1
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Fortier V, Levesque IR. MR-oximetry with fat DESPOT. Magn Reson Imaging 2023; 97:112-121. [PMID: 36608912 DOI: 10.1016/j.mri.2022.12.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 12/23/2022] [Accepted: 12/31/2022] [Indexed: 01/07/2023]
Abstract
PURPOSE The R1 relaxation rate of fat is a promising marker of tissue oxygenation. Existing techniques to map fat R1 in MR-oximetry offer limited spatial coverage, require long scan times, or pulse sequences that are not readily available on clinical scanners. This work addresses these limitations with a 3D voxel-wise fat R1 mapping technique for MR-oximetry based on a variable flip angle (VFA) approach at 3 T. METHODS Varying levels of dissolved oxygen (O2) were generated in a phantom consisting of vials of safflower oil emulsion, used to approximate human fat. Joint voxel-wise mapping of fat and water R1 was performed with a two-compartment VFA model fitted to multi-echo gradient-echo magnitude data acquired at four flip angles, referred to as Fat DESPOT. Global R1 was also calculated. Variations of fat, water, and global R1 were investigated as a function of the partial pressure of O2 (pO2). Inversion-prepared stimulated echo magnetic resonance spectroscopy was used as the reference technique for R1 measurements. RESULTS Fat R1 from Fat DESPOT was more sensitive than water R1 and global R1 to variations in pO2, consistent with previous studies performed with different R1 mapping techniques. Fat R1 sensitivity to pO2 variations with Fat DESPOT (median O2 relaxivity r1, O2 = 1.57× 10-3 s-1 mmHg-1) was comparable to spectroscopy-based measurements for methylene, the main fat resonance (median r1, O2= 1.80 × 10-3 s-1 mmHg-1). CONCLUSION Fat and water R1 can be measured on a voxel-wise basis using a two-component fit to multi-echo 3D VFA magnitude data in a clinically acceptable scan time. Fat and water R1 measured with Fat DESPOT were sensitive to variations in pO2. These observations suggest an approach to 3D in vivo MR oximetry.
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Affiliation(s)
- Véronique Fortier
- Medical Physics Unit, McGill University, Montréal, QC, Canada; Biomedical Engineering, McGill University, Montréal, QC, Canada; Medical Imaging, McGill University Health Centre, Montréal, QC, Canada; Department of Diagnostic Radiology, McGill University, Montréal, QC, Canada; Gerald Bronfman Department of Oncology, McGill University, Montréal, QC, Canada.
| | - Ives R Levesque
- Medical Physics Unit, McGill University, Montréal, QC, Canada; Biomedical Engineering, McGill University, Montréal, QC, Canada; Gerald Bronfman Department of Oncology, McGill University, Montréal, QC, Canada; Research Institute of the McGill University Health Centre, Montréal, QC, Canada
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2
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Gallez B. The Role of Imaging Biomarkers to Guide Pharmacological Interventions Targeting Tumor Hypoxia. Front Pharmacol 2022; 13:853568. [PMID: 35910347 PMCID: PMC9335493 DOI: 10.3389/fphar.2022.853568] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 06/23/2022] [Indexed: 12/12/2022] Open
Abstract
Hypoxia is a common feature of solid tumors that contributes to angiogenesis, invasiveness, metastasis, altered metabolism and genomic instability. As hypoxia is a major actor in tumor progression and resistance to radiotherapy, chemotherapy and immunotherapy, multiple approaches have emerged to target tumor hypoxia. It includes among others pharmacological interventions designed to alleviate tumor hypoxia at the time of radiation therapy, prodrugs that are selectively activated in hypoxic cells or inhibitors of molecular targets involved in hypoxic cell survival (i.e., hypoxia inducible factors HIFs, PI3K/AKT/mTOR pathway, unfolded protein response). While numerous strategies were successful in pre-clinical models, their translation in the clinical practice has been disappointing so far. This therapeutic failure often results from the absence of appropriate stratification of patients that could benefit from targeted interventions. Companion diagnostics may help at different levels of the research and development, and in matching a patient to a specific intervention targeting hypoxia. In this review, we discuss the relative merits of the existing hypoxia biomarkers, their current status and the challenges for their future validation as companion diagnostics adapted to the nature of the intervention.
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3
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Zalewski M, Janasik D, Kapała A, Minoshima M, Sugihara F, Raj W, Pietrasik J, Kikuchi K, Krawczyk T. Ph‐Sensitive Polymethacrylates as Potential Contrast Agents in
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F MRI. MACROMOL CHEM PHYS 2022. [DOI: 10.1002/macp.202200027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Mariusz Zalewski
- Department of Chemical Organic Technology and Petrochemistry Silesian University of Technology Krzywoustego 4 Gliwice 44–100 Poland
| | - Dawid Janasik
- Department of Chemical Organic Technology and Petrochemistry Silesian University of Technology Krzywoustego 4 Gliwice 44–100 Poland
| | - Anna Kapała
- Department of Chemical Organic Technology and Petrochemistry Silesian University of Technology Krzywoustego 4 Gliwice 44–100 Poland
| | - Masafumi Minoshima
- Graduate School of Engineering Osaka University Yamadaoka 2‐1 Suita Osaka 565–0871 Japan
| | - Fuminori Sugihara
- Immunology Frontier Research Center Osaka University Yamadaoka 3‐1 Suita Osaka 565–0871 Japan
| | - Wojciech Raj
- Institute of Polymer and Dye Technology Lodz University of Technology Stefanowskiego 16 Lodz 90–537 Poland
| | - Joanna Pietrasik
- Institute of Polymer and Dye Technology Lodz University of Technology Stefanowskiego 16 Lodz 90–537 Poland
| | - Kazuya Kikuchi
- Graduate School of Engineering Osaka University Yamadaoka 2‐1 Suita Osaka 565–0871 Japan
| | - Tomasz Krawczyk
- Department of Chemical Organic Technology and Petrochemistry Silesian University of Technology Krzywoustego 4 Gliwice 44–100 Poland
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Nanotechnology as a Versatile Tool for 19F-MRI Agent’s Formulation: A Glimpse into the Use of Perfluorinated and Fluorinated Compounds in Nanoparticles. Pharmaceutics 2022; 14:pharmaceutics14020382. [PMID: 35214114 PMCID: PMC8874484 DOI: 10.3390/pharmaceutics14020382] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 01/28/2022] [Accepted: 02/02/2022] [Indexed: 02/04/2023] Open
Abstract
Simultaneously being a non-radiative and non-invasive technique makes magnetic resonance imaging (MRI) one of the highly sought imaging techniques for the early diagnosis and treatment of diseases. Despite more than four decades of research on finding a suitable imaging agent from fluorine for clinical applications, it still lingers as a challenge to get the regulatory approval compared to its hydrogen counterpart. The pertinent hurdle is the simultaneous intrinsic hydrophobicity and lipophobicity of fluorine and its derivatives that make them insoluble in any liquids, strongly limiting their application in areas such as targeted delivery. A blossoming technique to circumvent the unfavorable physicochemical characteristics of perfluorocarbon compounds (PFCs) and guarantee a high local concentration of fluorine in the desired body part is to encapsulate them in nanosystems. In this review, we will be emphasizing different types of nanocarrier systems studied to encapsulate various PFCs and fluorinated compounds, headway to be applied as a contrast agent (CA) in fluorine-19 MRI (19F MRI). We would also scrutinize, especially from studies over the last decade, the different types of PFCs and their specific applications and limitations concerning the nanoparticle (NP) system used to encapsulate them. A critical evaluation for future opportunities would be speculated.
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5
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Chapelin F, Gedaly R, Sweeney Z, Gossett LJ. Prognostic Value of Fluorine-19 MRI Oximetry Monitoring in cancer. Mol Imaging Biol 2021; 24:208-219. [PMID: 34708396 DOI: 10.1007/s11307-021-01648-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 08/27/2021] [Accepted: 08/30/2021] [Indexed: 11/24/2022]
Abstract
Hypoxia is a key prognostic indicator in most solid tumors, as it is correlated to tumor angiogenesis, metastasis, recurrence, and response to therapy. Accurate measurement and mapping of tumor oxygenation profile and changes upon intervention could facilitate disease progression assessment and assist in treatment planning. Currently, no gold standard exists for non-invasive spatiotemporal measurement of hypoxia. Magnetic resonance imaging (MRI) represents an attractive option as it is a clinically available and non-ionizing imaging modality. Specifically, perfluorocarbon (PFC) beacons can be externally introduced into the tumor tissue and the linear dependence of their spin-lattice relaxation rate (R1) on the local partial pressure of oxygen (pO2) exploited for real-time tissue oxygenation monitoring in vivo. In this review, we will focus on early studies and recent developments of fluorine-19 MRI and spectroscopy (MRS) for evaluation of tumor oximetry and response to therapy.
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Affiliation(s)
- Fanny Chapelin
- F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, University of Kentucky, 514F RMB, 143 Graham Avenue, Lexington, KY, USA. .,Lucille Parker Markey Cancer Center, University of Kentucky, Lexington, KY, USA.
| | - Roberto Gedaly
- Lucille Parker Markey Cancer Center, University of Kentucky, Lexington, KY, USA.,Department of Surgery, Transplant Division, University of Kentucky, Lexington, KY, USA
| | - Zachary Sweeney
- College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Liza J Gossett
- F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, University of Kentucky, 514F RMB, 143 Graham Avenue, Lexington, KY, USA
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6
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Mali A, Kaijzel EL, Lamb HJ, Cruz LJ. 19F-nanoparticles: Platform for in vivo delivery of fluorinated biomaterials for 19F-MRI. J Control Release 2021; 338:870-889. [PMID: 34492234 DOI: 10.1016/j.jconrel.2021.09.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 09/01/2021] [Accepted: 09/02/2021] [Indexed: 11/19/2022]
Abstract
Fluorine-19 (19F) magnetic resonance imaging (MRI) features one of the most investigated and innovative techniques for quantitative and unambiguous cell tracking, providing information for both localization and number of cells. Because of the relative insensitivity of the MRI technique, a high number of magnetically equivalent fluorine atoms are required to gain detectable signals. However, an increased amount of 19F nuclei induces low solubility in aqueous solutions, making fluorine-based probes not suitable for in vivo imaging applications. In this context, nanoparticle-based platforms play a crucial role, since nanoparticles may carry a high payload of 19F-based contrast agents into the relevant cells or tissues, increase the imaging agents biocompatibility, and provide a highly versatile platform. In this review, we present an overview of the 19F-based nanoprobes for sensitive 19F-MRI, focusing on the main nanotechnologies employed to date, such as fluorine and theranostic nanovectors, including their design and applications.
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Affiliation(s)
- Alvja Mali
- Translational Nanobiomaterials and Imaging (TNI) Group, Department of Radiology, Leiden University Medical Center (LUMC), Albinusdreef 2, 2333 ZA Leiden, the Netherlands
| | - Eric L Kaijzel
- Translational Nanobiomaterials and Imaging (TNI) Group, Department of Radiology, Leiden University Medical Center (LUMC), Albinusdreef 2, 2333 ZA Leiden, the Netherlands
| | - Hildo J Lamb
- Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Luis J Cruz
- Translational Nanobiomaterials and Imaging (TNI) Group, Department of Radiology, Leiden University Medical Center (LUMC), Albinusdreef 2, 2333 ZA Leiden, the Netherlands.
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7
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D'Alonzo RA, Gill S, Rowshanfarzad P, Keam S, MacKinnon KM, Cook AM, Ebert MA. In vivo noninvasive preclinical tumor hypoxia imaging methods: a review. Int J Radiat Biol 2021; 97:593-631. [PMID: 33703994 DOI: 10.1080/09553002.2021.1900943] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Tumors exhibit areas of decreased oxygenation due to malformed blood vessels. This low oxygen concentration decreases the effectiveness of radiation therapy, and the resulting poor perfusion can prevent drugs from reaching areas of the tumor. Tumor hypoxia is associated with poorer prognosis and disease progression, and is therefore of interest to preclinical researchers. Although there are multiple different ways to measure tumor hypoxia and related factors, there is no standard for quantifying spatial and temporal tumor hypoxia distributions in preclinical research or in the clinic. This review compares imaging methods utilized for the purpose of assessing spatio-temporal patterns of hypoxia in the preclinical setting. Imaging methods provide varying levels of spatial and temporal resolution regarding different aspects of hypoxia, and with varying advantages and disadvantages. The choice of modality requires consideration of the specific experimental model, the nature of the required characterization and the availability of complementary modalities as well as immunohistochemistry.
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Affiliation(s)
- Rebecca A D'Alonzo
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia
| | - Suki Gill
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia.,Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, Australia
| | - Pejman Rowshanfarzad
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia
| | - Synat Keam
- School of Medicine, The University of Western Australia, Crawley, Australia
| | - Kelly M MacKinnon
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia
| | - Alistair M Cook
- School of Medicine, The University of Western Australia, Crawley, Australia
| | - Martin A Ebert
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Australia.,Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, Australia.,5D Clinics, Claremont, Australia
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8
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Lodhi T, Song YP, West C, Hoskin P, Choudhury A. Hypoxia and its Modification in Bladder Cancer: Current and Future Perspectives. Clin Oncol (R Coll Radiol) 2021; 33:376-390. [PMID: 33762140 DOI: 10.1016/j.clon.2021.03.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 03/01/2021] [Indexed: 02/06/2023]
Abstract
Radiotherapy plays an essential role in the curative treatment of muscle-invasive bladder cancer (MIBC). Hypoxia affects the response to MIBC radiotherapy, limiting radiocurability. Likewise, hypoxia influences MIBC genetic instability and malignant progression being associated with metastatic disease and a worse prognosis. Hypoxia identification in MIBC enables treatment stratification and the promise of improved survival. The most promising methods are histopathological markers such as necrosis; biomarkers of protein expression such as HIF-1α, GLUT-1 and CAIX; microRNAs; and novel mRNA signatures. Although hypoxia modification can take different forms, the gold standard remains carbogen and nicotinamide, which improve local control rates in bladder preservation and absolute overall survival with no significant increase in late toxicity. This is an exciting time for evolving therapies such as bioreductive agents, novel oxygen delivery techniques, immunotherapy and poly (ADP-ribose) polymerase 1 (PARP) inhibitors, all in development and representing upcoming trends in MIBC hypoxia modification. Whatever the future holds for hypoxia-modified radiotherapy, there is no doubt of its importance in MIBC. mRNA signatures provide an ideal platform for the selection of those with hypoxic tumours but are yet to qualified and integrated into the clinic. Future interventional trials will require biomarker stratification to ensure optimal treatment response to improve outcomes for patients with MIBC.
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Affiliation(s)
- T Lodhi
- Department of Clinical Oncology, The Christie NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
| | - Y P Song
- Department of Clinical Oncology, The Christie NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
| | - C West
- Division of Cancer Sciences, University of Manchester, Manchester Academic Health Science Centre, The Christie NHS Foundation Trust, Manchester, UK
| | - P Hoskin
- Division of Cancer Sciences, University of Manchester, Manchester Academic Health Science Centre, The Christie NHS Foundation Trust, Manchester, UK; Cancer Centre, Mount Vernon Hospital, Northwood, UK
| | - A Choudhury
- Department of Clinical Oncology, The Christie NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK; Division of Cancer Sciences, University of Manchester, Manchester Academic Health Science Centre, The Christie NHS Foundation Trust, Manchester, UK.
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9
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Imaging Hypoxia. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00074-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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10
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Dognini P, Killoran PM, Hanson GS, Halsall L, Chaudhry T, Islam Z, Giuntini F, Coxon CR. Using
19
F NMR
and two‐level factorial design to explore thiol‐fluoride substitution in hexafluorobenzene and its application in peptide stapling and cyclisation. Pept Sci (Hoboken) 2020. [DOI: 10.1002/pep2.24182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Paolo Dognini
- School of Pharmacy and Biomolecular Sciences Byrom Street Campus, Liverpool John Moores University Liverpool UK
| | - Patrick M. Killoran
- Division of Structural Biology (STRUBI) University of Oxford, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus Harwell UK
| | - George S. Hanson
- School of Pharmacy and Biomolecular Sciences Byrom Street Campus, Liverpool John Moores University Liverpool UK
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot‐Watt University Edinburgh UK
| | - Lewis Halsall
- School of Pharmacy and Biomolecular Sciences Byrom Street Campus, Liverpool John Moores University Liverpool UK
| | - Talhat Chaudhry
- School of Pharmacy and Biomolecular Sciences Byrom Street Campus, Liverpool John Moores University Liverpool UK
| | - Zasharatul Islam
- School of Pharmacy and Biomolecular Sciences Byrom Street Campus, Liverpool John Moores University Liverpool UK
| | - Francesca Giuntini
- School of Pharmacy and Biomolecular Sciences Byrom Street Campus, Liverpool John Moores University Liverpool UK
| | - Christopher R. Coxon
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot‐Watt University Edinburgh UK
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11
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Taylor NG, Chung SH, Kwansa AL, Johnson RR, Teator AJ, Milliken NJB, Koshlap KM, Yingling YG, Lee YZ, Leibfarth FA. Partially Fluorinated Copolymers as Oxygen Sensitive
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F MRI Agents. Chemistry 2020; 26:9982-9990. [DOI: 10.1002/chem.202001505] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 05/19/2020] [Indexed: 01/03/2023]
Affiliation(s)
- Nicholas G. Taylor
- Department of Chemistry The University of North Carolina at Chapel Hill 125 South Rd Chapel Hill NC 27599 USA
| | - Sang Hun Chung
- Department of Radiology The University of North Carolina at Chapel Hill 101 Manning Dr Chapel Hill NC 27599 USA
| | - Albert L. Kwansa
- Department of Materials Science and Engineering North Carolina State University 911 Partners Way Raleigh NC 27695 USA
| | - Rob R. Johnson
- Department of Chemistry The University of North Carolina at Chapel Hill 125 South Rd Chapel Hill NC 27599 USA
| | - Aaron J. Teator
- Department of Chemistry The University of North Carolina at Chapel Hill 125 South Rd Chapel Hill NC 27599 USA
| | - Nina J. B. Milliken
- Department of Materials Science and Engineering North Carolina State University 911 Partners Way Raleigh NC 27695 USA
| | - Karl M. Koshlap
- Eshelman School of Pharmacy The University of North Carolina at Chapel Hill 301 Pharmacy Ln Chapel Hill NC 27599 USA
| | - Yaroslava G. Yingling
- Department of Materials Science and Engineering North Carolina State University 911 Partners Way Raleigh NC 27695 USA
| | - Yueh Z. Lee
- Department of Radiology The University of North Carolina at Chapel Hill 101 Manning Dr Chapel Hill NC 27599 USA
| | - Frank A. Leibfarth
- Department of Chemistry The University of North Carolina at Chapel Hill 125 South Rd Chapel Hill NC 27599 USA
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12
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Toward noninvasive quantification of adipose tissue oxygenation with MRI. Int J Obes (Lond) 2020; 44:1776-1783. [PMID: 32231252 DOI: 10.1038/s41366-020-0567-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 02/27/2020] [Accepted: 03/04/2020] [Indexed: 12/17/2022]
Abstract
BACKGROUND Molecular oxygen (O2) plays a key role in normal and pathological adipose tissue function, yet technologies to measure its role in adipose tissue function are limited. O2 is paramagnetic and, in principle, directly influences the magnetic resonance (MR) 1H longitudinal relaxation rate constant of lipids, R1; thus, we hypothesize that MR imaging (MRI) can directly measure adipose O2 via a simple measure of R1. METHODS R1 was measured in a 4.7T preclinical MRI system at discrete oxygen partial pressure (pO2) levels. These measures were made in vitro in an idealized system and in vivo in subcutaneous and visceral white adipose of rodents. pO2 was determined using an invasive fiber-optic oxygen monitor. From the MRI and fiber optic data we determined the "relaxivity" of O2 in lipid, a critical parameter in converting the MRI-based R1 measurement into pO2. We used breathing gas challenge to estimate the changes in lipid pO2 (ΔpO2). RESULTS The relaxivity of O2 in lipid was determined to be 1.7·10-3 ± 4·10-4 mmHg-1s-1 at 4.7T and 37 °C, and was consistent between in vitro and in vivo adipose tissue. There was a strong, significant correlation between MRI- and gold standard OxyLite-based measurements of lipid ΔpO2 for in vivo visceral and subcutaneous fat depots in rodents. CONCLUSION This study lays the foundation for a direct, noninvasive measure of adipose pO2 using MRI and will allow for noninvasive measurement of O2 flux in adipose tissue. The proposed approach would be of particular importance in the interrogation of the pathogenesis of type 2 diabetes, where it has been suggested that adipose tissue hypoxia is an independent driver of insulin resistance pathway.
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13
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Agarwal S, Gulaka PK, Rastogi U, Kodibagkar VD. More bullets for PISTOL: linear and cyclic siloxane reporter probes for quantitative 1H MR oximetry. Sci Rep 2020; 10:1399. [PMID: 31996701 PMCID: PMC6989524 DOI: 10.1038/s41598-020-57889-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 12/18/2019] [Indexed: 12/12/2022] Open
Abstract
Tissue oximetry can assist in diagnosis and prognosis of many diseases and enable personalized therapy. Previously, we reported the ability of hexamethyldisiloxane (HMDSO) for accurate measurements of tissue oxygen tension (pO2) using Proton Imaging of Siloxanes to map Tissue Oxygenation Levels (PISTOL) magnetic resonance imaging. Here we report the feasibility of several commercially available linear and cyclic siloxanes (molecular weight 162–410 g/mol) as PISTOL-based oxygen reporters by characterizing their calibration constants. Further, field and temperature dependence of pO2 calibration curves of HMDSO, octamethyltrisiloxane (OMTSO) and polydimethylsiloxane (PDMSO) were also studied. The spin-lattice relaxation rate R1 of all siloxanes studied here exhibited a linear relationship with oxygenation (R1 = A′ + B′*pO2) at all temperatures and field strengths evaluated here. The sensitivity index η( = B′/A′) decreased with increasing molecular weight with values ranged from 4.7 × 10−3–11.6 × 10−3 torr−1 at 4.7 T. No substantial change in the anoxic relaxation rate and a slight decrease in pO2 sensitivity was observed at higher magnetic fields of 7 T and 9.4 T for HMDSO and OMTSO. Temperature dependence of calibration curves for HMDSO, OMTSO and PDMSO was small and simulated errors in pO2 measurement were 1–2 torr/°C. In summary, we have demonstrated the feasibility of various linear and cyclic siloxanes as pO2-reporters for PISTOL-based oximetry.
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Affiliation(s)
- Shubhangi Agarwal
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, 85295, USA
| | - Praveen K Gulaka
- Department of Radiology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, 75390, USA
| | - Ujjawal Rastogi
- Department of Radiology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, 75390, USA
| | - Vikram D Kodibagkar
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, 85295, USA.
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14
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Simkins JW, Stewart PS, Codd SL, Seymour JD. Non-invasive imaging of oxygen concentration in a complex in vitro biofilm infection model using 19 F MRI: Persistence of an oxygen sink despite prolonged antibiotic therapy. Magn Reson Med 2019; 82:2248-2256. [PMID: 31373035 DOI: 10.1002/mrm.27888] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 06/11/2019] [Accepted: 06/12/2019] [Indexed: 01/29/2023]
Abstract
PURPOSE Oxygen availability is a critical determinant of microbial biofilm activity and antibiotic susceptibility. However, measuring oxygen gradients in these systems remains difficult, with the standard microelectrode approach being both invasive and limited to single-point measurement. The goal of the study was to develop a 19 F MRI approach for 2D oxygen mapping in biofilm systems and to visualize oxygen consumption behavior in real time during antibiotic therapy. METHODS Oxygen-sensing beads were created by encapsulating an emulsion of oxygen-sensing fluorocarbon into alginate gel. Escherichia coli biofilms were grown in and on the alginate matrix, which was contained inside a packed bed column subjected to nutrient flow, mimicking the complex porous structure of human wound tissue, and subjected to antibiotic challenge. RESULTS The linear relationship between 19 F spin-lattice relaxation rate R1 and local oxygen concentration permitted noninvasive spatial mapping of oxygen distribution in real time over the course of biofilm growth and subsequent antibiotic challenge. This technique was used to visualize persistence of microbial oxygen respiration during continuous gentamicin administration, providing a time series of complete spatial maps detailing the continued bacterial utilization of oxygen during prolonged chemotherapy in an in vitro biofilm model with complex spatial structure. CONCLUSIONS Antibiotic exposure temporarily causes oxygen consumption to enter a pseudosteady state wherein oxygen distribution becomes fixed; oxygen sink expansion resumes quickly after antibiotic clearance. This technique may provide valuable information for future investigations of biofilms by permitting the study of complex geometries (typical of in vivo biofilms) and facilitating noninvasive oxygen measurement.
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Affiliation(s)
- Jeffrey W Simkins
- Center for Biofilm Engineering, Montana State University, Bozeman, Montana.,Department of Chemical and Biological Engineering, Montana State University, Bozeman, Montana
| | - Philip S Stewart
- Center for Biofilm Engineering, Montana State University, Bozeman, Montana.,Department of Chemical and Biological Engineering, Montana State University, Bozeman, Montana
| | - Sarah L Codd
- Center for Biofilm Engineering, Montana State University, Bozeman, Montana.,Department of Mechanical and Industrial Engineering, Montana State University, Bozeman, Montana
| | - Joseph D Seymour
- Center for Biofilm Engineering, Montana State University, Bozeman, Montana.,Department of Chemical and Biological Engineering, Montana State University, Bozeman, Montana
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15
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Simkins JW, Stewart PS, Seymour JD. Spatiotemporal mapping of oxygen in a microbially-impacted packed bed using 19F Nuclear magnetic resonance oximetry. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 293:123-133. [PMID: 29940412 PMCID: PMC6047901 DOI: 10.1016/j.jmr.2018.06.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 06/12/2018] [Accepted: 06/13/2018] [Indexed: 06/08/2023]
Abstract
19F magnetic resonance has been used in the medical field for quantifying oxygenation in blood, tissues, and tumors. The 19F NMR oximetry technique exploits the affinity of molecular oxygen for liquid fluorocarbon phases, and the resulting linear dependence of 19F spin-lattice relaxation rate R1 on local oxygen concentration. Bacterial biofilms, aggregates of bacteria encased in a self-secreted matrix of extracellular polymers, are important in environmental, industrial, and clinical settings and oxygen gradients represent a critical determinant of biofilm function. However, measurement of oxygen distribution in biofilms and biofouled porous media is difficult. Here the ability of 19F NMR oximetry to accurately track oxygen profile development in microbial impacted packed bed systems without impacting oxygen transport is demonstrated. Time-stable and inert fluorocarbon containing particles are designed which act as oxygen reporters in porous media systems. Particles are generated by emulsifying and entrapping perfluorooctylbromide (PFOB) into alginate gel, resulting in oxygen-sensing alginate beads that are then used as the solid matrix of the packed bed. 19F oxygenation maps, when combined with 1H velocity maps, allow for insight into the interplay between fluid dynamics and oxygen transport phenomena in these complex biofouled systems. Spatial maps of oxygen consumption rate constants are calculated. The growth characteristics of two bacteria, a non-biofilm forming Escherichia coli and Staphylococcus epidermidis, a strong biofilm-former, are used to demonstrate the novel data provided by the method.
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Affiliation(s)
- Jeffrey W Simkins
- Center for Biofilm Engineering, Montana State University, 366 Barnard Hall, Bozeman, MT 59715, United States; Department of Chemical and Biological Engineering, Montana State University, 306 Cobleigh Hall, Bozeman, MT 59715, United States.
| | - Philip S Stewart
- Center for Biofilm Engineering, Montana State University, 366 Barnard Hall, Bozeman, MT 59715, United States; Department of Chemical and Biological Engineering, Montana State University, 306 Cobleigh Hall, Bozeman, MT 59715, United States.
| | - Joseph D Seymour
- Center for Biofilm Engineering, Montana State University, 366 Barnard Hall, Bozeman, MT 59715, United States; Department of Chemical and Biological Engineering, Montana State University, 306 Cobleigh Hall, Bozeman, MT 59715, United States.
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Dregely I, Prezzi D, Kelly‐Morland C, Roccia E, Neji R, Goh V. Imaging biomarkers in oncology: Basics and application to MRI. J Magn Reson Imaging 2018; 48:13-26. [PMID: 29969192 PMCID: PMC6587121 DOI: 10.1002/jmri.26058] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 03/26/2018] [Indexed: 12/12/2022] Open
Abstract
Cancer remains a global killer alongside cardiovascular disease. A better understanding of cancer biology has transformed its management with an increasing emphasis on a personalized approach, so-called "precision cancer medicine." Imaging has a key role to play in the management of cancer patients. Imaging biomarkers that objectively inform on tumor biology, the tumor environment, and tumor changes in response to an intervention complement genomic and molecular diagnostics. In this review we describe the key principles for imaging biomarker development and discuss the current status with respect to magnetic resonance imaging (MRI). LEVEL OF EVIDENCE 5 TECHNICAL EFFICACY: Stage 5 J. Magn. Reson. Imaging 2018;48:13-26.
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Affiliation(s)
- Isabel Dregely
- Biomedical Engineering, School of Biomedical Engineering & Imaging SciencesKing's Health Partners, St Thomas' HospitalLondon, UK
| | - Davide Prezzi
- Cancer Imaging, School of Biomedical Engineering & Imaging Sciences King's College London, King's Health Partners, St Thomas' Hospital, LondonUK
- RadiologyGuy's & St Thomas' NHS Foundation TrustLondonUK
| | - Christian Kelly‐Morland
- Cancer Imaging, School of Biomedical Engineering & Imaging Sciences King's College London, King's Health Partners, St Thomas' Hospital, LondonUK
- RadiologyGuy's & St Thomas' NHS Foundation TrustLondonUK
| | - Elisa Roccia
- Biomedical Engineering, School of Biomedical Engineering & Imaging SciencesKing's Health Partners, St Thomas' HospitalLondon, UK
| | - Radhouene Neji
- Biomedical Engineering, School of Biomedical Engineering & Imaging SciencesKing's Health Partners, St Thomas' HospitalLondon, UK
- MR Research CollaborationsSiemens HealthcareFrimleyUK
| | - Vicky Goh
- Cancer Imaging, School of Biomedical Engineering & Imaging Sciences King's College London, King's Health Partners, St Thomas' Hospital, LondonUK
- RadiologyGuy's & St Thomas' NHS Foundation TrustLondonUK
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Basal LA, Bailey MD, Romero J, Ali MM, Kurenbekova L, Yustein J, Pautler RG, Allen MJ. Fluorinated Eu II-based multimodal contrast agent for temperature- and redox-responsive magnetic resonance imaging. Chem Sci 2017; 8:8345-8350. [PMID: 29780447 PMCID: PMC5933353 DOI: 10.1039/c7sc03142d] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 10/18/2017] [Indexed: 01/09/2023] Open
Abstract
Magnetic resonance imaging (MRI) using redox-active, EuII-containing complexes is one of the most promising techniques for noninvasively imaging hypoxia in vivo. In this technique, positive (T1-weighted) contrast enhancement persists in areas of relatively low oxidizing ability, such as hypoxic tissue. Herein, we describe a fluorinated, EuII-containing complex in which the redox-active metal is caged by intramolecular interactions. The position of the fluorine atoms enables temperature-responsive contrast enhancement in the reduced form of the contrast agent and detection of the oxidized contrast agent via MRI in vivo. Positive contrast is observed in 1H-MRI with Eu in the +2 oxidation state, and chemical exchange saturation transfer and 19F-MRI signal are observed with Eu in the +3 oxidation state. Contrast enhancement is controlled by the redox state of Eu, and modulated by the fluorous interactions that cage a bound water molecule reduce relaxivity in a temperature-dependent fashion. Together, these advancements constitute the first report of in vivo, redox-responsive imaging using 19F-MRI.
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Affiliation(s)
- Lina A Basal
- Department of Chemistry , Wayne State University , 5101 Cass Avenue , Detroit , Michigan 48202 , USA .
| | - Matthew D Bailey
- Department of Chemistry , Wayne State University , 5101 Cass Avenue , Detroit , Michigan 48202 , USA .
| | - Jonathan Romero
- Department of Molecular Physiology and Biophysics , Baylor College of Medicine , One Baylor Plaza , Houston , Texas 77030 , USA .
| | - Meser M Ali
- Department of Neurosurgery , Henry Ford Hospital , 1 Ford Place , Detroit , Michigan 48202 , USA
| | - Lyazat Kurenbekova
- Integrative Molecular and Biomedical Sciences , Baylor College of Medicine , Houston , TX 77030 , USA
| | - Jason Yustein
- Integrative Molecular and Biomedical Sciences , Baylor College of Medicine , Houston , TX 77030 , USA
- Department of Pediatrics , Texas Children's Cancer and Hematology Centers , Baylor College of Medicine , Houston , TX 77030 , USA
| | - Robia G Pautler
- Department of Molecular Physiology and Biophysics , Baylor College of Medicine , One Baylor Plaza , Houston , Texas 77030 , USA .
| | - Matthew J Allen
- Department of Chemistry , Wayne State University , 5101 Cass Avenue , Detroit , Michigan 48202 , USA .
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Development of highly-sensitive detection system in 19 F NMR for bioactive compounds based on the assembly of paramagnetic complexes with fluorinated cubic silsesquioxanes. Bioorg Med Chem 2017; 25:1389-1393. [DOI: 10.1016/j.bmc.2016.12.044] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Revised: 12/27/2016] [Accepted: 12/27/2016] [Indexed: 01/06/2023]
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Kubota H, Komarov DA, Yasui H, Matsumoto S, Inanami O, Kirilyuk IA, Khramtsov VV, Hirata H. Feasibility of in vivo three-dimensional T 2* mapping using dicarboxy-PROXYL and CW-EPR-based single-point imaging. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2017; 30:291-298. [PMID: 28063096 DOI: 10.1007/s10334-016-0606-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 12/13/2016] [Accepted: 12/22/2016] [Indexed: 12/21/2022]
Abstract
OBJECTIVES The aim of this study was to demonstrate the feasibility of in vivo three-dimensional (3D) relaxation time T 2* mapping of a dicarboxy-PROXYL radical using continuous-wave electron paramagnetic resonance (CW-EPR) imaging. MATERIALS AND METHODS Isotopically substituted dicarboxy-PROXYL radicals, 3,4-dicarboxy-2,2,5,5-tetra(2H3)methylpyrrolidin-(3,4-2H2)-(1-15N)-1-oxyl (2H,15N-DCP) and 3,4-dicarboxy-2,2,5,5-tetra(2H3)methylpyrrolidin-(3,4-2H2)-1-oxyl (2H-DCP), were used in the study. A clonogenic cell survival assay was performed with the 2H-DCP radical using squamous cell carcinoma (SCC VII) cells. The time course of EPR signal intensities of intravenously injected 2H,15N-DCP and 2H-DCP radicals were determined in tumor-bearing hind legs of mice (C3H/HeJ, male, n = 5). CW-EPR-based single-point imaging (SPI) was performed for 3D T 2* mapping. RESULTS 2H-DCP radical did not exhibit cytotoxicity at concentrations below 10 mM. The in vivo half-life of 2H,15N-DCP in tumor tissues was 24.7 ± 2.9 min (mean ± standard deviation [SD], n = 5). The in vivo time course of the EPR signal intensity of the 2H,15N-DCP radical showed a plateau of 10.2 ± 1.2 min (mean ± SD) where the EPR signal intensity remained at more than 90% of the maximum intensity. During the plateau, in vivo 3D T 2* maps with 2H,15N-DCP were obtained from tumor-bearing hind legs, with a total acquisition time of 7.5 min. CONCLUSION EPR signals of 2H,15N-DCP persisted long enough after bolus intravenous injection to conduct in vivo 3D T 2* mapping with CW-EPR-based SPI.
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Affiliation(s)
- Harue Kubota
- Division of Bioengineering and Bioinformatics, Graduate School of Information Science and Technology, Hokkaido University, North 14, West 9, Kita-ku, Sapporo, 060-0814, Japan
| | - Denis A Komarov
- Division of Bioengineering and Bioinformatics, Graduate School of Information Science and Technology, Hokkaido University, North 14, West 9, Kita-ku, Sapporo, 060-0814, Japan
| | - Hironobu Yasui
- Central Institute of Isotope Science, Hokkaido University, North 15, West 7, Kita-ku, Sapporo, 060-0815, Japan
| | - Shingo Matsumoto
- Division of Bioengineering and Bioinformatics, Graduate School of Information Science and Technology, Hokkaido University, North 14, West 9, Kita-ku, Sapporo, 060-0814, Japan
| | - Osamu Inanami
- Laboratory of Radiation Biology, Graduate School of Veterinary Medicine, Hokkaido University, North 18, West 9, Kita-ku, Sapporo, 060-0818, Japan
| | - Igor A Kirilyuk
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, 9, Ac. Lavrentieva Ave., Novosibirsk, 630090, Russia
| | - Valery V Khramtsov
- Department of Biochemistry, West Virginia University, Robert C. Byrd Health Sciences Center, 1 Medical Center Drive, Morgantown, WV, 26506, USA
| | - Hiroshi Hirata
- Division of Bioengineering and Bioinformatics, Graduate School of Information Science and Technology, Hokkaido University, North 14, West 9, Kita-ku, Sapporo, 060-0814, Japan.
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Kegel S, Chacon-Caldera J, Tsagogiorgas C, Theisinger B, Glatting G, Schad LR. 19F Oximetry with semifluorinated alkanes. ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY 2015; 44:1861-1866. [PMID: 26631543 DOI: 10.3109/21691401.2015.1111228] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
This work examines the variation of longitudinal relaxation rate R1(= 1/T1) of the 19F-CF3-resonance of semifluorinated alkanes (SFAs) with oxygen tension (pO2), temperature (T) and pH in vitro. Contrary to their related perfluorocarbons (PFCs), SFA are amphiphilic and facilitate stable emulsions, a prerequisite for clinical use. A linear relationship between R1 and pO2 was confirmed for the observed SFAs at different temperatures. Using a standard saturation recovery sequence, T1 has been successfully measured using fluorine 19F-MRI with a self-constructed birdcage resonator at 9.4 T. A calibration curve to calculate pO2 depending on T and R1 was found for each SFA used. In contrast to the commonly used PFC, SFAs are less sensitive to changes in pO2, but more sensitive to changes in temperature. The influence of pH to R1 was found to be negligible.
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Affiliation(s)
- Stefan Kegel
- a Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University , Mannheim , Germany
| | - Jorge Chacon-Caldera
- b Computer Assisted Clinical Medicine, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University , Mannheim , Germany
| | - Charalambos Tsagogiorgas
- c Department of Anaesthesiology and Surgical Intensive Care Medicine , Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University , Mannheim , Germany
| | | | - Gerhard Glatting
- a Medical Radiation Physics/Radiation Protection, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University , Mannheim , Germany
| | - Lothar R Schad
- b Computer Assisted Clinical Medicine, Universitätsmedizin Mannheim, Medical Faculty Mannheim, Heidelberg University , Mannheim , Germany
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Beeman SC, Shui YB, Perez-Torres CJ, Engelbach JA, Ackerman JJH, Garbow JR. O2 -sensitive MRI distinguishes brain tumor versus radiation necrosis in murine models. Magn Reson Med 2015; 75:2442-7. [PMID: 26175346 DOI: 10.1002/mrm.25821] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 05/28/2015] [Accepted: 05/31/2015] [Indexed: 12/20/2022]
Abstract
PURPOSE The goal of this study was to quantify the relationship between the (1) H longitudinal relaxation rate constant, R1 , and oxygen (O2 ) concentration (relaxivity, r1 ) in tissue and to quantify O2 -driven changes in R1 (ΔR1 ) during a breathing gas challenge in normal brain, radiation-induced lesions, and tumor lesions. METHODS R1 data were collected in control-state mice (n = 4) during three different breathing gas (and thus tissue O2 ) conditions. In parallel experiments, pO2 was measured in the thalamus of control-state mice (n = 4) under the same breathing gas conditions using an O2 -sensitive microprobe. The relaxivity of tissue O2 was calculated using the R1 and pO2 data. R1 data were collected in control-state (n = 4) mice, a glioma model (n = 7), and a radiation necrosis model (n = 6) during two breathing gas (thus tissue O2 ) conditions. R1 and ΔR1 were calculated for each cohort. RESULTS O2 r1 in the brain was 9 × 10(-4) ± 3 × 10(-4) mm Hg(-1) · s(-1) at 4.7T. R1 and ΔR1 measurements distinguished radiation necrosis from tumor (P< 0.03 and P< 0.01, respectively). CONCLUSION The relaxivity of O2 in the brain is determined. R1 and ΔR1 measurements differentiate tumor lesions from radiation necrosis lesions in the mouse models. These pathologies are difficult to distinguish by traditional imaging techniques; O2 -driven changes in R1 holds promise in this regard. Magn Reson Med 75:2442-2447, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Scott C Beeman
- Department of Radiology, Washington University, St. Louis, Missouri, USA
| | - Ying-Bo Shui
- Department of Ophthalmology, Washington University, St. Louis, Missouri, USA
| | | | - John A Engelbach
- Department of Radiology, Washington University, St. Louis, Missouri, USA
| | - Joseph J H Ackerman
- Department of Radiology, Washington University, St. Louis, Missouri, USA.,Department of Chemistry, Washington University, St. Louis, Missouri, USA.,Department of Internal Medicine, Washington University, St. Louis, Missouri, USA.,Alvin J. Siteman Cancer Center, Washington University, St. Louis, Missouri, USA
| | - Joel R Garbow
- Department of Radiology, Washington University, St. Louis, Missouri, USA.,Alvin J. Siteman Cancer Center, Washington University, St. Louis, Missouri, USA
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Winfield JM, Payne GS, deSouza NM. Functional MRI and CT biomarkers in oncology. Eur J Nucl Med Mol Imaging 2015; 42:562-78. [PMID: 25578953 DOI: 10.1007/s00259-014-2979-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 12/15/2014] [Indexed: 02/07/2023]
Abstract
Imaging biomarkers derived from MRI or CT describe functional properties of tumours and normal tissues. They are finding increasing numbers of applications in diagnosis, monitoring of response to treatment and assessment of progression or recurrence. Imaging biomarkers also provide scope for assessment of heterogeneity within and between lesions. A wide variety of functional parameters have been investigated for use as biomarkers in oncology. Some imaging techniques are used routinely in clinical applications while others are currently restricted to clinical trials or preclinical studies. Apparent diffusion coefficient, magnetization transfer ratio and native T1 relaxation time provide information about structure and organization of tissues. Vascular properties may be described using parameters derived from dynamic contrast-enhanced MRI, dynamic contrast-enhanced CT, transverse relaxation rate (R2*), vessel size index and relative blood volume, while magnetic resonance spectroscopy may be used to probe the metabolic profile of tumours. This review describes the mechanisms of contrast underpinning each technique and the technical requirements for robust and reproducible imaging. The current status of each biomarker is described in terms of its validation, qualification and clinical applications, followed by a discussion of the current limitations and future perspectives.
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Affiliation(s)
- J M Winfield
- CRUK Imaging Centre at the Institute of Cancer Research, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Sutton, UK,
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Danhier P, Gallez B. Electron paramagnetic resonance: a powerful tool to support magnetic resonance imaging research. CONTRAST MEDIA & MOLECULAR IMAGING 2014; 10:266-81. [PMID: 25362845 DOI: 10.1002/cmmi.1630] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 09/18/2014] [Indexed: 12/31/2022]
Abstract
The purpose of this paper is to describe some of the areas where electron paramagnetic resonance (EPR) has provided unique information to MRI developments. The field of application mainly encompasses the EPR characterization of MRI paramagnetic contrast agents (gadolinium and manganese chelates, nitroxides) and superparamagnetic agents (iron oxide particles). The combined use of MRI and EPR has also been used to qualify or disqualify sources of contrast in MRI. Illustrative examples are presented with attempts to qualify oxygen sensitive contrast (i.e. T1 - and T2 *-based methods), redox status or melanin content in tissues. Other areas are likely to benefit from the combined EPR/MRI approach, namely cell tracking studies. Finally, the combination of EPR and MRI studies on the same models provides invaluable data regarding tissue oxygenation, hemodynamics and energetics. Our description will be illustrative rather than exhaustive to give to the readers a flavour of 'what EPR can do for MRI'.
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Affiliation(s)
- Pierre Danhier
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Bernard Gallez
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
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Tirotta I, Dichiarante V, Pigliacelli C, Cavallo G, Terraneo G, Bombelli FB, Metrangolo P, Resnati G. (19)F magnetic resonance imaging (MRI): from design of materials to clinical applications. Chem Rev 2014; 115:1106-29. [PMID: 25329814 DOI: 10.1021/cr500286d] [Citation(s) in RCA: 327] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Ilaria Tirotta
- Laboratory of Nanostructured Fluorinated Materials (NFMLab), Department of Chemistry, Materials, and Chemical Engineering "Giulio Natta" and ‡Fondazione Centro Europeo Nanomedicina, Politecnico di Milano , Milan 20131, Italy
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Swartz HM, Williams BB, Zaki BI, Hartford AC, Jarvis LA, Chen EY, Comi RJ, Ernstoff MS, Hou H, Khan N, Swarts SG, Flood AB, Kuppusamy P. Clinical EPR: unique opportunities and some challenges. Acad Radiol 2014; 21:197-206. [PMID: 24439333 DOI: 10.1016/j.acra.2013.10.011] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 10/03/2013] [Accepted: 10/14/2013] [Indexed: 11/29/2022]
Abstract
Electron paramagnetic resonance (EPR) spectroscopy has been well established as a viable technique for measurement of free radicals and oxygen in biological systems, from in vitro cellular systems to in vivo small animal models of disease. However, the use of EPR in human subjects in the clinical setting, although attractive for a variety of important applications such as oxygen measurement, is challenged with several factors including the need for instrumentation customized for human subjects, probe, and regulatory constraints. This article describes the rationale and development of the first clinical EPR systems for two important clinical applications, namely, measurement of tissue oxygen (oximetry) and radiation dose (dosimetry) in humans. The clinical spectrometers operate at 1.2 GHz frequency and use surface-loop resonators capable of providing topical measurements up to 1 cm depth in tissues. Tissue pO2 measurements can be carried out noninvasively and repeatedly after placement of an oxygen-sensitive paramagnetic material (currently India ink) at the site of interest. Our EPR dosimetry system is capable of measuring radiation-induced free radicals in the tooth of irradiated human subjects to determine the exposure dose. These developments offer potential opportunities for clinical dosimetry and oximetry, which include guiding therapy for individual patients with tumors or vascular disease by monitoring of tissue oxygenation. Further work is in progress to translate this unique technology to routine clinical practice.
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Affiliation(s)
- Harold M Swartz
- Department of Radiology, Geisel School of Medicine at Dartmouth, Dartmouth College, 48 Lafayette Street, Lebanon, NH 03766.
| | - Benjamin B Williams
- Department of Radiology, Geisel School of Medicine at Dartmouth, Dartmouth College, 48 Lafayette Street, Lebanon, NH 03766
| | - Bassem I Zaki
- Department of Medicine, Geisel School of Medicine at Dartmouth, Dartmouth College, Hanover, NH
| | - Alan C Hartford
- Department of Medicine, Geisel School of Medicine at Dartmouth, Dartmouth College, Hanover, NH
| | - Lesley A Jarvis
- Department of Medicine, Geisel School of Medicine at Dartmouth, Dartmouth College, Hanover, NH
| | - Eunice Y Chen
- Department of Surgery, Geisel School of Medicine at Dartmouth, Dartmouth College, Hanover, NH
| | - Richard J Comi
- Department of Medicine, Geisel School of Medicine at Dartmouth, Dartmouth College, Hanover, NH
| | - Marc S Ernstoff
- Department of Medicine, Geisel School of Medicine at Dartmouth, Dartmouth College, Hanover, NH
| | - Huagang Hou
- Department of Radiology, Geisel School of Medicine at Dartmouth, Dartmouth College, 48 Lafayette Street, Lebanon, NH 03766
| | - Nadeem Khan
- Department of Radiology, Geisel School of Medicine at Dartmouth, Dartmouth College, 48 Lafayette Street, Lebanon, NH 03766
| | - Steven G Swarts
- Dept. of Radiation Oncology, University of Florida, Gainesville, FL
| | - Ann B Flood
- Department of Radiology, Geisel School of Medicine at Dartmouth, Dartmouth College, 48 Lafayette Street, Lebanon, NH 03766
| | - Periannan Kuppusamy
- Department of Radiology, Geisel School of Medicine at Dartmouth, Dartmouth College, 48 Lafayette Street, Lebanon, NH 03766
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Nielsen T, Nielsen NC, Holm TH, Ostergaard L, Horsman MR, Busk M. Ultra-high field 1H magnetic resonance imaging approaches for acute hypoxia. Acta Oncol 2013; 52:1287-92. [PMID: 23992112 DOI: 10.3109/0284186x.2013.824608] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Currently, radiation treatments are being optimised based on in vivo imaging of radioresistant, hypoxic tumour areas. This study aimed at detecting nicotinamide's reduction of acute hypoxia in a mouse tumour model by two clinically relevant magnetic resonance imaging (MRI) methods at ultra-high magnetic field strength. MATERIAL AND METHODS The C3H mammary carcinoma was grown to 200 mm(3) in the right rear foot of CDF1 mice. The mice were anaesthetised with ketamine and xylazine prior to imaging. A treatment group received nicotinamide intraperitoneally (i.p.) at the dose 1000 mg/kg, and a control group received saline. MRI was performed at 16.4 T with a spatial resolution of 0.156 × 0.156 × 0.5 mm(3). The imaging protocol included BOLD imaging and two DCE-MRI scans. Initial area under the curve (IAUC) and the parameters from the extended Toft's model were estimated from the DCE-MRI data. Tumour median values of 1) T2* mean, 2) T2* standard deviation, 3) DCE-MRI parameters, and 4) DCE-MRI parameter differences between scans were compared between the treatment groups using Student's t-test (significance level p < 0.05). RESULTS Parametric maps showed intra- and inter-tumour heterogeneity. Blood volume was significantly larger in the nicotinamide-treated group, and also the blood volume difference between the two DCE-MRI scans was significantly larger in the treatment group. CONCLUSION Higher blood volume and blood volume variation was observed by DCE-MRI in the treatment group. Other DCE-MRI parameters showed no significant differences, and the higher blood volume was not detected by BOLD MRI. The higher blood volume variation seen with DCE-MRI may be influenced by the drug effect reducing over time, and furthermore the anaesthesia may play an important role.
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Affiliation(s)
- Thomas Nielsen
- Department of Experimental Clinical Oncology, Aarhus University Hospital , Aarhus Denmark
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Yu JX, Hallac RR, Chiguru S, Mason RP. New frontiers and developing applications in 19F NMR. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2013; 70:25-49. [PMID: 23540575 PMCID: PMC3613763 DOI: 10.1016/j.pnmrs.2012.10.001] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 10/23/2012] [Indexed: 05/06/2023]
Affiliation(s)
- Jian-Xin Yu
- Laboratory of Prognostic Radiology, Division of Advanced Radiological Sciences, Department of Radiology, UT Southwestern Medical Center, Dallas, Texas
| | - Rami R. Hallac
- Laboratory of Prognostic Radiology, Division of Advanced Radiological Sciences, Department of Radiology, UT Southwestern Medical Center, Dallas, Texas
| | - Srinivas Chiguru
- Laboratory of Prognostic Radiology, Division of Advanced Radiological Sciences, Department of Radiology, UT Southwestern Medical Center, Dallas, Texas
| | - Ralph P. Mason
- Laboratory of Prognostic Radiology, Division of Advanced Radiological Sciences, Department of Radiology, UT Southwestern Medical Center, Dallas, Texas
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Bobko AA, Dhimitruka I, Komarov DA, Khramtsov VV. Dual-function pH and oxygen phosphonated trityl probe. Anal Chem 2012; 84:6054-60. [PMID: 22703565 DOI: 10.1021/ac3008994] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Triarylmethyl radicals (TAMs) are used as persistent paramagnetic probes for electron paramagnetic resonance (EPR) spectroscopic and imaging applications and as hyperpolarizing and contrast agents for magnetic resonance imaging (MRI) and proton-electron double-resonance imaging (PEDRI). Recently we proposed the concept of dual-function pH and oxygen TAM probes based on the incorporation of ionizable groups into the TAM structure ( J. Am. Chem. Soc. 2007 , 129 , 7240 - 7241 ). In this paper we report the synthesis of a deuterated derivative of phosphonated trityl radical, pTAM. The presence of phosphono substitutes in the structure of TAM provides pH sensitivity of its EPR spectrum in the physiological range from 6 to 8, the phosphorus hyperfine splitting acting as a convenient and highly sensitive pH marker (spectral sensitivity, 3Δa(P)/ΔpH ≈ 0.5 G/pH unit; accuracy of pH measurements, ±0.05). In addition, substitution of 36 methyl protons with deuterons significantly decreased the individual line width of pTAM down to 40 mG and, as consequence, provided high sensitivity of the line-width broadening to pO(2) (ΔH/ΔpO(2) ≈ 0.4 mG/mmHg; accuracy of pO(2) measurements, ≈1 mmHg). The independent character of pH and [O(2)] effects on the EPR spectra of pTAM provides dual functionality to this probe, allowing extraction of both parameters from a single EPR spectrum.
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Affiliation(s)
- Andrey A Bobko
- Dorothy M. Davis Heart & Lung Research Institute and Division of Pulmonary, Allergy, Critical Care & Sleep Medicine, Department of Internal Medicine, The Ohio State University, Columbus, Ohio 43210, United States
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Jordan BF, Sonveaux P. Targeting tumor perfusion and oxygenation to improve the outcome of anticancer therapy. Front Pharmacol 2012; 3:94. [PMID: 22661950 PMCID: PMC3357106 DOI: 10.3389/fphar.2012.00094] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 04/30/2012] [Indexed: 11/13/2022] Open
Abstract
Radiotherapy and chemotherapy are widespread clinical modalities for cancer treatment. Among other biological influences, hypoxia is a main factor limiting the efficacy of radiotherapy, primarily because oxygen is involved in the stabilization of the DNA damage caused by ionizing radiations. Radiobiological hypoxia is found in regions of rodent and human tumors with a tissue oxygenation level below 10 mmHg at which tumor cells become increasingly resistant to radiation damage. Since hypoxic tumor cells remain clonogenic, their resistance to the treatment strongly influences the therapeutic outcome of radiotherapy. There is therefore an urgent need to identify adjuvant treatment modalities aimed to increase tumor pO(2) at the time of radiotherapy. Since tumor hypoxia fundamentally results from an imbalance between oxygen delivery by poorly efficient blood vessels and oxygen consumption by tumor cells with high metabolic activities, two promising approaches are those targeting vascular reactivity and tumor cell respiration. This review summarizes the current knowledge about the development and use of tumor-selective vasodilators, inhibitors of tumor cell respiration, and drugs and treatments combining both activities in the context of tumor sensitization to X-ray radiotherapy. Tumor-selective vasodilation may also be used to improve the delivery of circulating anticancer agents to tumors. Imaging tumor perfusion and oxygenation is of importance not only for the development and validation of such combination treatments, but also to determine which patients could benefit from the therapy. Numerous techniques have been developed in the preclinical setting. Hence, this review also briefly describes both magnetic resonance and non-magnetic resonance in vivo methods and compares them in terms of sensitivity, quantitative or semi-quantitative properties, temporal, and spatial resolutions, as well as translational aspects.
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Affiliation(s)
- Bénédicte F. Jordan
- Nuclear Magnetic Resonance Research Group, Louvain Drug Research Institute, Université catholique de Louvain Medical SchoolBrussels, Belgium
| | - Pierre Sonveaux
- Pole of Pharmacology, Institute of Experimental and Clinical Research, Université Catholique de Louvain Medical SchoolBrussels, Belgium
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McIntyre DJO, Madhu B, Lee SH, Griffiths JR. Magnetic resonance spectroscopy of cancer metabolism and response to therapy. Radiat Res 2012; 177:398-435. [PMID: 22401303 DOI: 10.1667/rr2903.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Magnetic resonance spectroscopy allows noninvasive in vivo measurements of biochemical information from living systems, ranging from cultured cells through experimental animals to humans. Studies of biopsies or extracts offer deeper insights by detecting more metabolites and resolving metabolites that cannot be distinguished in vivo. The pharmacokinetics of certain drugs, especially fluorinated drugs, can be directly measured in vivo. This review briefly describes these methods and their applications to cancer metabolism, including glycolysis, hypoxia, bioenergetics, tumor pH, and tumor responses to radiotherapy and chemotherapy.
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Affiliation(s)
- Dominick J O McIntyre
- Cancer Research UK, Cambridge Research Institute, Li Ka Shing Centre, Robinson Way, Cambridge CB2 0RE, UK.
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Ogawa M, Kataoka H, Nitahara S, Fujimoto H, Aoki H, Ito S, Narazaki M, Matsuda T. Water-Soluble Fluorinated Polymer Nanoparticle as 19F MRI Contrast Agent Prepared by Living Random Copolymerization from Dendrimer Initiator. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2012. [DOI: 10.1246/bcsj.20110048] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Michihiro Ogawa
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University
| | - Hiromasa Kataoka
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University
| | - Satoshi Nitahara
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University
| | - Hiroyuki Fujimoto
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University
| | - Hiroyuki Aoki
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University
| | - Shinzaburo Ito
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University
| | - Michiko Narazaki
- Department of Systems Science, Graduate School of Informatics, Kyoto University
| | - Tetsuya Matsuda
- Department of Systems Science, Graduate School of Informatics, Kyoto University
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Liu S, Shah SJ, Wilmes LJ, Feiner J, Kodibagkar VD, Wendland MF, Mason RP, Hylton N, Hopf HW, Rollins MD. Quantitative tissue oxygen measurement in multiple organs using 19F MRI in a rat model. Magn Reson Med 2011; 66:1722-30. [PMID: 21688315 DOI: 10.1002/mrm.22968] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Revised: 02/24/2011] [Accepted: 03/23/2011] [Indexed: 11/10/2022]
Abstract
Measurement of individual organ tissue oxygen levels can provide information to help evaluate and optimize medical interventions in many areas including wound healing, resuscitation strategies, and cancer therapeutics. Echo planar (19) F MRI has previously focused on tumor oxygen measurement at low oxygen levels (pO(2)) <30 mmHg. It uses the linear relationship between spin-lattice relaxation rate (R(1)) of hexafluorobenzene (HFB) and pO(2). The feasibility of this technique for a wider range of pO(2) values and individual organ tissue pO(2) measurement was investigated in a rat model. Spin-lattice relaxation times (T(1) = 1/R(1)) of hexafluorobenzene were measured using (19) F saturation recovery echo planar imaging. Initial in vitro studies validated the linear relationship between R(1) and pO(2) from 0 to 760 mmHg oxygen partial pressure at 25, 37, and 41°C at 7 Tesla for hexafluorobenzene. In vivo experiments measured rat tissue oxygen (ptO2) levels of brain, kidney, liver, gut, muscle, and skin during inhalation of both 30 and 100% oxygen. All organ ptO(2) values significantly increased with hyperoxia (P < 0.001). This study demonstrates that (19) F MRI of hexafluorobenzene offers a feasible tool to measure regional ptO2 in vivo, and that hyperoxia significantly increases ptO2 of multiple organs in a rat model.
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Affiliation(s)
- Siyuan Liu
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California 94143-0464, USA
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Diepart C, Magat J, Jordan BF, Gallez B. In vivo mapping of tumor oxygen consumption using (19)F MRI relaxometry. NMR IN BIOMEDICINE 2011; 24:458-463. [PMID: 20891023 DOI: 10.1002/nbm.1604] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Revised: 07/14/2010] [Accepted: 07/14/2010] [Indexed: 05/29/2023]
Abstract
Recently, we have developed a new electron paramagnetic resonance (EPR) protocol in order to estimate tissue oxygen consumption in vivo. Because it is crucial to probe the heterogeneity of response in tumors, the aim of this study was to apply our protocol, together with (19)F MRI relaxometry, to the mapping of the oxygen consumption in tumors. The protocol includes the continuous measurement of tumor po(2) during the following respiratory challenge: (i) basal values during air breathing; (ii) increasing po(2) values during carbogen breathing until saturation of tissue with oxygen; (iii) switching back to air breathing. We have demonstrated previously using EPR oximetry that the kinetics of return to the basal value after oxygen saturation are mainly governed by tissue oxygen consumption. This challenge was applied in hyperthyroid mice (generated by chronic treatment with L-thyroxine) and control mice, as hyperthyroidism is known to dramatically affect the oxygen consumption rate of tumor cells. Our recently developed snapshot inversion recovery MRI fluorocarbon oximetry technique allowed the po(2) return kinetics to be measured with a high temporal resolution. The kinetic constants (i.e. oxygen consumption rates) were higher for tumors from hyperthyroid mice than from control mice, data that are consistent with our previous EPR study. The corresponding histograms of the (19)F MRI data showed that the kinetic constants displayed a shift to the right for the hyperthyroid group, indicating a higher oxygen consumption in these tumors. The color maps showed a large heterogeneity in terms of oxygen consumption rate within a tumor. In conclusion, (19)F MRI relaxometry allows the noninvasive mapping of the oxygen consumption in tumors. The ability to assess the heterogeneity of tumor response is critical in order to identify potential tumor regions that might be resistant to treatment and therefore produce a poor response to therapy.
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Affiliation(s)
- Caroline Diepart
- Biomedical Magnetic Resonance Group, Louvain Drug Research Institute, Université Catholique de Louvain, Brussels, Belgium
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Baete SH, Vandecasteele J, De Deene Y. 19F MRI oximetry: simulation of perfluorocarbon distribution impact. Phys Med Biol 2011; 56:2535-57. [PMID: 21444970 DOI: 10.1088/0031-9155/56/8/013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
In (19)F MRI oximetry, a method used to image tumour hypoxia, perfluorocarbons serve as oxygenation markers. The goal of this study is to evaluate the impact of perfluorocarbon distribution and concentration in (19)F MRI oximetry through a computer simulation. The simulation studies the correspondence between (19)F measured (pO(FNMR)(2)) and actual tissue oxygen tension (pO(2)) for several tissue perfluorocarbon distributions. For this, a Krogh tissue model is implemented which incorporates the presence of perfluorocarbons in blood and tissue. That is, in tissue the perfluorocarbons are distributed homogeneously according to Gaussian diffusion profiles, or the perfluorocarbons are concentrated in the capillary wall. Using these distributions, the oxygen tension in the simulation volume is calculated. The simulated mean oxygen tension is then compared with pO(FNMR)(2), the (19)F MRI-based measure of pO(2) and with pO(0)(2), pO(2) in the absence of perfluorocarbons. The agreement between pO(FNMR)(2) and actual pO(2) is influenced by vascular density and perfluorocarbon distribution. The presence of perfluorocarbons generally gives rise to a pO(2) increase in tissue. This effect is enhanced when perfluorocarbons are also present in blood. Only the homogeneous perfluorocarbon distribution in tissue with no perfluorocarbons in blood guarantees small deviations of pO(FNMR)(2) from pO(2). Hence, perfluorocarbon distribution in tissue and blood has a serious impact on the reliability of (19)F MRI-based measures of oxygen tension. In addition, the presence of perfluorocarbons influences the actual oxygen tension. This finding may be of great importance for further development of (19)F MRI oximetry.
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Affiliation(s)
- S H Baete
- Department of Radiation Oncology and Experimental Cancer Research, Ghent University, De Pintelaan 185, 9000 Gent, Belgium.
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Ruiz-Cabello J, Barnett BP, Bottomley PA, Bulte JW. Fluorine (19F) MRS and MRI in biomedicine. NMR IN BIOMEDICINE 2011; 24:114-29. [PMID: 20842758 PMCID: PMC3051284 DOI: 10.1002/nbm.1570] [Citation(s) in RCA: 363] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Revised: 04/23/2010] [Accepted: 04/26/2010] [Indexed: 05/04/2023]
Abstract
Shortly after the introduction of (1)H MRI, fluorinated molecules were tested as MR-detectable tracers or contrast agents. Many fluorinated compounds, which are nontoxic and chemically inert, are now being used in a broad range of biomedical applications, including anesthetics, chemotherapeutic agents, and molecules with high oxygen solubility for respiration and blood substitution. These compounds can be monitored by fluorine ((19)F) MRI and/or MRS, providing a noninvasive means to interrogate associated functions in biological systems. As a result of the lack of endogenous fluorine in living organisms, (19)F MRI of 'hotspots' of targeted fluorinated contrast agents has recently opened up new research avenues in molecular and cellular imaging. This includes the specific targeting and imaging of cellular surface epitopes, as well as MRI cell tracking of endogenous macrophages, injected immune cells and stem cell transplants.
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Affiliation(s)
- Jesús Ruiz-Cabello
- Russell H. Morgan Department of Radiology, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Vascular Biology Program and Cellular Imaging Section, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, USA
- NMR Group, Institute of Functional Studies, Complutense University and CIBERES, Madrid, Spain
| | - Brad P. Barnett
- Russell H. Morgan Department of Radiology, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Vascular Biology Program and Cellular Imaging Section, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, USA
| | - Paul A. Bottomley
- Russell H. Morgan Department of Radiology, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jeff W.M. Bulte
- Russell H. Morgan Department of Radiology, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Vascular Biology Program and Cellular Imaging Section, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Abstract
MR oximetry includes methods for assessing tissue oxygenation. This chapter focuses on direct measurements of oxygenation. These can be divided into three methods. The first and most common has been termed BOLD MRI and relates to the quantification of deoxyhemoglobin. The second method uses an injected fluorinated agent which has a T (1) that is sensitive to tissue oxygen levels. The third is a direct measurement of T (1) under conditions where the variation in T (1) can be limited to that caused by changes in pO(2). These conditions can be met in the vitreous of the eye or the cerebrospinal fluids. Such changes in the eye have been called the retinal oxygenation response.
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Affiliation(s)
- Jeff F Dunn
- Department of Radiology, Physiology, and Biophysics, Faculty of Medicine, University of Calgary, Calgary, Canada.
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Pacheco-Torres J, López-Larrubia P, Ballesteros P, Cerdán S. Imaging tumor hypoxia by magnetic resonance methods. NMR IN BIOMEDICINE 2011; 24:1-16. [PMID: 21259366 DOI: 10.1002/nbm.1558] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2009] [Revised: 03/21/2010] [Accepted: 04/01/2010] [Indexed: 05/10/2023]
Abstract
Tumor hypoxia results from the negative balance between the oxygen demands of the tissue and the capacity of the neovasculature to deliver sufficient oxygen. The resulting oxygen deficit has important consequences with regard to the aggressiveness and malignancy of tumors, as well as their resistance to therapy, endowing the imaging of hypoxia with vital repercussions in tumor prognosis and therapy design. The molecular and cellular events underlying hypoxia are mediated mainly through hypoxia-inducible factor, a transcription factor with pleiotropic effects over a variety of cellular processes, including oncologic transformation, invasion and metastasis. However, few methodologies have been able to monitor noninvasively the oxygen tensions in vivo. MRI and MRS are often used for this purpose. Most MRI approaches are based on the effects of the local oxygen tension on: (i) the relaxation times of (19)F or (1)H indicators, such as perfluorocarbons or their (1)H analogs; (ii) the hemodynamics and magnetic susceptibility effects of oxy- and deoxyhemoglobin; and (iii) the effects of paramagnetic oxygen on the relaxation times of tissue water. (19)F MRS approaches monitor tumor hypoxia through the selective accumulation of reduced nitroimidazole derivatives in hypoxic zones, whereas electron spin resonance methods determine the oxygen level through its influence on the linewidths of appropriate paramagnetic probes in vivo. Finally, Overhauser-enhanced MRI combines the sensitivity of EPR methodology with the resolution of MRI, providing a window into the future use of hyperpolarized oxygen probes.
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Affiliation(s)
- Jesús Pacheco-Torres
- Laboratory for Imaging and Spectroscopy by Magnetic Resonance LISMAR, Institute of Biomedical Research Alberto Sols, CSIC/UAM, c/Arturo Duperier 4, Madrid, Spain
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Winter PM, Caruthers SD, Lanza GM, Wickline SA. Quantitative cardiovascular magnetic resonance for molecular imaging. J Cardiovasc Magn Reson 2010; 12:62. [PMID: 21047411 PMCID: PMC2987770 DOI: 10.1186/1532-429x-12-62] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Accepted: 11/03/2010] [Indexed: 12/14/2022] Open
Abstract
Cardiovascular magnetic resonance (CMR) molecular imaging aims to identify and map the expression of important biomarkers on a cellular scale utilizing contrast agents that are specifically targeted to the biochemical signatures of disease and are capable of generating sufficient image contrast. In some cases, the contrast agents may be designed to carry a drug payload or to be sensitive to important physiological factors, such as pH, temperature or oxygenation. In this review, examples will be presented that utilize a number of different molecular imaging quantification techniques, including measuring signal changes, calculating the area of contrast enhancement, mapping relaxation time changes or direct detection of contrast agents through multi-nuclear imaging or spectroscopy. The clinical application of CMR molecular imaging could offer far reaching benefits to patient populations, including early detection of therapeutic response, localizing ruptured atherosclerotic plaques, stratifying patients based on biochemical disease markers, tissue-specific drug delivery, confirmation and quantification of end-organ drug uptake, and noninvasive monitoring of disease recurrence. Eventually, such agents may play a leading role in reducing the human burden of cardiovascular disease, by providing early diagnosis, noninvasive monitoring and effective therapy with reduced side effects.
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Affiliation(s)
- Patrick M Winter
- Cincinnati Children's Hospital, Department of Radiology, 3333 Burnet Ave., ML 5033, Cincinnati, OH, 45229, USA
| | - Shelton D Caruthers
- Washington University, C-TRAIN Labs, 660 S. Euclid Ave., Campus Box 8215, St. Louis, MO, 63110, USA
| | - Gregory M Lanza
- Washington University, C-TRAIN Labs, 660 S. Euclid Ave., Campus Box 8215, St. Louis, MO, 63110, USA
| | - Samuel A Wickline
- Washington University, C-TRAIN Labs, 660 S. Euclid Ave., Campus Box 8215, St. Louis, MO, 63110, USA
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Magat J, Jordan BF, Cron GO, Gallez B. Noninvasive mapping of spontaneous fluctuations in tumor oxygenation using F19 MRI. Med Phys 2010; 37:5434-41. [DOI: 10.1118/1.3484056] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Hokland SL, Nielsen T, Busk M, Horsman MR. Imaging tumour physiology and vasculature to predict and assess response to heat. Int J Hyperthermia 2010; 26:264-72. [PMID: 20388023 DOI: 10.3109/02656730903585982] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The vascular supply of tumours and the tumour microenvironment both play an important role when tumours are treated with hyperthermia. Blood flow is one of the major vehicles by which heat is dissipated thus the vascular supply will influence the ability to heat the tumour. It also influences the type of microenvironment that exists within tumours, and it is now well-established that cells existing in areas of oxygen deficiency, nutrient deprivation and acidic conditions are more sensitive to the effect of hyperthermia. The vascular supply and microenvironment are also affected by hyperthermia. In general, mild heat temperatures transiently improve blood flow and oxygenation, while higher hyperthermia temperatures cause vascular collapse and so increase the adverse microenvironmental conditions. Being able to image these vascular and microenvironmental parameters both before and after heating will help in our ability to predict and assess response. Here we review the various techniques that can be applied to supply this information, especially using non-invasive imaging approaches.
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Affiliation(s)
- Steffen L Hokland
- Department of Experimental Clinical Oncology, Aarhus University Hospital NBG, Aarhus, Denmark
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Baete SHU, Vandecasteele J, Colman L, De Neve W, De Deene Y. An oxygen-consuming phantom simulating perfused tissue to explore oxygen dynamics and (19)F MRI oximetry. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2010; 23:217-26. [PMID: 20577778 DOI: 10.1007/s10334-010-0219-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Revised: 05/31/2010] [Accepted: 06/01/2010] [Indexed: 11/28/2022]
Abstract
OBJECTIVE This study presents a reproducible phantom which mimics oxygen-consuming tissue and can be used for the validation of (19)F MRI oximetry. MATERIALS AND METHODS The phantom consists of a haemodialysis filter of which the outer compartment is filled with a gelatin matrix containing viable yeast cells. Perfluorocarbon emulsions can be added to the gelatin matrix to simulate sequestered perfluorocarbons. A blood-substituting perfluorocarbon fluid is pumped through the lumen of the fibres in the filter. (19)F relaxometry MRI is performed with a fast 2D Look-Locker imaging sequence on a clinical 3T scanner. RESULTS Acute and perfusion-related hypoxia were simulated and imaged spatially and temporally using the phantom. CONCLUSIONS The presented experimental setup can be used to simulate oxygen consumption by somatic cells in vivo and for validating computational biophysical models of hypoxia, as measured with (19)F MRI oximetry.
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Affiliation(s)
- Steven H Ubert Baete
- Department of Radiation Oncology and Experimental Cancer Research, Ghent University, Gent, Belgium.
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Ahmad R, Kuppusamy P. Theory, instrumentation, and applications of electron paramagnetic resonance oximetry. Chem Rev 2010; 110:3212-36. [PMID: 20218670 PMCID: PMC2868962 DOI: 10.1021/cr900396q] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Rizwan Ahmad
- Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, Department of Internal Medicine, The Ohio State University, Columbus, Ohio 43210, USA
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Bartusik D, Tomanek B, Siluk D, Kaliszan R. 19F MRI of 3D CEM cells to study the effects of tocopherols and tocotrienols. J Pharm Biomed Anal 2010; 53:599-602. [PMID: 20439143 DOI: 10.1016/j.jpba.2010.04.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2009] [Revised: 04/06/2010] [Accepted: 04/08/2010] [Indexed: 11/15/2022]
Abstract
Oximetry of the human T-Lymphoblastoid (CEM) cells was measured using (19)F magnetic resonance imaging ((19)F MRI). The cells were treated with the analogues of vitamin E, alpha-, gamma-, delta-tocopherols and corresponding tocotrienols, ex vivo in three-dimensional (3D) cell culture. The study showed that (19)F MRI allows to measure the effect of the analogues due to changes of oxygenation, which were detected using MRI. Hexafluorobenzene was used as a (19)F MRI probe sensitive to oxygen concentrations. After 72h of treatment in HFBR with alpha-, gamma-, delta-tocopherols the oxygen concentration was 19.9+/-0.8%, 19.3+/-1.4%, 16+/-3.5%, respectively. The oxygen concentration in cells treated with alpha-, gamma-, delta-tocotrienols was found to be 14+/-1.5%, 10+/-1.2% and 8.8+/-1.1%, respectively whereas for the control cells it was 22.1+/-1%. The results show that delta-tocopherol and delta-tocotrienol are the most effective treatments in CEM cells among all the tested analogues.
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Affiliation(s)
- Dorota Bartusik
- National Research Council Canada, Institute for Biodiagnostics West, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada.
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Gussoni M, Cremonini MA, Vezzoli A, Greco F, Zetta L. A quantitative method to assess muscle tissue oxygenation in vivo by monitoring 1H nuclear magnetic resonance myoglobin resonances. Anal Biochem 2010; 400:33-45. [DOI: 10.1016/j.ab.2010.01.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Revised: 12/10/2009] [Accepted: 01/14/2010] [Indexed: 11/30/2022]
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Chopra S, Foltz WD, Milosevic MF, Toi A, Bristow RG, Ménard C, Haider MA. Comparing oxygen-sensitive MRI (BOLD R2*) with oxygen electrode measurements: a pilot study in men with prostate cancer. Int J Radiat Biol 2009; 85:805-13. [PMID: 19728195 DOI: 10.1080/09553000903043059] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
PURPOSE To explore the relationship between oxygen-sensitive Magnetic Resonance Imaging (MRI) and oxygen measurements in prostate cancer. METHODS Nine men underwent MRI examinations followed by needle oxygen measurements of tumor bearing region within prostate gland and five men further consented to biopsy. Median pO2 and hypoxic fraction < 5 mm Hg (HP5) were derived. Biopsies were immunostained for Carbonic Anhydrase IX (CA IX), Hypoxia Inducible Factor-1 (HIF 1) and Glucose Transporter-1 (GLUT 1). Corresponding Regions-of-Interest (ROI) were delineated on T2-weighted (T2w) MRI by two observers. Median R2* was calculated for each ROI. Spearman correlation was calculated between R2* and HP5/pO2. RESULTS MRI quality evaluation resulted in exclusion of 4/18 ROI due to motion (n = 2) and rectal air susceptibility artifact (n = 2). Quality of remaining data was validated by concordance of R2* with T2w, indices and with secondary observer R2* (r = 0.94, p = 0.005). Correlation was observed between R2* and HP5 (r = 0.76, p = 0.02) and a trend was noted between R2* and pO2 (r = -0.66, p = 0.07). GLUT 1 and HIF 1 were expressed in all patients, and CA IX was expressed in one patient with high HP5 (77%) and low pO2 (1.4 mm Hg). CONCLUSIONS MRI using R2* quantification is a promising tool for non-invasive imaging of prostate cancer hypoxia.
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Affiliation(s)
- Supriya Chopra
- Department of Radiation Oncology, University Health Network, Princess Margaret Hospital, University of Toronto, Toronto, Ontario, Canada
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Evans RG, Gardiner BS, Smith DW, O'Connor PM. Methods for studying the physiology of kidney oxygenation. Clin Exp Pharmacol Physiol 2009; 35:1405-12. [PMID: 18983577 DOI: 10.1111/j.1440-1681.2008.05063.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
1. An improved understanding of the regulation of kidney oxygenation has the potential to advance preventative, diagnostic and therapeutic strategies for kidney disease. Here, we review the strengths and limitations of available and emerging methods for studying kidney oxygen status. 2. To fully characterize kidney oxygen handling, we must quantify multiple parameters, including renal oxygen delivery (DO2) and consumption (VO2), as well as oxygen tension (Po2). Ideally, these parameters should be quantified both at the whole-organ level and within specific vascular, tubular and interstitial compartments. 3. Much of our current knowledge of kidney oxygen physiology comes from established techniques that allow measurement of global kidney DO2 and VO2, or local tissue Po2. When used in tandem, these techniques can help us understand oxygen mass balance in the kidney. Po2 can be resolved to specific tissue compartments in the superficial cortex, but not deep below the kidney surface. We have limited ability to measure local kidney tissue DO2 and VO2. 4. Mathematical modelling has the potential to provide new insights into the physiology of kidney oxygenation, but is limited by the quality of the information such models are based on. 5. Various imaging techniques and other emerging technologies have the potential to allow Po2 mapping throughout the kidney and/or spatial resolution of Po2 in specific renal tissues, even in humans. All currently available methods have serious limitations, but with further refinement should provide a pathway through which data obtained from experimental animal models can be related to humans in the clinical setting.
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Affiliation(s)
- Roger G Evans
- Department of Physiology, Monash University, Victoria, Australia.
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Moreno-Sánchez R, Rodríguez-Enríquez S, Saavedra E, Marín-Hernández A, Gallardo-Pérez JC. The bioenergetics of cancer: is glycolysis the main ATP supplier in all tumor cells? Biofactors 2009; 35:209-25. [PMID: 19449450 DOI: 10.1002/biof.31] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The molecular mechanisms by which tumor cells achieve an enhanced glycolytic flux and, presumably, a decreased oxidative phosphorylation are analyzed. As the O(2) concentration in hypoxic regions of tumors seems not limiting for oxidative phosphorylation, the role of this mitochondrial pathway in the ATP supply is re-evaluated. Drugs that inhibit glycoysis and oxidative phosphorylation are analyzed for their specificity toward tumor cells and effect on proliferation. The energy metabolism mechanisms involved in the use of positron emission tomography are revised and updated. It is proposed that energy metabolism may be an alternative therapeutic target for both hypoxic (glycolytic) and oxidative tumors. (c) 2009 International Union of Biochemistry and Molecular Biology, Inc.
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Affiliation(s)
- Rafael Moreno-Sánchez
- Instituto Nacional de Cardiología, Departamento de Bioquímica, Juan Badiano 1, Tlalpan, México DF, Mexico
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Nyström AM, Bartels JW, Du W, Wooley KL. Perfluorocarbon-loaded Shell Crosslinked Knedel-like Nanoparticles: Lessons regarding polymer mobility and self assembly. JOURNAL OF POLYMER SCIENCE. PART A, POLYMER CHEMISTRY 2009; 47:1023-1037. [PMID: 20157345 PMCID: PMC2779516 DOI: 10.1002/pola.23184] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Reversible addition-fragmentation chain transfer polymerization was employed to synthesize a set of copolymers of styrene (PS) and 2,3,4,5,6-pentafluorostyrene (PPFS), as well as block copolymers with tert-butyl acrylate (PtBA)-b-PS-co-PPFS, with control over molecular weight and polydispersity. It was found that the copolymerization of styrene and PFS allowed for the preparation of gradient copolymers with opposite levels of monomer consumption, depending on the feed ratio. Conversion to amphiphilic block copolymers, PAA-b-(PS-co-PPFS), by removing the protecting groups was followed by fitting with monomethoxy poly(ethylene glycol) chains. Solution-state assembly and intramicellar crosslinking afforded shell crosslinked (SCK) block copolymer nanoparticles. These fluorinated nanoparticles (ca. 20 nm diameters) were studied as potential magnetic resonance imaging (MRI) contrast agents based on the (19)F-nuclei, however, it was found that packaging of the hydrophobic fluorinated polymers into the core domain restricted the mobility of the chains and prohibited (19)F-NMR spectroscopy when the particles were dispersed in water without an organic cosolvent. Packing of perflouro-15-crown-5-ether (PFCE) into the polymer micelle was demonstrated with good uptake efficiency, however, it was necessary to swell the core with a good solvent (DMSO) to increase the mobility and observe the (19)F-NMR signal of the PFCE.
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Affiliation(s)
- Andreas M Nyström
- Department of Chemistry and Department of Radiology, Washington University in Saint Louis, Saint Louis, Missouri 63130-4899 (USA)
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Kodibagkar VD, Wang X, Pacheco-Torres J, Gulaka P, Mason RP. Proton imaging of siloxanes to map tissue oxygenation levels (PISTOL): a tool for quantitative tissue oximetry. NMR IN BIOMEDICINE 2008; 21:899-907. [PMID: 18574806 PMCID: PMC3027221 DOI: 10.1002/nbm.1279] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Hexamethyldisiloxane (HMDSO) has been identified as a sensitive proton NMR indicator of tissue oxygenation (pO(2)) based on spectroscopic spin-lattice relaxometry. A rapid MRI approach has now been designed, implemented, and tested. The technique, proton imaging of siloxanes to map tissue oxygenation levels (PISTOL), utilizes frequency-selective excitation of the HMDSO resonance and chemical-shift selective suppression of residual water signal to effectively eliminate water and fat signals and pulse-burst saturation recovery (1)H echo planar imaging to map T(1) of HMDSO and hence pO(2). PISTOL was used here to obtain maps of pO(2) in rat thigh muscle and Dunning prostate R3327 MAT-Lu tumor-implanted rats. Measurements were repeated to assess baseline stability and response to breathing of hyperoxic gas. Each pO(2) map was obtained in 3(1/2) min, facilitating dynamic measurements of response to oxygen intervention. Altering the inhaled gas to oxygen produced a significant increase in mean pO(2) from 55 Torr to 238 Torr in thigh muscle and a smaller, but significant, increase in mean pO(2) from 17 Torr to 78 Torr in MAT-Lu tumors. Thus, PISTOL enabled mapping of tissue pO(2) at multiple locations and dynamic changes in pO(2) in response to intervention. This new method offers a potentially valuable new tool to image pO(2) in vivo for any healthy or diseased state by (1)H MRI.
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Affiliation(s)
- Vikram D. Kodibagkar
- Cancer Imaging Program, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Xianghui Wang
- Cancer Imaging Program, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jesús Pacheco-Torres
- Cancer Imaging Program, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Instituto de Investigaciones Biomédicas ‘Alberto Sols’, CSIC, Madrid, Spain
| | - Praveen Gulaka
- Cancer Imaging Program, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Ralph P. Mason
- Cancer Imaging Program, Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
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Du W, Nyström AM, Zhang L, Powell KT, Li Y, Cheng C, Wickline SA, Wooley KL. Amphiphilic hyperbranched fluoropolymers as nanoscopic 19F magnetic resonance imaging agent assemblies. Biomacromolecules 2008; 9:2826-33. [PMID: 18795785 DOI: 10.1021/bm800595b] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Three hyperbranched fluoropolymers were synthesized and their micelles were constructed as potential (19)F MRI agents. A hyperbranched star-like core was first synthesized via atom transfer radical self-condensing vinyl (co)polymerization (ATR-SCVCP) of 4-chloromethyl styrene (CMS), lauryl acrylate (LA), and 1,1,1-tris(4'-(2''-bromoisobutyryloxy)phenyl)ethane (TBBPE). The polymerization gave a small core with M n of 5.5 kDa with PDI of 1.6, which served as a macroinitiator. Trifluoroethyl methacrylate (TFEMA) and tert-butyl acrylate (tBA) in different ratios were then "grafted" from the core to give three polymers with M(n) of about 120 kDa and PDI values of about 1.6-1.8. After acidolysis of the tert-butyl ester groups, amphiphilic, hyperbranched star-like polymers with M(n) of about 100 kDa were obtained. These structures were subjected to micelle formation in aqueous solution to give micelles having TEM-measured diameters ranging from 3-8 nm and DLS-measured hydrodynamic diameters from 20-30 nm. These micelles gave a narrow, single resonance by (19)F NMR spectroscopy, with a half-width of approximately 130 Hz. The T1/T2 parameters were about 500 and 50 ms, respectively, and were not significantly affected by the composition and sizes of the micelles. (19)F MRI phantom images of these fluorinated micelles were acquired, which demonstrated that these fluorinated micelles maybe useful as novel (19)F MRI agents for a variety of biomedical studies.
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Affiliation(s)
- Wenjun Du
- Department of Chemistry, Washington University in Saint Louis, Saint Louis, Missouri 63130, USA
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