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Mohanta Z, Stabinska J, Gilad AA, Barker PB, McMahon MT. The Proton Resonance Enhancement for CEST imaging and Shift Exchange (PRECISE) family of RF pulse shapes for Chemical Exchange Saturation Transfer MRI. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.19.599565. [PMID: 38948741 PMCID: PMC11212941 DOI: 10.1101/2024.06.19.599565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Purpose To optimize a 100 msec pulse for producing CEST MRI contrast and evaluate in mice. Methods A gradient ascent algorithm was employed to generate a family of 100 point, 100 msec pulses for use in CEST pulse trains ('PRECISE'). Gradient ascent optimizations were performed for exchange rates (k ca ) = 500 s -1 , 1,500 s -1 , 2,500 s -1 , 3,500 s -1 and 4,500 s -1 and offsets (Δω) = 9.6, 7.8, 4.2 and 2.0 ppm. 7 PRECISE pulse shapes were tested on an 11.7 T scanner using a phantom containing three representative CEST agents with peak saturation B 1 = 4 μT. The pulse producing the most contrast in phantoms was then evaluated for CEST MRI pH mapping of the kidneys in healthy mice after iopamidol administration. Results The most promising pulse in terms of contrast performance across all three phantoms was the 9.6 ppm, 2500 s -1 optimized pulse with ∼2.7 x improvement over Gaussian and ∼1.3x's over Fermi pulses. This pulse also displayed a large improvement in contrast over the Gaussian pulse after administration of iopamidol in live mice. Conclusion A new 100 msec pulse was developed based on gradient ascent optimizations which produced better contrast compared to standard Gaussian and Fermi pulses in phantoms. This shape also showed a substantial improvement for CEST MRI pH mapping in live mice over the Gaussian shape and appears promising for a wide range of CEST applications.
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Di Gregorio E, Rosa E, Ferrauto G, Diaferia C, Gallo E, Accardo A, Terreno E. Development of cationic peptide-based hydrogels loaded with iopamidol for CEST-MRI detection. J Mater Chem B 2023; 11:7435-7441. [PMID: 37435712 DOI: 10.1039/d3tb00187c] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2023]
Abstract
Peptide-based hydrogels have been recently investigated as materials for biomedical applications like tissue engineering and delivery of drugs and imaging agents. Among the synthetic peptide hydrogelators, the cationic hexapeptides Ac-K1 and Ac-K2 were proposed as scaffolds for bioprinting applications. Here, we report the formulation of Ac-K1 and Ac-K2 hydrogels loaded with iopamidol, an iodinated contrast agent clinically approved for X-ray computed tomography, and more recently identified as an efficient CEST-MRI probe. Iopamidol-loaded hydrogels were soft, injectable and non-toxic both in vitro (on three tumor cell lines: GL261, TS/A and 3T3-NIH) and in vivo (in Balb/c mice inoculated with TS/A breast cancer cells). The in vitro CEST-MRI study evidenced the typical features of the CEST pattern of iopamidol, with a CEST contrast higher than 50%. Due to their injectability and good ability to retain the contrast agent, the herein investigated systems can be considered as promising candidates for the development of smart MRI detectable hydrogels.
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Affiliation(s)
- Enza Di Gregorio
- Molecular and Preclinical Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Turin, Via Nizza 52, Turin, Italy.
| | - Elisabetta Rosa
- Department of Pharmacy and Interuniversity Research Centre on Bioactive Peptides (CIRPeB) "Carlo Pedone", University of Naples "Federico II", Via D. Montesano 49, Naples 80131, Italy
| | - Giuseppe Ferrauto
- Molecular and Preclinical Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Turin, Via Nizza 52, Turin, Italy.
| | - Carlo Diaferia
- Department of Pharmacy and Interuniversity Research Centre on Bioactive Peptides (CIRPeB) "Carlo Pedone", University of Naples "Federico II", Via D. Montesano 49, Naples 80131, Italy
| | - Enrico Gallo
- IRCCS Synlab SDN, Via Gianturco 113, Naples, 80143, Italy
| | - Antonella Accardo
- Department of Pharmacy and Interuniversity Research Centre on Bioactive Peptides (CIRPeB) "Carlo Pedone", University of Naples "Federico II", Via D. Montesano 49, Naples 80131, Italy
| | - Enzo Terreno
- Molecular and Preclinical Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Turin, Via Nizza 52, Turin, Italy.
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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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4
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Jardim-Perassi BV, Irrera P, Lau JYC, Budzevich M, Whelan CJ, Abrahams D, Ruiz E, Ibrahim-Hashim A, Damgaci Erturk S, Longo DL, Pilon-Thomas SA, Gillies RJ. Intraperitoneal Delivery of Iopamidol to Assess Extracellular pH of Orthotopic Pancreatic Tumor Model by CEST-MRI. CONTRAST MEDIA & MOLECULAR IMAGING 2023; 2023:1944970. [PMID: 36704211 PMCID: PMC9836819 DOI: 10.1155/2023/1944970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/05/2022] [Accepted: 12/06/2022] [Indexed: 01/07/2023]
Abstract
The extracellular pH (pHe) of solid tumors is often acidic, as a consequence of the Warburg effect, and an altered metabolic state is often associated with malignancy. It has been shown that acidosis can promote tumor progression; thus, many therapeutic strategies have been adopted against tumor metabolism; one of these involves alkalinization therapies to raise tumor pH to inhibit tumor progression, improve immune surveillance, and overcome resistance to chemotherapies. Chemical exchange saturation transfer-magnetic resonance imaging (CEST-MRI) is a noninvasive technique that can measure pH in vivo using pH-sensitive contrast agents. Iopamidol, an iodinated contrast agent, clinically used for computed tomography (CT), contains amide group protons with pH-dependent exchange rates that can reveal the pHe of the tumor microenvironment. In this study, we optimized intraperitoneal (IP) delivery of iopamidol to facilitate longitudinal assessments of orthotopic pancreatic tumor pHe by CEST-MRI. Following IV-infusion and IP-bolus injections, we compared the two protocols for assessing tumor pH. Time-resolved CT imaging was used to evaluate the uptake of iopamidol in the tumor, revealing that IP-bolus delivered a high amount of contrast agent 40 min postinjection, which was similar to the amounts reached with the IV-infusion protocol. As expected, both IP and IV injection protocols produced comparable measurements of tumor pHe, showing no statistically significant difference between groups (p=0.16). In addition, we showed the ability to conduct longitudinal monitoring of tumor pHe using CEST-MRI with the IP injection protocol, revealing a statistically significant increase in tumor pHe following bicarbonate administration (p < 0.001). In conclusion, this study shows the capability to measure pHe using an IP delivery of iopamidol into orthotopic pancreatic tumors, which is important to conduct longitudinal studies.
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Affiliation(s)
| | - Pietro Irrera
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Justin Y. C. Lau
- Small Animal Imaging Laboratory, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Mikalai Budzevich
- Small Animal Imaging Laboratory, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Christopher J. Whelan
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
- Department of Biological Sciences, University of Illinois, Chicago, IL, USA
| | | | - Epifanio Ruiz
- Small Animal Imaging Laboratory, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Arig Ibrahim-Hashim
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Sultan Damgaci Erturk
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Dario Livio Longo
- Institute of Biostructures and Bioimages (IBB), National Research Council of Italy (CNR), Turin, Italy
| | - Shari A. Pilon-Thomas
- Department of Immunology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Robert J. Gillies
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
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Longo DL, Pirotta E, Gambino R, Romdhane F, Carella A, Corrado A. Tumor pH Imaging Using Chemical Exchange Saturation Transfer (CEST)-MRI. Methods Mol Biol 2023; 2614:287-311. [PMID: 36587132 DOI: 10.1007/978-1-0716-2914-7_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Magnetic resonance imaging (MRI) is a noninvasive imaging technique that allows for physiological and functional studies of the tumor microenvironment. Within MRI, the emerging field of chemical exchange saturation transfer (CEST) has been largely exploited for assessing a salient feature of all solid tumors, extracellular acidosis. Iopamidol-based tumor pH imaging has been demonstrated to provide accurate and high spatial resolution extracellular tumor pH maps to elucidate tumor aggressiveness and for assessing response to therapy, with a high potential for clinical translation. Here, we describe the overall setup and steps for measuring tumor extracellular pH of tumor models in mice by exploiting MRI-CEST pH imaging with a preclinical MRI scanner following the administration of iopamidol. We address issues of pH calibration curve setup, animal handling, pH-responsive contrast agent injection, acquisition protocol, and image processing for accurate quantification and visualization of tumor acidosis.
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Affiliation(s)
- Dario Livio Longo
- Institute of Biostructures and Bioimaging (IBB), Italian National Research Council (CNR), Torino, Italy.
| | - Elisa Pirotta
- Institute of Biostructures and Bioimaging (IBB), Italian National Research Council (CNR), Torino, Italy
| | - Riccardo Gambino
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Feriel Romdhane
- Institute of Biostructures and Bioimaging (IBB), Italian National Research Council (CNR), Torino, Italy
| | - Antonella Carella
- Institute of Biostructures and Bioimaging (IBB), Italian National Research Council (CNR), Torino, Italy
| | - Alessia Corrado
- Institute of Biostructures and Bioimaging (IBB), Italian National Research Council (CNR), Torino, Italy
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Abdella S, Abid F, Youssef SH, Kim S, Afinjuomo F, Malinga C, Song Y, Garg S. pH and its applications in targeted drug delivery. Drug Discov Today 2023; 28:103414. [PMID: 36273779 DOI: 10.1016/j.drudis.2022.103414] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 08/09/2022] [Accepted: 10/17/2022] [Indexed: 02/02/2023]
Abstract
Physiologic pH is vital for the normal functioning of tissues and varies in different parts of the body. The varying pH of the body has been exploited to design pH-sensitive smart oral, transdermal and vaginal drug delivery systems (DDS). The DDS demonstrated promising results in hard-to-treat diseases such as cancer and Helicobacter pylori infection. In some cases, a change in pH of tissues or body fluids has also been employed as a useful diagnostic biomarker. This paper aims to comprehensively review the development and applications of pH-sensitive DDS as well as recent advances in the field.
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Affiliation(s)
- Sadikalmahdi Abdella
- Centre for Pharmaceutical Innovation (CPI), University of South Australia, Adelaide, SA 5000, Australia; Department of Pharmacology and Clinical Pharmacy, College of Health Sciences, Addis Ababa University, Zambia St, Addis Ababa, Ethiopia
| | - Fatima Abid
- Centre for Pharmaceutical Innovation (CPI), University of South Australia, Adelaide, SA 5000, Australia
| | - Souha H Youssef
- Centre for Pharmaceutical Innovation (CPI), University of South Australia, Adelaide, SA 5000, Australia
| | - Sangseo Kim
- Centre for Pharmaceutical Innovation (CPI), University of South Australia, Adelaide, SA 5000, Australia
| | - Franklin Afinjuomo
- Centre for Pharmaceutical Innovation (CPI), University of South Australia, Adelaide, SA 5000, Australia
| | - Constance Malinga
- Centre for Pharmaceutical Innovation (CPI), University of South Australia, Adelaide, SA 5000, Australia
| | - Yunmei Song
- Centre for Pharmaceutical Innovation (CPI), University of South Australia, Adelaide, SA 5000, Australia
| | - Sanjay Garg
- Centre for Pharmaceutical Innovation (CPI), University of South Australia, Adelaide, SA 5000, Australia.
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7
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Tao Q, Yi P, Cai Z, Chen Z, Deng Z, Liu R, Feng Y. Ratiometric chemical exchange saturation transfer pH mapping using two iodinated agents with nonequivalent amide protons and a single low saturation power. Quant Imaging Med Surg 2022; 12:3889-3902. [PMID: 35782235 PMCID: PMC9246745 DOI: 10.21037/qims-21-1229] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 04/29/2022] [Indexed: 07/26/2023]
Abstract
BACKGROUND As an essential physiological parameter, pH plays a critical role in maintaining cellular and tissue homeostasis. The ratiometric chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) method using clinically approved iodinated agents has emerged as one of the most promising noninvasive techniques for pH assessment. METHODS In this study, we investigated the ability to use the combination of two different nonequivalent amide protons, chosen from five iodinated agents, namely iodixanol, iohexol, iobitridol, iopamidol, and iopromide, for pH measurement. The ratio of two nonequivalent amide CEST signals was calculated and compared for pH measurements in the range of 5.6 to 7.6. To quantify the CEST signals at 4.3 and 5.5 parts per million (ppm), we employed two analytic methods: magnetization transfer ratio asymmetry and Lorentzian fitting analysis. Lastly, the established protocol was used to measure the pH values in healthy rat kidneys (n=5). RESULTS The combination of iodixanol and iobitridol at a ratio of 1:1 was found to be suitable for pH mapping. The saturation power level (B1) was also investigated, and a low B1 of 1.5 µT was adopted for subsequent pH measurements. Improved precision and an extended pH detection range were achieved using iodixanol and iobitridol (1:1 ratio) and a single low B1 of 1.5 µT in vitro. In vivo renal pH values were measured as 7.23±0.09, 6.55±0.15, and 6.29±0.23 for the cortex, medulla, and calyx, respectively. CONCLUSIONS These results show that the ratiometric CEST method using two iodinated agents with nonequivalent amide protons could be used for in vivo pH mapping of the kidney under a single low B1 saturation power.
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Affiliation(s)
- Quan Tao
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
- Guangdong Province Engineering Laboratory for Medical Imaging and Diagnostic Technology, Southern Medical University, Guangzhou, China
- Key Laboratory of Mental Health of the Ministry of Education & Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Southern Medical University, Guangzhou, China
| | - Peiwei Yi
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
- Guangdong Province Engineering Laboratory for Medical Imaging and Diagnostic Technology, Southern Medical University, Guangzhou, China
- Key Laboratory of Mental Health of the Ministry of Education & Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Southern Medical University, Guangzhou, China
| | - Zimeng Cai
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
- Guangdong Province Engineering Laboratory for Medical Imaging and Diagnostic Technology, Southern Medical University, Guangzhou, China
- Key Laboratory of Mental Health of the Ministry of Education & Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Southern Medical University, Guangzhou, China
| | - Zelong Chen
- Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Zongwu Deng
- CAS Key Laboratory of Nano-Bio Interface and Division of Nanobionics, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, China
| | - Ruiyuan Liu
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
- Guangdong Province Engineering Laboratory for Medical Imaging and Diagnostic Technology, Southern Medical University, Guangzhou, China
- Key Laboratory of Mental Health of the Ministry of Education & Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Southern Medical University, Guangzhou, China
| | - Yanqiu Feng
- School of Biomedical Engineering, Southern Medical University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China
- Guangdong Province Engineering Laboratory for Medical Imaging and Diagnostic Technology, Southern Medical University, Guangzhou, China
- Key Laboratory of Mental Health of the Ministry of Education & Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Southern Medical University, Guangzhou, China
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8
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Aime S, Longo DL, Reineri F, Geninatti Crich S. New tools to investigate tumor metabolism by NMR/MRI. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2022; 338:107198. [PMID: 35339957 DOI: 10.1016/j.jmr.2022.107198] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 03/09/2022] [Accepted: 03/15/2022] [Indexed: 06/14/2023]
Abstract
Changes in metabolism is an hallmark that characterizes tumour cells from healthy ones. Their detection can be highly relevant for staging the tumor and for monitoring the response to therapeutic treatments. Herein it is shown the readout of these changes can be achieved either by assessing the pH of the extracellular space in the tumour region and by monitoring real time transformations of hyperpolarized C-13 labelled substrates. Mapping pH in a MR image is possible by measuring the CEST response of an administered contrast agent such as Iopamidol that can provide accurate measurements of the heterogeneity of tumour acidosis. Direct detection of relevant enzymatic activities have been acquired by using Pyruvate and Fumarate hyperpolarized by the incorporation of a molecule of para-H2. Finally, it has been found that the tumour transformation involves an increase in the water exchange rate between the intra- and the extra-cellular compartments. A quantitative estimation of these changes can be obtained by acquiring the longitudinal relaxation times of tissue water protons at low magnetic field strength on Fast Field Cycling Relaxometers. This finding has been exploited in an application devoted to the assessment of the presence of residual tumour tissue in the margins of the resected mass in breast conservative surgery.
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Affiliation(s)
- Silvio Aime
- Department of Molecular Biotechnologies and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy.
| | - Dario Livio Longo
- Institute of Biostructures and Bioimaging (IBB), National Research Council of Italy (CNR), Via Nizza 52, 10126 Torino, Italy
| | - Francesca Reineri
- Department of Molecular Biotechnologies and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy
| | - Simonetta Geninatti Crich
- Department of Molecular Biotechnologies and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy
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9
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Perlman O, Ito H, Herz K, Shono N, Nakashima H, Zaiss M, Chiocca EA, Cohen O, Rosen MS, Farrar CT. Quantitative imaging of apoptosis following oncolytic virotherapy by magnetic resonance fingerprinting aided by deep learning. Nat Biomed Eng 2022; 6:648-657. [PMID: 34764440 PMCID: PMC9091056 DOI: 10.1038/s41551-021-00809-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Accepted: 07/07/2021] [Indexed: 12/17/2022]
Abstract
Non-invasive imaging methods for detecting intratumoural viral spread and host responses to oncolytic virotherapy are either slow, lack specificity or require the use of radioactive or metal-based contrast agents. Here we show that in mice with glioblastoma multiforme, the early apoptotic responses to oncolytic virotherapy (characterized by decreased cytosolic pH and reduced protein synthesis) can be rapidly detected via chemical-exchange-saturation-transfer magnetic resonance fingerprinting (CEST-MRF) aided by deep learning. By leveraging a deep neural network trained with simulated magnetic resonance fingerprints, CEST-MRF can generate quantitative maps of intratumoural pH and of protein and lipid concentrations by selectively labelling the exchangeable amide protons of endogenous proteins and the exchangeable macromolecule protons of lipids, without requiring exogenous contrast agents. We also show that in a healthy volunteer, CEST-MRF yielded molecular parameters that are in good agreement with values from the literature. Deep-learning-aided CEST-MRF may also be amenable to the characterization of host responses to other cancer therapies and to the detection of cardiac and neurological pathologies.
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Affiliation(s)
- Or Perlman
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
| | - Hirotaka Ito
- Department of Neurosurgery, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Kai Herz
- Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
- Department of Biomedical Magnetic Resonance, University of Tübingen, Tübingen, Germany
| | - Naoyuki Shono
- Department of Neurosurgery, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Hiroshi Nakashima
- Department of Neurosurgery, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Moritz Zaiss
- Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
- Department of Neuroradiology, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), University Hospital Erlangen, Erlangen, Germany
| | - E Antonio Chiocca
- Department of Neurosurgery, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Ouri Cohen
- Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Matthew S Rosen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Christian T Farrar
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
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10
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Perlman O, Farrar CT, Heo HY. MR fingerprinting for semisolid magnetization transfer and chemical exchange saturation transfer quantification. NMR IN BIOMEDICINE 2022; 36:e4710. [PMID: 35141967 PMCID: PMC9808671 DOI: 10.1002/nbm.4710] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 01/18/2022] [Accepted: 02/04/2022] [Indexed: 05/11/2023]
Abstract
Chemical exchange saturation transfer (CEST) MRI has positioned itself as a promising contrast mechanism, capable of providing molecular information at sufficient resolution and amplified sensitivity. However, it has not yet become a routinely employed clinical technique, due to a variety of confounding factors affecting its contrast-weighted image interpretation and the inherently long scan time. CEST MR fingerprinting (MRF) is a novel approach for addressing these challenges, allowing simultaneous quantitation of several proton exchange parameters using rapid acquisition schemes. Recently, a number of deep-learning algorithms have been developed to further boost the performance and speed of CEST and semi-solid macromolecule magnetization transfer (MT) MRF. This review article describes the fundamental theory behind semisolid MT/CEST-MRF and its main applications. It then details supervised and unsupervised learning approaches for MRF image reconstruction and describes artificial intelligence (AI)-based pipelines for protocol optimization. Finally, practical considerations are discussed, and future perspectives are given, accompanied by basic demonstration code and data.
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Affiliation(s)
- Or Perlman
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Christian T. Farrar
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Hye-Young Heo
- Division of MR Research, Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
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11
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Perlman O, Zhu B, Zaiss M, Rosen MS, Farrar CT. An end-to-end AI-based framework for automated discovery of rapid CEST/MT MRI acquisition protocols and molecular parameter quantification (AutoCEST). Magn Reson Med 2022; 87:2792-2810. [PMID: 35092076 PMCID: PMC9305180 DOI: 10.1002/mrm.29173] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 01/04/2022] [Accepted: 01/07/2022] [Indexed: 12/28/2022]
Abstract
Purpose To develop an automated machine‐learning‐based method for the discovery of rapid and quantitative chemical exchange saturation transfer (CEST) MR fingerprinting acquisition and reconstruction protocols. Methods An MR physics‐governed AI system was trained to generate optimized acquisition schedules and the corresponding quantitative reconstruction neural network. The system (termed AutoCEST) is composed of a CEST saturation block, a spin dynamics module, and a deep reconstruction network, all differentiable and jointly connected. The method was validated using a variety of chemical exchange phantoms and in vivo mouse brains at 9.4T. Results The acquisition times for AutoCEST optimized schedules ranged from 35 to 71 s, with a quantitative image reconstruction time of only 29 ms. The resulting exchangeable proton concentration maps for the phantoms were in good agreement with the known solute concentrations for AutoCEST sequences (mean absolute error = 2.42 mM; Pearson’s r=0.992, p<0.0001), but not for an unoptimized sequence (mean absolute error = 65.19 mM; Pearson’s r=‐0.161, p=0.522). Similarly, improved exchange rate agreement was observed between AutoCEST and quantification of exchange using saturation power (QUESP) methods (mean absolute error: 35.8 Hz, Pearson’s r=0.971, p<0.0001) compared to an unoptimized schedule and QUESP (mean absolute error = 58.2 Hz; Pearson’s r=0.959, p<0.0001). The AutoCEST in vivo mouse brain semi‐solid proton volume fractions were lower in the cortex (12.77% ± 0.75%) compared to the white matter (19.80% ± 0.50%), as expected. Conclusion AutoCEST can automatically generate optimized CEST/MT acquisition protocols that can be rapidly reconstructed into quantitative exchange parameter maps.
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Affiliation(s)
- Or Perlman
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Bo Zhu
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Moritz Zaiss
- Magnetic Resonance Center, Max Planck Institute For Biological Cybernetics, Tübingen, Germany.,Department of Neuroradiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Matthew S Rosen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.,Department of Physics, Harvard University, Cambridge, MA, USA
| | - Christian T Farrar
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
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12
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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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13
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Consolino L, Irrera P, Romdhane F, Anemone A, Longo DL. Investigating plasma volume expanders as novel macromolecular MRI-CEST contrast agents for tumor contrast-enhanced imaging. Magn Reson Med 2021; 86:995-1007. [PMID: 33764575 DOI: 10.1002/mrm.28778] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 12/29/2022]
Abstract
PURPOSE The aim of this study was to investigate two clinically approved plasma volume expanders (dextran 70 and voluven) as macromolecular MRI-chemical exchange saturation transfer (CEST) contrast agents to assess tumor vascular properties. METHODS CEST contrast efficiency of both molecules (6% w/v) was measured in vitro at various irradiation saturation powers (1-6 μT for 5 s) and pH values (range, 5.5-7.9) and the exchange rate of hydroxyl protons was calculated. In vivo studies in a murine adenocarcinoma model (n = 4 mice for each contrast agent) upon i.v. injection provided CEST-derived perfusion tumor properties that were compared with those obtained with a gadolinium-based blood-pool agent (Gd-AAZTA-Madec). RESULTS In vitro measurements showed a marked CEST contrast dependency to pH, with higher CEST contrast at lower pH values for both molecules. The measured prototropic exchange rates confirmed a base-catalyzed exchange rate that was faster for dextran 70 in comparison to voluven. Both molecules showed a similar CEST contrast increase (ΔST% > 3%) in the tumor tissue up to 30 min postinjection, with heterogeneous accumulation. In tumors receiving both CEST and T1 -weighted agents, a voxel-by-voxel analysis indicated moderate spatial correlation of perfusion properties between voluven/dextran 70 and Gd-AAZTA-Madec, suggesting different distribution patterns according to their molecular size. CONCLUSIONS The obtained results showed that both voluven and dextran 70 can be exploited as MRI-CEST contrast agents for evaluating tumor enhancement properties. Their increased accumulation in tumors and prolonged contrast enhancement promote their use as blood-pool MRI-CEST agents to examine tumor vascularization.
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Affiliation(s)
- Lorena Consolino
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - Pietro Irrera
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy.,University of Campania Luigi Vanvitelli, Caserta, Italy
| | - Feriel Romdhane
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - Annasofia Anemone
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - Dario Livio Longo
- Institute of Biostructures and Bioimaging (IBB), National Research Council of Italy (CNR), Turin, Italy
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14
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Prasad S, Chandra A, Cavo M, Parasido E, Fricke S, Lee Y, D'Amone E, Gigli G, Albanese C, Rodriguez O, Del Mercato LL. Optical and magnetic resonance imaging approaches for investigating the tumour microenvironment: state-of-the-art review and future trends. NANOTECHNOLOGY 2021; 32:062001. [PMID: 33065554 DOI: 10.1088/1361-6528/abc208] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The tumour microenvironment (TME) strongly influences tumorigenesis and metastasis. Two of the most characterized properties of the TME are acidosis and hypoxia, both of which are considered hallmarks of tumours as well as critical factors in response to anticancer treatments. Currently, various imaging approaches exist to measure acidosis and hypoxia in the TME, including magnetic resonance imaging (MRI), positron emission tomography and optical imaging. In this review, we will focus on the latest fluorescent-based methods for optical sensing of cell metabolism and MRI as diagnostic imaging tools applied both in vitro and in vivo. The primary emphasis will be on describing the current and future uses of systems that can measure intra- and extra-cellular pH and oxygen changes at high spatial and temporal resolution. In addition, the suitability of these approaches for mapping tumour heterogeneity, and assessing response or failure to therapeutics will also be covered.
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Affiliation(s)
- Saumya Prasad
- Institute of Nanotechnology, National Research Council (CNR-NANOTEC), c/o Campus Ecotekne, via Monteroni, 73100, Lecce, Italy
| | - Anil Chandra
- Institute of Nanotechnology, National Research Council (CNR-NANOTEC), c/o Campus Ecotekne, via Monteroni, 73100, Lecce, Italy
| | - Marta Cavo
- Institute of Nanotechnology, National Research Council (CNR-NANOTEC), c/o Campus Ecotekne, via Monteroni, 73100, Lecce, Italy
| | - Erika Parasido
- Department of Oncology, Georgetown University Medical Center, Washington, DC, United States of America
- Center for Translational Imaging, Georgetown University Medical Center, Washington, DC, United States of America
| | - Stanley Fricke
- Department of Oncology, Georgetown University Medical Center, Washington, DC, United States of America
- Center for Translational Imaging, Georgetown University Medical Center, Washington, DC, United States of America
- Department of Radiology, Georgetown University Medical Center, Washington, DC, United States of America
| | - Yichien Lee
- Department of Oncology, Georgetown University Medical Center, Washington, DC, United States of America
| | - Eliana D'Amone
- Institute of Nanotechnology, National Research Council (CNR-NANOTEC), c/o Campus Ecotekne, via Monteroni, 73100, Lecce, Italy
| | - Giuseppe Gigli
- Institute of Nanotechnology, National Research Council (CNR-NANOTEC), c/o Campus Ecotekne, via Monteroni, 73100, Lecce, Italy
- Department of Mathematics and Physics 'Ennio De Giorgi', University of Salento, via Arnesano, 73100, Lecce, Italy
| | - Chris Albanese
- Department of Oncology, Georgetown University Medical Center, Washington, DC, United States of America
- Center for Translational Imaging, Georgetown University Medical Center, Washington, DC, United States of America
- Department of Radiology, Georgetown University Medical Center, Washington, DC, United States of America
| | - Olga Rodriguez
- Department of Oncology, Georgetown University Medical Center, Washington, DC, United States of America
- Center for Translational Imaging, Georgetown University Medical Center, Washington, DC, United States of America
| | - Loretta L Del Mercato
- Institute of Nanotechnology, National Research Council (CNR-NANOTEC), c/o Campus Ecotekne, via Monteroni, 73100, Lecce, Italy
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15
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Romdhane F, Villano D, Irrera P, Consolino L, Longo DL. Evaluation of a similarity anisotropic diffusion denoising approach for improving in vivo CEST-MRI tumor pH imaging. Magn Reson Med 2021; 85:3479-3496. [PMID: 33496986 DOI: 10.1002/mrm.28676] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 12/18/2020] [Accepted: 12/18/2020] [Indexed: 12/16/2022]
Abstract
PURPOSE Chemical exchange saturation transfer MRI provides new approaches for investigating tumor microenvironment, including tumor acidosis that plays a key role in tumor progression and resistance to therapy. Following iopamidol injection, the detection of the contrast agent inside the tumor tissue allows measurements of tumor extracellular pH. However, accurate tumor pH quantifications are hampered by the low contrast efficiency of the CEST technique and by the low SNR of the acquired CEST images, hence in a reduced detectability of the injected agent. This work aims to investigate a novel denoising method for improving both tumor pH quantification and accuracy of CEST-MRI pH imaging. METHODS An hybrid denoising approach was investigated for CEST-MRI pH imaging based on the combination of the nonlocal mean filter and the anisotropic diffusion tensor method. The denoising approach was tested in simulated and in vitro data and compared with previously reported methods for CEST imaging and with established denoising approaches. Finally, it was validated with in vivo data to improve the accuracy of tumor pH maps. RESULTS The proposed method outperforms current denoising methods in CEST contrast quantification and detection of the administered contrast agent at several increasing noise levels with simulated data. In addition, it achieved a better pH quantification in in vitro data and demonstrated a marked improvement in contrast detection and a substantial improvement in tumor pH accuracy in in vivo data. CONCLUSION The proposed approach effectively reduces the noise in CEST images and increases the sensitivity detection in CEST-MRI pH imaging.
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Affiliation(s)
- Feriel Romdhane
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.,National Engineering School of Tunis, University al Manar, Tunis, Tunisia
| | - Daisy Villano
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Pietro Irrera
- University of Campania "Luigi Vanvitelli,", Caserta, Italy.,Institute of Biostructures and Bioimaging (IBB), Italian National Research Council (CNR), Torino, Italy
| | - Lorena Consolino
- Molecular Imaging Center, 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
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16
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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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17
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Liu G, van Zijl PC. CEST (Chemical Exchange Saturation Transfer) MR Molecular Imaging. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00012-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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18
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Anemone A, Consolino L, Conti L, Irrera P, Hsu MY, Villano D, Dastrù W, Porporato PE, Cavallo F, Longo DL. Tumour acidosis evaluated in vivo by MRI-CEST pH imaging reveals breast cancer metastatic potential. Br J Cancer 2021; 124:207-216. [PMID: 33257841 PMCID: PMC7782702 DOI: 10.1038/s41416-020-01173-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 10/07/2020] [Accepted: 10/28/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Tumour acidosis is considered to play a central role in promoting cancer invasion and migration, but few studies have investigated in vivo how tumour pH correlates with cancer invasion. This study aims to determine in vivo whether tumour acidity is associated with cancer metastatic potential. METHODS Breast cancer cell lines with different metastatic potentials have been characterised for several markers of aggressiveness and invasiveness. Murine tumour models have been developed and assessed for lung metastases and tumour acidosis has been assessed in vivo by a magnetic resonance imaging-based chemical exchange saturation transfer (CEST) pH imaging approach. RESULTS The higher metastatic potential of 4T1 and TS/A primary tumours, in comparison to the less aggressive TUBO and BALB-neuT ones, was confirmed by the highest expression of cancer cell stem markers (CD44+CD24-), highlighting their propensity to migrate and invade, coinciding with the measurement obtained by in vitro assays. MRI-CEST pH imaging successfully discriminated the more aggressive 4T1 and TS/A tumours that displayed a more acidic pH. Moreover, the observed higher tumour acidity was significantly correlated with an increased number of lung metastases. CONCLUSIONS The findings of this study indicate that the extracellular acidification is associated with the metastatic potential.
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Affiliation(s)
- Annasofia Anemone
- Department of Molecular Biotechnology and Health Sciences, Molecular Imaging Center, University of Torino, Via Nizza 52, Torino, Italy
| | - Lorena Consolino
- Department of Molecular Biotechnology and Health Sciences, Molecular Imaging Center, University of Torino, Via Nizza 52, Torino, Italy
| | - Laura Conti
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, Torino, Italy
| | - Pietro Irrera
- University of Campania "Luigi Vanvitelli", Viale Abramo Lincoln, 5, Caserta, Italy
| | - Myriam Y Hsu
- Department of Molecular Biotechnology and Health Sciences, Molecular Imaging Center, University of Torino, Via Nizza 52, Torino, Italy
| | - Daisy Villano
- Department of Molecular Biotechnology and Health Sciences, Molecular Imaging Center, University of Torino, Via Nizza 52, Torino, Italy
| | - Walter Dastrù
- Department of Molecular Biotechnology and Health Sciences, Molecular Imaging Center, University of Torino, Via Nizza 52, Torino, Italy
| | - Paolo E Porporato
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, Torino, Italy
| | - Federica Cavallo
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, Torino, Italy
| | - Dario Livio Longo
- Institute of Biostructures and Bioimaging (IBB), Italian National Research Council (CNR), Via Nizza 52, Torino, Italy.
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19
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Repurposing Clinical Agents for Chemical Exchange Saturation Transfer Magnetic Resonance Imaging: Current Status and Future Perspectives. Pharmaceuticals (Basel) 2020; 14:ph14010011. [PMID: 33374213 PMCID: PMC7824058 DOI: 10.3390/ph14010011] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 12/19/2020] [Accepted: 12/21/2020] [Indexed: 12/24/2022] Open
Abstract
Molecular imaging is becoming an indispensable tool to pursue precision medicine. However, quickly translating newly developed magnetic resonance imaging (MRI) agents into clinical use remains a formidable challenge. Recently, Chemical Exchange Saturation Transfer (CEST) MRI is emerging as an attractive approach with the capability of directly using low concentration, exchangeable protons-containing agents for generating quantitative MRI contrast. The ability to utilize diamagnetic compounds has been extensively exploited to detect many clinical compounds, such as FDA approved drugs, X-ray/CT contrast agents, nutrients, supplements, and biopolymers. The ability to directly off-label use clinical compounds permits CEST MRI to be rapidly translated to clinical settings. In this review, the current status of CEST MRI based on clinically available compounds will be briefly introduced. The advancements and limitations of these studies are reviewed in the context of their pre-clinical or clinical applications. Finally, future directions will be briefly discussed.
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20
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Tuchina DK, Meerovich IG, Sindeeva OA, Zherdeva VV, Savitsky AP, Bogdanov AA, Tuchin VV. Magnetic resonance contrast agents in optical clearing: Prospects for multimodal tissue imaging. JOURNAL OF BIOPHOTONICS 2020; 13:e201960249. [PMID: 32687263 DOI: 10.1002/jbio.201960249] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 07/12/2020] [Accepted: 07/13/2020] [Indexed: 06/11/2023]
Abstract
Skin optical clearing effect ex vivo and in vivo was achieved by topical application of low molecular weight paramagnetic magnetic resonance contrast agents. This novel feature has not been explored before. By using collimated transmittance the diffusion coefficients of three clinically used magnetic resonance contrast agents, that is Gadovist, Magnevist and Dotarem as well as X-ray contrast agent Visipaque in mouse skin were determined ex vivo as (4.29 ± 0.39) × 10-7 cm2 /s, (5.00 ± 0.72) × 10-7 cm2 /s, (3.72 ± 0.67) × 10-7 cm2 /s and (1.64 ± 0.18) × 10-7 cm2 /s, respectively. The application of gadobutrol (Gadovist) resulted in efficient optical clearing that in general, was superior to other contrast agents tested and allowed to achieve: (a) more than 12-fold increase of transmittance over 10 minutes after application ex vivo; (b) markedly improved images of skin architecture obtained with optical coherence tomography; (c) an increase of the fluorescence intensity/background ratio in TagRFP-red fluorescent marker protein expressing tumor by five times after 15 minutes application into the skin in vivo. The obtained results have immediate implications for multimodality imaging because many contrast agents are capable of simultaneously enhancing the contrast of multiple imaging modalities.
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Affiliation(s)
- Daria K Tuchina
- Saratov State University, Saratov, Russia
- Tomsk State University, Tomsk, Russia
- А.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
| | - Irina G Meerovich
- А.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
| | | | - Victoria V Zherdeva
- А.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
| | - Alexander P Savitsky
- А.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
| | - Alexei A Bogdanov
- А.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
- University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Department of Bioengineering and Bioinformatics, Moscow State University, Moscow, Russia
| | - Valery V Tuchin
- Saratov State University, Saratov, Russia
- Tomsk State University, Tomsk, Russia
- А.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
- Institute of Precision Mechanics and Control of the Russian Academy of Sciences, Saratov, Russia
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21
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Villano D, Romdhane F, Irrera P, Consolino L, Anemone A, Zaiss M, Dastrù W, Longo DL. A fast multislice sequence for 3D MRI-CEST pH imaging. Magn Reson Med 2020; 85:1335-1349. [PMID: 33031591 PMCID: PMC7756816 DOI: 10.1002/mrm.28516] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 07/30/2020] [Accepted: 08/22/2020] [Indexed: 12/13/2022]
Abstract
Purpose Chemical exchange saturation transfer MRI can provide accurate pH images, but the slow scan time (due to long saturation periods and multiple offsets sampling) reduce both the volume coverage and spatial resolution capability, hence the possibility to interrogate the heterogeneity in tumors and organs. To overcome these limitations, we propose a fast multislice CEST‐MRI sequence with high pH accuracy and spatial resolution. Methods The sequence first uses a long saturation pulse to induce the steady‐state CEST contrast and a second short saturation pulse repeated after each image acquisition to compensate for signal losses based on an uneven irradiation scheme combined with a single‐shot rapid acquisition with refocusing echoes readout. Sequence sensitivity and accuracy in measuring pH was optimized by simulation and assessed by in vitro studies in pH‐varying phantoms. In vivo validation was performed in two applications by acquiring multislice pH images covering the whole tumors and kidneys after iopamidol injection. Results Simulated and in vivo data showed comparable contrast efficiency and pH responsiveness by reducing saturation time. The experimental data from a homogeneous, pH‐varying, iopamidol‐containing phantom show that the sequence produced a uniform CEST contrast across slices and accurate values across slices in less than 10 minutes. In vivo measurements allowed us to quantify the 3D pH gradients of tumors and kidneys, with pH ranges comparable with the literature. Conclusion The proposed fast multislice CEST‐MRI sequence allows volumetric acquisitions with good pH sensitivity, accuracy, and spatial resolution for several in vivo pH imaging applications.
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Affiliation(s)
- Daisy Villano
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Feriel Romdhane
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.,National Engineering School of Tunis (ENIT), University al Manar, Tunis, Tunisia
| | - Pietro Irrera
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy.,Institute of Biostructures and Bioimaging, University of Campania "Luigi Vanvitelli," Italian National Research Council, Napoli, Italy
| | - Lorena Consolino
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Annasofia Anemone
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Moritz Zaiss
- Department of Neuroradiology, Friedrich-Alexander Universität Erlangen-Nürnberg, University Hospital Erlangen, Erlangen, Germany
| | - Walter Dastrù
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Dario Livio Longo
- Institute of Biostructures and Bioimaging, Italian National Research Council, Torino, Italy
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22
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Irrera P, Consolino L, Cutrin JC, Zöllner FG, Longo DL. Dual assessment of kidney perfusion and pH by exploiting a dynamic CEST-MRI approach in an acute kidney ischemia-reperfusion injury murine model. NMR IN BIOMEDICINE 2020; 33:e4287. [PMID: 32153058 DOI: 10.1002/nbm.4287] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 02/03/2020] [Accepted: 02/18/2020] [Indexed: 06/10/2023]
Abstract
Several factors can lead to acute kidney injury, but damage following ischemia and reperfusion injuries is the main risk factor and usually develops into chronic disease. MRI has often been proposed as a method with which to assess renal function. It does so by measuring the renal perfusion of an injected Gd-based contrast agent. The use of pH-responsive agents as part of the CEST (chemical exchange saturation transfer)-MRI technique has recently shown that pH homeostasis is also an important indicator of kidney functionality. However, there is still a need for methods that can provide more than one type of information following the injection of a single contrast agent for the characterization of renal function. Herein we propose, for the first time, dynamic CEST acquisition following iopamidol injection to quantify renal function by assessing both perfusion and pH homeostasis. The aim of this study is to assess renal functionality in a murine unilateral ischemia-reperfusion injury model at two time points (3 and 7 days) after acute kidney injury. The renal-perfusion estimates measured with iopamidol were compared with those obtained with a gadolinium-based agent, via a dynamic contrast enhanced (DCE)-MRI approach, to validate the proposed method. Compared with the contralateral kidneys, the clamped ones showed a significant decrease in renal perfusion, as measured using the DCE-MRI approach, which is consistent with reduced filtration capability. Dynamic CEST-MRI findings provided similar results, indicating that the clamped kidneys displayed significantly reduced renal filtration that persisted up to 7 days after the damage. In addition, CEST-MRI pH imaging showed that the clamped kidneys displayed significantly increased pH values, reflecting the disturbance to pH homeostasis. Our results demonstrate that a single CEST-MRI contrast agent can provide multiple types of information related to renal function and can discern healthy kidneys from pathological ones by combining perfusion measurements with renal pH mapping.
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Affiliation(s)
- Pietro Irrera
- Università degli Studi della Campania "Luigi Vanvitelli", Napoli, Italy
- Istituto di Biostrutture e Bioimmagini (IBB), Consiglio Nazionale delle Ricerche (CNR), Torino, Italy
| | - Lorena Consolino
- Centro di Imaging Molecolare, Dipartimento di Biotecnologie Molecolari e Scienze per la Salute, Università degli Studi di Torino, Torino, Italy
| | - Juan Carlos Cutrin
- Centro di Imaging Molecolare, Dipartimento di Biotecnologie Molecolari e Scienze per la Salute, Università degli Studi di Torino, Torino, Italy
| | - Frank G Zöllner
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Dario Livio Longo
- Istituto di Biostrutture e Bioimmagini (IBB), Consiglio Nazionale delle Ricerche (CNR), Torino, Italy
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23
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Gupta A, Caravan P, Price WS, Platas-Iglesias C, Gale EM. Applications for Transition-Metal Chemistry in Contrast-Enhanced Magnetic Resonance Imaging. Inorg Chem 2020; 59:6648-6678. [PMID: 32367714 DOI: 10.1021/acs.inorgchem.0c00510] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Contrast-enhanced magnetic resonance imaging (MRI) is an indispensable tool for diagnostic medicine. However, safety concerns related to gadolinium in commercial MRI contrast agents have emerged in recent years. For patients suffering from severe renal impairment, there is an important unmet medical need to perform contrast-enhanced MRI without gadolinium. There are also concerns over the long-term effects of retained gadolinium within the general patient population. Demand for gadolinium-free MRI contrast agents is driving a new wave of inorganic chemistry innovation as researchers explore paramagnetic transition-metal complexes as potential alternatives. Furthermore, advances in personalized care making use of molecular-level information have motivated inorganic chemists to develop MRI contrast agents that can detect pathologic changes at the molecular level. Recent studies have highlighted how reaction-based modulation of transition-metal paramagnetism offers a highly effective mechanism to achieve MRI contrast enhancement that is specific to biochemical processes. This Viewpoint highlights how recent advances in transition-metal chemistry are leading the way for a new generation of MRI contrast agents.
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Affiliation(s)
- Abhishek Gupta
- Nanoscale Organisation and Dynamics Group, School of Science and Health, Western Sydney University, Penrith, New South Wales 2751, Australia.,Ingham Institute of Applied Medical Research, Liverpool, New South Wales 2170, Australia
| | | | - William S Price
- Nanoscale Organisation and Dynamics Group, School of Science and Health, Western Sydney University, Penrith, New South Wales 2751, Australia.,Ingham Institute of Applied Medical Research, Liverpool, New South Wales 2170, Australia
| | - Carlos Platas-Iglesias
- Centro de Investigacións Científicas Avanzadas and Departamento de Química, Facultade de Ciencias, Universidade da Coruña, A Coruña, Galicia 15071, Spain
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24
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Abstract
OBJECTIVES The goal of this study was to demonstrate feasibility of measuring extracellular pH in cartilage and meniscus using acidoCEST technique with a 3-dimensional ultrashort echo time readout (acidoCEST-UTE) magnetic resonance imaging (MRI). MATERIALS AND METHODS Magnetization transfer ratio asymmetry, radiofrequency (RF) power mismatch, and relative saturation transfer were evaluated in liquid phantoms for iopromide, iopamidol, and iohexol over a pH range of 6.2 to 7.8, at various agent concentrations, temperatures, and buffer concentrations. Tissue phantoms containing cartilage and meniscus were evaluated with the same considerations for iopamidol and iohexol. Phantoms were imaged with the acidoCEST-UTE MRI sequence at 3 T. Correlation coefficients and coefficients of variations were calculated. Paired Wilcoxon rank-sum tests were used to evaluate for statistically significant differences. RESULTS The RF power mismatch and relative saturation transfer analyses of liquid phantoms showed iopamidol and iohexol to be the most promising agents for this study. Both these agents appeared to be concentration independent and feasible for use with or without buffer and at physiologic temperature over a pH range of 6.2 to 7.8. Ultimately, RF power mismatch fitting of iohexol showed the strongest correlation coefficients between cartilage, meniscus, and fluid. In addition, ratiometric values for iohexol are similar among liquid as well as different tissue types. CONCLUSIONS Measuring extracellular pH in cartilage and meniscus using acidoCEST-UTE MRI is feasible.
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25
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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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Anemone A, Consolino L, Arena F, Capozza M, Longo DL. Imaging tumor acidosis: a survey of the available techniques for mapping in vivo tumor pH. Cancer Metastasis Rev 2020; 38:25-49. [PMID: 30762162 PMCID: PMC6647493 DOI: 10.1007/s10555-019-09782-9] [Citation(s) in RCA: 98] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Cancer cells are characterized by a metabolic shift in cellular energy production, orchestrated by the transcription factor HIF-1α, from mitochondrial oxidative phosphorylation to increased glycolysis, regardless of oxygen availability (Warburg effect). The constitutive upregulation of glycolysis leads to an overproduction of acidic metabolic products, resulting in enhanced acidification of the extracellular pH (pHe ~ 6.5), which is a salient feature of the tumor microenvironment. Despite the importance of pH and tumor acidosis, there is currently no established clinical tool available to image the spatial distribution of tumor pHe. The purpose of this review is to describe various imaging modalities for measuring intracellular and extracellular tumor pH. For each technique, we will discuss main advantages and limitations, pH accuracy and sensitivity of the applied pH-responsive probes and potential translatability to the clinic. Particular attention is devoted to methods that can provide pH measurements at high spatial resolution useful to address the task of tumor heterogeneity and to studies that explored tumor pH imaging for assessing treatment response to anticancer therapies.
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Affiliation(s)
- Annasofia Anemone
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Turin, Via Nizza 52, Turin, Italy
| | - Lorena Consolino
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Turin, Via Nizza 52, Turin, Italy
| | - Francesca Arena
- Institute of Biostructures and Bioimaging (IBB), Italian National Research Council (CNR), Via Nizza 52, Turin, Italy.,Center for Preclinical Imaging, Department of Molecular Biotechnology and Health Sciences, University of Turin, Via Ribes 5, Colleretto Giacosa, Italy
| | - Martina Capozza
- Center for Preclinical Imaging, Department of Molecular Biotechnology and Health Sciences, University of Turin, Via Ribes 5, Colleretto Giacosa, Italy
| | - Dario Livio Longo
- Molecular Imaging Center, Department of Molecular Biotechnology and Health Sciences, University of Turin, Via Nizza 52, Turin, Italy. .,Institute of Biostructures and Bioimaging (IBB), Italian National Research Council (CNR), Via Nizza 52, Turin, Italy.
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27
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Tang Y, Xiao G, Shen Z, Zhuang C, Xie Y, Zhang X, Yang Z, Guan J, Shen Y, Chen Y, Lai L, Chen Y, Chen S, Dai Z, Wang R, Wu R. Noninvasive Detection of Extracellular pH in Human Benign and Malignant Liver Tumors Using CEST MRI. Front Oncol 2020; 10:578985. [PMID: 33224880 PMCID: PMC7667286 DOI: 10.3389/fonc.2020.578985] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 10/05/2020] [Indexed: 02/05/2023] Open
Abstract
PURPOSE In this study, we aimed to use 3T magnetic resonance imaging (MRI), which is clinically available, to determine the extracellular pH (pHe) of liver tumors and prospectively evaluate the ability of chemical exchange saturation transfer (CEST) MRI to distinguish between benign and malignant liver tumors. METHODS Different radiofrequency irradiation schemes were assessed for ioversol-based pH measurements at 3T. CEST effects were quantified in vitro using the asymmetric magnetization transfer ratio (MTRasym) at 4.3 ppm from the corrected Z spectrum. Generalized ratiometric analysis was conducted by rationing resolved ioversol CEST effects at 4.3 ppm at a flip angle of 60 and 350°. Fifteen patients recently diagnosed with hepatic carcinoma and five patients diagnosed with hepatic hemangioma [1 male; mean age, 48.6 (range, 37-59) years] were assessed. RESULTS By conducting dual-power CEST MRI, the pH of solutions was determined to be 6.0-7.2 at 3T in vitro. In vivo, ioversol signal intensities in the tumor region showed that the extracellular pH in hepatic carcinoma was acidic(mean ± standard deviation, 6.66 ± 0.19), whereas the extracellular pH was more physiologically neutral in hemangioma (mean ± standard deviation, 7.34 ± 0.09).The lesion size was similar between CEST pH MRI and T2-weighted imaging. CONCLUSION dual-power CEST MRI can detect extracellular pH in human liver tumors and can provide molecular-level diagnostic tools for differentiating benign and malignant liver tumors at 3T.
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Affiliation(s)
- Yanyan Tang
- Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China
- Department of Medical Imaging, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Gang Xiao
- Department of Mathematics and Statistics, Hanshan Normal University, Chaozhou, China
| | | | - Caiyu Zhuang
- Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Yudan Xie
- Department of General Surgery, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Xiaolei Zhang
- College of Air Traffic Management, Civil Aviation Flight University of China, Guanghan, China
| | - Zhongxian Yang
- Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Jitian Guan
- Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Yuanyu Shen
- Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Yanzi Chen
- Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Lihua Lai
- Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Yuanfeng Chen
- Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Shuo Chen
- Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Zhuozhi Dai
- Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Runrun Wang
- Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China
| | - Renhua Wu
- Department of Medical Imaging, The Second Affiliated Hospital, Shantou University Medical College, Shantou, China
- Provincial Key Laboratory of Medical Molecular Imaging, Shantou, China
- *Correspondence: Renhua Wu,
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28
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Chen Z, Li Y, Airan R, Han Z, Xu J, Chan KWY, Xu Y, Bulte JWM, van Zijl PCM, McMahon MT, Zhou S, Liu G. CT and CEST MRI bimodal imaging of the intratumoral distribution of iodinated liposomes. Quant Imaging Med Surg 2019; 9:1579-1591. [PMID: 31667143 DOI: 10.21037/qims.2019.06.10] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Background To develop liposomes loaded with iodinated agents as nanosized CT/MRI bimodal contrast agents for monitoring liposome-mediated drug delivery. Methods Rhodamine-labeled iodixanol (VisipaqueTM)-loaded liposomes (IX-lipo) were prepared and tested for their properties as a diamagnetic CEST contrast agent in vitro. Mice bearing subcutaneous CT26 colon tumors were injected i.v. with 1 g/kg (535 mg iodine/kg) IX-lipo, and in vivo CT and CEST MR images were acquired on day 3. CT and CEST MR images were also acquired for tumor-bearing mice co-injected with IX-lipo and tumor necrosis factor (TNF-α). Results In addition to CT contrast, IX-lipo exhibited a strong CEST contrast similar to its non-liposomal form, with a detectability of ~2 nM per liposome. Both CT imaging and CEST MRI showed that i.v. injection of IX-lipo resulted in a rim enhancement of CT26 tumors with a heterogeneous central distribution. In contrast, co-injection of TNF-α caused a significantly augmented CT/MRI contrast in the tumor center. The intratumoral biodistribution of IX-lipo correlated well to the rhodamine patterns observed with fluorescence microscopy. Conclusions We have developed a CT/MRI bimodal imaging approach for monitoring the delivery and biodistribution of liposomes by loading them with the clinically approved X-ray/CT contrast agent iodixanol. Our approach may be easily adapted for other-FDA approved iodinated agents and thus has great translational potential.
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Affiliation(s)
- Zelong Chen
- Russell H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Yuguo Li
- Russell H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Raag Airan
- Department of Radiology, Stanford University Medical Center, Stanford, CA, USA
| | - Zheng Han
- Russell H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Jiadi Xu
- Russell H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Kannie W Y Chan
- Russell H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA.,Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Yikai Xu
- Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Jeff W M Bulte
- Russell H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA.,Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Peter C M van Zijl
- Russell H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Michael T McMahon
- Russell H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Shibin Zhou
- Ludwig Center, Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Guanshu Liu
- Russell H. Morgan Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
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29
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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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30
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Pavuluri K, Manoli I, Pass A, Li Y, Vernon HJ, Venditti CP, McMahon MT. Noninvasive monitoring of chronic kidney disease using pH and perfusion imaging. SCIENCE ADVANCES 2019; 5:eaaw8357. [PMID: 31453331 PMCID: PMC6693904 DOI: 10.1126/sciadv.aaw8357] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 07/08/2019] [Indexed: 05/18/2023]
Abstract
Chronic Kidney Disease (CKD) is a cardinal feature of methylmalonic acidemia (MMA), a prototypic organic acidemia. Impaired growth, low activity, and protein restriction affect muscle mass and lower serum creatinine, which can delay diagnosis and management of renal disease. We have designed an alternative strategy for monitoring renal function based on administration of a pH sensitive MRI agent and assessed this in a mouse model. This protocol produced three metrics: kidney contrast, ~4% for severe renal disease mice compared to ~13% and ~25% for moderate renal disease and healthy controls, filtration fraction (FF), ~15% for severe renal disease mice compared to ~79% and 100% for moderate renal disease and healthy controls, and variation in pH, ~0.45 units for severe disease mice compared to 0.06 and 0.01 for moderate disease and healthy controls. Our results demonstrate that MRI can be used for early detection and monitoring of CKD.
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Affiliation(s)
- KowsalyaDevi Pavuluri
- Division of MR Research, The Russell H. Morgan Department of Radiology and Radiological Science, 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
| | - Irini Manoli
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health (NIH), Bethesda, MD, USA
| | - Alexandra Pass
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health (NIH), Bethesda, MD, USA
| | - Yuguo Li
- Division of MR Research, The Russell H. Morgan Department of Radiology and Radiological Science, 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
| | - Hilary J. Vernon
- McKusick-Nathans Institute of Genetic Medicine, Department of Pediatrics, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Charles P. Venditti
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health (NIH), Bethesda, MD, USA
| | - Michael T. McMahon
- Division of MR Research, The Russell H. Morgan Department of Radiology and Radiological Science, 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
- Corresponding author.
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Extracellular pH is a biomarker enabling detection of breast cancer and liver cancer using CEST MRI. Oncotarget 2018; 8:45759-45767. [PMID: 28501855 PMCID: PMC5542224 DOI: 10.18632/oncotarget.17404] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 04/03/2017] [Indexed: 02/04/2023] Open
Abstract
Extracellular pH (pHe) decrease is associated with tumor growth, invasion, metastasis, and chemoresistance, which can be detected by chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI). Here, we demonstrated that ioversol CEST MRI can be exploited to achieve pHe mapping of the liver cancer microenvironment. In in vitro studies, we firstly explored whether ioversol signal is pH-dependent, and calculated the function equation between the CEST effects of ioversol and pH values, in the range of 6.0 to 7.8, by a ratiometric method. Then we verified the feasibility of this technique and the equation in vivo by applying pHe imaging in an MMTV-Erbb2 transgenic mouse breast cancer model, which is often used in CEST pHe studies. Furthermore, in vivo ioversol CEST MRI, we were able to map relative pHe and differentiate between tumor and normal tissue in a McA-RH7777 rat hepatoma model. This suggests pHe may be a useful biomarker for human liver cancer.
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32
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Arena F, Irrera P, Consolino L, Colombo Serra S, Zaiss M, Longo DL. Flip-angle based ratiometric approach for pulsed CEST-MRI pH imaging. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 287:1-9. [PMID: 29272735 DOI: 10.1016/j.jmr.2017.12.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 11/14/2017] [Accepted: 12/09/2017] [Indexed: 06/07/2023]
Abstract
Several molecules have been exploited for developing MRI pH sensors based on the chemical exchange saturation transfer (CEST) technique. A ratiometric approach, based on the saturation of two exchanging pools at the same saturation power, or by varying the saturation power levels on the same pool, is usually needed to rule out the concentration term from the pH measurement. However, all these methods have been demonstrated by using a continuous wave saturation scheme that limits its translation to clinical scanners. This study shows a new ratiometric CEST-MRI pH-mapping approach based on a pulsed CEST saturation scheme for a radiographic contrast agent (iodixanol) possessing a single chemical exchange site. This approach is based on the ratio of the CEST contrast effects at two different flip angles combinations (180°/360° and 180°/720°), keeping constant the mean irradiation RF power (Bavg power). The proposed ratiometric approach index is concentration independent and it showed good pH sensitivity and accuracy in the physiological range between 6.0 and 7.4.
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Affiliation(s)
- Francesca Arena
- Dipartimento di Biotecnologie Molecolari e Scienze per la Salute, Università degli Studi di Torino, Torino, Italy
| | - Pietro Irrera
- Dipartimento di Biotecnologie Molecolari e Scienze per la Salute, Università degli Studi di Torino, Torino, Italy
| | - Lorena Consolino
- Dipartimento di Biotecnologie Molecolari e Scienze per la Salute, Università degli Studi di Torino, Torino, Italy
| | | | - Moritz Zaiss
- Department of High-field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Dario Livio Longo
- Dipartimento di Biotecnologie Molecolari e Scienze per la Salute, Università degli Studi di Torino, Torino, Italy; Consiglio Nazionale delle Ricerche (CNR), Istituto di Biostrutture e Bioimmagini, Torino, Italy.
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33
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Systematic Evaluation of Amide Proton Chemical Exchange Saturation Transfer at 3 T: Effects of Protein Concentration, pH, and Acquisition Parameters. Invest Radiol 2017; 51:635-46. [PMID: 27272542 DOI: 10.1097/rli.0000000000000292] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVE The goal of this work was to systematically evaluate the reproducibility of amide proton transfer chemical exchange saturation transfer (APT-CEST) at 3 T and its signal dependence on pH, protein concentration, and acquisition parameters. An in vitro system based on bovine serum albumin (BSA) was used, and its limitations were tested by comparing it to in vivo measurements. The contribution of small endogenous metabolites on the APT-CEST signal at 3 T was also investigated. In addition, the reliability of different z-spectrum interpolations as well as the use of only a few frequency offset data points instead of a whole z-spectrum were tested. MATERIALS AND METHODS We created both a BSA phantom at different concentrations and pH values and a metabolite phantom with different small molecules. Chemical exchange saturation transfer data were acquired using a 2-dimensional fast spoiled gradient-echo sequence with pulsed CEST preparation at different saturation durations and power levels. Healthy volunteer measurements were taken for comparison. Z-spectra were interpolated using a 24th-order polynomial (Poly), an eighth-order Fourier series (Fourier), and a smoothing Spline (sSpline) algorithm. To evaluate reduced data sets, only 6 to 14 frequency offsets of the z-spectrum were used and interpolated via a cubic Spline. Region of interest (ROI) evaluations were used to investigate the reproducibility of amide magnetization transfer ratio asymmetry [MTRasym(3.5 ppm)] and to analyze the MTRasym and z-spectra. RESULTS Interscan standard deviations of MTRasym(3.5 ppm) were always below 0.3%. MTRasym(3.5 ppm) increased when the BSA concentrations increased and decreased when the pH increased. The amine MTRasym signal of small molecules was very small compared with BSA and was only detectable using short saturation times and higher power levels. The MTRasym(3.5 ppm) between BSA concentration steps and between nearly all pH steps was significantly different for all 3 fitting methods. The Fourier and sSpline methods showed no statistically significant differences; however, the results for the Poly method were significantly higher at some concentrations and pH values. Using only few frequency offsets resulted in less significant differences compared with fitting the complete z-spectrum. In general, MTRasym(3.5 ppm) of gray matter, white matter, and ventricle ROIs from volunteer scans increased with an increase in saturation power and partially decreased with an increase in saturation duration. Intra-ROI covariances of MTRasym(3.5 ppm) revealed the highest variations for Poly, whereas using reduced spectral data resulted in an increased signal variation. CONCLUSIONS Amide proton transfer-CEST imaging is a highly reproducible method in which absolute signal differences of approximately 0.5% are detectable in principle. For in vivo applications, Fourier or sSpline interpolations of z-spectra are preferable. Using reduced data sets delivers similar results but with increased variation and therefore decreased (pH/concentration) differentiation capability. Differentiation capability increases with increases in the saturation duration and power level. The results from the in vitro BSA system cannot be directly transferred to the in vivo situation due to different chemical environments resulting in, for example, higher asymmetric macromolecular cMT effects in vivo. Amine signals from small molecules are unlikely to contribute to APT-CEST at 3 T (except for creatine); however, signals can be enhanced by using short saturation times and higher power levels.
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Longo DL, Cutrin JC, Michelotti F, Irrera P, Aime S. Noninvasive evaluation of renal pH homeostasis after ischemia reperfusion injury by CEST-MRI. NMR IN BIOMEDICINE 2017; 30:e3720. [PMID: 28370530 DOI: 10.1002/nbm.3720] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 02/06/2017] [Accepted: 02/06/2017] [Indexed: 06/07/2023]
Abstract
Acute kidney injury (AKI) in mice caused by sustained ischemia followed by reperfusion is associated with acute tubular necrosis and renal dysfunctional blood flow. Although the principal role of the kidney is the maintenance of acid-base balance, current imaging approaches are unable to assess this important parameter, and clinical biomarkers are not robust enough in evaluating the severity of kidney damage. Therefore, novel noninvasive imaging approaches are needed to assess the acid-base homeostasis in vivo. This study investigates the usefulness of MRI-chemical exchange saturation transfer (CEST) pH imaging (through iopamidol injection) in characterizing moderate and severe AKI in mice following unilateral ischemia reperfusion injury. Moderate (20 min) and severe (40 min) ischemia were induced in Balb/C mice, which were imaged at several time points thereafter (Days 0, 1, 2, 7). A significant increase of renal pH values was observed as early as one day after the ischemia reperfusion damage for both moderate and severe ischemia. MRI-CEST pH imaging distinguished the evolution of moderate from severe AKI. A recovery of normal renal pH values was observed for moderate AKI, whereas a persisting renal pH increase was observed for severe AKI on Day 7. Renal filtration fraction was significantly lower for clamped kidneys (0.54-0.57) in comparison to contralateral kidneys (0.84-0.86) following impairment of glomerular filtration. The severe AKI group showed a reduced filtration fraction even after 7 days (0.38 for the clamped kidneys). Notably, renal pH values were significantly correlated with the histopathological score. In conclusion, MRI-CEST pH mapping is a valid tool for the noninvasive evaluation of both acid-base balance and renal filtration in patients with ischemia reperfusion injury.
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Affiliation(s)
- Dario Livio Longo
- Istituto di Biostrutture e Bioimmagini (CNR), c/o Centro di Biotecnologie Molecolari, Torino, Italy
- Dipartimento di Biotecnologie Molecolari e Scienze per la Salute, Università degli Studi di Torino, Torino, Italy
| | - Juan Carlos Cutrin
- Dipartimento di Biotecnologie Molecolari e Scienze per la Salute, Università degli Studi di Torino, Torino, Italy
| | - Filippo Michelotti
- Dipartimento di Biotecnologie Molecolari e Scienze per la Salute, Università degli Studi di Torino, Torino, Italy
| | - Pietro Irrera
- Dipartimento di Biotecnologie Molecolari e Scienze per la Salute, Università degli Studi di Torino, Torino, Italy
| | - Silvio Aime
- Dipartimento di Biotecnologie Molecolari e Scienze per la Salute, Università degli Studi di Torino, Torino, Italy
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Anemone A, Consolino L, Conti L, Reineri F, Cavallo F, Aime S, Longo DL. In vivo evaluation of tumour acidosis for assessing the early metabolic response and onset of resistance to dichloroacetate by using magnetic resonance pH imaging. Int J Oncol 2017; 51:498-506. [DOI: 10.3892/ijo.2017.4029] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 05/15/2017] [Indexed: 11/05/2022] Open
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EXCI-CEST: Exploiting pharmaceutical excipients as MRI-CEST contrast agents for tumor imaging. Int J Pharm 2017; 525:275-281. [DOI: 10.1016/j.ijpharm.2017.04.040] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 04/11/2017] [Accepted: 04/18/2017] [Indexed: 12/22/2022]
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Zu Z, Li H, Jiang X, Gore JC. Spin-lock imaging of exogenous exchange-based contrast agents to assess tissue pH. Magn Reson Med 2017; 79:298-305. [PMID: 28321903 DOI: 10.1002/mrm.26681] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 01/31/2017] [Accepted: 02/26/2017] [Indexed: 12/22/2022]
Abstract
PURPOSE Some X-ray contrast agents contain exchangeable protons that give rise to exchange-based effects on MRI, including chemical exchange saturation transfer (CEST). However, CEST has poor specificity to explicit exchange parameters. Spin-lock sequences at high field are also sensitive to chemical exchange. Here, we evaluate whether spin-locking techniques can detect the contrast agent iohexol in vivo after intravenous administration, and their potential for measuring changes in tissue pH. METHODS Two metrics of contrast based on R1ρ , the spin lattice relaxation rate in the rotating frame, were derived from the behavior of R1ρ at different locking fields. Solutions containing iohexol at different concentrations and pH were used to evaluate the ability of the two metrics to quantify exchange effects. Images were also acquired from rat brains bearing tumors before and after intravenous injections of iohexol to evaluate the potential of spin-lock techniques for detecting the agent and pH variations. RESULTS The two metrics were found to depend separately on either agent concentration or pH. Spin-lock imaging may therefore provide specific quantification of iohexol concentration and the iohexol-water exchange rate, which reports on pH. CONCLUSIONS Spin-lock techniques may be used to assess the dynamics of intravenous contrast agents and detect extracellular acidification. Magn Reson Med 79:298-305, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Zhongliang Zu
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Hua Li
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Xiaoyu Jiang
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - John C Gore
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA.,Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA.,Deparment of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee, USA.,Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, USA.,Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
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Longo DL, Bartoli A, Consolino L, Bardini P, Arena F, Schwaiger M, Aime S. In Vivo Imaging of Tumor Metabolism and Acidosis by Combining PET and MRI-CEST pH Imaging. Cancer Res 2016; 76:6463-6470. [PMID: 27651313 DOI: 10.1158/0008-5472.can-16-0825] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 08/13/2016] [Accepted: 08/15/2016] [Indexed: 11/16/2022]
Abstract
The vast majority of cancers exhibit increased glucose uptake and glycolysis regardless of oxygen availability. This metabolic shift leads to an enhanced production of lactic acid that decreases extracellular pH (pHe), a hallmark of the tumor microenvironment. In this way, dysregulated tumor pHe and upregulated glucose metabolism are linked tightly and their relative assessment may be useful to gain understanding of the underlying biology. Here we investigated noninvasively the in vivo correlation between tumor 18F-FDG uptake and extracellular pH values in a murine model of HER2+ breast cancer. Tumor extracellular pH and perfusion were assessed by acquiring MRI-CEST (chemical exchange saturation transfer) images on a 3T scanner after intravenous administration of a pH-responsive contrast agent (iopamidol). Static PET images were recorded immediately after MRI acquisitions to quantify the extent of 18F-FDG uptake. We demonstrated the occurrence of tumor pHe changes that report on acidification of the interstitial fluid caused by an accelerated glycolysis. Combined PET and MRI-CEST images reported complementary spatial information of the altered glucose metabolism. Notably, a significant inverse correlation was found between extracellular tumor pH and 18F-FDG uptake, as a high 18F-FDG uptake corresponds to lower extracellular pH values. These results show how merging the information from 18F-FDG-uptake and extracellular pH measurements can improve characterization of the tumor microenvironment. Cancer Res; 76(22); 6463-70. ©2016 AACR.
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Affiliation(s)
- Dario L Longo
- Institute of Biostructure and Bioimaging (CNR) c/o Molecular Biotechnologies Center, Torino, Italy.,Molecular Imaging Center, University of Torino, Torino, Italy
| | - Antonietta Bartoli
- Molecular Imaging Center, University of Torino, Torino, Italy.,Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Lorena Consolino
- Molecular Imaging Center, University of Torino, Torino, Italy.,Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Paola Bardini
- Molecular Imaging Center, University of Torino, Torino, Italy.,Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Francesca Arena
- Molecular Imaging Center, University of Torino, Torino, Italy.,Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
| | - Markus Schwaiger
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technische Universitat Munchen, Munich, Germany
| | - Silvio Aime
- Molecular Imaging Center, University of Torino, Torino, Italy. .,Department of Molecular Biotechnology and Health Sciences, University of Torino, Torino, Italy
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MRI-CEST assessment of tumour perfusion using X-ray iodinated agents: comparison with a conventional Gd-based agent. Eur Radiol 2016; 27:2170-2179. [DOI: 10.1007/s00330-016-4552-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 07/08/2016] [Accepted: 08/09/2016] [Indexed: 12/28/2022]
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