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Hyperpolarized MRI

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https://www.readbyqxmd.com/read/28627764/illustration-of-a-simple-route-to-generate-strong-carbon-13-nmr-signals-that-are-detectable-for-several-minutes
#1
Simon Duckett, Soumya Roy, Philip Norcott, Peter J Rayner, Gary Gr Green
Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) suffer from low sensitivity and limited nuclear spin memory lifetimes. While hyperpolarization techniques increase sensitivity there is also a desire to increase relaxation times to expand the range of applications addressable by these methods. Here we demonstrate a route to create hyperpolarized magnetization in ¹³C nuclear spin pairs that last much longer than normal lifetimes by storage in a singlet state. By combining molecular design and low-field storage with para-hydrogen derived hyperpolarization we achieve more than three-orders of signal amplification relative to equilibrium Zeeman polarization and an order of magnitude extension in state lifetime...
June 19, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28609572/achieving-high-levels-of-nmr-hyperpolarization-in-aqueous-media-with-minimal-catalyst-contamination-via-sabre
#2
Simon Duckett, Wissam Iali, Alexandra M Olaru, Gary G R Green
Signal amplification by reversible exchange (SABRE) is shown to allow access to strongly enhanced ¹H NMR signals in a range of substrates in aqueous media. In order to achieve this outcome phase-transfer-catalysis is exploited which leads to less than less than 1.5 x 10-6 mol dm-3 of the iridium catalyst in the aqueous phase. These observations reflect a compelling route to produce a saline based hyperpolarized bolus in just a few seconds for subsequent in vivo MRI monitoring. The new process has been called CAtalyst Separated Hyperpolarization via Signal Amplification By Reversible Exchange or CASH-SABRE...
June 13, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28596156/hyperpolarized-mri-of-cancer-metabolism
#3
Andrew Cho, Justin Y C Lau, Benjamin J Geraghty, Charles H Cunningham, Kayvan R Keshari
This review will highlight recent advances in hyperpolarized (13)C magnetic resonance spectroscopy imaging (MRSI), which can be used to non-invasively interrogate tumor metabolism. After providing an overview of magnetic resonance and hyperpolarization, we will discuss the latest advances in data acquisition techniques. Next, we will shift our focus to hyperpolarized probe design and provide an overview of the latest hyperpolarized MRSI probes developed in the last several years.
June 8, 2017: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
https://www.readbyqxmd.com/read/28569840/thermal-annihilation-of-photo-induced-radicals-following-dynamic-nuclear-polarization-to-produce-transportable-frozen-hyperpolarized-13-c-substrates
#4
Andrea Capozzi, Tian Cheng, Giovanni Boero, Christophe Roussel, Arnaud Comment
Hyperpolarization via dynamic nuclear polarization (DNP) is pivotal for boosting magnetic resonance imaging (MRI) sensitivity and dissolution DNP can be used to perform in vivo real-time (13)C MRI. The type of applications is however limited by the relatively fast decay time of the hyperpolarized spin state together with the constraint of having to polarize the (13)C spins in a dedicated apparatus nearby but separated from the MRI magnet. We herein demonstrate that by polarizing (13)C with photo-induced radicals, which can be subsequently annihilated using a thermalization process that maintains the sample temperature below its melting point, hyperpolarized (13)C-substrates can be extracted from the DNP apparatus in the solid form, while maintaining the enhanced (13)C polarization...
June 1, 2017: Nature Communications
https://www.readbyqxmd.com/read/28551402/free-breathing-functional-pulmonary-mri-response-to-bronchodilator-and-bronchoprovocation-in-severe-asthma
#5
Dante P I Capaldi, Khadija Sheikh, Rachel L Eddy, Fumin Guo, Sarah Svenningsen, Parameswaran Nair, David G McCormack, Grace Parraga
RATIONALE AND OBJECTIVES: Ventilation heterogeneity is a hallmark feature of asthma. Our objective was to evaluate ventilation heterogeneity in patients with severe asthma, both pre- and post-salbutamol, as well as post-methacholine (MCh) challenge using the lung clearance index, free-breathing pulmonary (1)H magnetic resonance imaging (FDMRI), and inhaled-gas MRI ventilation defect percent (VDP). MATERIALS AND METHODS: Sixteen severe asthmatics (49 ± 10 years) provided written informed consent to an ethics board-approved protocol...
May 24, 2017: Academic Radiology
https://www.readbyqxmd.com/read/28517362/the-absence-of-quadrupolar-nuclei-facilitates-efficient-13-c-hyperpolarization-via-reversible-exchange-with-parahydrogen
#6
Danila A Barskiy, Roman V Shchepin, Christian P N Tanner, Johannes F P Colell, Boyd M Goodson, Thomas Theis, Warren S Warren, Eduard Y Chekmenev
Nuclear spin hyperpolarization techniques are revolutionizing the field of (13) C molecular MRI. While dissolution dynamic nuclear polarization (d-DNP) is currently the leading technique, it is generally slow (requiring ≈1 h) and costly (≈$USD10(6) ). As a consequence of carbon's central place in biochemistry, tremendous progress using (13) C d-DNP bioimaging has been demonstrated to date including a number of clinical trials. Despite numerous attempts to develop alternatives to d-DNP, the competing methods have faced significant translational challenges...
June 20, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/28514950/lung-function-imaging-methods-in-cystic-fibrosis-pulmonary-disease
#7
REVIEW
Magdalena Kołodziej, Michael J de Veer, Marian Cholewa, Gary F Egan, Bruce R Thompson
Monitoring of pulmonary physiology is fundamental to the clinical management of patients with Cystic Fibrosis. The current standard clinical practise uses spirometry to assess lung function which delivers a clinically relevant functional readout of total lung function, however does not supply any visible or localised information. High Resolution Computed Tomography (HRCT) is a well-established current 'gold standard' method for monitoring lung anatomical changes in Cystic Fibrosis patients. HRCT provides excellent morphological information, however, the X-ray radiation dose can become significant if multiple scans are required to monitor chronic diseases such as cystic fibrosis...
May 17, 2017: Respiratory Research
https://www.readbyqxmd.com/read/28508450/simultaneous-assessment-of-both-lung-morphometry-and-gas-exchange-function-within-a-single-breath-hold-by-hyperpolarized-129-xe-mri
#8
Jianping Zhong, Huiting Zhang, Weiwei Ruan, Junshuai Xie, Haidong Li, He Deng, Yeqing Han, Xianping Sun, Chaohui Ye, Xin Zhou
During the measurement of hyperpolarized (129) Xe magnetic resonance imaging (MRI), the diffusion-weighted imaging (DWI) technique provides valuable information for the assessment of lung morphometry at the alveolar level, whereas the chemical shift saturation recovery (CSSR) technique can evaluate the gas exchange function of the lungs. To date, the two techniques have only been performed during separate breaths. However, the request for multiple breaths increases the cost and scanning time, limiting clinical application...
May 16, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28484627/the-chinchilla-as-a-novel-animal-model-of-pregnancy
#9
Emmeli Mikkelsen, Henrik Lauridsen, Per Mose Nielsen, Haiyun Qi, Thomas Nørlinger, Maria Dahl Andersen, Niels Uldbjerg, Christoffer Laustsen, Puk Sandager, Michael Pedersen
Several parameters are important when choosing the most appropriate animal to model human obstetrics, including gestation period, number of fetuses per gestation and placental structure. The domesticated long-tailed chinchilla (Chinchilla lanigera) is a well-suited and appropriate animal model of pregnancy that often will carry only one offspring and has a long gestation period of 105-115 days. Furthermore, the chinchilla placenta is of the haemomonochorial labyrinthine type and is therefore comparable to the human villous haemomonochorial placenta...
April 2017: Royal Society Open Science
https://www.readbyqxmd.com/read/28473321/hyperpolarized-gas-diffusion-mri-of-biphasic-lung-inflation-in-short-and-long-term-emphysema-models
#10
Yi Xin, Maurizio Cereda, Stephen Kadlecek, Kiarash Emami, Hooman Hamedani, Ian Duncan, Jennia Rajaei, Liam Hughes, Natalie Meeder, Joseph Naji, Harrilla Profka, Brian J Bolognese, Joseph P Foley, Patricia L Podolin, Rahim R Rizi
During lung-inflation, airspace dimensions are affected non-linearly by both alveolar expansion and recruitment, potentially confounding the identification of emphysematous lung by hyperpolarized helium-3 diffusion magnetic resonance imaging (HP MRI). This study aimed to characterize lung inflation over a broad range of inflation volume and pressure values in two different models of emphysema, as well as in normal lungs. Elastase-treated rats (n=7) and healthy controls (n=7) were imaged with HP MRI. Gradual inflation was achieved by incremental changes to both inflation volume and airway pressure...
May 4, 2017: American Journal of Physiology. Lung Cellular and Molecular Physiology
https://www.readbyqxmd.com/read/28451127/cubic-three-dimensional-hybrid-silica-solids-for-nuclear-hyperpolarization
#11
D Baudouin, H A van Kalkeren, A Bornet, B Vuichoud, L Veyre, M Cavaillès, M Schwarzwälder, W-C Liao, D Gajan, G Bodenhausen, L Emsley, A Lesage, S Jannin, C Copéret, C Thieuleux
Hyperpolarization of metabolites by dissolution dynamic nuclear polarization (D-DNP) for MRI applications often requires fast and efficient removal of the radicals (polarizing agents). Ordered mesoporous SBA-15 silica materials containing homogeneously dispersed radicals, referred to as HYperPolarizing SOlids (HYPSOs), enable high polarization - P((1)H) = 50% at 1.2 K - and straightforward separation of the polarizing HYPSO material from the hyperpolarized solution by filtration. However, the one-dimensional tubular pores of SBA-15 type materials are not ideal for nuclear spin diffusion, which may limit efficient polarization...
November 1, 2016: Chemical Science
https://www.readbyqxmd.com/read/28443626/nanodiamond-enhanced-mri-via-in-situ-hyperpolarization
#12
David E J Waddington, Mathieu Sarracanie, Huiliang Zhang, Najat Salameh, David R Glenn, Ewa Rej, Torsten Gaebel, Thomas Boele, Ronald L Walsworth, David J Reilly, Matthew S Rosen
Nanodiamonds are of interest as nontoxic substrates for targeted drug delivery and as highly biostable fluorescent markers for cellular tracking. Beyond optical techniques, however, options for noninvasive imaging of nanodiamonds in vivo are severely limited. Here, we demonstrate that the Overhauser effect, a proton-electron polarization transfer technique, can enable high-contrast magnetic resonance imaging (MRI) of nanodiamonds in water at room temperature and ultra-low magnetic field. The technique transfers spin polarization from paramagnetic impurities at nanodiamond surfaces to (1)H spins in the surrounding water solution, creating MRI contrast on-demand...
April 26, 2017: Nature Communications
https://www.readbyqxmd.com/read/28407455/construction-and-13-c-hyperpolarization-efficiency-of-a-180%C3%A2-ghz-dissolution-dynamic-nuclear-polarization-system
#13
Andhika Kiswandhi, Peter Niedbalski, Christopher Parish, Sarah Ferguson, David Taylor, George McDonald, Lloyd Lumata
Dynamic nuclear polarization (DNP) via the dissolution method has become one of the rapidly emerging techniques to alleviate the low signal sensitivity in nuclear magnetic resonance (NMR) spectroscopy and imaging. In this paper, we report on the development and (13) C hyperpolarization efficiency of a homebuilt DNP system operating at 6.423 T and 1.4 K. The DNP hyperpolarizer system was assembled on a wide-bore superconducting magnet, equipped with a standard continuous-flow cryostat, and a 180 GHz microwave source with 120 mW power output and wide 4 GHz frequency tuning range...
April 13, 2017: Magnetic Resonance in Chemistry: MRC
https://www.readbyqxmd.com/read/28394085/dual-echo-epi-sequence-for-integrated-distortion-correction-in-3d-time-resolved-hyperpolarized-13-c-mri
#14
Benjamin J Geraghty, Justin Y C Lau, Albert P Chen, Charles H Cunningham
PURPOSE: To provide built-in off-resonance correction in time-resolved, volumetric hyperpolarized (13) C metabolic imaging by implementing a novel dual-echo 3D echo-planar imaging (EPI) sequence and reconstruction. METHODS: A spectral-spatial pulse for single-resonance excitation followed by a dual-echo 3D EPI readout was implemented to provide 64 × 8 × 6 cm(3) coverage at 5 × 5 × 5 mm(3) nominal resolution. Multiple sources of EPI distortions were encoded using a multi-echo (1) H EPI reference scan...
April 10, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28386017/multinuclear-nmr-and-mri-reveal-an-early-metabolic-response-to-mtor-inhibition-in-sarcoma
#15
Valentina Di Gialleonardo, Hannah N Aldeborgh, Vesselin Miloushev, Kelly M Folkers, Kristin Granlund, William D Tap, Jason S Lewis, Wolfgang A Weber, Kayvan R Keshari
Biomarkers predicting rapalog responses in sarcomas where PI3K and mTOR are often hyperactivated could improve the suitable recruitment of responsive patients to clinical trials. PI3K/mTOR pathway activation drives energy production by regulating anaerobic glycolysis in cancer cells, suggesting a route toward a monitoring strategy. In this study, we took a multimodality approach to evaluate the phenotypic effects and metabolic changes that occur with inhibition of the PI3K/mTOR pathway. Its central role in regulating glycolysis in human sarcomas was evaluated by short- and long-term rapamycin treatment in sarcoma cell lines...
June 1, 2017: Cancer Research
https://www.readbyqxmd.com/read/28384123/magnetic-resonance-imaging-with-hyperpolarized-agents-methods-and-applications
#16
Erin B Adamson, Kai D Ludwig, David G Mummy, Sean B Fain
In the past decade, hyperpolarized (HP) contrast agents have been under active development for MRI applications to address the twin challenges of functional and quantitative imaging. Both HP helium ((3)He) and xenon ((129)Xe) gases have reached the stage where they are under study in clinical research. HP (129)Xe, in particular, is poised for larger scale clinical research to investigate asthma, chronic obstructive pulmonary disease, and fibrotic lung diseases. With advances in polarizer technology and unique capabilities for imaging of (129)Xe gas exchange into lung tissue and blood, HP (129)Xe MRI is attracting new attention...
July 7, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28382694/quantitative-analysis-of-hyperpolarized-129-xe-gas-transfer-mri
#17
Ziyi Wang, Scott Haile Robertson, Jennifer Wang, Mu He, Rohan S Virgincar, Geoffry M Schrank, Elianna A Bier, Sudarshan Rajagopal, Yuh Chin Huang, Thomas G O'Riordan, Craig R Rackley, H Page McAdams, Bastiaan Driehuys
PURPOSE: Hyperpolarized (129) Xe magnetic resonance imaging (MRI) using Dixon-based decomposition enables single-breath imaging of (129) Xe in the airspaces, interstitial barrier tissues, and red blood cells (RBCs). However, methods to quantitatively visualize information from these images of pulmonary gas transfer are lacking. Here, we introduce a novel method to transform these data into quantitative maps of pulmonary ventilation, and (129) Xe gas transfer to barrier and RBC compartments...
April 6, 2017: Medical Physics
https://www.readbyqxmd.com/read/28377523/delivering-strong-1-h-nuclear-hyperpolarization-levels-and-long-magnetic-lifetimes-through-signal-amplification-by-reversible-exchange
#18
Peter J Rayner, Michael J Burns, Alexandra M Olaru, Philip Norcott, Marianna Fekete, Gary G R Green, Louise A R Highton, Ryan E Mewis, Simon B Duckett
Hyperpolarization turns typically weak NMR and MRI responses into strong signals so that ordinarily impractical measurements become possible. The potential to revolutionize analytical NMR and clinical diagnosis through this approach reflect this area's most compelling outcomes. Methods to optimize the low-cost parahydrogen-based approach signal amplification by reversible exchange with studies on a series of biologically relevant nicotinamides and methyl nicotinates are detailed. These procedures involve specific (2)H labeling in both the agent and catalyst and achieve polarization lifetimes of ca 2 min with 50% polarization in the case of methyl-4,6-d2 -nicotinate...
April 18, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28371091/novel-magnetic-resonance-imaging-for-assessment-of-bronchial-stenosis-in-lung-transplant-recipients
#19
Kamran Mahmood, Lukas Ebner, Mu He, Scott Haile Robertson, Ziyi Wang, H Page McAdams, Momen M Wahidi, Scott L Shofer, Yuh-Chin T Huang, Bastiaan Driehuys
Bronchial stenosis in lung transplant recipients is a common disorder that adversely affects clinical outcomes. It is evaluated by spirometry, CT scan and bronchoscopy with significant limitations. We hypothesize that magnetic resonance imaging (MRI) employing both ultrashort echo time (UTE) scans and hyperpolarized (HP) (129) Xe gas can offer structural and functional assessment of bronchial stenosis seen after lung transplantation. Six patients with lung transplantation-related bronchial stenosis underwent HP (129) Xe MRI and UTE MRI...
March 29, 2017: American Journal of Transplantation
https://www.readbyqxmd.com/read/28365086/synthesis-and-hyperpolarisation-of-enos-substrates-for-quantification-of-no-production-by-1-h-nmr-spectroscopy
#20
Fernando Fernandez Diaz-Rullo, Francesco Zamberlan, Ryan E Mewis, Marianna Fekete, Lionel Broche, Lesley A Cheyne, Sergio Dall'Angelo, Simon B Duckett, Dana Dawson, Matteo Zanda
Hyperpolarization enhances the intensity of the NMR signals of a molecule, whose in vivo metabolic fate can be monitored by MRI with higher sensitivity. SABRE is a hyperpolarization technique that could potentially be used to image nitric oxide (NO) production in vivo. This would be very important, because NO dysregulation is involved in several pathologies, including cardiovascular ones. The nitric oxide synthase (NOS) pathway leads to NO production via conversion of l-arginine into l-citrulline. NO is a free radical gas with a short half-life in vivo (≈5s), therefore direct NO quantification is challenging...
May 15, 2017: Bioorganic & Medicinal Chemistry
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