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Eubank TD, Bobko AA, Hoblitzell EH, Gencheva M, Driesschaert B, Khramtsov VV. In Vivo Electron Paramagnetic Resonance Molecular Profiling of Tumor Microenvironment upon Tumor Progression to Malignancy in an Animal Model of Breast Cancer. Mol Imaging Biol 2024; 26:424-434. [PMID: 37610610 PMCID: PMC10884355 DOI: 10.1007/s11307-023-01847-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 07/27/2023] [Accepted: 08/07/2023] [Indexed: 08/24/2023]
Abstract
PURPOSE Hypoxia and acidosis are recognized tumor microenvironment (TME) biomarkers of cancer progression. Alterations in cancer redox status and metabolism are also associated with elevated levels of intracellular glutathione (GSH) and interstitial inorganic phosphate (Pi). This study aims to evaluate the capability of these biomarkers to discriminate between stages and inform on a switch to malignancy. PROCEDURES These studies were performed using MMTV-PyMT( +) female transgenic mice that spontaneously develop breast cancer and emulate human tumor staging. In vivo assessment of oxygen concentration (pO2), extracellular acidity (pHe), Pi, and GSH was performed using L-band electron paramagnetic resonance spectroscopy and multifunctional trityl and GSH-sensitive nitroxide probes. RESULTS Profiling of the TME showed significant deviation of measured biomarkers upon tumor progression from pre-malignancy (pre-S4) to the malignant stage (S4). For the combined marker, HOP: (pHe × pO2)/Pi, a value > 186 indicated that the tumors were pre-malignant in 85% of the mammary glands analyzed, and when < 186, they were malignant 42% of the time. For GSH, a value < 3 mM indicated that the tumors were pre-malignant 74% of the time, and when > 3 mM, they were malignant 80% of the time. The only marker that markedly deviated as early as stage 1 (S1) from its value in pre-S1 was elevated Pi, followed by a decrease of pHe and pO2 and increase in GSH at later stages. CONCLUSION Molecular TME profiling informs on alteration of tumor redox and metabolism during tumor staging. Early elevation of interstitial Pi at S1 may reflect tumor metabolic alterations that demand elevated phosphorus supply in accordance with the high rate growth hypothesis. These metabolic changes are supported by the following decrease of pHe due to a high tumor reliance on glycolysis and increase of intracellular GSH, a major intracellular redox buffer. The appreciable decrease in TME pO2 was observed only at malignant S4, apparently as a consequence of tumor mass growth and corresponding decrease in perfusion efficacy and increase in oxygen consumption as the tumor cells proliferate.
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Affiliation(s)
- Timothy D Eubank
- In Vivo Multifunctional Magnetic Resonance Center, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV, 26506, USA.
- Department of Microbiology, Immunology, and Cell Biology, School of Medicine, West Virginia University, Morgantown, WV, 26506, USA.
| | - Andrey A Bobko
- In Vivo Multifunctional Magnetic Resonance Center, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV, 26506, USA
- Department of Biochemistry and Molecular Medicine, School of Medicine, West Virginia University, Morgantown, WV, 26506, USA
| | - E Hannah Hoblitzell
- In Vivo Multifunctional Magnetic Resonance Center, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV, 26506, USA
- Department of Microbiology, Immunology, and Cell Biology, School of Medicine, West Virginia University, Morgantown, WV, 26506, USA
| | - Marieta Gencheva
- In Vivo Multifunctional Magnetic Resonance Center, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV, 26506, USA
- Department of Biochemistry and Molecular Medicine, School of Medicine, West Virginia University, Morgantown, WV, 26506, USA
| | - Benoit Driesschaert
- In Vivo Multifunctional Magnetic Resonance Center, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV, 26506, USA
- Department of Pharmaceutical Sciences, School of Pharmacy, West Virginia University, Morgantown, WV, 26506, USA
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, WV, 26506, USA
| | - Valery V Khramtsov
- In Vivo Multifunctional Magnetic Resonance Center, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV, 26506, USA.
- Department of Biochemistry and Molecular Medicine, School of Medicine, West Virginia University, Morgantown, WV, 26506, USA.
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Longo DL, Carella A, Corrado A, Pirotta E, Mohanta Z, Singh A, Stabinska J, Liu G, McMahon MT. A snapshot of the vast array of diamagnetic CEST MRI contrast agents. NMR IN BIOMEDICINE 2023; 36:e4715. [PMID: 35187749 PMCID: PMC9724179 DOI: 10.1002/nbm.4715] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 05/11/2023]
Abstract
Since the inception of CEST MRI in the 1990s, a number of compounds have been identified as suitable for generating contrast, including paramagnetic lanthanide complexes, hyperpolarized atom cages and, most interesting, diamagnetic compounds. In the past two decades, there has been a major emphasis in this field on the identification and application of diamagnetic compounds that have suitable biosafety profiles for usage in medical applications. Even in the past five years there has been a tremendous growth in their numbers, with more and more emphasis being placed on finding those that can be ultimately used for patient studies on clinical 3 T scanners. At this point, a number of endogenous compounds present in tissue have been identified, and also natural and synthetic organic compounds that can be administered to highlight pathology via CEST imaging. Here we will provide a very extensive snapshot of the types of diamagnetic compound that can generate CEST MRI contrast, together with guidance on their utility on typical preclinical and clinical scanners and a review of the applications that might benefit the most from this new technology.
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Affiliation(s)
- Dario Livio Longo
- Institute of Biostructures and Bioimaging (IBB), National Research Council of Italy (CNR), Turin, Italy
| | - Antonella Carella
- Institute of Biostructures and Bioimaging (IBB), National Research Council of Italy (CNR), Turin, Italy
| | - Alessia Corrado
- Institute of Biostructures and Bioimaging (IBB), National Research Council of Italy (CNR), Turin, Italy
| | - Elisa Pirotta
- Institute of Biostructures and Bioimaging (IBB), National Research Council of Italy (CNR), Turin, Italy
| | - Zinia Mohanta
- F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Aruna Singh
- F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Julia Stabinska
- F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Guanshu Liu
- F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Michael T. McMahon
- F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
- Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Radiometal-Based PET/MRI Contrast Agents for Sensing Tumor Extracellular pH. BIOSENSORS 2022; 12:bios12020134. [PMID: 35200394 PMCID: PMC8870419 DOI: 10.3390/bios12020134] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 02/14/2022] [Accepted: 02/16/2022] [Indexed: 02/03/2023]
Abstract
Acidosis is a useful biomarker for tumor diagnoses and for evaluating early response to anti-cancer treatments. Despite these useful applications, there are few methods for non-invasively measuring tumor extracellular pH, and none are routinely used in clinics. Responsive MRI contrast agents have been developed, and they undergo a change in MRI signal with pH. However, these signal changes are concentration-dependent, and it is difficult to accurately measure the concentration of an MRI contrast agent in vivo. PET/MRI provides a unique opportunity to overcome this concentration dependence issue by using the PET component to report on the concentration of the pH-responsive MRI agent. Herein, we synthesized PET/MRI co-agents based on the design of a pH-dependent MRI agent, and we have correlated pH with the r1 relaxivity of the MRI co-agent. We have also developed a procedure that uses PET radioactivity measurements and MRI R1 relaxation rate measurements to determine the r1 relaxivity of the MRI co-agent, which can then be used to estimate pH. This simultaneous PET/MRI procedure accurately measured pH in solution, with a precision that depended on the concentration of the MRI co-agent. We used our procedure to measure extracellular pH in a subcutaneous flank model of MIA PaCa-2 pancreatic cancer. Although the PET co-agents were stable in serum, post-imaging studies showed evidence that the PET co-agents were degraded in vivo. These results showed that tumor acidosis can be evaluated with simultaneous PET/MRI, although improvements are needed to more precisely measure MRI R1 relaxation rates, and ensure the in vivo stability of the agents.
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Kombala CJ, Kotrotsou A, Schuler FW, de la Cerda J, Ma JC, Zhang S, Pagel MD. Development of a Nanoscale Chemical Exchange Saturation Transfer Magnetic Resonance Imaging Contrast Agent That Measures pH. ACS NANO 2021; 15:20678-20688. [PMID: 34870957 DOI: 10.1021/acsnano.1c10107] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
AcidoCEST MRI can measure the extracellular pH (pHe) of the tumor microenvironment in mouse models of human cancers and in patients who have cancer. However, chemical exchange saturation transfer (CEST) is an insensitive magnetic resonance imaging (MRI) contrast mechanism, requiring a high concentration of small-molecule agent to be delivered to the tumor. Herein, we developed a nanoscale CEST agent that can measure pH using acidoCEST MRI, which may decrease the requirement for high delivery concentrations of agent. We also developed a monomer agent for comparison to the polymer. After optimizing CEST experimental conditions, we determined that the polymer agent could be used during acidoCEST MRI studies at 125-fold and 488-fold lower concentration than the monomer agent and iopamidol, respectively. We also determined that both agents can measure pH with negligible dependence on temperature. However, pH measurements with both agents were dependent on concentration, which may be due to concentration-dependent changes in hydrogen bonding and/or steric hindrance. We performed in vivo acidoCEST MRI studies using the three agents to study a xenograft MDA-MB-231 model of mammary carcinoma. The tumor pHe measurements were 6.33 ± 0.12, 6.70 ± 0.15, and 6.85 ± 0.15 units with iopamidol, the monomer agent, and polymer agent, respectively. The higher pHe measurements with the monomer and polymer agents were attributed to the concentration dependence of these agents. This study demonstrated that nanoscale agents have merit for CEST MRI studies, but consideration should be given to the dependence of CEST contrast on the concentration of these agents.
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Affiliation(s)
- Chathuri J Kombala
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
- Department of Cancer Systems Imaging, University of Texas MD Anderson Cancer Center, Houston, Texas 77054, United States
| | - Aikaterini Kotrotsou
- Department of Cancer Systems Imaging, University of Texas MD Anderson Cancer Center, Houston, Texas 77054, United States
| | - F William Schuler
- Department of Cancer Systems Imaging, University of Texas MD Anderson Cancer Center, Houston, Texas 77054, United States
| | - Jorge de la Cerda
- Department of Cancer Systems Imaging, University of Texas MD Anderson Cancer Center, Houston, Texas 77054, United States
| | - Jacqueline C Ma
- Department of Cancer Systems Imaging, University of Texas MD Anderson Cancer Center, Houston, Texas 77054, United States
| | - Shu Zhang
- Department of Cancer Systems Imaging, University of Texas MD Anderson Cancer Center, Houston, Texas 77054, United States
| | - Mark D Pagel
- Department of Cancer Systems Imaging, University of Texas MD Anderson Cancer Center, Houston, Texas 77054, United States
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Kombala CJ, Lokugama SD, Kotrotsou A, Li T, Pollard AC, Pagel MD. Simultaneous Evaluations of pH and Enzyme Activity with a CEST MRI Contrast Agent. ACS Sens 2021; 6:4535-4544. [PMID: 34856102 DOI: 10.1021/acssensors.1c02408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The extracellular tumor microenvironment of many solid tumors has high acidosis and high protease activity. Simultaneously assessing both characteristics may improve diagnostic evaluations of aggressive tumors and the effects of anticancer treatments. Noninvasive imaging methods have previously been developed that measure extracellular pH or can detect enzyme activity using chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI). Herein, we developed a single-hybrid CEST agent that can simultaneously measure pH and evaluate protease activity using a combination of dual-power acidoCEST MRI and catalyCEST MRI. Our agent showed CEST signals at 9.2 ppm from a salicylic acid moiety and at 5.0 ppm from an aryl amide. The CEST signal at 9.2 ppm could be measured after selective saturation was applied at 1 and 4 μT, and these measurements could be used with a ratiometric analysis to determine pH. The CEST signal at 5.0 ppm from the aryl amide disappeared after the agent was treated with cathepsin B, while the CEST signal at 9.2 ppm remained, indicating that the agent could detect protease activity through the amide bond cleavage. Michaelis-Menten kinetics studies with catalyCEST MRI demonstrated that the binding affinity (as shown with the Michaelis constant KM), the catalytic turnover rate (kcat), and catalytic efficiency (kcat/KM) were each higher for cathepsin B at lower pH. The kcat rates measured with catalyCEST MRI were lower than the comparable rates measured with liquid chromatography-mass spectrometry (LC-MS), which reflected a limitation of inherently noisy and relatively insensitive CEST MRI analyses. Although this level of precision limited catalyCEST MRI to semiquantitative evaluations, these semiquantitative assessments of high and low protease activity still had value by demonstrating that high acidosis and high protease activity can be used as synergistic, multiparametric biomarkers.
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Affiliation(s)
- Chathuri J. Kombala
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
- Department of Cancer Systems Imaging, University of Texas MD Anderson Cancer Center, Houston, Texas 77054, United States
| | - Sanjaya D. Lokugama
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
- Department of Cancer Systems Imaging, University of Texas MD Anderson Cancer Center, Houston, Texas 77054, United States
| | - Aikaterini Kotrotsou
- Department of Cancer Systems Imaging, University of Texas MD Anderson Cancer Center, Houston, Texas 77054, United States
| | - Tianzhe Li
- Department of Cancer Systems Imaging, University of Texas MD Anderson Cancer Center, Houston, Texas 77054, United States
| | - Alyssa C. Pollard
- Department of Cancer Systems Imaging, University of Texas MD Anderson Cancer Center, Houston, Texas 77054, United States
- Department of Chemistry, Rice University, Houston, Texas 77251, United States
| | - Mark D. Pagel
- Department of Cancer Systems Imaging, University of Texas MD Anderson Cancer Center, Houston, Texas 77054, United States
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Chung JJ, Jin T. Low duty cycle pulse trains for exchange rate insensitive chemical exchange saturation transfer MRI. Magn Reson Med 2021; 86:2542-2551. [PMID: 34196028 DOI: 10.1002/mrm.28896] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 04/29/2021] [Accepted: 06/02/2021] [Indexed: 12/22/2022]
Abstract
PURPOSE To introduce and validate a pulse scheme that uses low duty cycle trains of π-pulses to achieve saturation that is relatively insensitive to exchange rate yet linearly dependent on labile proton concentration. METHODS Simulations were performed to explore the exchange rate sensitivity of π-pulse trains and continuous wave chemical exchange saturation transfer (CEST) signals. Creatine phantoms with varying pH and varying concentrations were imaged to demonstrate pH insensitivity and concentration dependence of low duty cycle π-pulse saturation. RESULTS Simulations show decreasing the duty cycle of π-pulse saturation decreases peak sensitivity to exchange rate, and this range of insensitivity can be tuned to different exchange rates through average B1 power. The range of insensitivity is unaffected by changes in relaxation and magnetization transfer, while the sensitivity of CEST signal maintains linear dependence on labile proton concentration. Under B1, avg = 0.48 μT, 30 mM creatine with pHs ranging between 6.36 and 8.21 exhibited CEST contrast ranging between ~6 and 11% under continuous wave and ~4% across all pHs using 10% duty cycle π-pulses. Imaging these phantoms using duty cycles of 5, 10, 25, and 50% showed decreasing pH sensitivity with decreased duty cycle. Creatine phantoms with varied concentrations and pHs reveal that π-pulse train saturation exhibited stricter correlation to concentration at lower DCs. CONCLUSION Low DC π-pulse train is an easy-to-implement way of providing labile proton concentration-dependent CEST MRI signal that is insensitive to exchange rate. This approach can be useful in studies where a change of chemical exchange rate may interfere with accurate assessments of physiology or pathology.
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Affiliation(s)
- Julius Juhyun Chung
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Tao Jin
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Kim H, Wu Y, Villano D, Longo DL, McMahon MT, Sun PZ. Analysis Protocol for the Quantification of Renal pH Using Chemical Exchange Saturation Transfer (CEST) MRI. Methods Mol Biol 2021; 2216:667-688. [PMID: 33476030 DOI: 10.1007/978-1-0716-0978-1_40] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
The kidney plays a major role in maintaining body pH homeostasis. Renal pH, in particular, changes immediately following injuries such as intoxication and ischemia, making pH an early biomarker for kidney injury before the symptom onset and complementary to well-established laboratory tests. Because of this, it is imperative to develop minimally invasive renal pH imaging exams and test pH as a new diagnostic biomarker in animal models of kidney injury before clinical translation. Briefly, iodinated contrast agents approved by the US Food and Drug Administration (FDA) for computed tomography (CT) have demonstrated promise as novel chemical exchange saturation transfer (CEST) MRI agents for pH-sensitive imaging. The generalized ratiometric iopamidol CEST MRI analysis enables concentration-independent pH measurement, which simplifies in vivo renal pH mapping. This chapter describes quantitative CEST MRI analysis for preclinical renal pH mapping, and their application in rodents, including normal conditions and acute kidney injury.This publication is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This analysis protocol chapter is complemented by two separate chapters describing the basic concepts and experimental procedure.
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Affiliation(s)
- Hahnsung Kim
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA.,Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, USA
| | - Yin Wu
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.,Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China
| | - Daisy Villano
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Dario Livio Longo
- Institute of Biostructures and Bioimaging (IBB), Italian National Research Council (CNR), Torino, Italy
| | - Michael T McMahon
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA.,The Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Phillip Zhe Sun
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA. .,Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, USA. .,Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
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Hyder F, Coman D. Imaging Extracellular Acidification and Immune Activation in Cancer. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2021; 18. [PMID: 33997581 DOI: 10.1016/j.cobme.2021.100278] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Metabolism reveals pathways by which cells, in healthy and disease tissues, use nutrients to fuel their function and (re)growth. However, gene-centric views have dominated cancer hallmarks, relegating metabolic reprogramming that all cells in the tumor niche undergo as an incidental phenomenon. Aerobic glycolysis in cancer is well known, but recent evidence suggests that diverse symbolic traits of cancer cells are derived from oncogene-directed metabolism required for their sustenance and evolution. Cells in the tumor milieu actively metabolize different nutrients, but proficiently secrete acidic by-products using diverse mechanisms to create a hostile ecosystem for host cells, and where local immune cells suffer collateral damage. Since metabolic interactions between cancer and immune cells hold promise for future cancer therapies, here we focus on translational magnetic resonance methods enabling in vivo and simultaneous detection of tumor habitat acidification and immune activation - innovations for monitoring personalized treatments.
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Affiliation(s)
- Fahmeed Hyder
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
- Department of Radiology & Biomedical Imaging, Yale University, New Haven, CT, USA
- Magnetic Resonance Research Center (MRRC), Yale University, New Haven, CT, USA
- Quantitative Neuroimaging with Magnetic Resonance (QNMR) Research Program, Yale University, New Haven, CT, USA
| | - Daniel Coman
- Department of Radiology & Biomedical Imaging, Yale University, New Haven, CT, USA
- Magnetic Resonance Research Center (MRRC), Yale University, New Haven, CT, USA
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Bo S, Sedaghat F, Pavuluri K, Rowe SP, Cohen A, Kates M, McMahon MT. Dynamic Contrast Enhanced-MR CEST Urography: An Emerging Tool in the Diagnosis and Management of Upper Urinary Tract Obstruction. Tomography 2021; 7:80-94. [PMID: 33801533 PMCID: PMC8103243 DOI: 10.3390/tomography7010008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 02/16/2021] [Indexed: 02/04/2023] Open
Abstract
Upper urinary tract obstructions (UTOs) are blockages that inhibit the flow of urine through its normal course, leading to impaired kidney function. Imaging plays a significant role in the initial diagnosis of UTO, with anatomic imaging (primarily ultrasound (US) and non-contrast computed tomography (CT)) serving as screening tools for the detection of the dilation of the urinary collecting systems (i.e., hydronephrosis). Whether hydronephrosis represents UTO or a non-obstructive process is determined by functional imaging (typically nuclear medicine renal scintigraphy). If these exams reveal evidence of UTO but no discernable source, multiphase contrast enhanced CT urography and/or dynamic contrast enhanced MR urography (DCE-MRU) may be performed to delineate a cause. These are often performed in conjunction with direct ureteroscopic evaluation. While contrast-enhanced CT currently predominates, it can induce renal injury due to contrast induced nephropathy (CIN), subject patients to ionizing radiation and is limited in quantifying renal function (traditionally assessed by renal scintigraphy) and establishing the extent to which hydronephrosis is due to functional obstruction. Traditional MRI is similarly limited in its ability to quantify function. DCE-MRU presents concerns regarding nephrogenic systemic fibrosis (NSF), although decreased with newer gadolinium-based contrast agents, and regarding cumulative gadolinium deposition in the basal ganglia. DCE-MR CEST urography is a promising alternative, employing new MRI contrast agents and imaging schemes and allowing for concurrent assessment of renal anatomy and functional parameters. In this review we highlight clinical challenges in the diagnosis and management of UTO, identify key advances in imaging agents and techniques for DCE-MR CEST urography and provide perspective on how this technique may evolve in clinical importance.
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Affiliation(s)
- Shaowei Bo
- The Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, The Johns Hopkins University, Baltimore, MD 21205, USA; (S.B.); (F.S.); (K.P.); (S.P.R.)
| | - Farzad Sedaghat
- The Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, The Johns Hopkins University, Baltimore, MD 21205, USA; (S.B.); (F.S.); (K.P.); (S.P.R.)
| | - KowsalyaDevi Pavuluri
- The Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, The Johns Hopkins University, Baltimore, MD 21205, USA; (S.B.); (F.S.); (K.P.); (S.P.R.)
| | - Steven P. Rowe
- The Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, The Johns Hopkins University, Baltimore, MD 21205, USA; (S.B.); (F.S.); (K.P.); (S.P.R.)
- The James Buchanan Brady Urological Institute, Department of Urology, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA; (A.C.); (M.K.)
| | - Andrew Cohen
- The James Buchanan Brady Urological Institute, Department of Urology, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA; (A.C.); (M.K.)
| | - Max Kates
- The James Buchanan Brady Urological Institute, Department of Urology, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA; (A.C.); (M.K.)
| | - Michael T. McMahon
- The Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, The Johns Hopkins University, Baltimore, MD 21205, USA; (S.B.); (F.S.); (K.P.); (S.P.R.)
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD 21205, USA
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Longo DL, Irrera P, Consolino L, Sun PZ, McMahon MT. Renal pH Imaging Using Chemical Exchange Saturation Transfer (CEST) MRI: Basic Concept. Methods Mol Biol 2021; 2216:241-256. [PMID: 33476004 DOI: 10.1007/978-1-0716-0978-1_14] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
Abstract
Magnetic Resonance Imaging (MRI) has been actively explored in the last several decades for assessing renal function by providing several physiological information, including glomerular filtration rate, renal plasma flow, tissue oxygenation and water diffusion. Within MRI, the developing field of chemical exchange saturation transfer (CEST) has potential to provide further functional information for diagnosing kidney diseases. Both endogenous produced molecules as well as exogenously administered CEST agents have been exploited for providing functional information related to kidney diseases in preclinical studies. In particular, CEST MRI has been exploited for assessing the acid-base homeostasis in the kidney and for monitoring pH changes in several disease models. This review summarizes several CEST MRI procedures for assessing kidney functionality and pH, for monitoring renal pH changes in different kidney injury models and for evaluating renal allograft rejection.This chapter is based upon work from the COST Action PARENCHIMA, a community-driven network funded by the European Cooperation in Science and Technology (COST) program of the European Union, which aims to improve the reproducibility and standardization of renal MRI biomarkers. This introduction chapter is complemented by two separate chapters describing the experimental procedure and data analysis.
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Affiliation(s)
- Dario Livio Longo
- Institute of Biostructures and Bioimaging (IBB), Italian National Research Council (CNR), Torino, Italy.
| | - Pietro Irrera
- University of Campania "Luigi Vanvitelli", Napoli, Italy
| | - Lorena Consolino
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Phillip Zhe Sun
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA
- Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Michael T McMahon
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- Division of MR Research, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Chen YW, Liu HQ, Wu QX, Huang YH, Tung YY, Lin MH, Lin CH, Chen TC, Lin EC, Hwang DW. pH Mapping of Skeletal Muscle by Chemical Exchange Saturation Transfer (CEST) Imaging. Cells 2020; 9:E2610. [PMID: 33291803 PMCID: PMC7762073 DOI: 10.3390/cells9122610] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/13/2020] [Accepted: 12/02/2020] [Indexed: 12/13/2022] Open
Abstract
Magnetic resonance imaging (MRI) is extensively used in clinical and basic biomedical research. However, MRI detection of pH changes still poses a technical challenge. Chemical exchange saturation transfer (CEST) imaging is a possible solution to this problem. Using saturation transfer, alterations in the exchange rates between the solute and water protons because of small pH changes can be detected with greater sensitivity. In this study, we examined a fatigued skeletal muscle model in electrically stimulated mice. The measured CEST signal ratio was between 1.96 ppm and 2.6 ppm in the z-spectrum, and this was associated with pH values based on the ratio between the creatine (Cr) and the phosphocreatine (PCr). The CEST results demonstrated a significant contrast change at the electrical stimulation site. Moreover, the pH value was observed to decrease from 7.23 to 7.15 within 20 h after electrical stimulation. This pH decrease was verified by 31P magnetic resonance spectroscopy and behavioral tests, which showed a consistent variation over time.
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Affiliation(s)
- Yu-Wen Chen
- Biomedical Translation Research Center, Academia Sinica, Taipei 115, Taiwan; (Y.-W.C.); (Y.-Y.T.); (M.-H.L.); (C.-H.L.)
| | - Hong-Qing Liu
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan; (H.-Q.L.); (Q.-X.W.); (Y.-H.H.); (T.-C.C.)
| | - Qi-Xuan Wu
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan; (H.-Q.L.); (Q.-X.W.); (Y.-H.H.); (T.-C.C.)
- Department of Chemistry and Biochemistry, National Chung Cheng University, Chiayi 621, Taiwan;
| | - Yu-Han Huang
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan; (H.-Q.L.); (Q.-X.W.); (Y.-H.H.); (T.-C.C.)
- The Department of Biotechnology, Ming Chuan University, Taoyuan 333, Taiwan
| | - Yu-Ying Tung
- Biomedical Translation Research Center, Academia Sinica, Taipei 115, Taiwan; (Y.-W.C.); (Y.-Y.T.); (M.-H.L.); (C.-H.L.)
| | - Ming-Huang Lin
- Biomedical Translation Research Center, Academia Sinica, Taipei 115, Taiwan; (Y.-W.C.); (Y.-Y.T.); (M.-H.L.); (C.-H.L.)
| | - Chia-Huei Lin
- Biomedical Translation Research Center, Academia Sinica, Taipei 115, Taiwan; (Y.-W.C.); (Y.-Y.T.); (M.-H.L.); (C.-H.L.)
| | - Tsai-Chen Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan; (H.-Q.L.); (Q.-X.W.); (Y.-H.H.); (T.-C.C.)
- The Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei 112, Taiwan
| | - Eugene C. Lin
- Department of Chemistry and Biochemistry, National Chung Cheng University, Chiayi 621, Taiwan;
| | - Dennis W. Hwang
- Biomedical Translation Research Center, Academia Sinica, Taipei 115, Taiwan; (Y.-W.C.); (Y.-Y.T.); (M.-H.L.); (C.-H.L.)
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan; (H.-Q.L.); (Q.-X.W.); (Y.-H.H.); (T.-C.C.)
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12
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Ratnakar SJ, Chirayil S, Funk AM, Zhang S, Queiró JF, Geraldes CFGC, Kovacs Z, Sherry AD. A Frequency-Selective pH-Responsive paraCEST Agent. Angew Chem Int Ed Engl 2020; 59:21671-21676. [PMID: 32726500 DOI: 10.1002/anie.202008888] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Indexed: 01/01/2023]
Abstract
Paramagnetic chemical exchange saturation transfer (paraCEST) agents are well-suited for imaging tissue pH because the basis of CEST, chemical exchange, is inherently sensitive to pH. Several previous pH-sensitive paraCEST agents were based on an exchanging Ln3+ -bound water molecule as the CEST antenna but this design often added additional line-broadening to the bulk water signal due to T2 exchange. We report herein a pH-sensitive paraCEST agent that lacks an inner-sphere water molecule but contains one Ln-bound -OH group for CEST activation. The Yb3+ complex, Yb(1), displayed a single, highly shifted CEST peak originating from the exchangeable Yb-OH proton, the frequency of which changed over the biologically relevant pH range. CEST images of phantoms ranging in pH from 6 to 8 demonstrate the potential of this agent for imaging pH. Initial rodent imaging studies showed that Gd(1) remains in the vascular system much longer than anticipated but is cleared slowly via renal filtration.
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Affiliation(s)
- S James Ratnakar
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Sara Chirayil
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Alexander M Funk
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Shanrong Zhang
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - João F Queiró
- CMUC, Department of Mathematics, University of Coimbra, Coimbra, Portugal
| | - Carlos F G C Geraldes
- Department of Life Sciences and Coimbra Chemistry Center, University of Coimbra, Coimbra, Portugal.,CIBIT- Coimbra Institute for Biomedical Imaging and Translational Research, University of Coimbra, Coimbra, Portugal
| | - Zoltan Kovacs
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - A Dean Sherry
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, TX, USA
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13
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Ratnakar SJ, Chirayil S, Funk AM, Zhang S, Queiró JF, Geraldes CFGC, Kovacs Z, Sherry AD. A Frequency‐Selective pH‐Responsive paraCEST Agent. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202008888] [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)
- S. James Ratnakar
- Advanced Imaging Research Center University of Texas Southwestern Medical Center Dallas TX USA
| | - Sara Chirayil
- Advanced Imaging Research Center University of Texas Southwestern Medical Center Dallas TX USA
| | - Alexander M. Funk
- Advanced Imaging Research Center University of Texas Southwestern Medical Center Dallas TX USA
| | - Shanrong Zhang
- Advanced Imaging Research Center University of Texas Southwestern Medical Center Dallas TX USA
| | - João F. Queiró
- CMUC, Department of Mathematics University of Coimbra Coimbra Portugal
| | - Carlos F. G. C. Geraldes
- Department of Life Sciences and Coimbra Chemistry Center University of Coimbra Coimbra Portugal
- CIBIT- Coimbra Institute for Biomedical Imaging and Translational Research University of Coimbra Coimbra Portugal
| | - Zoltan Kovacs
- Advanced Imaging Research Center University of Texas Southwestern Medical Center Dallas TX USA
| | - A. Dean Sherry
- Advanced Imaging Research Center University of Texas Southwestern Medical Center Dallas TX USA
- Department of Chemistry and Biochemistry University of Texas at Dallas Richardson TX USA
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14
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Rodríguez-Rodríguez A, Zaiss M, Esteban-Gómez D, Angelovski G, Platas-Iglesias C. Paramagnetic chemical exchange saturation transfer agents and their perspectives for application in magnetic resonance imaging. INT REV PHYS CHEM 2020. [DOI: 10.1080/0144235x.2020.1823167] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Aurora Rodríguez-Rodríguez
- Departamento de Química, Facultade de Ciencias & Centro de Investigacións Científicas Avanzadas (CICA), Universidade da Coruña, 15071 A Coruña, Spain
| | - Moritz Zaiss
- Department of Neuroradiology, University Clinic Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - David Esteban-Gómez
- Departamento de Química, Facultade de Ciencias & Centro de Investigacións Científicas Avanzadas (CICA), Universidade da Coruña, 15071 A Coruña, Spain
| | - Goran Angelovski
- MR Neuroimaging Agents, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
- Lab of Molecular and Cellular Neuroimaging, International Center for Primate Brain Research (ICPBR), Center for Excellence in Brain Science and Intelligence Technology (CEBSIT), Chinese Academy of Science (CAS), Shanghai, P.R. China
| | - Carlos Platas-Iglesias
- Departamento de Química, Facultade de Ciencias & Centro de Investigacións Científicas Avanzadas (CICA), Universidade da Coruña, 15071 A Coruña, Spain
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15
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Kwiatkowski G, Kozerke S. Accelerating CEST MRI in the mouse brain at 9.4 T by exploiting sparsity in the Z-spectrum domain. NMR IN BIOMEDICINE 2020; 33:e4360. [PMID: 32621367 DOI: 10.1002/nbm.4360] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 05/20/2020] [Accepted: 06/05/2020] [Indexed: 06/11/2023]
Abstract
PURPOSE Chemical exchange saturation transfer (CEST) is an MR contrast modality offering an enhanced sensitivity for the detection of dilute metabolites with exchangeable protons. Quantitative analysis requires the acquisition of a number of images (usually between 20 and 50 RF offsets) per Z-spectrum, leading to long acquisition times of the order of 5-40 min in practice. In this work, we explore the possibility of employing sparsity in the Z-spectrum domain (irradiation offset dimension) to provide an accelerated acquisition scheme without compromising the quality of reconstructed CEST spectra. METHOD AND THEORY Ex vivo and in vivo data were acquired on an experimental, small animal 9.4 T system. Three different reconstruction methods were tested: k-Z SPARSE, k-Z SLR and k-Z principal component analysis (PCA) using retrospective undersampling with net acceleration factors R = 2, 3, 5. The quality of the reconstructed data was compared with respect to CEST spectra and full magnetization transfer ratio (MTR) asymmetry maps. RESULTS In both phantom and in vivo data, CEST spectra and the resulting MTR asymmetry maps were reconstructed without significant deterioration in data quality. For a low acceleration factor (R = 2, 3) all applied methods resulted in similar data quality, while for high acceleration factor (R = 5) only k-Z PCA and k-Z SLR could be used. Loss in spatial resolution was observed in reconstruction with k-Z PCA for all acceleration factors. An example of prospective undersampling with acceleration factor R = 3 and k-Z PCA reconstruction demonstrates improved CEST maps when compared with fully sampled data acquisition with either three times longer scan duration or threefold prolonged acquisition window per frequency offset. CONCLUSION The acquisition time of CEST spectra can be significantly accelerated by exploiting the sparsity of the Z-domain. For prospective and retrospective analysis using k-Z PCA, an acceleration factor of up to R = 3 can be used without significant loss in data quality.
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Affiliation(s)
- Grzegorz Kwiatkowski
- Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - Sebastian Kozerke
- Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland
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16
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Huang J, Han X, Chen L, Xu X, Xu J, Chan KWY. Relayed nuclear Overhauser enhancement imaging with magnetization transfer contrast suppression at 3 T. Magn Reson Med 2020; 85:254-267. [PMID: 32738080 DOI: 10.1002/mrm.28433] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 06/10/2020] [Accepted: 06/24/2020] [Indexed: 12/11/2022]
Abstract
PURPOSE To develop a pulsed CEST magnetization-transfer method for rapidly acquiring relayed nuclear Overhauser enhancement (rNOE)-weighted images with magnetic transfer contrast (MTC) suppression at clinical field strength (3 T). METHODS Using a pulsed CEST magnetization-transfer method with low saturation powers (B1 ) and long mixing time (tmix ) to suppress contributions due to strong MTC from solid-like macromolecules, a low B1 also minimized direct water saturation. These MTC contributions were further reduced by subtracting the Z-spectral signals at two or three offsets by assuming that the residual MTC is a linear function between -3.5 ppm and -12.5 ppm. RESULTS Phantom studies of a lactic acid (Lac) solution mixed with cross-linked bovine serum albumin show that strong MTC interference has a significant impact on the optimum B1 for detecting rNOEs, due to lactate binding. The MTC could be effectively suppressed using a pulse train with a B1 of 0.8 μT, a pulse duration (tp ) of 40 ms, a tmix of 60 ms, and a pulse number (N) of 30, while rNOE signal was well maintained. As a proof of concept, we applied the method in mouse brain with injected hydrogel and a cell-hydrogel phantom. Results showed that rNOE-weighted images could provide good contrast between brain/cell and hydrogel. CONCLUSION The developed pulsed CEST magnetization-transfer method can achieve MTC suppression while preserving most of the rNOE signal at 3 T, which indicates the potential for translation of this technique to clinical applications related to mobile proteins/lipids change.
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Affiliation(s)
- Jianpan Huang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Xiongqi Han
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Lin Chen
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA.,Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Xiang Xu
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA.,Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jiadi Xu
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA.,Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Kannie W Y Chan
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China.,Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,City University of Hong Kong Shenzhen Research Institute, Shenzhen, China
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17
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Consolino L, Anemone A, Capozza M, Carella A, Irrera P, Corrado A, Dhakan C, Bracesco M, Longo DL. Non-invasive Investigation of Tumor Metabolism and Acidosis by MRI-CEST Imaging. Front Oncol 2020; 10:161. [PMID: 32133295 PMCID: PMC7040491 DOI: 10.3389/fonc.2020.00161] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 01/29/2020] [Indexed: 12/15/2022] Open
Abstract
Altered metabolism is considered a core hallmark of cancer. By monitoring in vivo metabolites changes or characterizing the tumor microenvironment, non-invasive imaging approaches play a fundamental role in elucidating several aspects of tumor biology. Within the magnetic resonance imaging (MRI) modality, the chemical exchange saturation transfer (CEST) approach has emerged as a new technique that provides high spatial resolution and sensitivity for in vivo imaging of tumor metabolism and acidosis. This mini-review describes CEST-based methods to non-invasively investigate tumor metabolism and important metabolites involved, such as glucose and lactate, as well as measurement of tumor acidosis. Approaches that have been exploited to assess response to anticancer therapies will also be reported for each specific technique.
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Affiliation(s)
- Lorena Consolino
- Department of Nanomedicines and Theranostics, Institute for Experimental Molecular Imaging, RWTH Aachen University, Aachen, Germany.,Department of Molecular Biotechnology and Health Sciences, Molecular Imaging Center, University of Torino, Turin, Italy
| | - Annasofia Anemone
- Department of Molecular Biotechnology and Health Sciences, Molecular Imaging Center, University of Torino, Turin, Italy
| | - Martina Capozza
- Department of Molecular Biotechnology and Health Sciences, Molecular Imaging Center, University of Torino, Turin, Italy
| | - Antonella Carella
- Institute of Biostructures and Bioimaging (IBB), Italian National Research Council (CNR), Turin, Italy
| | - Pietro Irrera
- University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Alessia Corrado
- Institute of Biostructures and Bioimaging (IBB), Italian National Research Council (CNR), Turin, Italy
| | - Chetan Dhakan
- Institute of Biostructures and Bioimaging (IBB), Italian National Research Council (CNR), Turin, Italy.,University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Martina Bracesco
- Department of Molecular Biotechnology and Health Sciences, Molecular Imaging Center, University of Torino, Turin, Italy
| | - Dario Livio Longo
- Institute of Biostructures and Bioimaging (IBB), Italian National Research Council (CNR), Turin, Italy
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18
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Sun PZ. Fast correction of B 0 field inhomogeneity for pH-specific magnetization transfer and relaxation normalized amide proton transfer imaging of acute ischemic stroke without Z-spectrum. Magn Reson Med 2019; 83:1688-1697. [PMID: 31631414 DOI: 10.1002/mrm.28040] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/17/2019] [Accepted: 09/23/2019] [Indexed: 01/04/2023]
Abstract
PURPOSE The magnetization transfer and relaxation normalized amide proton transfer (MRAPT) analysis is promising to provide a highly pH-specific mapping of tissue acidosis, complementing commonly used CEST asymmetry analysis. We aimed to develop a fast B0 inhomogeneity correction algorithm for acute stroke magnetization transfer and relaxation normalized amide proton transfer imaging without Z-spectral interpolation. METHODS The proposed fast field inhomogeneity correction describes B0 artifacts with linear regression. We compared the new algorithm with the routine interpolation correction approach in CEST imaging of a dual-pH phantom. The fast B0 correction was further evaluated in amide proton transfer imaging of normal and acute stroke rats. RESULTS Our phantom data showed that the proposed fast B0 inhomogeneity correction significantly improved pH MRI contrast, recovering over 80% of the pH MRI contrast-to-noise-ratio difference between the raw magnetization transfer ratio asymmetry and that using the routine interpolation-based B0 correction approach. In normal rat brains, the proposed fast B0 correction improved pH-specific MRI uniformity across the intact tissue, with the ratio of magnetization transfer and relaxation normalized amide proton transfer ratio being 10% of that without B0 inhomogeneity correction. In acute stroke rats, fast B0 inhomogeneity-corrected pH MRI reveals substantially improved pH lesion conspicuity, particularly in regions with nonnegligible B0 inhomogeneity. The pH MRI contrast-to-noise ratio between the ipsilateral diffusion lesion and contralateral normal tissue improved significantly with fast B0 correction (from 1.88 ± 0.48 to 2.20 ± 0.44, P < .01). CONCLUSIONS Our study established an expedient B0 inhomogeneity correction algorithm for fast pH imaging of acute ischemia.
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Affiliation(s)
- Phillip Zhe Sun
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.,Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, Georgia.,Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia
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19
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Goldenberg JM, Pagel MD. Assessments of tumor metabolism with CEST MRI. NMR IN BIOMEDICINE 2019; 32:e3943. [PMID: 29938857 PMCID: PMC7377947 DOI: 10.1002/nbm.3943] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 04/13/2018] [Accepted: 04/18/2018] [Indexed: 05/06/2023]
Abstract
Chemical exchange saturation transfer (CEST) is a relatively new contrast mechanism for MRI. CEST MRI exploits a specific MR frequency (chemical shift) of a molecule while generating an image with good spatial resolution using standard MRI techniques, combining the specificity of MRS with the spatial resolution of MRI. Many CEST MRI acquisition methods have been developed to improve analyses of tumor metabolism. GluCEST, CrCEST, and LATEST can map glutamate, creatine, and lactate, which are important metabolites involved in tumor metabolism. GlucoCEST MRI tracks the pharmacokinetics of glucose transport and cell internalization within tumors. CatalyCEST MRI detects enzyme catalysis that changes a substrate CEST agent. AcidoCEST MRI measures extracellular pH of the tumor microenvironment by exploiting a ratio of two pH-dependent CEST signals. This review describes each technique, the technical issues involved with CEST MRI and each specific technique, and the merits and challenges associated with applying each CEST MRI technique to study tumor metabolism.
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Affiliation(s)
- Joshua M. Goldenberg
- Department of Pharmaceutical Sciences, The University of Arizona, Tucson, AZ, USA
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Mark D. Pagel
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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Abstract
This article aimed at reviewing the advances on the development of paramagnetic complexes used as chemical exchange saturation transfer agents in magnetic resonance imaging. This relatively new type of contrast opens new avenues in the development of MRI probes for molecular imaging, and coordination chemistry lies at the center of such advances. Strategies to detect important biomarkers such as pH, cations, anions, metabolites, enzyme, and O2 were described. The current challenges, limitations, and opportunities in this field of research were discussed.
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Pujales-Paradela R, Savić T, Pérez-Lourido P, Esteban-Gómez D, Angelovski G, Botta M, Platas-Iglesias C. Lanthanide Complexes with 1H paraCEST and 19F Response for Magnetic Resonance Imaging Applications. Inorg Chem 2019; 58:7571-7583. [DOI: 10.1021/acs.inorgchem.9b00869] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Rosa Pujales-Paradela
- Centro de Investigacións Científicas Avanzadas and Departamento de Química, Facultade de Ciencias, Universidade da Coruña, 15071 Coruña, Galicia Spain
| | - Tanja Savić
- MR Neuroimaging Agents, Max Planck Institute for Biological Cybernetics, 72076 Tuebingen, Germany
| | - Paulo Pérez-Lourido
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidade de Vigo, As Lagoas, Marcosende, 36310 Pontevedra, Spain
| | - David Esteban-Gómez
- Centro de Investigacións Científicas Avanzadas and Departamento de Química, Facultade de Ciencias, Universidade da Coruña, 15071 Coruña, Galicia Spain
| | - Goran Angelovski
- MR Neuroimaging Agents, Max Planck Institute for Biological Cybernetics, 72076 Tuebingen, Germany
| | - Mauro Botta
- Dipartimento di Scienze e Innovazione Tecnologica, Università del Piemonte Orientale “A. Avogadro”, Viale T. Michel 11, 15121 Alessandria, Italy
| | - Carlos Platas-Iglesias
- Centro de Investigacións Científicas Avanzadas and Departamento de Química, Facultade de Ciencias, Universidade da Coruña, 15071 Coruña, Galicia Spain
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22
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Du K, Thorarinsdottir AE, Harris TD. Selective Binding and Quantitation of Calcium with a Cobalt-Based Magnetic Resonance Probe. J Am Chem Soc 2019; 141:7163-7172. [PMID: 30946580 DOI: 10.1021/jacs.9b02661] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
We report a cobalt-based paramagnetic chemical exchange saturation transfer (PARACEST) magnetic resonance (MR) probe that is able to selectively bind and quantitate the concentration of Ca2+ ions under physiological conditions. The parent LCo complex features CEST-active carboxamide groups and an uncoordinated crown ether moiety in close proximity to a high-spin pseudo-octahedral CoII center. Addition of Na+, Mg2+, K+, and Ca2+ leads to binding of these metal ions within the crown ether. Single-crystal X-ray diffraction and solid-state magnetic measurements reveal the presence of a cation-specific coordination environment and magnetic anisotropy of CoII, with axial zero-field splitting parameters for the Na+- and Ca2+-bound complexes differing by over 90%. Owing to these differences, solution-based measurements under physiological conditions indicate reversible binding of Na+ and Ca2+ to give well-separated CEST peaks at 69 and 80 ppm for [LCoNa]+ and [LCoCa]2+, respectively. Dissociation constants for different cation-bound complexes of LCo, as determined by 1H NMR spectroscopy, demonstrate high selectivity toward Ca2+. This finding, in conjunction with the large excess of Na+ in physiological environments, minimizes interference from related cations, such as Mg2+ and K+. Finally, variable-[Ca2+] CEST spectra establish the ratio between the CEST peak intensities for the Ca2+- and Na+-bound probes (CEST80 ppm/CEST69 ppm) as a measure of [Ca2+], providing the first example of a ratiometric quantitation of Ca2+ concentration using PARACEST. Taken together, these results demonstrate the ability of transition metal PARACEST probes to afford a concentration-independent measure of [Ca2+] and provide a new approach for designing MR probes for cation sensing.
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Affiliation(s)
- Kang Du
- Department of Chemistry , Northwestern University , Evanston , Illinois 60208-3113 , United States
| | - Agnes E Thorarinsdottir
- Department of Chemistry , Northwestern University , Evanston , Illinois 60208-3113 , United States
| | - T David Harris
- Department of Chemistry , Northwestern University , Evanston , Illinois 60208-3113 , United States
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23
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Ntziachristos V, Pleitez MA, Aime S, Brindle KM. Emerging Technologies to Image Tissue Metabolism. Cell Metab 2019; 29:518-538. [PMID: 30269982 DOI: 10.1016/j.cmet.2018.09.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 07/24/2018] [Accepted: 09/02/2018] [Indexed: 12/19/2022]
Abstract
Due to the implication of altered metabolism in a large spectrum of tissue function and disease, assessment of metabolic processes becomes essential in managing health. In this regard, imaging can play a critical role in allowing observation of biochemical and physiological processes. Nuclear imaging methods, in particular positron emission tomography, have been widely employed for imaging metabolism but are mainly limited by the use of ionizing radiation and the sensing of only one parameter at each scanning session. Observations in healthy individuals or longitudinal studies of disease could markedly benefit from non-ionizing, multi-parameter imaging methods. We therefore focus this review on progress with the non-ionizing radiation methods of MRI, hyperpolarized magnetic resonance and magnetic resonance spectroscopy, chemical exchange saturation transfer, and emerging optoacoustic (photoacoustic) imaging. We also briefly discuss the role of nuclear and optical imaging methods for research and clinical protocols.
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Affiliation(s)
- Vasilis Ntziachristos
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg 85764, Germany; Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Ismaningerstr. 22, Munich 81675, Germany.
| | - Miguel A Pleitez
- Institute of Biological and Medical Imaging, Helmholtz Zentrum München, Neuherberg 85764, Germany; Chair of Biological Imaging, TranslaTUM, Technical University of Munich, Ismaningerstr. 22, Munich 81675, Germany
| | - Silvio Aime
- Molecular Imaging Center, Department of Molecular Biotechnologies and Health Sciences, University of Turin, Turin 10126, Italy
| | - Kevin M Brindle
- Department of Biochemistry, University of Cambridge, Old Addenbrooke's Site, Cambridge CB2 1GA, UK; Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Robinson Way, Cambridge CB2 0RE, UK
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Wahsner J, Gale EM, Rodríguez-Rodríguez A, Caravan P. Chemistry of MRI Contrast Agents: Current Challenges and New Frontiers. Chem Rev 2019; 119:957-1057. [PMID: 30350585 PMCID: PMC6516866 DOI: 10.1021/acs.chemrev.8b00363] [Citation(s) in RCA: 832] [Impact Index Per Article: 166.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Tens of millions of contrast-enhanced magnetic resonance imaging (MRI) exams are performed annually around the world. The contrast agents, which improve diagnostic accuracy, are almost exclusively small, hydrophilic gadolinium(III) based chelates. In recent years concerns have arisen surrounding the long-term safety of these compounds, and this has spurred research into alternatives. There has also been a push to develop new molecularly targeted contrast agents or agents that can sense pathological changes in the local environment. This comprehensive review describes the state of the art of clinically approved contrast agents, their mechanism of action, and factors influencing their safety. From there we describe different mechanisms of generating MR image contrast such as relaxation, chemical exchange saturation transfer, and direct detection and the types of molecules that are effective for these purposes. Next we describe efforts to make safer contrast agents either by increasing relaxivity, increasing resistance to metal ion release, or by moving to gadolinium(III)-free alternatives. Finally we survey approaches to make contrast agents more specific for pathology either by direct biochemical targeting or by the design of responsive or activatable contrast agents.
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Affiliation(s)
- Jessica Wahsner
- Athinoula A. Martinos Center for Biomedical Imaging and the Institute for Innovation in Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Eric M. Gale
- Athinoula A. Martinos Center for Biomedical Imaging and the Institute for Innovation in Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Aurora Rodríguez-Rodríguez
- Athinoula A. Martinos Center for Biomedical Imaging and the Institute for Innovation in Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
| | - Peter Caravan
- Athinoula A. Martinos Center for Biomedical Imaging and the Institute for Innovation in Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA
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25
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Zhou IY, Lu D, Ji Y, Wu L, Wang E, Cheung JS, Zhang XA, Sun PZ. Determination of multipool contributions to endogenous amide proton transfer effects in global ischemia with high spectral resolution in vivo chemical exchange saturation transfer MRI. Magn Reson Med 2019; 81:645-652. [PMID: 30058148 PMCID: PMC6258351 DOI: 10.1002/mrm.27385] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 04/26/2018] [Accepted: 05/08/2018] [Indexed: 12/31/2022]
Abstract
PURPOSE Chemical exchange saturation transfer (CEST) MRI has been used for quantitative assessment of dilute metabolites and/or pH in disorders such as acute stroke and tumor. However, routine asymmetry analysis (MTRasym ) may be confounded by concomitant effects such as semisolid macromolecular magnetization transfer (MT) and nuclear Overhauser enhancement. Resolving multiple contributions is essential for elucidating the origins of in vivo CEST contrast. METHODS Here we used a newly proposed image downsampling expedited adaptive least-squares fitting on densely sampled Z-spectrum to quantify multipool contribution from water, nuclear Overhauser enhancement, MT, guanidinium, amine, and amide protons in adult male Wistar rats before and after global ischemia. RESULTS Our results revealed the major contributors to in vivo T1 -normalized MTRasym (3.5 ppm) contrast between white and gray matter (WM/GM) in normal brain (-1.96%/second) are pH-insensitive macromolecular MT (-0.89%/second) and nuclear Overhauser enhancement (-1.04%/second). Additionally, global ischemia resulted in significant changes of MTRasym , being -2.05%/second and -1.56%/second in WM and GM, which are dominated by changes in amide (-1.05%/second, -1.14%/second) and MT (-0.88%/second, -0.62%/second). Notably, the pH-sensitive amine and amide effects account for nearly 60% and 80% of the MTRasym changes seen in WM and GM, respectively, after global ischemia, indicating that MTRasym is predominantly pH-sensitive. CONCLUSION Combined amide and amine effects dominated the MTRasym changes after global ischemia, indicating that MTRasym is predominantly pH-sensitive and suitable for detecting tissue acidosis following acute stroke.
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Affiliation(s)
- Iris Yuwen Zhou
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Dongshuang Lu
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Yang Ji
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Limin Wu
- Neuroscience Center and Department of Pediatrics, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Enfeng Wang
- Department of Radiology, 3rd Affiliated Hospital, Zhengzhou University, Henan China
| | - Jerry S. Cheung
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Xiao-An Zhang
- Department of Radiology, 3rd Affiliated Hospital, Zhengzhou University, Henan China
| | - Phillip Zhe Sun
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
- Yerkes Imaging Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA
- Department of Radiology, Emory University School of Medicine, Atlanta, GA, USA
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26
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Thorarinsdottir AE, Harris TD. Dramatic enhancement in pH sensitivity and signal intensity through ligand modification of a dicobalt PARACEST probe. Chem Commun (Camb) 2019; 55:794-797. [DOI: 10.1039/c8cc09520e] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A ratiometric dicobalt PARACEST pH probe that exhibits dramatic enhancements in sensitivity and signal intensity over analogous probes is reported.
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27
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Som A, Raliya R, Paranandi K, High RA, Reed N, Beeman SC, Brandenburg M, Sudlow G, Prior JL, Akers W, Mah-Som AY, Habimana-Griffin L, Garbow J, Ippolito JE, Pagel MD, Biswas P, Achilefu S. Calcium carbonate nanoparticles stimulate tumor metabolic reprogramming and modulate tumor metastasis. Nanomedicine (Lond) 2019; 14:169-182. [PMID: 30730790 PMCID: PMC6369564 DOI: 10.2217/nnm-2018-0302] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 11/06/2018] [Indexed: 11/21/2022] Open
Abstract
AIM CaCO3 nanoparticles (nano-CaCO3) can neutralize the acidic pHe of solid tumors, but the lack of intrinsic imaging signal precludes noninvasive monitoring of pH-perturbation in tumor microenvironment. We aim to develop a theranostic version of nano-CaCO3 to noninvasively monitor pH modulation and subsequent tumor response. MATERIALS & METHODS We synthesized ferromagnetic core coated with CaCO3 (magnetite CaCO3). Magnetic resonance imaging (MRI) was used to determine the biodistribution and pH modulation using murine fibrosarcoma and breast cancer models. RESULTS Magnetite CaCO3-MRI imaging showed that nano-CaCO3 rapidly raised tumor pHe, followed by excessive tumor-associated acid production after its clearance. Continuous nano-CaCO3 infusion could inhibit metastasis. CONCLUSION Nano-CaCO3 exposure induces tumor metabolic reprogramming that could account for the failure of previous intermittent pH-modulation strategies to achieve sustainable therapeutic effect.
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Affiliation(s)
- Avik Som
- Mallinckrodt Institute of Radiology, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
- Department of Biomedical Engineering, Washington University in St Louis, St Louis, MO 63130, USA
| | - Ramesh Raliya
- Department of Energy, Environmental, Chemical Engineering, Washington University in St Louis, St Louis, MO 63130, USA
| | - Krishna Paranandi
- Mallinckrodt Institute of Radiology, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
| | - Rachel A High
- Cancer Biology Graduate Interdisciplinary Program, University of Arizona Cancer Center, Tucson, AZ 54724, USA
| | - Nathan Reed
- Department of Energy, Environmental, Chemical Engineering, Washington University in St Louis, St Louis, MO 63130, USA
| | - Scott C Beeman
- Mallinckrodt Institute of Radiology, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
| | - Matthew Brandenburg
- Mallinckrodt Institute of Radiology, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
| | - Gail Sudlow
- Mallinckrodt Institute of Radiology, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
| | - Julie L Prior
- Mallinckrodt Institute of Radiology, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
| | - Walter Akers
- Mallinckrodt Institute of Radiology, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
- Department of Biochemistry & Biophysics, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
| | - Annelise Y Mah-Som
- Center for In Vivo Imaging & Therapeutics, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Lemoyne Habimana-Griffin
- Mallinckrodt Institute of Radiology, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
- Department of Biomedical Engineering, Washington University in St Louis, St Louis, MO 63130, USA
| | - Joel Garbow
- Mallinckrodt Institute of Radiology, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
| | - Joseph E Ippolito
- Mallinckrodt Institute of Radiology, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
- Department of Pediatrics, Division of Rheumatology, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
| | - Mark D Pagel
- Cancer Biology Graduate Interdisciplinary Program, University of Arizona Cancer Center, Tucson, AZ 54724, USA
| | - Pratim Biswas
- Department of Energy, Environmental, Chemical Engineering, Washington University in St Louis, St Louis, MO 63130, USA
| | - Samuel Achilefu
- Mallinckrodt Institute of Radiology, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
- Department of Biomedical Engineering, Washington University in St Louis, St Louis, MO 63130, USA
- Department of Genetics, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
- Department of Medicine, Washington University in St Louis School of Medicine, St Louis, MO 63110, USA
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28
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Zhou Z, Han P, Zhou B, Christodoulou AG, Shaw JL, Deng Z, Li D. Chemical exchange saturation transfer fingerprinting for exchange rate quantification. Magn Reson Med 2018; 80:1352-1363. [PMID: 29845651 PMCID: PMC6592698 DOI: 10.1002/mrm.27363] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 04/17/2018] [Accepted: 04/24/2018] [Indexed: 01/18/2023]
Abstract
PURPOSE There is an increased interest to determine the exchange rate using CEST to provide pH information. However, current CEST quantification methods require lengthy scan times and do not address magnetization transfer effects. The purpose of this work was to apply the magnetic resonance fingerprinting (MRF) concept to CEST to achieve more efficient and accurate exchange rate quantification. METHODS The proposed CEST fingerprinting method used varying saturation powers and saturation times to create unique signal evolutions for different exchange rates. The acquired signal was matched to a predefined dictionary to determine the exchange rate. The magnetization transfer effects were also addressed in the framework of CEST fingerprinting: The simulated dictionary could predict the signal curves without magnetization transfer effects, and comparing the dictionary to the acquired signals allowed the correction of the magnetization transfer effects. The CEST fingerprinting method was compared with the conventional pulsed quantitative CEST method using omega plots in the creatine phantom study. RESULTS The CEST fingerprinting method has a significantly reduced scan time (10 minutes versus 50 minutes) while providing more accurate exchange rate quantification using literature values as the reference. CONCLUSION In this study, we demonstrate that CEST fingerprinting is more efficient (5 times faster) compared with pulsed quantitative CEST. It is also shown that the results of the proposed CEST fingerprinting technique are much closer to the literature values than pulsed quantitative CEST at 3 T.
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Affiliation(s)
- Zhengwei Zhou
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California
- Department of Bioengineering, University of California Los Angeles, Los Angeles, California
| | - Pei Han
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California
- Department of Engineering Physics, Tsinghua University, Beijing, China
| | - Bill Zhou
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California
- University of California Los Angeles David Geffen School of Medicine, Los Angeles, California
| | | | - Jaime L. Shaw
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California
- Department of Bioengineering, University of California Los Angeles, Los Angeles, California
| | - Zixin Deng
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California
- Department of Bioengineering, University of California Los Angeles, Los Angeles, California
| | - Debiao Li
- Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California
- Department of Bioengineering, University of California Los Angeles, Los Angeles, California
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29
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Thorarinsdottir AE, Tatro SM, Harris TD. Electronic Effects of Ligand Substitution in a Family of CoII2 PARACEST pH Probes. Inorg Chem 2018; 57:11252-11263. [DOI: 10.1021/acs.inorgchem.8b01896] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
| | - Scott M. Tatro
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - T. David Harris
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
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30
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Jones KM, Randtke EA, Yoshimaru ES, Howison CM, Chalasani P, Klein RR, Chambers SK, Kuo PH, Pagel MD. Clinical Translation of Tumor Acidosis Measurements with AcidoCEST MRI. Mol Imaging Biol 2018; 19:617-625. [PMID: 27896628 DOI: 10.1007/s11307-016-1029-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
PURPOSE We optimized acido-chemical exchange saturation transfer (acidoCEST) magnetic resonance imaging (MRI), a method that measures extracellular pH (pHe), and translated this method to the radiology clinic to evaluate tumor acidosis. PROCEDURES A CEST-FISP MRI protocol was used to image a flank SKOV3 tumor model. Bloch fitting modified to include the direct estimation of pH was developed to generate parametric maps of tumor pHe in the SKOV3 tumor model, a patient with high-grade invasive ductal carcinoma, and a patient with metastatic ovarian cancer. The acidoCEST MRI results of the patient with metastatic ovarian cancer were compared with DCE MRI and histopathology. RESULTS The pHe maps of a flank model showed pHe measurements between 6.4 and 7.4, which matched with the expected tumor pHe range from past acidoCEST MRI studies in flank tumors. In the patient with metastatic ovarian cancer, the average pHe value of three adjacent tumors was 6.58, and the most reliable pHe measurements were obtained from the right posterior tumor, which favorably compared with DCE MRI and histopathological results. The average pHe of the kidney showed an average pHe of 6.73 units. The patient with high-grade invasive ductal carcinoma failed to accumulate sufficient agent to generate pHe measurements. CONCLUSIONS Optimized acidoCEST MRI generated pHe measurements in a flank tumor model and could be translated to the clinic to assess a patient with metastatic ovarian cancer.
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Affiliation(s)
- Kyle M Jones
- Biomedical Engineering Graduate Interdisciplinary Program, University of Arizona, Tucson, AZ, USA
| | - Edward A Randtke
- Department of Medical Imaging, University of Arizona, 1515 N. Campbell Ave., Tucson, AZ, 85724-5024, USA
| | | | - Christine M Howison
- Department of Medical Imaging, University of Arizona, 1515 N. Campbell Ave., Tucson, AZ, 85724-5024, USA
| | - Pavani Chalasani
- Division of Hematology-Oncology, University of Arizona, Tucson, AZ, USA
| | - Robert R Klein
- Department of Pathology, University of Arizona, Tucson, AZ, USA
| | - Setsuko K Chambers
- University of Arizona Cancer Center, Tucson, AZ, USA.,Department of Obstetrics and Gynecology, University of Arizona, Tucson, AZ, USA
| | - Phillip H Kuo
- Biomedical Engineering Graduate Interdisciplinary Program, University of Arizona, Tucson, AZ, USA.,Department of Medical Imaging, University of Arizona, 1515 N. Campbell Ave., Tucson, AZ, 85724-5024, USA.,University of Arizona Cancer Center, Tucson, AZ, USA
| | - Mark D Pagel
- Biomedical Engineering Graduate Interdisciplinary Program, University of Arizona, Tucson, AZ, USA. .,Department of Medical Imaging, University of Arizona, 1515 N. Campbell Ave., Tucson, AZ, 85724-5024, USA. .,University of Arizona Cancer Center, Tucson, AZ, USA.
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Abstract
Metabolism is central to neuroimaging because it can reveal pathways by which neuronal and glial cells use nutrients to fuel their growth and function. We focus on advanced magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) methods used in brain metabolic studies. 17O-MRS and 31P-MRS, respectively, provide rates of oxygen use and ATP synthesis inside mitochondria, whereas 19F-MRS enables measurement of cytosolic glucose metabolism. Calibrated functional MRI (fMRI), an advanced form of fMRI that uses contrast generated by deoxyhemoglobin, provides maps of oxygen use that track neuronal firing across brain regions. 13C-MRS is the only noninvasive method of measuring both glutamatergic neurotransmission and cell-specific energetics with signaling and nonsignaling purposes. Novel MRI contrasts, arising from endogenous diamagnetic agents and exogenous paramagnetic agents, permit pH imaging of glioma. Overall, these magnetic resonance methods for imaging brain metabolism demonstrate translational potential to better understand brain disorders and guide diagnosis and treatment.
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Affiliation(s)
- Fahmeed Hyder
- Department of Biomedical Engineering, Department of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, and Quantitative Neuroscience with Magnetic Resonance Core Center, Yale University, New Haven, Connecticut 06520;
| | - Douglas L Rothman
- Department of Biomedical Engineering, Department of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, and Quantitative Neuroscience with Magnetic Resonance Core Center, Yale University, New Haven, Connecticut 06520;
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32
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Hao G, Xu ZP, Li L. Manipulating extracellular tumour pH: an effective target for cancer therapy. RSC Adv 2018; 8:22182-22192. [PMID: 35541713 PMCID: PMC9081285 DOI: 10.1039/c8ra02095g] [Citation(s) in RCA: 181] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 06/07/2018] [Indexed: 12/12/2022] Open
Abstract
The pH in tumour cells and the tumour microenvironment has played important roles in cancer development and treatment.
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Affiliation(s)
- Guanyu Hao
- Australian Institute for Bioengineering and Nanotechnology (AIBN)
- The University of Queensland
- Brisbane
- Australia 4072
| | - Zhi Ping Xu
- Australian Institute for Bioengineering and Nanotechnology (AIBN)
- The University of Queensland
- Brisbane
- Australia 4072
| | - Li Li
- Australian Institute for Bioengineering and Nanotechnology (AIBN)
- The University of Queensland
- Brisbane
- Australia 4072
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33
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Thorarinsdottir AE, Du K, Collins JHP, Harris TD. Ratiometric pH Imaging with a CoII2 MRI Probe via CEST Effects of Opposing pH Dependences. J Am Chem Soc 2017; 139:15836-15847. [DOI: 10.1021/jacs.7b08574] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
| | - Kang Du
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - James H. P. Collins
- Advanced
Magnetic Resonance Imaging and Spectroscopy Facility, University of Florida, Gainesville, Florida 32611, United States
| | - T. David Harris
- Department
of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
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34
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Srivastava K, Ferrauto G, Young VG, Aime S, Pierre VC. Eight-Coordinate, Stable Fe(II) Complex as a Dual 19F and CEST Contrast Agent for Ratiometric pH Imaging. Inorg Chem 2017; 56:12206-12213. [DOI: 10.1021/acs.inorgchem.7b01629] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Kriti Srivastava
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Giuseppe Ferrauto
- Molecular Imaging Center, Department of Molecular Biotechnologies & Health Sciences, University of Torino, 10126 Torino, Italy
| | - Victor G. Young
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Silvio Aime
- Molecular Imaging Center, Department of Molecular Biotechnologies & Health Sciences, University of Torino, 10126 Torino, Italy
| | - Valérie C. Pierre
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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35
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Jones KM, Pollard AC, Pagel MD. Clinical applications of chemical exchange saturation transfer (CEST) MRI. J Magn Reson Imaging 2017; 47:11-27. [PMID: 28792646 DOI: 10.1002/jmri.25838] [Citation(s) in RCA: 184] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Accepted: 05/30/2017] [Indexed: 02/06/2023] Open
Abstract
Chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) has been developed and employed in multiple clinical imaging research centers worldwide. Selective radiofrequency (RF) saturation pulses with standard 2D and 3D MRI acquisition schemes are now routinely performed, and CEST MRI can produce semiquantitative results using magnetization transfer ratio asymmetry (MTRasym ) analysis while accounting for B0 inhomogeneity. Faster clinical CEST MRI acquisition methods and more quantitative acquisition and analysis routines are under development. Endogenous biomolecules with amide, amine, and hydroxyl groups have been detected during clinical CEST MRI studies, and exogenous CEST agents have also been administered to patients. These CEST MRI tools show promise for contributing to assessments of cerebral ischemia, neurological disorders, lymphedema, osteoarthritis, muscle physiology, and solid tumors. This review summarizes the salient features of clinical CEST MRI protocols and critically evaluates the utility of CEST MRI for these clinical imaging applications. LEVEL OF EVIDENCE 5 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:11-27.
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Affiliation(s)
- Kyle M Jones
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona, USA
| | | | - Mark D Pagel
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona, USA.,Department of Chemistry, Rice University, Houston, Texas, USA.,Department of Cancer Systems Imaging, MD Anderson Cancer Center, Houston, Texas, USA
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36
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Zaiss M, Angelovski G, Demetriou E, McMahon MT, Golay X, Scheffler K. QUESP and QUEST revisited - fast and accurate quantitative CEST experiments. Magn Reson Med 2017; 79:1708-1721. [PMID: 28686796 DOI: 10.1002/mrm.26813] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 05/17/2017] [Accepted: 06/03/2017] [Indexed: 01/24/2023]
Abstract
PURPOSE Chemical exchange saturation transfer (CEST) NMR or MRI experiments allow detection of low concentrated molecules with enhanced sensitivity via their proton exchange with the abundant water pool. Be it endogenous metabolites or exogenous contrast agents, an exact quantification of the actual exchange rate is required to design optimal pulse sequences and/or specific sensitive agents. METHODS Refined analytical expressions allow deeper insight and improvement of accuracy for common quantification techniques. The accuracy of standard quantification methodologies, such as quantification of exchange rate using varying saturation power or varying saturation time, is improved especially for the case of nonequilibrium initial conditions and weak labeling conditions, meaning the saturation amplitude is smaller than the exchange rate (γB1 < k). RESULTS The improved analytical 'quantification of exchange rate using varying saturation power/time' (QUESP/QUEST) equations allow for more accurate exchange rate determination, and provide clear insights on the general principles to execute the experiments and to perform numerical evaluation. The proposed methodology was evaluated on the large-shift regime of paramagnetic chemical-exchange-saturation-transfer agents using simulated data and data of the paramagnetic Eu(III) complex of DOTA-tetraglycineamide. CONCLUSIONS The refined formulas yield improved exchange rate estimation. General convergence intervals of the methods that would apply for smaller shift agents are also discussed. Magn Reson Med 79:1708-1721, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Moritz Zaiss
- High Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Goran Angelovski
- MR Neuroimaging Agents, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Eleni Demetriou
- Brain Repair & Rehabilitation, Institute of Neurology, University College London, United Kingdom
| | - Michael T McMahon
- Division of MR Research, The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, Maryland, USA
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Xavier Golay
- Brain Repair & Rehabilitation, Institute of Neurology, University College London, United Kingdom
| | - Klaus Scheffler
- High Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
- Department of Biomedical Magnetic Resonance, Eberhard Karl's University of Tübingen and University Hospital, Tübingen, Germany
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37
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Jin T, Wang P, Hitchens TK, Kim SG. Enhancing sensitivity of pH-weighted MRI with combination of amide and guanidyl CEST. Neuroimage 2017; 157:341-350. [PMID: 28602944 DOI: 10.1016/j.neuroimage.2017.06.007] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Revised: 05/26/2017] [Accepted: 06/01/2017] [Indexed: 11/17/2022] Open
Abstract
Amide-proton-transfer weighted (APTw) MRI has emerged as a non-invasive pH-weighted imaging technique for studies of several diseases such as ischemic stroke. However, its pH-sensitivity is relatively low, limiting its capability to detect small pH changes. In this work, computer simulations, protamine phantom experiments, and in vivo gas challenge and experimental stroke in rats showed that, with judicious selection of the saturation pulse power, the amide-CEST at 3.6ppm and guanidyl-CEST signals at 2.0ppm changed in opposite directions with decreased pH. Thus, the difference between amide-CEST and guanidyl-CEST can enhance the pH measurement sensitivity, and is dubbed as pHenh. Acidification induced a negative contrast in APTw, but a positive contrast in pHenh. In vivo experiments showed that pHenh can detect hypercapnia-induced acidosis with about 3-times higher sensitivity than APTw. Also, pHenh slightly reduced gray and white matter contrast compared to APTw. In stroke animals, the CEST contrast between the ipsilateral ischemic core and contralateral normal tissue was -1.85 ± 0.42% for APTw and 3.04 ± 0.61% (n = 5) for pHenh, and the contrast to noise was 2.9 times higher for pHenh than APTw. Our results suggest that pHenh can be a useful tool for non-invasive pH-weighted imaging.
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Affiliation(s)
- Tao Jin
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, United States; Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States.
| | - Ping Wang
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, United States
| | - T Kevin Hitchens
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Seong-Gi Kim
- Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, South Korea; Department of Biomedical Engineering, Sungkyunkwan University, Suwon, South Korea
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Daryaei I, Jones KM, Pagel MD. Detection of DT-diaphorase Enzyme with a ParaCEST MRI Contrast Agent. Chemistry 2017; 23:6514-6517. [PMID: 28370655 DOI: 10.1002/chem.201700721] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Indexed: 12/26/2022]
Abstract
A responsive magnetic resonance (MRI) contrast agent has been developed that can detect the enzyme activity of DT-diaphorase. The agent produced different chemical exchange saturation transfer (CEST) MRI signals before and after incubation with the enzyme, NADH, and GSH at different pH values whereas it showed good stability in a reducing environment without enzyme.
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Affiliation(s)
- Iman Daryaei
- Department of Chemistry and Biochemistry, University of Arizona, 1306 E. University Blvd., Room 221, Tucson, Arizona, 85721-0041, USA
| | - Kyle M Jones
- Department of Biomedical Engineering, University of Arizona, 1127 E James E. Rogers Way P.O. Box 210020, Tucson, AZ, 85721-0020, USA
| | - Mark D Pagel
- Department of Medical Imaging, University of Arizona, 1501 N. Campbell, P.O. Box 245067, Tucson, Arizona, 85724, USA
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Abstract
Frequently observed phenotypes of tumours include high metabolic activity, hypoxia and poor perfusion; these act to produce an acidic microenvironment. Cellular function depends on pH homoeostasis, and thus, tumours become dependent on pH regulatory mechanisms. Many of the proteins involved in pH regulation are highly expressed in tumours, and their expression is often of prognostic significance. The more acidic tumour microenvironment also has important implications with regard to chemotherapeutic and radiotherapeutic interventions. In addition, we review pH-sensing mechanisms, the role of pH regulation in tumour phenotype and the use of pH regulatory mechanisms as therapeutic targets.
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Affiliation(s)
- Alan McIntyre
- Molecular Oncology Laboratories, Department of Medical Oncology, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Adrian L Harris
- Molecular Oncology Laboratories, Department of Medical Oncology, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK.
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Krchová T, Herynek V, Gálisová A, Blahut J, Hermann P, Kotek J. Eu(III) Complex with DO3A-amino-phosphonate Ligand as a Concentration-Independent pH-Responsive Contrast Agent for Magnetic Resonance Spectroscopy (MRS). Inorg Chem 2017; 56:2078-2091. [PMID: 28170242 DOI: 10.1021/acs.inorgchem.6b02749] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A new DOTA-like ligand H5do3aNP with a 2-[amino(methylphosphonic acid)]ethyl-coordinating pendant arm was prepared, and its coordinating properties were studied by NMR spectroscopy and potentiometry. The study revealed a rare slow exchange (on the 1H and 31P NMR time scale) between protonated and unprotonated complex species with a corresponding acidity constant pKA ∼ 8.0. This unusually slow time scale associated with protonation is caused by a significant geometric change from square-antiprismatic (SA) arrangement observed for protonated complex SA-[Eu(Hdo3aNP)]- to twisted-square-antiprismatic (TSA) arrangement found for deprotonated complex TSA-[Eu(do3aNP)]2-. This behavior results in simultaneous occurrence of the signals of both species in the 31P NMR spectra at approximately -118 and +70 ppm, respectively. Such an unprecedented difference in the chemical shifts between species differing by a proton is caused by a significant movement of the principal magnetic axis and by a change of phosphorus atom position in the coordination sphere of the central Eu(III) ion (i.e., by relative movement of the phosphorus atom with respect to the principal magnetic axis). It changes the sign of the paramagnetic contribution to the 31P NMR chemical shift. The properties discovered can be employed in the measurement of pH by MRS techniques as presented by proof-of-principle experiments on phantoms.
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Affiliation(s)
- Tereza Krchová
- Department of Inorganic Chemistry, Faculty of Science, Charles University , Hlavova 2030, Prague 2 128 43, Czech Republic
| | - Vít Herynek
- Department of Radiodiagnostic and Interventional Radiology, Magnetic Resonance Unit, Institute for Clinical and Experimental Medicine , Vídeňská 1958/9, Prague 4 140 21, Czech Republic
| | - Andrea Gálisová
- Department of Radiodiagnostic and Interventional Radiology, Magnetic Resonance Unit, Institute for Clinical and Experimental Medicine , Vídeňská 1958/9, Prague 4 140 21, Czech Republic
| | - Jan Blahut
- Department of Inorganic Chemistry, Faculty of Science, Charles University , Hlavova 2030, Prague 2 128 43, Czech Republic
| | - Petr Hermann
- Department of Inorganic Chemistry, Faculty of Science, Charles University , Hlavova 2030, Prague 2 128 43, Czech Republic
| | - Jan Kotek
- Department of Inorganic Chemistry, Faculty of Science, Charles University , Hlavova 2030, Prague 2 128 43, Czech Republic
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Abadjian MCZ, Edwards WB, Anderson CJ. Imaging the Tumor Microenvironment. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1036:229-257. [PMID: 29275475 DOI: 10.1007/978-3-319-67577-0_15] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The tumor microenvironment consists of tumor, stromal, and immune cells, as well as extracellular milieu. Changes in numbers of these cell types and their environments have an impact on cancer growth and metastasis. Non-invasive imaging of aspects of the tumor microenvironment can provide important information on the aggressiveness of the cancer, whether or not it is metastatic, and can also help to determine early response to treatment. This chapter provides an overview on non-invasive in vivo imaging in humans and mouse models of various cell types and physiological parameters that are unique to the tumor microenvironment. Current clinical imaging and research investigation are in the areas of nuclear imaging (positron emission tomography (PET) and single photon emission computed tomography (SPECT)), magnetic resonance imaging (MRI) and optical (near infrared (NIR) fluorescence) imaging. Aspects of the tumor microenvironment that have been imaged by PET, MRI and/or optical imaging are tumor associated inflammation (primarily macrophages and T cells), hypoxia, pH changes, as well as enzymes and integrins that are highly prevalent in tumors, stroma and immune cells. Many imaging agents and strategies are currently available for cancer patients; however, the investigation of novel avenues for targeting aspects of the tumor microenvironment in pre-clinical models of cancer provides the cancer researcher with a means to monitor changes and evaluate novel treatments that can be translated into the clinic.
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Affiliation(s)
| | - W Barry Edwards
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Carolyn J Anderson
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA.
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA.
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA.
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In Vitro and In Vivo Assessment of Nonionic Iodinated Radiographic Molecules as Chemical Exchange Saturation Transfer Magnetic Resonance Imaging Tumor Perfusion Agents. Invest Radiol 2016; 51:155-62. [PMID: 26460826 DOI: 10.1097/rli.0000000000000217] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES The aim of this study was to evaluate 4 nonionic x-ray iodinated contrast agents (CAs), commonly used in radiographic procedures, as novel chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) agents by assessing their in vitro exchange properties and preliminary in vivo use as tumor enhancing agents. MATERIALS AND METHODS The CEST properties, as function of pH (range, 5.5-7.9) and of radio frequency conditions (irradiation field strength range of 1-9 μT and time of 1-9 seconds), have been determined at 7 T and 310 K for 4 x-ray CAs commonly used in clinical settings, namely, iomeprol, iohexol, ioversol, and iodixanol. Their in vivo properties have been investigated upon intravenous injection in a murine HER2+ breast tumor model (n = 4 mice for each CA) using both computed tomography (CT) and MRI modalities. RESULTS The prototropic exchange rates measured for the 4 investigated iodinated molecules showed strong pH dependence with base catalyzed exchange rate that was faster for monomeric compounds (20-4000 Hz in the pH range of 5.5-7.9). Computed tomography quantification showed marked (up to 2 mg I/mL concentration) and prolonged accumulation (up to 30 minutes postinjection) inside tumor regions. Among the 4 agents we tested, iohexol and ioversol display good CEST contrast properties at 7 T, and in vivo results confirmed strong and prolonged contrast enhancement of the tumors, with elevated extravasation fractions (74%-91%). A strong and significant correlation was found between CT and CEST-MRI tumor-enhanced images (R = 0.70, P < 0.01). CONCLUSIONS The obtained results demonstrate that iohexol and ioversol, 2 commonly used radiographic compounds, can be used as MRI perfusion agents, particularly useful when serial images acquisitions are needed to complement CT information.
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Randtke EA, Granados JC, Howison CM, Pagel MD, Cárdenas-Rodríguez J. Multislice CEST MRI improves the spatial assessment of tumor pH. Magn Reson Med 2016; 78:97-106. [PMID: 27465207 DOI: 10.1002/mrm.26348] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/25/2016] [Accepted: 06/28/2016] [Indexed: 12/19/2022]
Abstract
PURPOSE Multislice maps of extracellular pH (pHe) are needed to interrogate the heterogeneities of tumors and normal organs. To address this need, we have developed a multislice chemical exchange saturation transfer (CEST) MRI acquisition method with a CEST spectrum-fitting method that measures in vivo pHe over a range of 6.3 to 7.4. METHODS The phase offset multiplanar (POMP) method was adapted for CEST fast imaging with steady-state free precession (FISP) MRI to acquire multiple image slices with a single CEST saturation pulse. The Bloch-McConnell equations were modified to include pH based on a calibration of pH and chemical exchange rate for the contrast agent iopamidol. These equations were used to estimate the pixel-wise pHe values throughout the multislice acidoCEST MR images of the tumor, kidney, bladder, and other tissues of a MDA-MB-231 tumor model. RESULTS Multislice acidoCEST MRI successfully mapped a gradient of pHe from 6.73 to 6.81 units from the tumor core to rim, and also mapped a gradient of pHe 6.56 to 6.97 across the mouse kidney. The bladder was found to be pHe 6.3. CONCLUSION AcidoCEST MRI with POMP acquisition and Bloch-McConnel analysis can map pHe in multiple imaging slices through the tumor, kidney, and bladder. This multislice evaluation facilitates assessments of spatial heterogeneity of tissue pHe. Magn Reson Med 78:97-106, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Edward A Randtke
- Department of Medical Imaging, University of Arizona, Tucson, Arizona, USA
| | - Jeffry C Granados
- Department of Biomedical Engineering, University of Arizona, Tucson, Arizona, USA
| | | | - Mark D Pagel
- Department of Medical Imaging, University of Arizona, Tucson, Arizona, USA
| | - Julio Cárdenas-Rodríguez
- Department of Medical Imaging, University of Arizona, Tucson, Arizona, USA.,Department of Biomedical Engineering, University of Arizona, Tucson, Arizona, USA
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Guo Y, Zhou IY, Chan ST, Wang Y, Mandeville ET, Igarashi T, Lo EH, Ji X, Sun PZ. pH-sensitive MRI demarcates graded tissue acidification during acute stroke - pH specificity enhancement with magnetization transfer and relaxation-normalized amide proton transfer (APT) MRI. Neuroimage 2016; 141:242-249. [PMID: 27444569 DOI: 10.1016/j.neuroimage.2016.07.025] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 07/06/2016] [Accepted: 07/11/2016] [Indexed: 11/26/2022] Open
Abstract
pH-sensitive amide proton transfer (APT) MRI provides a surrogate metabolic biomarker that complements the widely-used perfusion and diffusion imaging. However, the endogenous APT MRI is often calculated using the asymmetry analysis (MTRasym), which is susceptible to an inhomogeneous shift due to concomitant semisolid magnetization transfer (MT) and nuclear overhauser (NOE) effects. Although the intact brain tissue has little pH variation, white and gray matter appears distinct in the MTRasym image. Herein we showed that the heterogeneous MTRasym shift not related to pH highly correlates with MT ratio (MTR) and longitudinal relaxation rate (R1w), which can be reasonably corrected using the multiple regression analysis. Because there are relatively small MT and R1w changes during acute stroke, we postulate that magnetization transfer and relaxation-normalized APT (MRAPT) analysis increases MRI specificity to acidosis over the routine MTRasym image, hence facilitates ischemic lesion segmentation. We found significant differences in perfusion, pH and diffusion lesion volumes (P<0.001, ANOVA). Furthermore, MRAPT MRI depicted graded ischemic acidosis, with the most severe acidosis in the diffusion lesion (-1.05±0.29%/s), moderate acidification within the pH/diffusion mismatch (i.e., metabolic penumbra, -0.67±0.27%/s) and little pH change in the perfusion/pH mismatch (i.e., benign oligemia, -0.04±0.14%/s), providing refined stratification of ischemic tissue injury.
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Affiliation(s)
- Yingkun Guo
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Iris Yuwen Zhou
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Suk-Tak Chan
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Yu Wang
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA; China-America Joint Neuroscience Institute, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Emiri T Mandeville
- Neuroprotection Research Laboratory, Department of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Takahiro Igarashi
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Eng H Lo
- Neuroprotection Research Laboratory, Department of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Xunming Ji
- China-America Joint Neuroscience Institute, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Phillip Zhe Sun
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA; China-America Joint Neuroscience Institute, Xuanwu Hospital, Capital Medical University, Beijing, China; Neuroprotection Research Laboratory, Department of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.
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45
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Yang X, Song X, Banerjee SR, Li Y, Byun Y, Liu G, Bhujwalla ZM, Pomper MG, McMahon MT. Developing imidazoles as CEST MRI pH sensors. CONTRAST MEDIA & MOLECULAR IMAGING 2016; 11:304-12. [PMID: 27071959 PMCID: PMC5201433 DOI: 10.1002/cmmi.1693] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 02/17/2016] [Accepted: 02/22/2016] [Indexed: 12/21/2022]
Abstract
A series of intra-molecular hydrogen bonded imidazoles and related heterocyclic compounds were screened for their N-H chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) contrast properties. Of the compounds, imidazole-4,5-dicarboxamides (I45DCs) were found to provide the strongest contrast, with the contrast produced at a large chemical shift from water (7.8 ppm) and strongly dependent on pH. We have tested several probes based on this scaffold, and demonstrated that these probes could be applied for in vivo detection of kidney pH after intravenous administration. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Xing Yang
- Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Xiaolei Song
- Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Sangeeta Ray Banerjee
- Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Yuguo Li
- Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Youngjoo Byun
- College of Pharmacy, Korea University, Sejong, South Korea
| | - Guanshu Liu
- Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Zaver M. Bhujwalla
- Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Martin G. Pomper
- Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Michael T. McMahon
- Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
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Sinharay S, Pagel MD. Advances in Magnetic Resonance Imaging Contrast Agents for Biomarker Detection. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2016; 9:95-115. [PMID: 27049630 PMCID: PMC4911245 DOI: 10.1146/annurev-anchem-071015-041514] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Recent advances in magnetic resonance imaging (MRI) contrast agents have provided new capabilities for biomarker detection through molecular imaging. MRI contrast agents based on the T2 exchange mechanism have more recently expanded the armamentarium of agents for molecular imaging. Compared with T1 and T2* agents, T2 exchange agents have a slower chemical exchange rate, which improves the ability to design these MRI contrast agents with greater specificity for detecting the intended biomarker. MRI contrast agents that are detected through chemical exchange saturation transfer (CEST) have even slower chemical exchange rates. Another emerging class of MRI contrast agents uses hyperpolarized (13)C to detect the agent with outstanding sensitivity. These hyperpolarized (13)C agents can be used to track metabolism and monitor characteristics of the tissue microenvironment. Together, these various MRI contrast agents provide excellent opportunities to develop molecular imaging for biomarker detection.
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Affiliation(s)
- Sanhita Sinharay
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85724;
| | - Mark D Pagel
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85724;
- Department of Medical Imaging, University of Arizona, Tucson, Arizona 85724;
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Chan KWY, Jiang L, Cheng M, Wijnen JP, Liu G, Huang P, van Zijl PCM, McMahon MT, Glunde K. CEST-MRI detects metabolite levels altered by breast cancer cell aggressiveness and chemotherapy response. NMR IN BIOMEDICINE 2016; 29:806-16. [PMID: 27100284 PMCID: PMC4873340 DOI: 10.1002/nbm.3526] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 02/27/2016] [Accepted: 02/29/2016] [Indexed: 05/08/2023]
Abstract
Chemical exchange saturation transfer (CEST) is an MRI contrast mechanism that detects the exchange of protons from distinct hydroxyl, amine, and amide groups to tissue water through the transfer of signal loss, with repeated exchange enhancing their effective signal. We applied CEST to detect systematically 15 common cellular metabolites in a panel of differentially aggressive human breast cancer cell lines. The highest CEST contrast was generated by creatine, myo-inositol, glutamate, and glycerophosphocholine, whose cellular concentrations decreased with increasing breast cancer aggressiveness. These decreased metabolite concentrations resulted in turn in a decreased CEST profile with increasing breast cancer aggressiveness in water-soluble extracts of breast cell lines. Treatment of both breast cancer cell lines with the chemotherapy drug doxorubicin resulted in increased metabolic CEST profiles, which correlated with significant increases in creatine, phosphocreatine, and glycerophosphocholine. CEST can detect breast cancer aggressiveness and response to chemotherapy in water-soluble extracts of breast cell lines. The presented results help shed light on possible contributions from CEST-active metabolites to the CEST contrast produced by breast cancers. The metabolic CEST profile may improve detection sensitivity over conventional MRS, and may have the potential to assess breast cancer aggressiveness and response to chemotherapy non-invasively using MRI if specialized metabolic CEST profile detection can be realized in vivo. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Kannie W. Y. Chan
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Center for Nanomedicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Lu Jiang
- Russell H. Morgan Department of Radiology and Radiological Science, Division of Cancer Imaging Research, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Menglin Cheng
- Russell H. Morgan Department of Radiology and Radiological Science, Division of Cancer Imaging Research, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jannie P. Wijnen
- Russell H. Morgan Department of Radiology and Radiological Science, Division of Cancer Imaging Research, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Radiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Guanshu Liu
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Peng Huang
- Department of Oncology, Biostatistics and Bioinformatics Division, School of Medicine and Department of Biostatistics, Bloomberg School of Public Health, The Johns Hopkins University, Baltimore, MD, USA
- Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Peter C. M. van Zijl
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Michael T. McMahon
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- To whom correspondence may be addressed. ,
| | - Kristine Glunde
- Russell H. Morgan Department of Radiology and Radiological Science, Division of Cancer Imaging Research, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
- To whom correspondence may be addressed. ,
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MRI Reporter Genes for Noninvasive Molecular Imaging. Molecules 2016; 21:molecules21050580. [PMID: 27213309 PMCID: PMC6273230 DOI: 10.3390/molecules21050580] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 04/21/2016] [Accepted: 04/25/2016] [Indexed: 01/17/2023] Open
Abstract
Magnetic resonance imaging (MRI) is one of the most important imaging technologies used in clinical diagnosis. Reporter genes for MRI can be applied to accurately track the delivery of cell in cell therapy, evaluate the therapy effect of gene delivery, and monitor tissue/cell-specific microenvironments. Commonly used reporter genes for MRI usually include genes encoding the enzyme (e.g., tyrosinase and β-galactosidase), the receptor on the cells (e.g., transferrin receptor), and endogenous reporter genes (e.g., ferritin reporter gene). However, low sensitivity limits the application of MRI and reporter gene-based multimodal imaging strategies are common including optical imaging and radionuclide imaging. These can significantly improve diagnostic efficiency and accelerate the development of new therapies.
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Akhenblit PJ, Hanke NT, Gill A, Persky DO, Howison CM, Pagel MD, Baker AF. Assessing Metabolic Changes in Response to mTOR Inhibition in a Mantle Cell Lymphoma Xenograft Model Using AcidoCEST MRI. Mol Imaging 2016; 15:15/0/1536012116645439. [PMID: 27140422 PMCID: PMC4878391 DOI: 10.1177/1536012116645439] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 02/23/2016] [Indexed: 01/16/2023] Open
Abstract
AcidoCEST magnetic resonance imaging (MRI) has previously been shown to measure tumor extracellular pH (pHe) with excellent accuracy and precision. This study investigated the ability of acidoCEST MRI to monitor changes in tumor pHe in response to therapy. To perform this study, we used the Granta 519 human mantle cell lymphoma cell line, which is an aggressive B-cell malignancy that demonstrates activation of the phosphatidylinositol-3-kinase/Akt/mammalian target of rapamycin (mTOR) pathway. We performed in vitro and in vivo studies using the Granta 519 cell line to investigate the efficacy and associated changes induced by the mTOR inhibitor, everolimus (RAD001). AcidoCEST MRI studies showed a statistically significant increase in tumor pHe of 0.10 pH unit within 1 day of initiating treatment, which foreshadowed a decrease in tumor growth of the Granta 519 xenograft model. AcidoCEST MRI then measured a decrease in tumor pHe 7 days after initiating treatment, which foreshadowed a return to normal tumor growth rate. Therefore, this study is a strong example that acidoCEST MRI can be used to measure tumor pHe that may serve as a marker for therapeutic efficacy of anticancer therapies.
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Affiliation(s)
- Paul J Akhenblit
- Cancer Biology Graduate Interdisciplinary Program, University of Arizona, Tucson, AZ, USA
| | - Neale T Hanke
- University of Arizona Cancer Center, University of Arizona, Tucson, AZ, USA
| | - Alexander Gill
- University of Arizona Cancer Center, University of Arizona, Tucson, AZ, USA
| | - Daniel O Persky
- University of Arizona Cancer Center, University of Arizona, Tucson, AZ, USA
| | | | - Mark D Pagel
- Cancer Biology Graduate Interdisciplinary Program, University of Arizona, Tucson, AZ, USA University of Arizona Cancer Center, University of Arizona, Tucson, AZ, USA Department of Medical Imaging, University of Arizona, Tucson, AZ, USA
| | - Amanda F Baker
- University of Arizona Cancer Center, University of Arizona, Tucson, AZ, USA
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Liu Z, Dimitrov IE, Lenkinski RE, Hajibeigi A, Vinogradov E. UCEPR: Ultrafast localized CEST-spectroscopy with PRESS in phantoms and in vivo. Magn Reson Med 2016; 75:1875-85. [PMID: 26033357 PMCID: PMC4663188 DOI: 10.1002/mrm.25780] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 04/02/2015] [Accepted: 04/27/2015] [Indexed: 11/10/2022]
Abstract
PURPOSE Chemical exchange saturation transfer (CEST) is a contrast mechanism enhancing low-concentration molecules through saturation transfer from their exchangeable protons to bulk water. Often many scans are acquired to form a Z-spectrum, making the CEST method time-consuming. Here, an ultrafast localized CEST-spectroscopy with PRESS (UCEPR) is proposed to obtain the entire Z-spectrum of a voxel using only two scans, significantly accelerating CEST. THEORY AND METHODS The approach combines ultrafast nonlocalized CEST spectroscopy with localization using PRESS. A field gradient is applied concurrently with the saturation pulse producing simultaneous saturation of all Z-spectrum frequencies that are also spatially encoded. A readout gradient during data acquisition resolves the spatial dependence of the CEST responses into frequency. UCEPR was tested on a 3T scanner both in phantoms and in vivo. RESULTS In phantoms, a fast Z-spectroscopy acquisition of multiple pH-variant iopamidol samples was achieved with four- to seven-fold acceleration as compared to the conventional CEST methods. In vivo, amide proton transfer (APT) in white matter of healthy human brain was measured rapidly in 48 s and with high frequency resolution (≤ 0.2 ppm). CONCLUSION Compared with conventional CEST methods, UCEPR has the advantage of rapidly acquiring high-resolution Z-spectra. Potential in vivo applications include ultrafast localized Z-spectroscopy, quantitative, or dynamic CEST studies.
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Affiliation(s)
- Zheng Liu
- Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon, USA
| | - Ivan E. Dimitrov
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Philips Medical Systems, Highland Heights, Ohio, USA
| | - Robert E. Lenkinski
- Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Asghar Hajibeigi
- Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Elena Vinogradov
- Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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