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Storey P, Novikov DS. Signatures of microstructure in gradient-echo and spin-echo signals. Magn Reson Med 2024; 92:269-288. [PMID: 38520259 DOI: 10.1002/mrm.30022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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] [Received: 03/26/2023] [Revised: 01/06/2024] [Accepted: 01/08/2024] [Indexed: 03/25/2024]
Abstract
PURPOSE To determine whether the spatial scale and magnetic susceptibility of microstructure can be evaluated robustly from the decay of gradient-echo and spin-echo signals. THEORY AND METHODS Gradient-echo and spin-echo images were acquired from suspensions of spherical polystyrene microbeads of 10, 20, and 40 μm nominal diameter. The sizes of the beads and their magnetic susceptibility relative to the medium were estimated from the signal decay curves, using a lookup table generated from Monte Carlo simulations and an analytic model based on the Gaussian phase approximation. RESULTS Fitting Monte Carlo predictions to spin-echo data yielded acceptable estimates of microstructural parameters for the 20 and 40 μm microbeads. Using gradient-echo data, the Monte Carlo lookup table provided satisfactory parameter estimates for the 20 μm beads but unstable results for the diameter of the largest beads. Neither spin-echo nor gradient-echo data allowed accurate parameter estimation for the smallest beads. The analytic model performed poorly over all bead sizes. CONCLUSIONS Microstructural sources of magnetic susceptibility produce distinctive non-exponential signatures in the decay of gradient-echo and spin-echo signals. However, inverting the problem to extract microstructural parameters from the signals is nontrivial and, in certain regimes, ill-conditioned. For microstructure with small characteristic length scales, parameter estimation is hampered by the difficulty of acquiring accurate data at very short echo times. For microstructure with large characteristic lengths, the gradient-echo signal approaches the static-dephasing regime, where it becomes insensitive to size. Applicability of the analytic model was further limited by failure of the Gaussian phase approximation for all but the smallest beads.
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Affiliation(s)
- Pippa Storey
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - Dmitry S Novikov
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York, USA
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2
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Vara Almirall B, Inthavong K, Bradshaw K, Singh N, Johnson A, Storey P, Salati H. Flow Patterns and Particle Residence Times in the Oral Cavity during Inhaled Drug Delivery. Pharmaceuticals (Basel) 2022; 15:ph15101259. [PMID: 36297371 PMCID: PMC9612176 DOI: 10.3390/ph15101259] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/05/2022] [Accepted: 10/08/2022] [Indexed: 12/05/2022] Open
Abstract
Pulmonary drug delivery aims to deliver particles deep into the lungs, bypassing the mouth−throat airway geometry. However, micron particles under high flow rates are susceptible to inertial impaction on anatomical sites that serve as a defense system to filter and prevent foreign particles from entering the lungs. The aim of this study was to understand particle aerodynamics and its possible deposition in the mouth−throat airway that inhibits pulmonary drug delivery. In this study, we present an analysis of the aerodynamics of inhaled particles inside a patient-specific mouth−throat model generated from MRI scans. Computational Fluid Dynamics with a Discrete Phase Model for tracking particles was used to characterize the airflow patterns for a constant inhalation flow rate of 30 L/min. Monodisperse particles with diameters of 7 μm to 26 μm were introduced to the domain within a 3 cm-diameter sphere in front of the oral cavity. The main outcomes of this study showed that the time taken for particle deposition to occur was 0.5 s; a narrow stream of particles (medially and superiorly) were transported by the flow field; larger particles > 20 μm deposited onto the oropharnyx, while smaller particles < 12 μm were more disperse throughout the oral cavity and navigated the curved geometry and laryngeal jet to escape through the tracheal outlet. It was concluded that at a flow rate of 30 L/min the particle diameters depositing on the larynx and trachea in this specific patient model are likely to be in the range of 7 μm to 16 μm. Particles larger than 16 μm primarily deposited on the oropharynx.
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Affiliation(s)
- Brenda Vara Almirall
- Mechanical & Automotive Engineering, School of Engineering, Royal Melbourne Institute of Technology University, Bundoora, VIC 3083, Australia
| | - Kiao Inthavong
- Mechanical & Automotive Engineering, School of Engineering, Royal Melbourne Institute of Technology University, Bundoora, VIC 3083, Australia
- Correspondence:
| | - Kimberley Bradshaw
- Department of Otolaryngology, Head and Neck Surgery, Westmead Hospital, Westmead, NSW 2145, Australia
| | - Narinder Singh
- Department of Otolaryngology, Head and Neck Surgery, Westmead Hospital, Westmead, NSW 2145, Australia
- Sydney Medical School, Faculty of Medicine & Health, The University of Sydney, Sydney, NSW 2006, Australia
| | - Aaron Johnson
- Department of Otolaryngology-Head and Neck Surgery & Department of Rehabilitation Medicine, Grossman School of Medicine, New York University, New York, NY 10017, USA
| | - Pippa Storey
- Department of Radiology, Grossman School of Medicine, New York University, New York, NY 10016, USA
| | - Hana Salati
- Mechanical & Automotive Engineering, School of Engineering, Royal Melbourne Institute of Technology University, Bundoora, VIC 3083, Australia
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Glodzik L, Rusinek H, Butler T, Li Y, Storey P, Sweeney E, Osorio RS, Biskaduros A, Tanzi E, Harvey P, Woldstad C, Maloney T, de Leon MJ. Higher body mass index is associated with worse hippocampal vasoreactivity to carbon dioxide. Front Aging Neurosci 2022; 14:948470. [PMID: 36158536 PMCID: PMC9491849 DOI: 10.3389/fnagi.2022.948470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 07/22/2022] [Indexed: 11/24/2022] Open
Abstract
Background and objectives Obesity is a risk factor for cognitive decline. Probable mechanisms involve inflammation and cerebrovascular dysfunction, leading to diminished cerebral blood flow (CBF) and cerebrovascular reactivity (CVR). The hippocampus, crucially involved in memory processing and thus relevant to many types of dementia, poses a challenge in studies of perfusion and CVR, due to its location, small size, and complex shape. We examined the relationships between body mass index (BMI) and hippocampal resting CBF and CVR to carbon dioxide (CVRCO2) in a group of cognitively normal middle-aged and older adults. Methods Our study was a retrospective analysis of prospectively collected data. Subjects were enrolled for studies assessing the role of hippocampal hemodynamics as a biomarker for AD among cognitively healthy elderly individuals (age > 50). Participants without cognitive impairment, stroke, and active substance abuse were recruited between January 2008 and November 2017 at the NYU Grossman School of Medicine, former Center for Brain Health. All subjects underwent medical, psychiatric, and neurological assessments, blood tests, and MRI examinations. To estimate CVR, we increased their carbon dioxide levels using a rebreathing protocol. Relationships between BMI and brain measures were tested using linear regression. Results Our group (n = 331) consisted of 60.4% women (age 68.8 ± 7.5 years; education 16.8 ± 2.2 years) and 39.6% men (age 70.4 ± 6.4 years; education 16.9 ± 2.4 years). Approximately 22% of them (n = 73) were obese. BMI was inversely associated with CVRCO2 (β = -0.12, unstandardized B = -0.06, 95% CI -0.11, -0.004). A similar relationship was observed after excluding subjects with diabetes and insulin resistance (β = -0.15, unstandardized B = -0.08, 95% CI -0.16, -0.000). In the entire group, BMI was more strongly related to hippocampal CVRCO2 in women (β = -0.20, unstandardized B = -0.08, 95% CI -0.13, -0.02). Discussion These findings lend support to the notion that obesity is a risk factor for hippocampal hemodynamic impairment and suggest targeting obesity as an important prevention strategy. Prospective studies assessing the effects of weight loss on brain hemodynamic measures and inflammation are warranted.
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Affiliation(s)
- Lidia Glodzik
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Henry Rusinek
- Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States
| | - Tracy Butler
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Yi Li
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Pippa Storey
- Department of Radiology, New York University Grossman School of Medicine, New York, NY, United States
| | - Elizabeth Sweeney
- Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, PA, United States
| | - Ricardo S. Osorio
- Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, United States
| | - Adrienne Biskaduros
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Emily Tanzi
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Patrick Harvey
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Christopher Woldstad
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Thomas Maloney
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
| | - Mony J. de Leon
- Department of Radiology, Brain Health Imaging Institute, Weill Cornell Medicine, New York, NY, United States
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4
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Sui YV, Bertisch H, Lee HH, Storey P, Babb JS, Goff DC, Samsonov A, Lazar M. Quantitative Macromolecular Proton Fraction Mapping Reveals Altered Cortical Myelin Profile in Schizophrenia Spectrum Disorders. Cereb Cortex Commun 2021; 2:tgab015. [PMID: 34296161 PMCID: PMC8271044 DOI: 10.1093/texcom/tgab015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 02/15/2021] [Accepted: 02/19/2021] [Indexed: 01/12/2023] Open
Abstract
Myelin abnormalities have been reported in schizophrenia spectrum disorders (SSD) in white matter. However, in vivo examinations of cortical myeloarchitecture in SSD, especially those using quantitative measures, are limited. Here, we employed macromolecular proton fraction (MPF) obtained from quantitative magnetization transfer imaging to characterize intracortical myelin organization in 30 SSD patients versus 34 healthy control (HC) participants. We constructed cortical myelin profiles by extracting MPF values at various cortical depths and quantified their shape using a nonlinearity index (NLI). To delineate the association of illness duration with myelin changes, SSD patients were further divided into 3 duration groups. Between-group comparisons revealed reduced NLI in the SSD group with the longest illness duration (>5.5 years) compared with HC predominantly in bilateral prefrontal areas. Within the SSD group, cortical NLI decreased with disease duration and was positively associated with a measure of spatial working memory capacity as well as with cortical thickness (CT). Layer-specific analyses suggested that NLI decreases in the long-duration SSD group may arise in part from significantly increased MPF values in the midcortical layers. The current study reveals cortical myelin profile changes in SSD with illness progression, which may reflect an abnormal compensatory mechanism of the disorder.
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Affiliation(s)
- Yu Veronica Sui
- Department of Radiology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Hilary Bertisch
- Department of Rehabilitation Medicine, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Hong-Hsi Lee
- Department of Radiology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Pippa Storey
- Department of Radiology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - James S Babb
- Department of Radiology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Donald C Goff
- Department of Psychiatry, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Alexey Samsonov
- Department of Radiology, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Mariana Lazar
- Department of Radiology, NYU Grossman School of Medicine, New York, NY 10016, USA
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5
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Baboli M, Storey P, Sood TP, Fogarty J, Moccaldi M, Lewin A, Moy L, Kim SG. Bilateral gradient-echo spectroscopic imaging with correction of frequency variations for measurement of fatty acid composition in mammary adipose tissue. Magn Reson Med 2021; 86:33-45. [PMID: 33533056 PMCID: PMC8005455 DOI: 10.1002/mrm.28692] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 12/29/2020] [Accepted: 12/30/2020] [Indexed: 12/20/2022]
Abstract
PURPOSE To develop a simultaneous dual-slab three-dimensional gradient-echo spectroscopic imaging (GSI) technique with frequency drift compensation for rapid (<6 min) bilateral measurement of fatty acid composition (FAC) in mammary adipose tissue. METHODS A bilateral GSI sequence was developed using a simultaneous dual-slab excitation followed by 128 monopolar echoes. A short train of navigator echoes without phase or partition encoding was included at the beginning of each pulse repetition time period to correct for frequency variation caused by respiration and heating of the cryostat. Voxel-wise spectral fitting was applied to measure the areas of the lipid spectral peaks to estimate the number of double-bond (ndb), number of methylene-interrupted double-bond (nmidb), and chain length (cl). The proposed method was tested in an oil phantom and 10 postmenopausal women to assess the influence of the frequency variation on FAC estimation. RESULTS The frequency drift observed over 5:27 min during the phantom scan was about 10 Hz. Phase correction based on the navigator reduced the median error of ndb, nmidb, and cl from 9.7%, 17.6%, and 3.2% to 2.1%, 9.5%, and 2.8%, respectively. The in vivo data showed a mean ± standard deviation frequency drift of 17.4 ± 2.5 Hz, with ripples at 0.3 ± 0.1 Hz. Our reconstruction algorithm successfully separated signals from the left and right breasts with negligible residual aliasing. Phase correction reduced the interquartile range within each subject's adipose tissue of ndb, nmidb, and cl by 18.4 ± 10.6%, 18.5 ± 13.9%, and 18.4 ± 10.6%, respectively. CONCLUSION This study shows the feasibility of obtaining bilateral spectroscopic imaging data in the breast and that incorporation of a frequency navigator improves the estimation of FAC.
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Affiliation(s)
- Mehran Baboli
- Bernard and Irene Schwartz Center for Biomedical Imaging, Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY 10016, USA,Department of Radiology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Pippa Storey
- Bernard and Irene Schwartz Center for Biomedical Imaging, Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY 10016, USA
| | - Terlika Pandit Sood
- Bernard and Irene Schwartz Center for Biomedical Imaging, Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY 10016, USA
| | - Justin Fogarty
- Bernard and Irene Schwartz Center for Biomedical Imaging, Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY 10016, USA
| | - Melanie Moccaldi
- Bernard and Irene Schwartz Center for Biomedical Imaging, Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY 10016, USA,New York University Laura and Isaac Perlmutter Cancer Center 160 East 34th Street, New York, NY 10016
| | - Alana Lewin
- Bernard and Irene Schwartz Center for Biomedical Imaging, Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY 10016, USA,New York University Laura and Isaac Perlmutter Cancer Center 160 East 34th Street, New York, NY 10016
| | - Linda Moy
- Bernard and Irene Schwartz Center for Biomedical Imaging, Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY 10016, USA,New York University Laura and Isaac Perlmutter Cancer Center 160 East 34th Street, New York, NY 10016
| | - Sungheon Gene Kim
- Bernard and Irene Schwartz Center for Biomedical Imaging, Center for Advanced Imaging Innovation and Research (CAI2R), Department of Radiology, New York University School of Medicine, New York, NY 10016, USA,New York University Laura and Isaac Perlmutter Cancer Center 160 East 34th Street, New York, NY 10016,Department of Radiology, Weill Cornell Medicine, New York, NY 10065, USA
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6
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Ameratunga R, Jordan A, Cavadino A, Ameratunga S, Hills T, Steele R, Hurst M, McGettigan B, Chua I, Brewerton M, Kennedy N, Koopmans W, Ahn Y, Barker R, Allan C, Storey P, Slade C, Baker A, Huang L, Woon ST. Bronchiectasis is associated with delayed diagnosis and adverse outcomes in the New Zealand Common Variable Immunodeficiency Disorders cohort study. Clin Exp Immunol 2021; 204:352-360. [PMID: 33755987 DOI: 10.1111/cei.13595] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 02/19/2021] [Accepted: 03/13/2021] [Indexed: 02/06/2023] Open
Abstract
Common variable immunodeficiency disorders (CVID) are multi-system disorders where target organ damage is mediated by infective, autoimmune and inflammatory processes. Bronchiectasis is probably the most common disabling complication of CVID. The risk factors for bronchiectasis in CVID patients are incompletely understood. The New Zealand CVID study (NZCS) is a nationwide longitudinal observational study of adults, which commenced in 2006. In this analysis, the prevalence and risk factors for bronchiectasis were examined in the NZCS. After informed consent, clinical and demographic data were obtained with an interviewer-assisted questionnaire. Linked electronic clinical records and laboratory results were also reviewed. Statistical methods were applied to determine if variables such as early-onset disease, delay in diagnosis and increased numbers of infections were associated with greater risk of bronchiectasis. One hundred and seven adult patients with a diagnosis of CVID are currently enrolled in the NZCS, comprising approximately 70% of patients known to have CVID in New Zealand. Fifty patients (46·7%) had radiologically proven bronchiectasis. This study has shown that patients with compared to those without bronchiectasis have an increased mortality at a younger age. CVID patients with bronchiectasis had a greater number of severe infections consequent to early-onset disease and delayed diagnosis. Indigenous Māori have a high prevalence of CVID and a much greater burden of bronchiectasis compared to New Zealand Europeans. Diagnostic latency has not improved during the study period. Exposure to large numbers of infections because of early-onset disease and delayed diagnosis was associated with an increased risk of bronchiectasis. Earlier diagnosis and treatment of CVID may reduce the risk of bronchiectasis and premature death in some patients.
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Affiliation(s)
- R Ameratunga
- Department of Clinical Immunology, Auckland City Hospital, Auckland, New Zealand.,Department of Virology and Immunology, Auckland City Hospital, Auckland, New Zealand.,Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand
| | - A Jordan
- Department of Clinical Immunology, Auckland City Hospital, Auckland, New Zealand
| | - A Cavadino
- School of Population Health, University of Auckland, Auckland, New Zealand
| | - S Ameratunga
- School of Population Health, University of Auckland, Auckland, New Zealand.,Population Health Directorate, Counties Manukau Health, Auckland, New Zealand
| | - T Hills
- Department of Clinical Immunology, Auckland City Hospital, Auckland, New Zealand
| | - R Steele
- Department of Virology and Immunology, Auckland City Hospital, Auckland, New Zealand
| | - M Hurst
- Department of Clinical Immunology, Auckland City Hospital, Auckland, New Zealand
| | - B McGettigan
- Department of Clinical Immunology, Fiona Stanley Hospital, Perth, WA, Australia
| | - I Chua
- Department of Clinical Immunology, Christchurch Hospital, Christchurch, New Zealand
| | - M Brewerton
- Department of Clinical Immunology, Auckland City Hospital, Auckland, New Zealand
| | - N Kennedy
- Department of Respiratory Medicine, Wellington Hospital, Wellington, New Zealand
| | - W Koopmans
- Department of Virology and Immunology, Auckland City Hospital, Auckland, New Zealand
| | - Y Ahn
- Department of Clinical Immunology, Auckland City Hospital, Auckland, New Zealand.,Department of Virology and Immunology, Auckland City Hospital, Auckland, New Zealand
| | - R Barker
- Department of Clinical Immunology, Auckland City Hospital, Auckland, New Zealand
| | - C Allan
- Department of Clinical Immunology, Auckland City Hospital, Auckland, New Zealand
| | - P Storey
- Department of Clinical Immunology, Auckland City Hospital, Auckland, New Zealand
| | - C Slade
- Walter and Eliza Hall Institute, Melbourne, VIC, Australia
| | - A Baker
- Department of Clinical Immunology, Auckland City Hospital, Auckland, New Zealand
| | - L Huang
- Department of Virology and Immunology, Auckland City Hospital, Auckland, New Zealand
| | - S-T Woon
- Department of Clinical Immunology, Auckland City Hospital, Auckland, New Zealand.,Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand
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7
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Chung S, Storey P, Shepherd TM, Lui YW. MR Susceptibility Imaging with a Short TE (MR-SISET): A Clinically Feasible Technique to Resolve Thalamic Nuclei. AJNR Am J Neuroradiol 2020; 41:1629-1631. [PMID: 32675340 DOI: 10.3174/ajnr.a6683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 05/11/2020] [Indexed: 11/07/2022]
Abstract
The thalamus consists of several functionally distinct nuclei, some of which serve as targets for functional neurosurgery. Visualization of such nuclei is a major challenge due to their low signal contrast on conventional imaging. We introduce MR susceptibility imaging with a short TE, leveraging susceptibility differences among thalamic nuclei, to automatically delineate 15 thalamic subregions. The technique has the potential to enable direct targeting of thalamic nuclei for functional neurosurgical guidance.
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Affiliation(s)
- S Chung
- From the Center for Advanced Imaging Innovation and Research (CAI2R), and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, New York.
| | - P Storey
- From the Center for Advanced Imaging Innovation and Research (CAI2R), and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, New York
| | - T M Shepherd
- From the Center for Advanced Imaging Innovation and Research (CAI2R), and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, New York
| | - Y W Lui
- From the Center for Advanced Imaging Innovation and Research (CAI2R), and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, New York
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8
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Lewin AA, Storey P, Moccaldi M, Moy L, Gene Kim S. Fatty acid composition in mammary adipose tissue measured by Gradient-echo Spectroscopic MRI and its association with breast cancers. Eur J Radiol 2019; 116:205-211. [PMID: 31153566 DOI: 10.1016/j.ejrad.2019.04.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 04/04/2019] [Accepted: 04/29/2019] [Indexed: 12/20/2022]
Abstract
PURPOSE To assess the association of fatty acid levels in mammary adipose tissue of postmenopausal women with the presence of breast cancer using the Gradient-echo Spectroscopic Imaging (GSI). MATERIALS AND METHODS Unilateral GSI was performed at 3 T in 61 postmenopausal women undergoing breast MRI exams. The study included 19 women with breast cancer, 23 women with benign/high risk lesions, and 19 women with a history of cancer. Voxel-wise spectral analysis of fatty acids was conducted to measure relative portions of monounsaturated (MUFA), polyunsaturated (PUFA), and saturated fatty acids (SFA) in each voxel. The voxels within mammary adipose tissue were automatically selected and their median fatty acid fractions were used for quantitative analysis. Statistical analyses were performed using χ2 test, one-way analysis of variance (ANOVA) with Tukey-Kramer multiple comparison tests, and linear regression. RESULTS Postmenopausal women with malignancies had significantly higher SFA (0.336 ± 0.038) in mammary adipose tissue compared to those with benign disease (0.283 ± 0.046, p = 0.0008) and to those with a history of breast cancer (0.287 ± 0.050, p = 0.0038). Postmenopausal women with malignant lesions had significantly lower MUFA (0.352 ± 0.041) compared to those with benign disease (0.401 ± 0.043, p = 0.0032) and with history of breast cancer (0.388 ± 0.055, p = 0.0484). The history of cancer group had a significant correlation (r = 0.60, p = 0.006) between SFA and BMI, and the cancer group had a significant correlation (r = 0.57, p = 0.010) between PUFA and BMI. CONCLUSIONS Fatty acid composition of mammary adipose tissue, particularly higher SFA and lower MUFA, may be associated with breast cancer. The GSI method utilizes an automated voxel-based analysis to measure fatty acid composition, and may be used to assess the role of mammary adipose tissue in cancer development and progress.
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Affiliation(s)
- Alana A Lewin
- New York University School of Medicine, Department of Radiology, Center for Biomedical Imaging, 660 First Avenue, 4th Floor, New York, NY 10016, United States.
| | - Pippa Storey
- New York University School of Medicine, Department of Radiology, Center for Biomedical Imaging, 660 First Avenue, 4th Floor, New York, NY 10016, United States
| | - Melanie Moccaldi
- New York University School of Medicine, Department of Radiology, Center for Biomedical Imaging, 660 First Avenue, 4th Floor, New York, NY 10016, United States
| | - Linda Moy
- New York University School of Medicine, Department of Radiology, Center for Biomedical Imaging, 660 First Avenue, 4th Floor, New York, NY 10016, United States
| | - S Gene Kim
- New York University School of Medicine, Department of Radiology, Center for Biomedical Imaging, 660 First Avenue, 4th Floor, New York, NY 10016, United States
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9
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Glodzik L, Rusinek H, Tsui W, Pirraglia E, Kim HJ, Deshpande A, Li Y, Storey P, Randall C, Chen J, Osorio RS, Butler T, Tanzi E, McQuillan M, Harvey P, Williams SK, Ogedegbe OG, Babb JS, de Leon MJ. Different Relationship Between Systolic Blood Pressure and Cerebral Perfusion in Subjects With and Without Hypertension. Hypertension 2019; 73:197-205. [PMID: 30571554 PMCID: PMC7986962 DOI: 10.1161/hypertensionaha.118.11233] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although there is an increasing agreement that hypertension is associated with cerebrovascular compromise, relationships between blood pressure (BP) and cerebral blood flow are not fully understood. It is not known what BP level, and consequently what therapeutic goal, is optimal for brain perfusion. Moreover, there is limited data on how BP affects hippocampal perfusion, a structure critically involved in memory. We conducted a cross-sectional (n=445) and longitudinal (n=185) study of adults and elderly without dementia or clinically apparent stroke, who underwent clinical examination and brain perfusion assessment (age 69.2±7.5 years, 62% women, 45% hypertensive). Linear models were used to test baseline BP-blood flow relationship and to examine how changes in BP influence changes in perfusion. In the entire group, systolic BP (SBP) was negatively related to cortical (β=-0.13, P=0.005) and hippocampal blood flow (β=-0.12, P=0.01). Notably, this negative relationship was apparent already in subjects without hypertension. Hypertensive subjects showed a quadratic relationship between SBP and hippocampal blood flow (β=-1.55, P=0.03): Perfusion was the highest in subjects with mid-range SBP around 125 mm Hg. Longitudinally, in hypertensive subjects perfusion increased with increased SBP at low baseline SBP but increased with decreased SBP at high baseline SBP. Cortical and hippocampal perfusion decrease with increasing SBP across the entire BP spectrum. However, in hypertension, there seems to be a window of mid-range SBP which maximizes perfusion.
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Affiliation(s)
- Lidia Glodzik
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York,Department of Radiology, NYU School of Medicine, New York,Corresponding author: Lidia Glodzik, Center for Brain Health, Department of Psychiatry, NYU School of Medicine, 145 East 32 Street, New York, NY, 10016. Tel: 212-263-5698, Fax: 212-263-3270;
| | - Henry Rusinek
- Department of Radiology, NYU School of Medicine, New York
| | - Wai Tsui
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | - Elizabeth Pirraglia
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | - Hee-Jin Kim
- Department of Neurology, Konkuk University College of Medicine, Seoul, South Korea
| | - Anup Deshpande
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | - Yi Li
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | - Pippa Storey
- Department of Radiology, NYU School of Medicine, New York
| | - Catherine Randall
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | - Jingyun Chen
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | - Ricardo S. Osorio
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | - Tracy Butler
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | - Emily Tanzi
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | - Molly McQuillan
- The Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, Massachusetts
| | - Patrick Harvey
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
| | | | | | - James S. Babb
- Department of Radiology, NYU School of Medicine, New York
| | - Mony J. de Leon
- Center for Brain Health, Department of Psychiatry, New York University (NYU) School of Medicine, New York
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10
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Frosch OH, Yau PL, Osorio RS, Rusinek H, Storey P, Convit A. Insulin resistance among obese middle-aged is associated with decreased cerebrovascular reactivity. Neurology 2017; 89:249-255. [PMID: 28615420 DOI: 10.1212/wnl.0000000000004110] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 04/14/2017] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE To evaluate differences in cerebrovascular reactivity (CVR) to mild hypercapnia in obese/overweight individuals with and without insulin resistance (IR) compared to comparable lean controls. METHODS A total of 60 cognitively normal participants (20 lean controls and 24 obese/overweight individuals with and 16 without IR) were evaluated using a high spatial resolution arterial spin labeling MRI technique at rest and during mild hypercapnia. We analyzed group differences in CVR in cerebral cortex and ascertained the relationships between CVR, IR, and body mass index (BMI). RESULTS Obese/overweight participants with and without IR had significantly lower CVR to hypercapnia than lean controls after controlling for age, sex, and the presence of hypertension (F2,53 = 5.578, p = 0.006 [Formula: see text] = 0.174). In the obese/overweight participants with IR, there was a significant correlation between higher CVR and a measure of insulin sensitivity, even after accounting for BMI (rp = 0.575, p = 0.004). In contrast, there was no relationship between CVR and BMI when controlling for IR. No such relationships existed for the other 2 groups. CONCLUSIONS IR is associated with impaired CVR; the relationship appears to be driven by the degree of IR and not by obesity. These rarely reported results suggest that early forms of cerebrovascular dysfunction exist among obese middle-aged individuals with significant IR but without type 2 diabetes mellitus. These functional vascular abnormalities may help explain the associations among IR, diabetes, and dementia, and suggest that interventions aiming to improve IR or CVR may help prevent cognitive decline later in life.
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Affiliation(s)
- Olivia H Frosch
- From the Departments of Psychiatry (O.H.F., P.L.Y., R.S.O., H.R., A.C.), Radiology (H.R., P.S., A.C.), and Medicine (A.C.), New York University School of Medicine, New York; and Nathan Kline Institute for Psychiatric Research (A.C.), Orangeburg, NY
| | - Po Lai Yau
- From the Departments of Psychiatry (O.H.F., P.L.Y., R.S.O., H.R., A.C.), Radiology (H.R., P.S., A.C.), and Medicine (A.C.), New York University School of Medicine, New York; and Nathan Kline Institute for Psychiatric Research (A.C.), Orangeburg, NY
| | - Ricardo S Osorio
- From the Departments of Psychiatry (O.H.F., P.L.Y., R.S.O., H.R., A.C.), Radiology (H.R., P.S., A.C.), and Medicine (A.C.), New York University School of Medicine, New York; and Nathan Kline Institute for Psychiatric Research (A.C.), Orangeburg, NY
| | - Henry Rusinek
- From the Departments of Psychiatry (O.H.F., P.L.Y., R.S.O., H.R., A.C.), Radiology (H.R., P.S., A.C.), and Medicine (A.C.), New York University School of Medicine, New York; and Nathan Kline Institute for Psychiatric Research (A.C.), Orangeburg, NY
| | - Pippa Storey
- From the Departments of Psychiatry (O.H.F., P.L.Y., R.S.O., H.R., A.C.), Radiology (H.R., P.S., A.C.), and Medicine (A.C.), New York University School of Medicine, New York; and Nathan Kline Institute for Psychiatric Research (A.C.), Orangeburg, NY
| | - Antonio Convit
- From the Departments of Psychiatry (O.H.F., P.L.Y., R.S.O., H.R., A.C.), Radiology (H.R., P.S., A.C.), and Medicine (A.C.), New York University School of Medicine, New York; and Nathan Kline Institute for Psychiatric Research (A.C.), Orangeburg, NY.
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11
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Freed M, Storey P, Lewin AA, Babb J, Moccaldi M, Moy L, Kim SG. Evaluation of Breast Lipid Composition in Patients with Benign Tissue and Cancer by Using Multiple Gradient-Echo MR Imaging. Radiology 2016; 281:43-53. [PMID: 27266558 DOI: 10.1148/radiol.2016151959] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Purpose To demonstrate the feasibility of the use of a rapid, noninvasive, in vivo imaging method to measure fatty acid fractions of breast adipose tissue during diagnostic breast magnetic resonance (MR) examinations and to investigate associations between fatty acid fractions in breast adipose tissue and breast cancer status by using this method. Materials and Methods The institutional review board approved this retrospective HIPAA-compliant study and informed consent was waived. Between July 2013 and September 2014, multiple-echo three-dimensional gradient-echo data were acquired for 89 women. Spectra were generated and used to estimate fractions of monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA), and saturated fatty acid (SFA) in the breast adipose tissue. Analysis of covariance and exact Mann-Whitney tests were used to compare groups and the Spearman rank correlation coefficient was used to characterize the association of each imaging measure with each attribute. Results For postmenopausal women, MUFA was lower (0.38 ± 0.06 vs 0.46 ± 0.10; P < .05) and SFA was higher (0.31 ± 0.07 vs 0.19 ± 0.11; P < .05) for women with invasive ductal carcinoma than for those with benign tissue. No correlation was found between body mass index (BMI) and fatty acid fractions in breast adipose tissue. In women with benign tissue, postmenopausal women had a higher PUFA (0.35 ± 0.06 vs 0.27 ± 0.05; P < .01) and lower SFA (0.19 ± 0.11 vs 0.30 ± 0.12; P < .05) than premenopausal women. Conclusion There is a possible link between the presence of invasive ductal carcinoma and fatty acid fractions in breast adipose tissue for postmenopausal women in whom BMI values are not correlated with the fatty acid fractions. (©) RSNA, 2016 Online supplemental material is available for this article.
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Affiliation(s)
- Melanie Freed
- From the Center for Advanced Imaging Innovation and Research (CAI2R) and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, 660 First Ave, 4th Floor, New York, NY 10016
| | - Pippa Storey
- From the Center for Advanced Imaging Innovation and Research (CAI2R) and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, 660 First Ave, 4th Floor, New York, NY 10016
| | - Alana Amarosa Lewin
- From the Center for Advanced Imaging Innovation and Research (CAI2R) and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, 660 First Ave, 4th Floor, New York, NY 10016
| | - James Babb
- From the Center for Advanced Imaging Innovation and Research (CAI2R) and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, 660 First Ave, 4th Floor, New York, NY 10016
| | - Melanie Moccaldi
- From the Center for Advanced Imaging Innovation and Research (CAI2R) and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, 660 First Ave, 4th Floor, New York, NY 10016
| | - Linda Moy
- From the Center for Advanced Imaging Innovation and Research (CAI2R) and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, 660 First Ave, 4th Floor, New York, NY 10016
| | - Sungheon G Kim
- From the Center for Advanced Imaging Innovation and Research (CAI2R) and Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, 660 First Ave, 4th Floor, New York, NY 10016
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12
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Chung S, Storey P, Axel L. Whole-heart T1-mapping with single breath-hold. J Cardiovasc Magn Reson 2015. [PMCID: PMC4328698 DOI: 10.1186/1532-429x-17-s1-p389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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13
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14
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Rusinek H, Ha J, Yau PL, Storey P, Tirsi A, Tsui WH, Frosch O, Azova S, Convit A. Cerebral perfusion in insulin resistance and type 2 diabetes. J Cereb Blood Flow Metab 2015; 35:95-102. [PMID: 25315860 PMCID: PMC4294398 DOI: 10.1038/jcbfm.2014.173] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 08/19/2014] [Accepted: 09/10/2014] [Indexed: 11/09/2022]
Abstract
Cerebral perfusion was evaluated in 87 subjects prospectively enrolled in three study groups-healthy controls (HC), patients with insulin resistance (IR) but not with diabetes, and type 2 diabetes mellitus (T2DM). Participants received a comprehensive 8-hour clinical evaluation and arterial spin labeling magnetic resonance imaging (MRI). In order of decreasing significance, an association was found between cerebral blood flow (CBF) and sex, waist circumference, diastolic blood pressure (BP), end tidal CO2, and verbal fluency score (R(2)=0.27, F=5.89, P<0.001). Mean gray-matter CBF in IR was 4.4 mL/100 g per minute lower than in control subjects (P=0.005), with no hypoperfusion in T2DM (P=0.312). Subjects with IR also showed no CO2 relationship (slope=-0.012) in the normocapnic range, in contrast to a strong relationship in healthy brains (slope=0.800) and intermediate response (slope=0.445) in diabetic patients. Since the majority of T2DM but few IR subjects were aggressively treated with blood glucose, cholesterol, and BP lowering medications, our finding could be attributed to the beneficial effect of these drugs.
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Affiliation(s)
- Henry Rusinek
- Department of Radiology, NYU School of Medicine, New York, New York, USA
| | - Jenny Ha
- Department of Psychiatry, NYU School of Medicine, New York, New York, USA
| | - Po Lai Yau
- Department of Psychiatry, NYU School of Medicine, New York, New York, USA
| | - Pippa Storey
- Department of Radiology, NYU School of Medicine, New York, New York, USA
| | - Aziz Tirsi
- Department of Psychiatry, NYU School of Medicine, New York, New York, USA
| | - Wai Hon Tsui
- Department of Psychiatry, NYU School of Medicine, New York, New York, USA
| | | | | | - Antonio Convit
- 1] Department of Psychiatry, NYU School of Medicine, New York, New York, USA [2] Nathan Kline Institute for Psychiatric Research, Orangeburg, New York, USA
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15
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Soher BJ, Wu WE, Tal A, Storey P, Zhang K, Babb JS, Lui YW, Gonen O. Automated whole-brain N-acetylaspartate proton MRS quantification. NMR Biomed 2014; 27:1275-84. [PMID: 25196714 PMCID: PMC4212831 DOI: 10.1002/nbm.3185] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [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: 01/15/2014] [Revised: 07/16/2014] [Accepted: 07/18/2014] [Indexed: 06/03/2023]
Abstract
Concentration of the neuronal marker, N-acetylaspartate (NAA), a quantitative metric for the health and density of neurons, is currently obtained by integration of the manually defined peak in whole-head proton ((1) H)-MRS. Our goal was to develop a full spectral modeling approach for the automatic estimation of the whole-brain NAA concentration (WBNAA) and to compare the performance of this approach with a manual frequency-range peak integration approach previously employed. MRI and whole-head (1) H-MRS from 18 healthy young adults were examined. Non-localized, whole-head (1) H-MRS obtained at 3 T yielded the NAA peak area through both manually defined frequency-range integration and the new, full spectral simulation. The NAA peak area was converted into an absolute amount with phantom replacement and normalized for brain volume (segmented from T1 -weighted MRI) to yield WBNAA. A paired-sample t test was used to compare the means of the WBNAA paradigms and a likelihood ratio test used to compare their coefficients of variation. While the between-subject WBNAA means were nearly identical (12.8 ± 2.5 mm for integration, 12.8 ± 1.4 mm for spectral modeling), the latter's standard deviation was significantly smaller (by ~50%, p = 0.026). The within-subject variability was 11.7% (±1.3 mm) for integration versus 7.0% (±0.8 mm) for spectral modeling, i.e., a 40% improvement. The (quantifiable) quality of the modeling approach was high, as reflected by Cramer-Rao lower bounds below 0.1% and vanishingly small (experimental - fitted) residuals. Modeling of the whole-head (1) H-MRS increases WBNAA quantification reliability by reducing its variability, its susceptibility to operator bias and baseline roll, and by providing quality-control feedback. Together, these enhance the usefulness of the technique for monitoring the diffuse progression and treatment response of neurological disorders.
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Affiliation(s)
- Brian J. Soher
- Department of Radiology, Duke University Medical Center, Durham NC, 27710, USA
| | - William E. Wu
- Department of Radiology, New York University School of Medicine, New York, NY 10016, USA
| | - Assaf Tal
- Department of Radiology, New York University School of Medicine, New York, NY 10016, USA
| | - Pippa Storey
- Department of Radiology, New York University School of Medicine, New York, NY 10016, USA
| | - Ke Zhang
- Department of Radiology, New York University School of Medicine, New York, NY 10016, USA
| | - James. S. Babb
- Department of Radiology, New York University School of Medicine, New York, NY 10016, USA
| | - Yvonne W. Lui
- Department of Radiology, New York University School of Medicine, New York, NY 10016, USA
| | - Oded Gonen
- Department of Radiology, New York University School of Medicine, New York, NY 10016, USA
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16
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Ghugre NR, Doyle EK, Storey P, Wood JC. Relaxivity-iron calibration in hepatic iron overload: Predictions of a Monte Carlo model. Magn Reson Med 2014; 74:879-83. [PMID: 25242237 DOI: 10.1002/mrm.25459] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 08/21/2014] [Accepted: 08/21/2014] [Indexed: 11/06/2022]
Abstract
PURPOSE R2* (1/T2*) and single echo R2 (1/T2) have been calibrated to liver iron concentration (LIC) in patients with thalassemia and transfusion-dependent sickle cell disease at 1.5T. The R2*-LIC relationship is linear, whereas that of R2 is curvilinear. However, the increasing popularity of high-field scanners requires generalizing these relationships to higher field strengths. In this study, we tested the hypothesis that numerical simulation can accurately determine the field dependence of iron-mediated transverse relaxation rates. METHODS We previously replicated the calibration curves between R2 and R2* and iron at 1.5T using Monte Carlo models incorporating realistic liver structure, iron deposit susceptibility, and proton mobility. In this paper, we extend our model to predict relaxivity-iron calibrations at higher field strengths. Predictions were validated by measuring R2 and R2* at 1.5T and 3T in six β-thalassemia major patients. RESULTS Predicted R2* increased twofold at 3T from 1.5T, whereas R2 increased by a factor of 1.47. Patient data exhibited a coefficient of variation of 3.6% and 7.2%, respectively, to the best-fit simulated data. Simulations over the range 0.25T-7T showed R2* increasing linearly with field strength, whereas R2 exhibited a concave-downward relationship. CONCLUSION A model-based approach predicts alterations in relaxivity-iron calibrations with field strength without repeating imaging studies. The model may generalize to alternative pulse sequences and tissue iron distribution.
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Affiliation(s)
- Nilesh R Ghugre
- Physical Sciences Platform, Sunnybrook Research Institute, Toronto, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Eamon K Doyle
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, USA
| | - Pippa Storey
- Department of Radiology, New York University School of Medicine, New York, New York, USA
| | - John C Wood
- Division of Cardiology and Radiology, Children's Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
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17
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Atanasova IP, Lim RP, Chandarana H, Storey P, Bruno MT, Kim D, Lee VS. Quadruple inversion-recovery b-SSFP MRA of the abdomen: initial clinical validation. Eur J Radiol 2014; 83:1612-9. [PMID: 24998363 PMCID: PMC4706232 DOI: 10.1016/j.ejrad.2014.05.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [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] [Received: 01/20/2014] [Revised: 05/13/2014] [Accepted: 05/14/2014] [Indexed: 11/18/2022]
Abstract
The purpose of this study is to assess the image quality and diagnostic accuracy of non-contrast quadruple inversion-recovery balanced-SSFP MRA (QIR MRA) for detection of aortoiliac disease in a clinical population. QIR MRA was performed in 26 patients referred for routine clinical gadolinium-enhanced MRA (Gd-MRA) for known or suspected aortoiliac disease. Non-contrast images were independently evaluated for image quality and degree of stenosis by two radiologists, using consensus Gd-MRA as the reference standard. Hemodynamically significant stenosis (≥50%) was found in 10% (22/226) of all evaluable segments on Gd-MRA. The sensitivity and specificity for stenosis evaluation by QIR MRA for the two readers were 86%/86% and 95%/93% respectively. Negative predictive value and positive predictive value were 98%/98% and 63%/53% respectively. For stenosis evaluation of the aortoiliac region QIR MRA showed good agreement with the reference standard with high negative predictive value and a tendency to overestimate mild disease presumably due to the flow-dependence of the technique. QIR MRA could be a reasonable alternative to Gd-MRA for ruling out stenosis when contrast is contraindicated due to impaired kidney function or in patients who undergo abdominal MRA for screening purposes. Further work is necessary to improve performance and justify routine clinical use.
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Affiliation(s)
- Iliyana P Atanasova
- Department of Radiology, New York University School of Medicine and Department of Biomedical Engineering, Columbia University, United States.
| | - Ruth P Lim
- Department of Radiology, Austin Health, Heidelberg, Victoria 3084, Australia; University of Melbourne, Melbourne, Victoria, Australia.
| | - Hersh Chandarana
- Department of Radiology, New York University School of Medicine, 660 First Avenue, New York, NY 10016, United States.
| | - Pippa Storey
- Department of Radiology, New York University School of Medicine, 660 First Avenue, New York, NY 10016, United States.
| | - Mary T Bruno
- Department of Radiology, New York University School of Medicine, 660 First Avenue, New York, NY 10016, United States.
| | - Daniel Kim
- Utah Center for Advanced Imaging Research, Department of Radiology, University of Utah, United States.
| | - Vivian S Lee
- Utah Center for Advanced Imaging Research, Department of Radiology, University of Utah, United States.
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18
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Brown R, Storey P, Geppert C, McGorty K, Leite APK, Babb J, Sodickson DK, Wiggins GC, Moy L. Breast MRI at 7 Tesla with a bilateral coil and robust fat suppression. J Magn Reson Imaging 2014; 39:540-9. [PMID: 24123517 PMCID: PMC3945054 DOI: 10.1002/jmri.24205] [Citation(s) in RCA: 21] [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] [Received: 08/08/2012] [Accepted: 04/12/2013] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To develop a bilateral coil and fat suppressed T1-weighted sequence for 7 Tesla (T) breast MRI. MATERIALS AND METHODS A dual-solenoid coil and three-dimensional (3D) T1w gradient echo sequence with B1+ insensitive fat suppression (FS) were developed. T1w FS image quality was characterized through image uniformity and fat-water contrast measurements in 11 subjects. Signal-to-noise ratio (SNR) and flip angle maps were acquired to assess the coil performance. Bilateral contrast-enhanced and unilateral high resolution (0.6 mm isotropic, 6.5 min acquisition time) imaging highlighted the 7T SNR advantage. RESULTS Reliable and effective FS and high image quality was observed in all subjects at 7T, indicating that the custom coil and pulse sequence were insensitive to high-field obstacles such as variable tissue loading. 7T and 3T image uniformity was similar (P=0.24), indicating adequate 7T B1+ uniformity. High 7T SNR and fat-water contrast enabled 0.6 mm isotropic imaging and visualization of a high level of fibroglandular tissue detail. CONCLUSION 7T T1w FS bilateral breast imaging is feasible with a custom radiofrequency (RF) coil and pulse sequence. Similar image uniformity was achieved at 7T and 3T, despite different RF field behavior and variable coil-tissue interaction due to anatomic differences that might be expected to alter magnetic field patterns.
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Affiliation(s)
- Ryan Brown
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, NY, United States
| | - Pippa Storey
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, NY, United States
| | | | - KellyAnne McGorty
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, NY, United States
| | - Ana Paula Klautau Leite
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, NY, United States
| | - James Babb
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, NY, United States
| | - Daniel K. Sodickson
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, NY, United States
| | - Graham C. Wiggins
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, NY, United States
| | - Linda Moy
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Langone Medical Center, New York, NY, United States
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Lindley MD, Kim D, Morrell G, Heilbrun ME, Storey P, Hanrahan C, Lee VS. High-permittivity thin dielectric pad improves peripheral non-contrast MRA at 3T. J Cardiovasc Magn Reson 2014. [PMCID: PMC4045138 DOI: 10.1186/1532-429x-16-s1-p166] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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20
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Storey P, Arbini AA. Bone marrow uptake of ferumoxytol: a preliminary study in healthy human subjects. J Magn Reson Imaging 2013; 39:1401-10. [PMID: 24123697 DOI: 10.1002/jmri.24320] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 06/25/2013] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To characterize the uptake and elimination of ferumoxytol, an ultrasmall superparamagnetic iron oxide (USPIO) agent, in bone marrow of healthy human subjects. MATERIALS AND METHODS Four men and two postmenopausal women, aged 22 to 57 years, were prospectively included. Simultaneous fat, water, and T2* mapping of the proximal femora was performed at 1.5 Tesla using a three-dimensional multiple gradient echo sequence. After baseline imaging, ferumoxytol (Feraheme/Rienso) was injected intravenously at a dose of 5 mg Fe/kg body weight. Imaging was repeated at 3 days, 1 month, 3 months, and 5 months after administration. RESULTS Imaging at 3 days revealed large increases in R2* ( =1/T2*) in hematopoietic marrow and lower average responses in fatty marrow, consistent with macrophage-specific uptake. However, certain regions of the diaphysis exhibited substantial R2* enhancement despite having very high fat content. This suggests the persistence of residual marrow stroma following adipose conversion, and may reflect the ability of diaphyseal marrow to adapt dynamically to fluctuating demand for hematopoiesis. Follow-up imaging demonstrated almost complete R2* recovery within 3 months. CONCLUSION The observed R2* enhancement characteristics support applications for ferumoxytol in distinguishing normal or hypercellular marrow from neoplasms, infection and inflammation. Further studies are warranted in specific patient populations.
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Affiliation(s)
- Pippa Storey
- Department of Radiology, New York University School of Medicine, New York, New York, USA
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21
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Amin MR, Achlatis S, Lazarus CL, Branski RC, Storey P, Praminik B, Fang Y, Sodickson DK. Dynamic magnetic resonance imaging of the pharynx during deglutition. Ann Otol Rhinol Laryngol 2013; 122:145-50. [PMID: 23577565 DOI: 10.1177/000348941312200301] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVES We utilized dynamic magnetic resonance imaging to visualize the pharynx and upper esophageal segment in normal, healthy subjects. METHODS A 3-T scanner with a 4-channel head coil and a dual-channel neck coil was used to obtain high-speed magnetic resonance images of subjects who were swallowing liquids and pudding. Ninety sequential images were acquired with a temporal resolution of 113 ms. Imaging was performed in axial planes at the levels of the oropharynx and the pharyngoesophageal segment. The images were then analyzed for variables related to alterations in the area of the pharynx and pharyngoesophageal segment during swallowing, as well as temporal measures related to these structures. RESULTS All subjects tolerated the study protocol without complaint. Changes in the area of the pharyngeal wall lumen and temporal measurements were consistent within and between subjects. The inter-rater and intra-rater reliabilities for the measurement tool were excellent. CONCLUSIONS Dynamic magnetic resonance imaging of the swallow sequence is both feasible and reliable and may eventually complement currently used diagnostic methods, as it adds substantive information.
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Affiliation(s)
- Milan R Amin
- New York University Voice Center, Department of Otolaryngology-Head and Neck Surgery, New York University School of Medicine, New York, NY 10016, USA
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Gyftopoulos S, Yemin A, Mulholland T, Bloom M, Storey P, Geppert C, Recht MP. 3DMR osseous reconstructions of the shoulder using a gradient-echo based two-point Dixon reconstruction: a feasibility study. Skeletal Radiol 2013; 42:347-52. [PMID: 22829026 DOI: 10.1007/s00256-012-1489-z] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 06/29/2012] [Accepted: 07/02/2012] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To create 3DMR osseous models of the shoulder similar to 3DCT models using a gradient-echo-based two-point/Dixon sequence. MATERIALS AND METHODS CT and 3TMR examinations of 7 cadaveric shoulders were obtained. Glenoid defects were created in 4 of the cadaveric shoulders. Each MR study included an axial Dixon 3D-dual-echo-time T1W-FLASH (acquisition time of 3 min/30 s). The water-only image data from the Dixon sequence and CT data were post-processed using 3D software. The following measurements were obtained on the shoulders: surface area (SA), height/width of the glenoid and humeral head, and width of the biceps groove. The glenoid defects were measured on imaging and compared with measurements made on en face digital photographs of the glenoid fossae (reference standard). Paired t tests/ANOVA were used to assess the differences between the imaging modalities. RESULTS The differences between the glenoid and humeral measurements were not statistically significant (cm): glenoid SA 0.12 ± 0.04 (p = 0.45) and glenoid width 0.13 ± 0.06 (p = 0.06) with no difference in glenoid height measurement; humeral head SA 0.07 ± 0.12 (p = 0.42), humeral head height 0.03 ± 0.06 (p = 0.42), humeral head width 0.07 ± 0.06(p = 0.18), and biceps groove width 0.02 ± 0.01 (p = 0.07). The mean/standard deviation difference between the reference standard and 3DMR measurements was 0.25 ± 0.96 %/0.30 ± 0.14 mm; 3DCT 0.25 ± 0.96 /0.75 ± 0.39 mm. There was no statistical difference between the measurements obtained on 3DMR and 3DCT (percentage, p = 0.45; mm, p = 0.20). CONCLUSION Accurate 3D osseous models of the shoulder can be produced using a 3D two-point/Dixon sequence and can be added to MR examinations with a minor increase in imaging time, used to quantify glenoid loss, and may eliminate the need for pre-surgical CT examinations.
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Atanasova IP, Kim D, Storey P, Rosenkrantz AB, Lim RP, Lee VS. Sagittal fresh blood imaging with interleaved acquisition of systolic and diastolic data for improved robustness to motion. Magn Reson Med 2013; 69:321-8. [PMID: 23300129 DOI: 10.1002/mrm.24576] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 11/07/2012] [Accepted: 11/08/2012] [Indexed: 11/08/2022]
Abstract
PURPOSE To improve robustness to patient motion of "fresh blood imaging" (FBI) for lower extremity noncontrast MR angiography. METHODS In FBI, two sets of three-dimensional fast spin echo images are acquired at different cardiac phases and subtracted to generate bright-blood angiograms. Routinely performed with a single coronal slab and sequential acquisition of systolic and diastolic data, FBI is prone to subtraction errors due to patient motion. In this preliminary feasibility study, FBI was implemented with two sagittal imaging slabs, and the systolic and diastolic acquisitions were interleaved to minimize sensitivity to motion. The proposed technique was evaluated in volunteers and patients. RESULTS In 10 volunteers, imaged while performing controlled movements, interleaved FBI demonstrated better tolerance to subject motion than sequential FBI. In one patient with peripheral arterial disease, interleaved FBI offered better depiction of collateral flow by reducing sensitivity to inadvertent motion. CONCLUSIONS FBI with interleaved acquisition of diastolic and systolic data in two sagittal imaging slabs offers improved tolerance to patient motion.
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Affiliation(s)
- Iliyana P Atanasova
- Department of Radiology, Center for Biomedical Imaging, New York University School of Medicine, New York, New York 10016, USA.
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Lim RP, Fan Z, Chatterji M, Baadh A, Atanasova IP, Storey P, Kim DC, Kim S, Hodnett PA, Ahmad A, Stoffel DR, Babb JS, Adelman MA, Xu J, Li D, Lee VS. Comparison of nonenhanced MR angiographic subtraction techniques for infragenual arteries at 1.5 T: a preliminary study. Radiology 2013; 267:293-304. [PMID: 23297320 DOI: 10.1148/radiol.12120859] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To evaluate diagnostic performance of three nonenhanced methods: variable-refocusing-flip angle (FA) fast spin-echo (SE)-based magnetic resonance (MR) angiography (variable FA MR) and constant-refocusing-FA fast SE-based MR angiography (constant-FA MR) and flow-sensitive dephasing (FSD)-prepared steady-state free precession MR angiography (FSD MR) for calf arteries, with dual-injection three-station contrast material-enhanced MR angiography (gadolinium-enhanced MR) as reference. MATERIALS AND METHODS This prospective study was institutional review board approved and HIPAA compliant, with informed consent. Twenty-one patients (13 men, eight women; mean age, 62.6 years) underwent calf-station variable-FA MR, constant-FA MR, and FSD MR at 1.5 T, with gadolinium-enhanced MR as reference. Image quality and stenosis severity were assessed in 13 segments per leg by two radiologists blinded to clinical data. Combined constant-FA MR and FSD MR reading was also performed. Methods were compared (logistic regression for correlated data) for diagnostic accuracy. RESULTS Of 546 arterial segments, 148 (27.1%) had a hemodynamically significant (≥ 50%) stenosis. Image quality was satisfactory for all nonenhanced MR sequences. FSD MR was significantly superior to both other sequences (P < .0001), with 5-cm smaller field of view; 9.6% variable-FA MR, 9.6% constant-FA MR, and 0% FSD MR segmental evaluations had nondiagnostic image quality scores, mainly from high diastolic flow (variable-FA MR) and motion artifact (constant-FA MR). Stenosis sensitivity and specificity were highest for FSD MR (80.3% and 81.7%, respectively), compared with those for constant-FA MR (72.3%, P = .086; and 81.8%, P = .96) and variable-FA MR (75.9%, P = .54; and 75.6%, P = .22). Combined constant-FA MR and FSD MR had superior sensitivity (81.8%) and specificity (88.3%) compared with constant-FA MR (P = .0076), variable-FA MR (P = .0044), and FSD MR (P = .0013). All sequences had an excellent negative predictive value (NPV): 93.2%, constant-FA MR; 94.7%, variable-FA MR; 91.7%, FSD MR; and 92.9%, combined constant-FA MR and FSD MR. CONCLUSION At 1.5 T, all evaluated nonenhanced MR angiographic methods demonstrated satisfactory image quality and excellent NPV for hemodynamically significant stenosis. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120859/-/DC1.
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Affiliation(s)
- Ruth P Lim
- Department of Radiology, New York University Medical Center, New York, NY, USA.
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Lim RP, Winchester PA, Bruno MT, Xu J, Storey P, McGorty KA, Sodickson DK, Srichai MB. Highly accelerated single breath-hold non-contrast thoracic MRA: evaluation in a clinical population. J Cardiovasc Magn Reson 2013. [PMCID: PMC3559363 DOI: 10.1186/1532-429x-15-s1-e84] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Sigmund EE, Vivier PH, Sui D, Lamparello NA, Tantillo K, Mikheev A, Rusinek H, Babb JS, Storey P, Lee VS, Chandarana H. Intravoxel incoherent motion and diffusion-tensor imaging in renal tissue under hydration and furosemide flow challenges. Radiology 2012; 263:758-69. [PMID: 22523327 DOI: 10.1148/radiol.12111327] [Citation(s) in RCA: 167] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE To assess the reproducibility and the distribution of intravoxel incoherent motion (IVIM) and diffusion-tensor (DT) imaging parameters in healthy renal cortex and medulla at baseline and after hydration or furosemide challenges. MATERIALS AND METHODS Using an institutional review board-approved HIPAA-compliant protocol with written informed consent, IVIM and DT imaging were performed at 3 T in 10 volunteers before and after water loading or furosemide administration. IVIM (apparent diffusion coefficient [ADC], tissue diffusivity [D(t)], perfusion fraction [f(p)], pseudodiffusivity [D(p)]) and DT (mean diffusivity [MD], fractional anisotropy [FA], eigenvalues [λ(i)]) imaging parameters and urine output from serial bladder volumes were calculated. (a)Reproducibility was quantified with coefficient of variation, intraclass correlation coefficient, and Bland-Altman limits of agreement; (b) contrast and challenge response were quantified with analysis of variance; and (c) Pearson correlations were quantified with urine output. RESULTS Good reproducibility was found for ADC, D(t), MD, FA, and λ(i) (average coefficient of variation, 3.7% [cortex] and 5.0% [medulla]), and moderate reproducibility was found for D(p), f(p), and f(p) · D(p) (average coefficient of variation, 18.7% [cortex] and 25.9% [medulla]). Baseline cortical diffusivities significantly exceeded medullary values except D(p), for which medullary values significantly exceeded cortical values, and λ(1,) which showed no contrast. ADC, D(t), MD, and λ(i) increased significantly for both challenges. Medullary diffusivity increases were dominated by transverse diffusion (1.72 ± 0.09 [baseline] to 1.79 ± 0.10 [hydration] μm(2)/msec, P = .0059; or 1.86 ± 0.07 [furosemide] μm(2)/msec, P = .0094). Urine output correlated with cortical ADC with furosemide (r = 0.7, P = .034) and with medullary λ(1) (r = 0.83, P = .0418), λ(2) (r = 0.85, P = .0301), and MD (r = 0.82, P = .045) with hydration. CONCLUSION Diffusion MR metrics are sensitive to flow changes in kidney induced by diuretic challenges. The results of this study suggest that vascular flow, tubular dilation, water reabsorption, and intratubular flow all play important roles in diffusion-weighted imaging contrast.
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Affiliation(s)
- Eric E Sigmund
- Department of Radiology, NYU Langone Medical Center, 660 First Ave, 4th Floor, New York, NY 10016, USA.
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Rosenkrantz AB, Storey P, Gilet AG, Niver BE, Babb JS, Hajdu CH, Lee VS. Magnetization Transfer Contrast–prepared MR Imaging of the Liver: Inability to Distinguish Healthy from Cirrhotic Liver. Radiology 2012; 262:136-43. [DOI: 10.1148/radiol.11111043] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Cho GY, Kim S, Jensen JH, Storey P, Sodickson DK, Sigmund EE. A versatile flow phantom for intravoxel incoherent motion MRI. Magn Reson Med 2011; 67:1710-20. [DOI: 10.1002/mrm.23193] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 07/18/2011] [Accepted: 08/02/2011] [Indexed: 01/22/2023]
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Raya JG, Horng A, Dietrich O, Krasnokutsky S, Beltran LS, Storey P, Reiser MF, Recht MP, Sodickson DK, Glaser C. Articular cartilage: in vivo diffusion-tensor imaging. Radiology 2011; 262:550-9. [PMID: 22106350 DOI: 10.1148/radiol.11110821] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
PURPOSE To investigate technical feasibility, test-retest reproducibility, and the ability to differentiate healthy subjects from subjects with osteoarthritis (OA) with diffusion-tensor (DT) imaging parameters and T2 relaxation time. MATERIALS AND METHODS This study was approved by the institutional review board and was HIPAA compliant. All subjects provided written informed consent. DT imaging parameters and T2 (resolution=0.6×0.6×2 mm) of patellar cartilage were measured at 7.0 T in 16 healthy volunteers and 10 patients with OA with subtle inhomogeneous signal intensity but no signs of cartilage erosion at clinical magnetic resonance (MR) imaging. Ten volunteers were imaged twice to determine test-retest reproducibility. After cartilage segmentation, maps of mean apparent diffusion coefficient (ADC), fractional anisotropy (FA), and T2 relaxation time were calculated. Differences for ADC, FA, and T2 between the healthy and OA populations were assessed with nonparametric tests. The ability of each MR imaging parameter to help discriminate healthy subjects from subjects with OA was assessed by using receiver operating characteristic curve analysis. RESULTS Test-retest reproducibility was better than 10% for mean ADC (8.1%), FA (9.7%), and T2 (5.9%). Mean ADC and FA differed significantly (P<.01) between the OA and healthy populations, but T2 did not. For ADC, the optimal threshold to differentiate both populations was 1.2×10(-3) mm2/sec, achieving specificity of 1.0 (16 of 16) and sensitivity of 0.80 (eight of 10). For FA, the optimal threshold was 0.25, yielding specificity of 0.88 (14 of 16) and sensitivity of 0.80 (eight of 10). T2 showed poor differentiation between groups (optimal threshold=22.9 msec, specificity=0.69 [11 of 16], sensitivity=0.60 [six of 10]). CONCLUSION In vivo DT imaging of patellar cartilage is feasible, has good test-retest reproducibility, and may be accurate in discriminating healthy subjects from subjects with OA. ADC and FA are two promising biomarkers for early OA.
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Affiliation(s)
- José G Raya
- Department of Radiology, New York University Langone Medical Center, 660 First Ave, 4th Floor, New York, NY 10016, USA.
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Wu Y, Du H, Storey P, Glielmi C, Malone F, Sidharthan S, Ragin A, Tofts PS, Edelman RR. Comprehensive brain analysis with automated high-resolution magnetization transfer measurements. J Magn Reson Imaging 2011; 35:309-17. [PMID: 21990125 DOI: 10.1002/jmri.22835] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 09/14/2011] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To enhance the reliability and spatial resolution of magnetization transfer ratio (MTR) measurements for interrogation of subcortical brain regions with an automated volume of interest (VOI) approach. MATERIALS AND METHODS A 3D magnetization transfer (MT) sequence was acquired using a scan-rescan imaging protocol in nine healthy volunteers. VOI definition masks for the MTR measurements were generated using FreeSurfer and compared to a manual region of interest (ROI) approach. (The longitudinal stability of MTR was monitored using agar gel phantom over a 5-month period.) Intraclass correlation coefficients (ICCs), coefficients of variation (CVs), and instrumental standard deviation (ISD) were determined. RESULTS CVs ranged from 1.29%-2.64% (automated) vs. 1.30%-3.40% (manual). ISDs ranged from 0.62-1.10 pu (automated) vs. 0.68-1.67 pu (manual). The SD of the running difference was 1.70% for the phantom scans. The Bland-Altman method indicated interchangeability of the automated VOI and manual ROI measurements. CONCLUSION The automated VOI approach for MTR measurement yielded higher ICCs, lower CVs, and lower ISDs compared to the manual method, supporting the utility of this strategy. These results demonstrate the feasibility of obtaining reliable MTR measurements in hippocampus and other critical subcortical regions.
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Affiliation(s)
- Ying Wu
- Radiology, NorthShore University HealthSystem, Evanston, Illinois 60201, USA.
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Atanasova IP, Kim D, Lim RP, Storey P, Kim S, Guo H, Lee VS. Noncontrast MR angiography for comprehensive assessment of abdominopelvic arteries using quadruple inversion-recovery preconditioning and 3D balanced steady-state free precession imaging. J Magn Reson Imaging 2011; 33:1430-9. [PMID: 21591013 DOI: 10.1002/jmri.22564] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [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: 11/07/2022] Open
Abstract
PURPOSE To develop a noncontrast magnetic resonance angiography (MRA) method for comprehensive evaluation of abdominopelvic arteries in a single 3D acquisition. MATERIALS AND METHODS A noncontrast MRA (NC MRA) pulse sequence was developed using four inversion-recovery (IR) pulses and 3D balanced steady-state free precession (b-SSFP) readout to provide arterial imaging from renal to external iliac arteries. Respiratory triggered, high spatial resolution (1.3 × 1.3 × 1.7 mm(3)) noncontrast angiograms were obtained in seven volunteers and ten patients referred for gadolinium-enhanced MRA (CE MRA). Images were assessed for diagnostic quality by two radiologists. Quantitative measurements of arterial signal contrast were also performed. RESULTS NC MRA imaging was successfully completed in all subjects in 7.0 ± 2.3 minutes. In controls, image quality of NC MRA averaged 2.79 ± 0.39 on a scale of 0-3, where 3 is maximum. Image quality of NC MRA (2.65 ± 0.41) was comparable to that of CE MRA (2.9 ± 0.32) in all patients. Contrast ratio measurements in patients demonstrated that NC MRA provides arterial contrast comparable to source CE MRA images with adequate venous and excellent background tissue suppression. CONCLUSION The proposed noncontrast MRA pulse sequence provides high-quality visualization of abdominopelvic arteries within clinically feasible scan times.
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Affiliation(s)
- Iliyana P Atanasova
- Department of Radiology, Center for Biomedical Imaging, New York University School of Medicine, New York, New York 10016, USA.
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Storey P, Ji L, Li LP, Prasad PV. Sensitivity of USPIO-enhanced R2 imaging to dynamic blood volume changes in the rat kidney. J Magn Reson Imaging 2011; 33:1091-9. [PMID: 21509866 DOI: 10.1002/jmri.22526] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To determine whether MRI in combination with an intravascular contrast agent is sensitive to pharmacologically induced vasodilation and vasoconstriction in the rat kidney. MATERIALS AND METHODS R(2) imaging was performed in 25 Sprague Dawley rats at 3 Tesla in the presence of ferumoxytol, an ultrasmall superparamagnetic iron oxide (USPIO) agent with a long plasma half-life. R(2) changes were measured following manipulation of blood volume by intravenous administration of adenosine, a short-acting vasodilator, or N(G)-nitro-L-arginine methyl ester (L-NAME), a long-acting nitric oxide synthase inhibitor with known vasoconstrictive effects. As a control, R(2) responses to adenosine and L-NAME were also examined in the absence of ferumoxytol. RESULTS In the presence of ferumoxytol, adenosine induced a significant increase in R(2), while L-NAME produced a reduction, although the latter was not statistically significant. Control experiments revealed small R(2) changes in the absence of ferumoxytol. An incidental finding was that the cross-sectional area of the kidney also varied dynamically with adenosine and L-NAME. CONCLUSION Our results suggest that ferumoxytol-enhanced R(2) imaging is sensitive to adenosine-induced vasodilation. The responses to L-NAME, however, were not statistically significant. The variations in kidney size and the R(2) changes in the absence of ferumoxytol may reflect alterations in the volume of the renal tubules.
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Affiliation(s)
- Pippa Storey
- Radiology Department, Evanston Hospital, Evanston, Illinois, USA.
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Storey P, Lim RP, Kim S, Stoffel DR, Lee VS. Arterial flow characteristics in the presence of vascular disease and implications for fast spin echo-based noncontrast MR angiography. J Magn Reson Imaging 2011; 34:1472-9. [PMID: 21959828 DOI: 10.1002/jmri.22812] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 08/12/2011] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To investigate arterial flow characteristics in the setting of vascular disease, and examine their effect on the performance of fast spin-echo (FSE)-based noncontrast MR angiography (NC-MRA). MATERIALS AND METHODS Seventeen patients were recruited from among those scheduled for routine contrast-enhanced MR angiography (CE-MRA) of the lower extremities at 1.5 Tesla. The research portion of the exam was performed before the clinically-indicated protocol and included phase-contrast imaging at multiple levels in the legs and FSE-based NC-MRA in the calf and thigh, using a three-dimensional ECG-gated technique that exploits differences in arterial flow velocity between diastole and systole. RESULTS Vascular occlusions were associated with reduced systolic velocity, a delayed systolic peak, and, in two middle-aged patients, an increase in diastolic velocity. Elevated systolic and diastolic velocities were observed in a subject with a nonhealing ulcer. NC-MRA allowed visualization of arteries with systolic velocities as low as 3 cm/s, and exhibited comparable depiction to CE-MRA for diastolic velocities as high as 6 cm/s. At the highest diastolic velocities observed (15 cm/s) arterial depiction was severely degraded. CONCLUSION FSE-based NC-MRA as presently implemented performs successfully over a wide range of flow patterns, but does not accommodate extremely low systolic velocities or very high diastolic velocities.
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Affiliation(s)
- Pippa Storey
- Radiology Department, New York University School of Medicine, New York, USA.
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Storey P, Otazo R, Lim RP, Kim S, Fleysher L, Oesingmann N, Lee VS, Sodickson DK. Exploiting sparsity to accelerate noncontrast MR angiography in the context of parallel imaging. Magn Reson Med 2011; 67:1391-400. [PMID: 22081482 DOI: 10.1002/mrm.23132] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Revised: 06/16/2011] [Accepted: 07/11/2011] [Indexed: 11/09/2022]
Abstract
Noncontrast techniques for peripheral MR angiography are receiving renewed interest because of safety concerns about the use of gadolinium in patients with renal insufficiency. One class of techniques involves subtraction of dark-blood images acquired during fast systolic flow from bright-blood images obtained during slow diastolic flow. The goal of this work was to determine whether the inherent sparsity of the difference images could be exploited to achieve greater acceleration without loss of image quality in the context of generalized autocalibrating partially parallel acquisition (GRAPPA). It is shown that noise amplification at high acceleration factors can be reduced by performing subtraction on the raw data, before calculation of the GRAPPA weights, rather than on the final magnitude images. Use of the difference data to calculate the GRAPPA weights decreases the geometry factor (g-factor), because the difference data represent a sparse image set. This demonstrates an inherent property of GRAPPA and does not require the use of compressed sensing. Application of this approach to highly accelerated data from healthy volunteers resulted in similar depiction of large arteries to that obtained with low acceleration and standard reconstruction. However, visualization of very small vessels and arterial branches was compromised.
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Affiliation(s)
- Pippa Storey
- Department of Radiology, New York University School of Medicine, New York, New York 10016, USA.
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Zhang JL, Sigmund EE, Rusinek H, Chandarana H, Storey P, Chen Q, Lee VS. Optimization of b-value sampling for diffusion-weighted imaging of the kidney. Magn Reson Med 2011; 67:89-97. [PMID: 21702062 DOI: 10.1002/mrm.22982] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 04/05/2011] [Indexed: 12/20/2022]
Abstract
Diffusion-weighted imaging (DWI) involves data acquisitions at multiple b values. In this paper, we presented a method of selecting the b values that maximize estimation precision of the biexponential analysis of renal DWI data. We developed an error propagation factor for the biexponential model, and proposed to optimize the b-value samplings by minimizing the error propagation factor. A prospective study of four healthy human subjects (eight kidneys) was done to verify the feasibility of the proposed protocol and to assess the validity of predicted precision for DWI measures, followed by Monte Carlo simulations of DWI signals based on acquired data from renal lesions of 16 subjects. In healthy subjects, the proposed methods improved precision (P = 0.003) and accuracy (P < 0.001) significantly in region-of-interest based biexponential analysis. In Monte Carlo simulation of renal lesions, the b-sampling optimization lowered estimation error by at least 20-30% compared with uniformly distributed b values, and improved the differentiation between malignant and benign lesions significantly. In conclusion, the proposed method has the potential of maximizing the precision and accuracy of the biexponential analysis of renal DWI.
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Affiliation(s)
- Jeff L Zhang
- Department of Radiology, New York University, New York, New York, USA.
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Vivier PH, Storey P, Rusinek H, Zhang JL, Yamamoto A, Tantillo K, Khan U, Lim RP, Babb JS, John D, Teperman LW, Chandarana H, Friedman K, Benstein JA, Skolnik EY, Lee VS. Kidney function: glomerular filtration rate measurement with MR renography in patients with cirrhosis. Radiology 2011; 259:462-70. [PMID: 21386050 DOI: 10.1148/radiol.11101338] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
PURPOSE To assess the accuracy of glomerular filtration rate (GFR) measurements obtained with low-contrast agent dose dynamic contrast material-enhanced magnetic resonance (MR) renography in patients with liver cirrhosis who underwent routine liver MR imaging, with urinary clearance of technetium 99m ((99m)Tc) pentetic acid (DTPA) as the reference standard. MATERIALS AND METHODS This HIPAA-compliant study was institutional review board approved. Written informed patient consent was obtained. Twenty patients with cirrhosis (14 men, six women; age range, 41-70 years; mean age, 54.6 years) who were scheduled for routine 1.5-T liver MR examinations to screen for hepatocellular carcinoma during a 6-month period were prospectively included. Five-minute MR renography with a 3-mL dose of gadoteridol was performed instead of a routine test-dose timing examination. The GFR was estimated at MR imaging with use of two kinetic models. In one model, only the signal intensities in the aorta and kidney parenchyma were considered, and in the other, renal cortical and medullary signal intensities were treated separately. The GFR was also calculated by using serum creatinine levels according to the Cockcroft-Gault and modification of diet in renal disease (MDRD) formulas. All patients underwent a (99m)Tc-DTPA urinary clearance examination on the same day to obtain a reference GFR measurement. The accuracies of all MR- and creatinine-based GFR estimations were compared by using Wilcoxon signed rank tests. RESULTS The mean reference GFR, based on (99m)Tc-DTPA clearance, was 74.9 mL/min/1.73 m(2) ± 27.7 (standard deviation) (range, 10.3-120.7 mL/min/1.73 m(2)). With both kinetic models, 95% of MR-based GFRs were within 30% of the reference values, whereas only 40% and 60% of Cockcroft-Gault- and MDRD-based GFRs, respectively, were within this range. MR-based GFR estimates were significantly more accurate than creatinine level-based estimates (P < .001). CONCLUSION GFR assessment with MR imaging, which outperformed the Cockcroft-Gault and MDRD formulas, adds less than 10 minutes of table time to a clinically indicated liver MR examination without ionizing radiation. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11101338/-/DC1.
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Storey P, Atanasova IP, Lim RP, Xu J, Kim D, Chen Q, Lee VS. Tailoring the flow sensitivity of fast spin-echo sequences for noncontrast peripheral MR angiography. Magn Reson Med 2011; 64:1098-108. [PMID: 20725934 DOI: 10.1002/mrm.22510] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
There has recently been renewed interest in noncontrast techniques for peripheral MR angiography following the discovery of an association between gadolinium-based contrast agents and nephrogenic systemic fibrosis in patients with renal insufficiency. The "fresh blood imaging" technique proposed by Miyazaki et al. involves the subtraction of two three-dimensional fast spin-echo image sets, one acquired in systole, when the arteries appear dark due to flow-related dephasing, and the other obtained in diastole, when the arteries are brighter. Our goal was to investigate how parameters of the fast spin-echo sequence influence its flow sensitivity, and how that in turn impacts the depiction of large and small arteries. Results from phantom experiments and human studies in the calf suggest that the flow sensitivity is governed largely by the flip angle of the radiofrequency refocusing pulses. The area of the spoiler gradients has a lesser effect, and at low flip angles the echo time plays a role. These parameters can be optimized to obtain good depiction of the calf arteries in healthy subjects. It remains to be seen whether they provide sufficient control over flow sensitivity to achieve diagnostic-quality images in other vascular beds and in the presence of pathology.
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Affiliation(s)
- Pippa Storey
- Radiology Department, New York University School of Medicine, New York, New York, USA.
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Fernandes JL, Storey P, da Silva JA, de Figueiredo GS, Kalaf JM, Coelho OR. Preliminary assessment of cardiac short term safety and efficacy of manganese chloride for cardiovascular magnetic resonance in humans. J Cardiovasc Magn Reson 2011; 13:6. [PMID: 21235750 PMCID: PMC3032736 DOI: 10.1186/1532-429x-13-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Accepted: 01/14/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Manganese based agents are intracellular and accumulate inside myocytes allowing for different imaging strategies compared to gadolinium contrasts. While previous agents release manganese very slowly in the circulation, MnCl2 allows for rapid Mn2+ uptake in myocytes, creating a memory effect that can be potentially explored. Data on animal models are very encouraging but the safety and efficacy of this approach in humans has not yet been investigated. Therefore, our objectives were to study the safety and efficacy of a rapid infusion of manganese chloride (MnCl2) for cardiovascular magnetic resonance (CMR) in humans. METHODS Fifteen healthy volunteers underwent a CMR scan on a 1.5 T scanner. Before the infusion, cardiac function was calculated and images of a short axis mid-ventricular slice were obtained using a 2D and 3D gradient-echo inversion recovery (GRE-IR) sequence, a phase-sensitive IR sequence and a single breath-hold segmented IR prepared steady-state precession acquisition for T1 calculations. MnCl2 was infused over three minutes at a total dose of 5 μMol/kg. Immediately after the infusion, and at 15 and 30 minutes later, new images were obtained and cardiac function re-evaluated. RESULTS There was a significant decrease in T1 values compared to baseline, sustained up to 30 minutes after the MnCl2 infusion (pre,839 ± 281 ms; 0 min, 684 ± 99; 15 min, 714 ± 168; 30 min, 706 ± 172, P = 0.003). The 2D and 3D GRE-IR sequence showed the greatest increase in signal-to-noise ratio compared to the other sequences (baseline 6.6 ± 4.2 and 9.7 ± 5.3; 0 min, 11.3 ± 4.1 and 15.0 ± 8.7; 15 min, 10.8 ± 4.0 and 16.9 ± 10.2; 30 min, 10.6 ± 5.2 and 16.5 ± 8.3, P < 0.001 for both). There was a slight increase in systolic pressure and heart rate after three and four minutes of the infusion with normalization of these parameters thereafter. Patients showed good tolerance to MnCl2 with no major adverse events, despite all reporting transient facial flush. CONCLUSIONS In the short term, MnCl2 appears safe for human use. It effectively decreases myocardium T1, maintaining this effect for a relatively long period of time and allowing for the development of new imaging strategies in CMR, especially in ischemia research.
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Affiliation(s)
- Juliano L Fernandes
- Department of Internal Medicine - University of Campinas - Unicamp - R. Antonio Lapa 1032 - Campinas - Brazil
| | - Pippa Storey
- Center for Biomedical Imaging - New York University - 660 First Avenue 4th floor - New York - USA
| | - Jose Alvaro da Silva
- Department of Radiology - Radiologia Clinica de Campinas - Av Jose de Souza Campos 870 - Campinas - Brazil
| | - Gabriel S de Figueiredo
- Department of Radiology - Radiologia Clinica de Campinas - Av Jose de Souza Campos 870 - Campinas - Brazil
| | - Jose M Kalaf
- Department of Radiology - Radiologia Clinica de Campinas - Av Jose de Souza Campos 870 - Campinas - Brazil
| | - Otavio R Coelho
- Department of Internal Medicine - University of Campinas - Unicamp - R. Antonio Lapa 1032 - Campinas - Brazil
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Zhang JL, Rusinek H, Bokacheva L, Chen Q, Storey P, Lee VS. Use of cardiac output to improve measurement of input function in quantitative dynamic contrast-enhanced MRI. J Magn Reson Imaging 2009; 30:656-65. [PMID: 19711414 DOI: 10.1002/jmri.21891] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
PURPOSE To validate a new method for converting MR arterial signal intensity versus time curves to arterial input functions (AIFs). MATERIALS AND METHODS The method constrains AIF with patient's cardiac output (Q). Monte Carlo simulations of MR renography and tumor perfusion protocols were carried out for comparison with two alternative methods: direct measurement and population-averaged input function. MR renography was performed to assess the method's inter- and intraday reproducibility for renal parameters. RESULTS In simulations of tumor perfusion, the precision of the parameters (K(trans) and v(e)) computed using the proposed method was improved by at least a factor of three compared to direct measurement. Similar improvements were obtained in simulations of MR renography. Volunteer study for testing interday reproducibility confirmed the improvement of precision in renal parameters when using the proposed method compared to conventional methods. In another patient study (two injections within one session), the proposed method significantly increased the correlation coefficient (R) between GFR of the two exams (0.92 vs. 0.83) compared to direct measurement. CONCLUSION A new method significantly improves the precision of dynamic contrast-enhanced (DCE) parameters. The method may be especially useful for analyzing repeated DCE examinations, such as monitoring tumor therapy or angiotensin converting enzyme-inhibitor renography.
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Affiliation(s)
- Jeff L Zhang
- Department of Radiology, New York University School of Medicine, New York, NY, USA.
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Abstract
Echo-planar imaging (EPI) -based diffusion tensor imaging (DTI) is particularly prone to spike noise. However, existing spike noise correction methods are impractical for corrupted DTI data because the methods correct the complex MRI signal, which is not usually stored on clinical MRI systems. The present work describes a novel Outlier Detection De-spiking technique (ODD) that consists of three steps: detection, localization, and correction. Using automated outlier detection schemes, ODD exploits the data redundancy available in DTI data sets that are acquired with a minimum of six different diffusion-weighted images (DWIs) with similar signal and noise properties. A mathematical formulation, describing the effects of spike noise on magnitude images, yields appropriate measures for an outlier detection scheme used for spike detection while a normalization-dependent outlier detection scheme is used for spike localization. ODD performs accurately on diverse DTI data sets corrupted by spike noise and can be used for automated control of DTI data quality. ODD can also be extended to other MRI applications with data redundancy, such as dynamic imaging and functional MRI.
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Affiliation(s)
- S Chavez
- Imaging Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
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Lim RP, Storey P, Atanasova IP, Xu J, Hecht EM, Babb JS, Stoffel DR, Chang H, McGorty K, Chen Q, Rusinek H, Belmont HM, Lee VS. Three-dimensional electrocardiographically gated variable flip angle FSE imaging for MR angiography of the hands at 3.0 T: initial experience. Radiology 2009; 252:874-81. [PMID: 19567653 DOI: 10.1148/radiol.2531090290] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
After institutional review board approval and informed consent were obtained for this HIPAA-compliant investigation, a three-dimensional electrocardiographically gated variable flip angle (VFA) fast spin-echo magnetic resonance (MR) angiography technique was evaluated as an unenhanced method for imaging hand arteries in 13 subjects (including four patients) at 3.0 T; this included evaluation of vessel visualization with warming and cooling in seven subjects. Examinations were evaluated for image quality and vessel conspicuity. Clear separation of arteries from veins was achieved in all subjects, with excellent vessel conspicuity and depiction of stenoses. Warming improved vessel visualization in healthy volunteers. VFA MR angiography is a high-spatial-resolution technique that enables the assessment of vascular reactivity in response to temperature challenge.
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Affiliation(s)
- Ruth P Lim
- Department of Radiology, New York University Langone Medical Center, 530 First Ave, Basement Schwartz Bldg, New York, NY 10016, USA.
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Zhang JL, Rusinek H, Bokacheva L, Lim RP, Chen Q, Storey P, Prince K, Hecht EM, Kim DC, Lee VS. Angiotensin-converting enzyme inhibitor-enhanced MR renography: repeated measures of GFR and RPF in hypertensive patients. Am J Physiol Renal Physiol 2009; 296:F884-91. [PMID: 19158343 DOI: 10.1152/ajprenal.90648.2008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study aims to assess the feasibility of a protocol to diagnose renovascular disease using dual MR renography acquisitions: before and after administration of angiotensin-converting enzyme inhibitor (ACEi). Results of our simulation study aimed at testing the reproducibility of glomerular filtration rate (GFR) and renal plasma flow demonstrate that for a fixed overall dose of 12 ml gadolinium-based contrast material (500 mmol/l), the second dose should be approximately twice as large as the first dose. A three-compartment model for analyzing the second-injection data was shown to appropriately handle the tracer residue from the first injection. The optimized protocol was applied to 18 hypertensive patients without renovascular disease, showing minimal systematic difference in GFR measurements before and after ACEi of 0.8 +/- 4.4 ml/min or 2.7 +/- 14.9%. For 10 kidneys with significant renal artery stenosis, GFR decreased significantly after ACEi (P < 0.001, T value = 3.79), and the difference in GFR measurements before and after ACEi averaged 8.3 +/- 6.9 ml/min or 26.2 +/- 43.9%. Dual-injection MRI with optimized dose distribution appears promising for ACEi renography by offering measures of GFR changes with clinically acceptable precision and accuracy.
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Affiliation(s)
- Jeff L Zhang
- Dept. of Radiology, New York Univ. School of Medicine, 660 First Ave., 4th Floor, New York, NY 10016, USA.
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Fernandes JL, Storey P, da Silva AA, de Figueiredo GS, Kalaf JM, Coelho OR. 1073 Short term safety and efficacy of manganese chloride cardiovascular magnetic resonance imaging in humans. J Cardiovasc Magn Reson 2008. [DOI: 10.1186/1532-429x-10-s1-a198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Abstract
We describe a novel physical basis and methodology for gadolinium (Gd)-enhanced MRA, which we call "off-resonance contrast angiography" (ORCA). Unlike standard contrast-enhanced (CE) MR angiography (MRA), ORCA contrast depends not on T(1) but on Gd-induced shifts in intravascular resonance frequency due to the bulk magnetic susceptibility (BMS) effects of Gd. The method was tested at 3 Tesla in phantoms with a range of dilutions of Gd-DTPA and ultrasmall iron oxide contrast agent (CA). With the use of ORCA, complete background suppression was obtained without image subtraction. As a result, catheters filled with various Gd dilutions proved to be highly conspicuous in ORCA projection images. This feature may make ORCA particularly attractive for passive catheter tracking during MR-guided endovascular procedures. Gd-induced intravascular frequency shifts were measured in human subjects and found to be in the expected range. ORCA was used to create angiograms of forearm veins that were comparable in quality to standard CE-MRA. In addition, ORCA images of the extracranial carotid bifurcation were successfully acquired during intravenous contrast administration. However, significant technical restrictions also exist, including a dependence on vessel orientation with respect to B(0), and sensitivity to static field inhomogeneities. Further study is needed to determine the practicality and potential clinical utility of this method.
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Affiliation(s)
- Robert R Edelman
- Department of Radiology, Evanston Northwestern Healthcare and Northwestern University School of Medicine, Evanston, Illinois 60201, USA.
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Storey P, Frigo FJ, Hinks RS, Mock BJ, Collick BD, Baker N, Marmurek J, Graham SJ. Partial k-space reconstruction in single-shot diffusion-weighted echo-planar imaging. Magn Reson Med 2007; 57:614-9. [PMID: 17326165 DOI: 10.1002/mrm.21132] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Partial k-space sampling is frequently used in single-shot diffusion-weighted echo-planar imaging (DW-EPI) to reduce the TE and thereby improve the SNR. However, it increases the sensitivity of the technique to bulk rotational motion, which introduces a phase gradient across the tissue that shifts the echo in k-space. If the echo is displaced into the high spatial frequencies, conventional homodyne reconstruction fails, causing intensity oscillations across the image. Zero-padding, on the other hand, compromises the image resolution and may cause truncation artifacts. We present an adaptive version of the homodyne algorithm that detects the location of the echo in k-space and adjusts the center and width of the homodyne filters accordingly. The adaptive algorithm produces artifact-free images when the echo is shifted into the high positive k-space range, and reduces to the standard homodyne algorithm in the absence of bulk motion.
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Affiliation(s)
- Pippa Storey
- Radiology Department, Evanston Northwestern Healthcare, Evanston, Illinois 60201, USA.
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Wu Y, Storey P, Carrillo A, Saglamer C, Cohen BA, Epstein LG, Edelman RR, Ragin AB. Whole brain and localized magnetization transfer measurements are associated with cognitive impairment in patients infected with human immunodeficiency virus. AJNR Am J Neuroradiol 2007; 29:140-5. [PMID: 17928382 DOI: 10.3174/ajnr.a0740] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Patients infected with human immunodeficiency virus (HIV) are susceptible to cognitive deterioration. This study investigated the utility of magnetization transfer (MT) imaging for quantification of brain tissue alterations associated with cognitive deficits in patients with HIV. MATERIALS AND METHODS MT ratios (MTR) were derived for whole brain and for regions of interest (ROIs) in the basal ganglia and white matter in 11 HIV and 12 control subjects. Relationships with severity of cognitive impairment and specific neuropsychological deficits were also evaluated. RESULTS MTR values for normalized whole brain histogram peak height, whole brain histogram mean, and all examined ROIs were reduced in the HIV subjects. Normalized histogram peak height and mean for whole brain, as well as means for the corpus callosum, basal ganglia, and frontal white matter (FWM), were significantly correlated with severity of cognitive impairment. MTR values for white matter regions (corpus callosum, FWM, and centrum semiovale) were correlated with specific cognitive deficits. CONCLUSION Quantitative MTR measurements, determined for the whole brain and for vulnerable ROIs, are sensitive to neuropathologic changes associated with cognitive impairment in HIV-infected patients.
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Affiliation(s)
- Y Wu
- Department of Radiology, Evanston Northwestern Healthcare, Evanston, Ill, USA.
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Drobyshevsky A, Bregman J, Storey P, Meyer J, Prasad PV, Derrick M, MacKendrick W, Tan S. Serial diffusion tensor imaging detects white matter changes that correlate with motor outcome in premature infants. Dev Neurosci 2007; 29:289-301. [PMID: 17762197 DOI: 10.1159/000105470] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [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] [Received: 09/15/2006] [Accepted: 02/16/2007] [Indexed: 11/19/2022] Open
Abstract
The objective of the study was to assess predictive value of serial diffusion tensor MRI (DTI) for the white matter injury and neurodevelopmental outcome in a cohort of premature infants. Twenty-four infants less than 32 weeks' gestation were stratified to a control group (n = 11), mild brain injury with grades 1-2 of intraventricular hemorrhage (n = 6) and severe brain injury with grades 3-4 intraventricular hemorrhage (n = 4). Serial DTI studies were performed at around 30 and 36 weeks' gestation. Fractional anisotropy (FA) and apparent diffusion coefficient were calculated. Twelve infants were followed up for developmental outcome. Developmental testing was performed with the Bayley Scales of Infant Development to obtain psychomotor index (Performance Developmental Index). Apparent diffusion coefficient was higher in the severe injury group at the second MRI in the central and occipital white matter, and corona radiata; FA was lower in optic radiation compared to controls. Performance Developmental Index score correlated with FA on the scan taken at the 30th week and inversely with the change of FA between scans in internal capsule and occipital white matter. A low value of FA at 30 weeks and a higher change of FA predicted less favorable motor outcome at 2 years and suggests that early subtle white matter injury can be detected in premature infants even without obvious signs of injury.
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Storey P, Thompson AA, Carqueville CL, Wood JC, de Freitas RA, Rigsby CK. R2* imaging of transfusional iron burden at 3T and comparison with 1.5T. J Magn Reson Imaging 2007; 25:540-7. [PMID: 17326089 PMCID: PMC2884049 DOI: 10.1002/jmri.20816] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
PURPOSE To determine normative R2* values in the liver and heart at 3T, and establish the relationship between R2* at 3T and 1.5T over a range of tissue iron concentrations. MATERIALS AND METHODS A total of 20 healthy control subjects and 14 transfusion-dependent patients were scanned at 1.5T and 3T. At each field strength R2* imaging was performed in the liver and heart. RESULTS Normative R2* values in the liver were estimated from the control group to be 39.2 +/- 9.0 second(-1) at 1.5T and 69.1 +/- 21.9 second(-1) at 3T. Normative cardiac values were estimated as 23.4 +/- 2.2 second(-1) at 1.5T and 30.0 +/- 3.7 second(-1) at 3T. The combined R2* data from patients and control subjects exhibited a linear relationship between 3T and 1.5T. In the liver, the line of best fit to the 3T vs. 1.5T data had a slope of 2.00 +/- 0.06 and an intercept of -11 +/- 4 second(-1). In the heart, it had a slope of 1.88 +/- 0.14 and an intercept of -15 +/- 4 second(-1). CONCLUSION These preliminary data suggest that the iron-dependent component of R2* scales linearly with field strength over a wide range of tissue iron concentrations. The incidence of susceptibility artifacts may, however, also increase with field strength.
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Affiliation(s)
- Pippa Storey
- Radiology Department, Evanston Northwestern Healthcare, Evanston, Illinois 60201, USA.
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Storey P, Theron J, Maree FF, O'Neill HG. A second RGD motif in the 1D capsid protein of a SAT1 type foot-and-mouth disease virus field isolate is not essential for attachment to target cells. Virus Res 2006; 124:184-92. [PMID: 17161881 DOI: 10.1016/j.virusres.2006.11.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2006] [Revised: 11/03/2006] [Accepted: 11/08/2006] [Indexed: 11/25/2022]
Abstract
The amino acid sequence motif Arg-Gly-Asp (RGD), located in the surface-exposed betaG-betaH loop of the 1D protein of different serotypes and subtypes of foot-and-mouth disease virus (FMDV), is highly conserved and participates in binding of FMDV to susceptible cells. Previous sequence analyses of the 1D-encoding region of a FMDV serotype SAT1 field isolate from Namibia (NAM/307/98) indicated the presence of a second RGD motif upstream of the conserved betaG-betaH loop RGD. The role of these RGD sequences in virus infection was investigated by mutating the betaG-betaH loop RGD to a KGE tripeptide, using a genome-length infectious chimeric cDNA clone. Although the infectivity of the derived mutant viruses for baby hamster kidney cells (BHK-21) was lost, subsequent replacement of the KGE sequence with RGD in the mutant cDNA clone led to recovery of infectious viruses. Furthermore, viral RNA replication could be demonstrated with the genetically engineered mutant and non-mutant viruses. The presence of virus particles in the transfected cells could be also demonstrated by electron microscopy. These results demonstrate that, in contrast to the betaG-betaH loop RGD motif, the second RGD sequence in the capsid protein 1D of NAM/307/98 does not function as a ligand for receptor binding in BHK-21 cells.
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Affiliation(s)
- P Storey
- Onderstepoort Veterinary Institute, Exotic Diseases Division, Private Bag X05, Onderstepoort 0010, South Africa
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