structure and dynamics, but suffers from its low sensitivity. Here, we developed a novel helium-cooling MAS NMR probe system adopting a closed-loop gas recirculation mechanism. In addition to the sensitivity gain due to low temperature, the present system has enabled highly stable MAS (vR=4-12 kHz) at cryogenic temperatures (T=35-120 K) for over a week without consuming helium at a cost for electricity of 16 kW/h. High-resolution 1D and 2D data were recorded for a crystalline tri-peptide sample at T=40 K and B0=16.4 T, where an order of magnitude of sensitivity gain was demonstrated versus room temperature measurement. The low-cost and long-term stable MAS strongly promotes broader application of the brute-force sensitivity-enhanced multi-dimensional MAS NMR, as well as dynamic nuclear polarization (DNP)-enhanced NMR in a temperature range lower than 100 K.
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Affiliation(s)
- Yoh Matsuki
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Shinji Nakamura
- JEOL RESONANCE Inc., 3-1-2 Musashino, Akishima, Tokyo 196-8558, Japan
| | - Shigeo Fukui
- Cryovac Corporation, 2-12-14 Chibune, Nishi Yodogawa, Osaka 555-0013, Japan
| | - Hiroto Suematsu
- JEOL RESONANCE Inc., 3-1-2 Musashino, Akishima, Tokyo 196-8558, Japan
| | - Toshimichi Fujiwara
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
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4
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Savukov IM, Chen HY, Karaulanov T, Hilty C. Method for accurate measurements of nuclear-spin optical rotation for applications in correlated optical-NMR spectroscopy. J Magn Reson 2013; 232:31-38. [PMID: 23685716 DOI: 10.1016/j.jmr.2013.04.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 04/09/2013] [Accepted: 04/15/2013] [Indexed: 06/02/2023]
Abstract
The nuclear-spin optical rotation (NSOR) effect recently attracted much attention due to potential applications in combined optical-NMR spectroscopy and imaging. Currently, the main problem with applications of NSOR is low SNR and accuracy of measurements. In this work we demonstrate a new method for data acquisition and analysis based on a low-power laser and an emphasis on software based processing. This method significantly reduces cost and is suitable for application in most NMR spectroscopy laboratories for exploration of the NSOR effect. Despite the use of low laser power, SNR can be substantially improved with fairly simple strategies including the use of short wavelength and a multi-pass optical cell with in-flow pre-polarization in a 7 T magnet. Under these conditions, we observed that NSOR signal can be detected in less than 1 min and discuss strategies for further improvement of signal. With higher SNR than previously reported, NSOR constants can be extracted with improved accuracy. On the example of water, we obtained measurements at a level of accuracy of 5%. We include a detailed theoretical analysis of the geometrical factors of the experiment, which is required for accurate quantification of NSOR. This discussion is particularly important for relatively short detection cells, which will be necessary to use in spectroscopy or imaging applications that impose geometrical constraints.
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Affiliation(s)
- I M Savukov
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
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5
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Ratajczyk T, Gutmann T, Dillenberger S, Abdulhussaein S, Frydel J, Breitzke H, Bommerich U, Trantzschel T, Bernarding J, Magusin PCMM, Buntkowsky G. Time domain para hydrogen induced polarization. Solid State Nucl Magn Reson 2012; 43-44:14-21. [PMID: 22365288 DOI: 10.1016/j.ssnmr.2012.02.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 01/25/2012] [Accepted: 02/02/2012] [Indexed: 05/03/2023]
Abstract
Para hydrogen induced polarization (PHIP) is a powerful hyperpolarization technique, which increases the NMR sensitivity by several orders of magnitude. However the hyperpolarized signal is created as an anti-phase signal, which necessitates high magnetic field homogeneity and spectral resolution in the conventional PHIP schemes. This hampers the application of PHIP enhancement in many fields, as for example in food science, materials science or MRI, where low B(0)-fields or low B(0)-homogeneity do decrease spectral resolution, leading to potential extinction if in-phase and anti-phase hyperpolarization signals cannot be resolved. Herein, we demonstrate that the echo sequence (45°-τ-180°-τ) enables the acquisition of low resolution PHIP enhanced liquid state NMR signals of phenylpropiolic acid derivatives and phenylacetylene at a low cost low-resolution 0.54 T spectrometer. As low field TD-spectrometers are commonly used in industry or biomedicine for the relaxometry of oil-water mixtures, food, nano-particles, or other systems, we compare two variants of para-hydrogen induced polarization with data-evaluation in the time domain (TD-PHIP). In both TD-ALTADENA and the TD-PASADENA strong spin echoes could be detected under conditions when usually no anti-phase signals can be measured due to the lack of resolution. The results suggest that the time-domain detection of PHIP-enhanced signals opens up new application areas for low-field PHIP-hyperpolarization, such as non-invasive compound detection or new contrast agents and biomarkers in low-field Magnetic Resonance Imaging (MRI). Finally, solid-state NMR calculations are presented, which show that the solid echo (90y-τ-90x-τ) version of the TD-ALTADENA experiment is able to convert up to 10% of the PHIP signal into visible magnetization.
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Affiliation(s)
- Tomasz Ratajczyk
- Institute of Physical Chemistry, Technical University Darmstadt, Petersenstrasse 22, D-64287 Darmstadt, Germany
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6
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Abstract
One-dimensional NMR spectroscopy has proven to be a powerful technique for screening compound libraries in drug discovery. We report a novel water ligand-observed gradient spectroscopy (WaterLOGSY) pulse sequence, named Aroma WaterLOGSY, that selectively detects aromatic WaterLOGSY signals from compounds or ligands. In the Aroma WaterLOGSY, water magnetization is untouched after water excitation and utilizes the whole period of the remaining pulse sequence to relax back to the +z direction. Due to the phase cycling design, the water magnetization is allowed to relax for the period of two full scans before it gets inverted again. Therefore, the recycle delay can be significantly shortened. Within similar experimental time, Aroma WaterLOGSY shows approximately two times higher sensitivity than the standard scheme. This method also allows the use of non-deuterated reagents, thereby accelerating experimental set-up time for ligand-binding studies.
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Affiliation(s)
- Jun Hu
- AstraZeneca R&D Boston, Waltham, MA 02451, USA.
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7
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Sharma S, Zheng H, Huang YJ, Ertekin A, Hamuro Y, Rossi P, Tejero R, Acton TB, Xiao R, Jiang M, Zhao L, Ma LC, Swapna GVT, Aramini JM, Montelione GT. Construct optimization for protein NMR structure analysis using amide hydrogen/deuterium exchange mass spectrometry. Proteins 2009; 76:882-94. [PMID: 19306341 PMCID: PMC2739808 DOI: 10.1002/prot.22394] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Disordered or unstructured regions of proteins, while often very important biologically, can pose significant challenges for resonance assignment and three-dimensional structure determination of the ordered regions of proteins by NMR methods. In this article, we demonstrate the application of (1)H/(2)H exchange mass spectrometry (DXMS) for the rapid identification of disordered segments of proteins and design of protein constructs that are more suitable for structural analysis by NMR. In this benchmark study, DXMS is applied to five NMR protein targets chosen from the Northeast Structural Genomics project. These data were then used to design optimized constructs for three partially disordered proteins. Truncated proteins obtained by deletion of disordered N- and C-terminal tails were evaluated using (1)H-(15)N HSQC and (1)H-(15)N heteronuclear NOE NMR experiments to assess their structural integrity. These constructs provide significantly improved NMR spectra, with minimal structural perturbations to the ordered regions of the protein structure. As a representative example, we compare the solution structures of the full length and DXMS-based truncated construct for a 77-residue partially disordered DUF896 family protein YnzC from Bacillus subtilis, where deletion of the disordered residues (ca. 40% of the protein) does not affect the native structure. In addition, we demonstrate that throughput of the DXMS process can be increased by analyzing mixtures of up to four proteins without reducing the sequence coverage for each protein. Our results demonstrate that DXMS can serve as a central component of a process for optimizing protein constructs for NMR structure determination.
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Affiliation(s)
- Seema Sharma
- Center for Advanced Biotechnology and Medicine, Rutgers University, 679 Hoes Lane, Piscataway, New Jersey 08854
- Northeast Structural Genomics Consortium, Rutgers University, Piscataway, New Jersey 08854
| | - Haiyan Zheng
- Center for Advanced Biotechnology and Medicine, Rutgers University, 679 Hoes Lane, Piscataway, New Jersey 08854
| | - Yuanpeng J. Huang
- Center for Advanced Biotechnology and Medicine, Rutgers University, 679 Hoes Lane, Piscataway, New Jersey 08854
- Northeast Structural Genomics Consortium, Rutgers University, Piscataway, New Jersey 08854
| | - Asli Ertekin
- Center for Advanced Biotechnology and Medicine, Rutgers University, 679 Hoes Lane, Piscataway, New Jersey 08854
- Northeast Structural Genomics Consortium, Rutgers University, Piscataway, New Jersey 08854
| | | | - Paolo Rossi
- Center for Advanced Biotechnology and Medicine, Rutgers University, 679 Hoes Lane, Piscataway, New Jersey 08854
- Northeast Structural Genomics Consortium, Rutgers University, Piscataway, New Jersey 08854
| | - Roberto Tejero
- Center for Advanced Biotechnology and Medicine, Rutgers University, 679 Hoes Lane, Piscataway, New Jersey 08854
- Northeast Structural Genomics Consortium, Rutgers University, Piscataway, New Jersey 08854
| | - Thomas B. Acton
- Center for Advanced Biotechnology and Medicine, Rutgers University, 679 Hoes Lane, Piscataway, New Jersey 08854
- Northeast Structural Genomics Consortium, Rutgers University, Piscataway, New Jersey 08854
| | - Rong Xiao
- Center for Advanced Biotechnology and Medicine, Rutgers University, 679 Hoes Lane, Piscataway, New Jersey 08854
- Northeast Structural Genomics Consortium, Rutgers University, Piscataway, New Jersey 08854
| | - Mei Jiang
- Center for Advanced Biotechnology and Medicine, Rutgers University, 679 Hoes Lane, Piscataway, New Jersey 08854
- Northeast Structural Genomics Consortium, Rutgers University, Piscataway, New Jersey 08854
| | - Li Zhao
- Center for Advanced Biotechnology and Medicine, Rutgers University, 679 Hoes Lane, Piscataway, New Jersey 08854
- Northeast Structural Genomics Consortium, Rutgers University, Piscataway, New Jersey 08854
| | - Li-Chung Ma
- Center for Advanced Biotechnology and Medicine, Rutgers University, 679 Hoes Lane, Piscataway, New Jersey 08854
- Northeast Structural Genomics Consortium, Rutgers University, Piscataway, New Jersey 08854
| | - G. V. T. Swapna
- Center for Advanced Biotechnology and Medicine, Rutgers University, 679 Hoes Lane, Piscataway, New Jersey 08854
- Northeast Structural Genomics Consortium, Rutgers University, Piscataway, New Jersey 08854
| | - James M. Aramini
- Center for Advanced Biotechnology and Medicine, Rutgers University, 679 Hoes Lane, Piscataway, New Jersey 08854
- Northeast Structural Genomics Consortium, Rutgers University, Piscataway, New Jersey 08854
| | - Gaetano T. Montelione
- Center for Advanced Biotechnology and Medicine, Rutgers University, 679 Hoes Lane, Piscataway, New Jersey 08854
- Northeast Structural Genomics Consortium, Rutgers University, Piscataway, New Jersey 08854
- Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, New Jersey 08854
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Matsuki Y, Eddy MT, Herzfeld J. Spectroscopy by integration of frequency and time domain information for fast acquisition of high-resolution dark spectra. J Am Chem Soc 2009; 131:4648-56. [PMID: 19284727 PMCID: PMC2711035 DOI: 10.1021/ja807893k] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A simple and effective method, SIFT (spectroscopy by integration of frequency and time domain information), is introduced for processing nonuniformly sampled multidimensional NMR data. Applying the computationally efficient Gerchberg-Papoulis (G-P) algorithm, used previously in picture processing and medical imaging, SIFT supplements data at nonuniform points in the time domain with the information carried by known "dark" points (i.e., empty regions) in the frequency domain. We demonstrate that this rapid integration not only removes the severe pseudonoise characteristic of the Fourier transforms of nonuniformly sampled data, but also provides a robust procedure for using frequency information to replace time measurements. The latter can be used to avoid unnecessary sampling in sampling-limited experiments, and the former can be used to take advantage of the ability of nonuniformly sampled data to minimize trade-offs between the signal-to-noise ratio and the resolution in sensitivity-limited experiments. Processing 2D and 3D data sets takes about 0.1 and 2 min, respectively, on a personal computer. With these several attractive features, SIFT offers a novel, model-independent, flexible, and user-friendly tool for efficient and accurate processing of multidimensional NMR data.
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Affiliation(s)
- Yoh Matsuki
- Department of Chemistry, Brandeis University, Waltham, MA 02454, USA
- Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Matthew T. Eddy
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Judith Herzfeld
- Department of Chemistry, Brandeis University, Waltham, MA 02454, USA
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9
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Hofstraat H. Discussion on '(molecular) imaging: developments enabling evidence-based medicine'. Nestle Nutr Workshop Ser Pediatr Program 2008; 62:51-54. [PMID: 18626192 DOI: 10.1159/000146247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- H Hofstraat
- Healthcare Strategic Partnerships, Philips Research Laboratories/CTMM, Eindhoven, The Netherlands
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Demas V, Herberg JL, Malba V, Bernhardt A, Evans L, Harvey C, Chinn SC, Maxwell RS, Reimer J. Portable, low-cost NMR with laser-lathe lithography produced microcoils. J Magn Reson 2007; 189:121-9. [PMID: 17897853 DOI: 10.1016/j.jmr.2007.08.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2007] [Revised: 07/31/2007] [Accepted: 08/03/2007] [Indexed: 05/17/2023]
Abstract
Nuclear Magnetic Resonance (NMR) is unsurpassed in its ability to non-destructively probe chemical identity. Portable, low-cost NMR sensors would enable on-site identification of potentially hazardous substances, as well as the study of samples in a variety of industrial applications. Recent developments in RF microcoil construction (i.e. coils much smaller than the standard 5mm NMR RF coils), have dramatically increased NMR sensitivity and decreased the limits-of-detection (LOD). We are using advances in laser pantographic microfabrication techniques, unique to LLNL, to produce RF microcoils for field deployable, high sensitivity NMR-based detectors. This same fabrication technique can be used to produce imaging coils for MRI as well as for standard hardware shimming or "ex-situ" shimming of field inhomogeneities typically associated with inexpensive magnets. This paper describes a portable NMR system based on the use of a 2 kg hand-held permanent magnet, laser-fabricated microcoils, and a compact spectrometer. The main limitations for such a system are the low resolution and sensitivity associated with the low field values and quality of small permanent magnets, as well as the lack of large amounts of sample of interest in most cases. The focus of the paper is on the setting up of this system, initial results, sensitivity measurements, discussion of the limitations and future plans. The results, even though preliminary, are promising and provide the foundation for developing a portable, inexpensive NMR system for chemical analysis. Such a system will be ideal for chemical identification of trace substances on site.
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Affiliation(s)
- Vasiliki Demas
- Lawrence Livermore National Laboratory, Chemistry, Material, and Life Sciences Directorate, 7000 East Avenue, Livermore, CA 94550, USA
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Abstract
The development of isotope labeling methodology has had a significant impact on NMR studies of high-molecular-weight proteins and macromolecular complexes. Here we review some of this methodology that has been developed and used in our laboratory. In particular, experimental protocols are described for the production of highly deuterated, uniformly 15N- and 13C-labeled samples of large proteins, with optional incorporation of selective isotope labels into methyl groups of isoleucine, leucine and valine residues. Various types of methyl labeling schemes are assessed, and the utility of different methyl labeling strategies is highlighted for studies ranging from protein structure determination to the investigation of side-chain dynamics. In the case of malate synthase G (MSG), the time frame of the whole preparation, including the protein refolding step, is about 70 h.
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Affiliation(s)
- Vitali Tugarinov
- Department of Medical Genetics and Microbiology, University of Toronto, Medical Sciences Building, 1 King's College Circle, Toronto, Ontario, M5S 1A8 Canada
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13
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Smith JP. Solid-state NMR: no longer the outcast. Anal Chem 2002; 74:45A-47A. [PMID: 11795816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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14
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Miller S. Business: 900-MHz NMR is here. Anal Chem 2001; 73:253A-254A. [PMID: 11354507 DOI: 10.1021/ac0124383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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Alger JR. Regulatory, financial and ethical aspects of routine clinical magnetic resonance spectroscopy. NMR Biomed 2000; 13:III-V. [PMID: 10960924 DOI: 10.1002/1099-1492(200008)13:5<::aid-nbm650>3.0.co;2-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
After years of technological development, magnetic resonance spectroscopy (MRS) is now being used with increasing frequency as a routine diagnostic tool for medical evaluation of patients. The transition of MRS from the realm of pure research to that of routine clinical application has been accompanied by some confusion regarding regulatory, financial and ethical matters. This contribution summarizes these issues from the author's perspective and calls for increased discussion and learning within the MRS community regarding practical matters associated with routine clinical implementation of MRS.
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16
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Abstract
A new portable magnetic resonance imaging device was built. Spatially resolved NMR was achieved by placing a gradient coil pair and a Helmholtz pair type radio-frequency probe in the gap between two antiparallel polarized permanent magnets. The flat face of the low-field (nu(proton) = 20 MHz) apparatus allowed for the study of arbitrarily large objects in situ. Relaxation time weighted 1D images were achieved over a 15-mm field of view by a single-point spin-echo sequence. A phase encoding time on the order of 200 micros permited the scanning of a wide range of heterogeneous materials.
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Affiliation(s)
- P J Prado
- Quantum Magnetics, Inc., 7740 Kenamar Court, San Diego, California, 92121, USA
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17
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van Kaick G. [Diagnosis of tumor metabolism using positron emission tomography and magnetic resonance spectroscopy]. Radiologe 1989; 29:313-4. [PMID: 2787918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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18
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Steinberg EP, Anderson GF, Steinwachs DM. Changes in CT utilization between 1981 and 1984: implications for Medicare payment for MR imaging under the prospective payment system. Radiology 1987; 165:279-81. [PMID: 3114824 DOI: 10.1148/radiology.165.1.3114824] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
In the absence of data on current or likely patterns of use of magnetic resonance (MR) imaging, use of computed tomography (CT) at one institution in 1981 and 1984 was analyzed to provide data relevant to current federal deliberations regarding Medicare payment for inpatient MR imaging. Between 1981 and 1984 inpatient CT utilization increased 59%, primarily due to a 265% increase in body CT. In 1984 inpatients who underwent at least one CT procedure were as likely to undergo more than one procedure as to undergo only one. CT procedures were performed in a high proportion of diagnosis-related groups (DRGs), with more than one-half of head CT procedures performed in non-neurologic DRGs. Given the similarities between clinical applications of CT and MR imaging, these findings regarding CT utilization have the following implications: (a) a delay in recalibration of DRG payment rates may not take account of expected growth in utilization of MR imaging, (b) a DRG "add-on" for MR imaging should reflect the likelihood that more than one MR imaging procedure will be performed in many hospitalizations, and (c) adjustments in DRG payments for MR imaging should not be limited to the 35 neurologic DRGs.
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20
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Hughes CM, Amier N. Joint venturing in MRI. Cutting through red tape. Adm Radiol 1987; 6:82, 84. [PMID: 10283701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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21
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Carroll JJ, Newbould GD. Spreadsheets simplify sensitivity analysis for capital decisions. Healthc Financ Manage 1987; 41:78-88. [PMID: 10282141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
The availability and ease of use of electronic spreadsheets removes the previously cumbersome number crunching burden of sensitivity analysis. In this article, the advantages of sensitivity analysis will be reintroduced and a model will be presented using a pro forma statement for a freestanding magnetic resonance imaging center.
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22
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Holtås S, Larsson EM, Pettersson H. [Magnetic resonance imaging of the spine--a cheap and safe diagnostic method]. Lakartidningen 1987; 84:1544-7. [PMID: 3626702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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23
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Abstract
Indications for MR examinations and patient characteristics are evaluated for 4561 MR examinations performed at a freestanding outpatient MR imaging center between May 1984 and June 1986. Hospitalized patients accounted for less than 3% of the case load. Examinations of the head and spine accounted for 60% and 31% of the work load, respectively. Patients 65 years or older made up 15% of the case load during 1984 and 1985 and 21% in 1986. Referrals from neurologists, internists, and neurosurgeons accounted for 56%, 11% and 9% of patients, respectively. The percentage of patients who had CT, myelography, and other imaging procedures performed before referral for MR imaging declined significantly between 1984 and 1986. Indications for examination were mostly neoplastic diseases; degenerative diseases of the CNS, including multiple sclerosis; other disorders of the CNS; and disk diseases. Approximately 40% of all examinations were interpreted as normal. The number of patients referred for degenerative intervertebral disk disorders increased substantially between 1984 and 1985. This study documents the increasing acceptance of MR imaging as an important primary imaging technique for a variety of conditions, particularly those of the brain and spine.
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Diamond JF, Dix L. MRI equipment acquisition. Managing the vendor selection process. Adm Radiol 1987; 6:38-42. [PMID: 10282514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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25
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Riley E, Hill-Mischel J. MRI joint venturing today. Adm Radiol 1987; 6:45-7. [PMID: 10282515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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26
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Freedman GS, O'Brien B. MRI services: fixed vs. mobile. Adm Radiol 1987; 6:23-5. [PMID: 10282512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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27
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Caterinicchio RP. Managing the impact of DRG-PPS on capital investments. Adm Radiol 1987; 6:29-30, 32. [PMID: 10312057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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28
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Steinberg EP, diMonda R. Guideline report. Projecting MRI utilization: two new approaches. Hosp Technol Ser 1987; 6:1-37. [PMID: 10312080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
In today's competitive marketplace, hospitals must carefully analyze the financial impact of acquiring new technologies. The high cost of magnetic resonance imaging (MRI), one of the most prominent new technologies, makes it critical for hospitals to evaluate thoroughly the financial risks of providing this service. To determine whether it is likely to generate a sufficient number of MRI scans to break even financially, a hospital must carefully analyze its patient case mix. In 1984, the American Hospital Association (AHA) developed a method, the AHA MRI Utilization Model, for performing such an analysis. The original AHA model projected a hospital's potential demand for MRI procedures based on an analysis of that hospital's inpatient discharge data. The widespread use of the original AHA MRI Utilization Model by over 500 hospitals and a number of state health planning agencies has significantly influenced the diffusion of MRI throughout the United States. The original AHA model had several limitations, however: it ignored scans that might be performed to evaluate secondary diagnoses; its estimate of follow-up scans and replacement of CT by MRI was based on information from 1978; and it lacked a mechanism for considering outpatient scans. These limitations, together with the rapid evolution in clinical applications for MRI, led the AHA to improve its original MRI utilization projection methodology. In 1986, the AHA developed a new second generation MRI Utilization Model that employs two independently derived methodologies. The AHA's revised ICD-9-CM Projection method was developed by Richard diMonda, M.S.B.M.E., M.B.A.; the Diagnosis Related Groups (DRG) Projection Method was developed by Earl P. Steinberg, M.D., M.P.P. The second generation model has several advantages over the original model: it utilizes the opinions of a greater number of experts, as well as experts from more varied backgrounds; experts' opinions were obtained in 1986, rather than 1984, and so are more relevant to current patterns of practice; experts' opinions are employed to project CT, as well as MRI volume when both technologies are available, and the extent to which MRI will replace CT; total inpatient and outpatient scans are calculated; and hospital-specific adjustment factors are used to adjust for variations in patterns of practice across institutions. The DRG projection method also adds the ability to consider MRI and CT scans used to evaluate comorbid conditions and complications, as well as scans performed on patients who turned out to have no pathology. In addition, the DRG method provides a projection of potential MRI and CT volume in 1990, as well as currently.
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Carter K. Tax changes may jeopardize high-technology joint ventures. Mod Healthc 1986; 16:38, 40. [PMID: 10279859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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30
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Forbes G. The impact of computed tomography and magnetic resonance on diagnostic medical imaging. Trans Stud Coll Physicians Phila 1986; 8:215-31. [PMID: 3810808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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31
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Abstract
The use of magnetic resonance imaging, in the demonstration of internal human anatomy and in the diagnosis of disease, has the major advantages that the technique is noninvasive, does not require the use of ionizing radiation and that it can demonstrate neurological and cardiovascular lesions that cannot be diagnosed easily by other imaging methods. Magnetic resonance imaging is derived from the principle that certain atomic nuclei in a strong magnetic field will absorb pulses of radiofrequency energy; when the pulse is finished the nuclei will emit radiowaves at the same frequency. These radiowaves are received by specially designed aerials or coils and the information is collected by a computer which reconstructs an image of internal anatomy in a similar way to that of x-ray computed tomography (CT). By changing the strength of the magnetic fields and the frequency of the radiowave pulses, it is possible to examine different sections within the body. The first magnetic resonance images of humans were obtained in Australia in October 1985 on the research instrument of the Queensland Medical Magnetic Resonance Research Centre, which is based at the Mater Hospital in Brisbane, and is part of the University of Queensland's Department of Radiology.
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Abstract
Magnetic resonance imaging is a new, but expensive, modality that is being introduced into clinical use in Australia. While it promises increased safety and accuracy in many situations, its precise role when compared with computed tomography and other modalities is not fully established. Therefore, a Government financed evaluation of costs and efficacy of magnetic resonance imaging units in five teaching hospitals is to be conducted over two years (1986-1988). Experience with the introduction of computed tomography to Australia and other nations has revealed difficulties in the evaluation by conventional methods of a diagnostic technology that is improving rapidly; it is to be hoped that a systematic evaluation of the clinical applications of magnetic resonance imaging will be more achievable and useful. Open cooperation between the Commonwealth and State Governments and the medical profession in this evaluation should lead to a rational policy for the clinical availability of magnetic resonance imaging within Australia in the future.
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Cherskov M. Imaging centers continue to grow. Hospitals 1986; 60:90-1, 96, 102-5. [PMID: 3530966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Turner RJ, Hankins GD, Weinreb JC, Ziaya PR, Davis TN, Lowe TW, Gilstrap LC. Magnetic resonance imaging and ultrasonography in the antenatal evaluation of conjoined twins. Am J Obstet Gynecol 1986; 155:645-9. [PMID: 3529968 DOI: 10.1016/0002-9378(86)90295-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Magnetic resonance imaging and sonography were used as diagnostic aids in the antepartum evaluation of two sets of conjoined twins. Magnetic resonance imaging was performed at 20 weeks' estimated gestational age on thoracopagus/omphalopagus twins and on omphalopagus twins at 20 and 30 weeks. Magnetic resonance imaging is a complementary adjunct to ultrasonography and provides additional anatomically precise clinical data. The advantages of this noninvasive technique include a large diagnostic window allowing total fetal imaging with excellent resolution of tissue composition. Unlike computerized tomographic imaging, there is no associated radiation exposure. The principal disadvantages of magnetic resonance imaging at this time are the cost of the equipment and the lack of real-time imaging capability.
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Carter K. New York hospital first to test small imaging magnet in U.S. Mod Healthc 1986; 16:58, 60. [PMID: 10277384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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Abstract
The rate and pattern of magnetic resonance imaging (MRI) siting and ownership are examined in the context of the current turbulent health-care environment. By the end of 1984, 151 MRI units were located at 134 different sites. There was one MRI unit for every 1.55 million Americans. Most of the largest metropolitan areas had at least one unit. Overall, however, the diffusion rate of MRI has lagged behind that of computed tomography (CT). Trends in magnet preference, siting, and ownership are evolving. While the majority of all units are located within hospitals, the diffusion of nonhospital-based MRI units is accelerating. The deployment of hospital-based units is progressing at a slower rate, largely limited to academic institutions and urban centers. Purchase of superconducting and permanent magnets is accelerating, while that of resistive units is decreasing. Likewise, there is a trend toward adoption of intermediate (0.5 T-0.6 T) and large (1.0 T or 1.5 T) magnets. Ownership arrangements are highly varied and characterized by increased efforts at risk-sharing, trends that reflect a more competitive, profit-oriented medical-care environment. An analysis of recent health-policy initiatives and evolving market factors helps to explain some of these observations. Increased cost-consciousness, prospective reimbursement systems, loopholes in current regulations, and increased competition among health-care providers are influencing the diffusion of MRI and may herald the fate of other expensive medical technologies in the near future.
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38
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Perspectives. ProPAC recommends payment hike. Mcgraw Hills Wash Rep Med Health 1986; 40:suppl 4 p.. [PMID: 10300678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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39
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Is it now time to acquire magnetic resonance imaging? Issues and concerns. J Health Care Technol 1985; 2:23-50. [PMID: 10300489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Magnetic resonance imaging (MRI) is a diagnostic modality that permits images of a variety of pathologic conditions to be acquired safely and painlessly with remarkable anatomic detail. In research sites and in a few clinical locations, MRI has become the definitive diagnostic tool for many neurological conditions and promises to become a valuable modality for diagnosing thoracic, abdominal, pelvic, and perhaps even breast and eye diseases. Despite its accolades, MRI's diffusion and adoption are at the center of a storm of controversy. The spread of MRI to non-research hospitals throughout the country--even to those with large neurology services--has not yet been shown to be clinically appropriate or cost effective. This article examines the accumulated information on MRI in order to help the administrator and trustees of a typical acute-care hospital to decide whether their community needs--and is able to support--an MRI service. Rather than reviewing the ever-changing frontiers of MRI research, this assessment considers the issues that are of immediate concern to hospital decisionmakers who must answer the question, "Should we plan to buy an MRI system in 1985?"
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40
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Ordway JM. MRI reimbursement approved, technologist standards published. Radiol Manage 1986; 8:14. [PMID: 10300671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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41
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42
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Wende S, Kretzschmar K. [Efficiency and efficacy of neuroradiologic diagnosis of brain tumors]. Radiologe 1985; 25:497-501. [PMID: 4089163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Working as neuroradiologists for many years permits us to discuss the development of neuroradiological diagnosis in intracranial disease in adults measuring efficacy and efficiency by critical comparison with therapeutic results.
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Margulis AR, Amparo E. Magnetic resonance imaging in clinical practice. Current value and future prospects. Postgrad Med 1985; 78:127-32. [PMID: 4048025 DOI: 10.1080/00325481.1985.11699157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Wallace C. Joint ventures. Alta Bates' subsidiary mulls network of MRI centers in San Francisco area. Mod Healthc 1985; 15:76. [PMID: 10272889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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45
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Pittsburgh area is home of largest MRI joint venture. Hospitals 1985; 59:106. [PMID: 4018761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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46
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Joint ventures for MRIs create 'regulatory grey areas'. Hospitals 1985; 59:100, 105. [PMID: 3894206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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47
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Abstract
The benefits and costs of routinely using computerized tomography (CT) to diagnose surgically treatable causes of dementia compared to a more selective strategy were assessed, using a decision-analytic model, for hypothetical cohorts at 60, 70, and 80 years of age. The model was also used to project what the impact would be if magnetic resonance imaging (MRI) were to replace CT, assuming that MRI is a perfect test. Given plausible assumptions, routine CT could be expected to detect between 1 425 and 14 930 additional surgically treatable cases at an extra cost of between $0 and $49 million per 100 000 persons scanned. Replacing CT with MRI might yield an additional 70 to 150 cases of surgically treatable dementia, at an additional cost of $20-$30 million. Given current treatment limitations in dementia, it appears that, as a clinical tool, MRI will have little immediate health impact on this problem.
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48
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Schwartz HW, Jarl DF. MRI: unique costing and pricing issues. Radiol Manage 1985; 7:15-8. [PMID: 10273665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Acquisition of magnetic resonance imaging (MRI) involves a plethora of costs not traditionally encountered in radiology procedure cost accounting models. Experiences with MRI gained at the University of Minnesota Hospitals and Clinics during 1984 uncovered a wide variety of unique costing issues which were eventually identified at the time when the MRI hospital charge was being established. Our experience at UMHC can provide those radiology departments now acquiring MRI with an earlier awareness of these special costing issues, hopefully resulting in better and more timely data collection. Current reimbursement and pricing issues are also having a dramatic impact on MRI costs at each institution and must be assessed in terms of third-party payor intentions.
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49
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Cryan TV. The MRI experience. Radiol Manage 1985; 7:8-12. [PMID: 10272547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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50
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diMonda R. Is NMR right for your hospital? Hospitals 1985; 59:55, 58-9. [PMID: 3922873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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