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Hyperpolarized xenon

Le Zhang, Alex Burant, Andrew McCallister, Victor Zhao, Karl M Koshlap, Simone Degan, Michael Antonacci, Rosa Tamara Branca
PURPOSE: To investigate the temperature dependence of the resonance frequency of lipid-dissolved xenon (LDX) and to assess the accuracy of LDX-based MR thermometry. METHODS: The chemical shift temperature dependence of water protons, methylene protons, and LDX was measured from samples containing tissues with varying fat contents using a high-resolution NMR spectrometer. LDX results were then used to acquire relative and absolute temperature maps in vivo and the results were compared with PRF-based MR thermometry...
October 19, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Tahreema N Matin, Najib Rahman, Annabel H Nickol, Mitchell Chen, Xiaojun Xu, Neil J Stewart, Tom Doel, Vicente Grau, James M Wild, Fergus V Gleeson
Purpose To compare lobar ventilation and apparent diffusion coefficient (ADC) values obtained with hyperpolarized xenon 129 ((129)Xe) magnetic resonance (MR) imaging to quantitative computed tomography (CT) metrics on a lobar basis and pulmonary function test (PFT) results on a whole-lung basis in patients with chronic obstructive pulmonary disease (COPD). Materials and Methods The study was approved by the National Research Ethics Service Committee; written informed consent was obtained from all patients. Twenty-two patients with COPD (Global Initiative for Chronic Obstructive Lung Disease stage II-IV) underwent hyperpolarized (129)Xe MR imaging at 1...
October 12, 2016: Radiology
Lukas Ebner, Jeff Kammerman, Bastiaan Driehuys, Mark L Schiebler, Robert V Cadman, Sean B Fain
In the last two decades, functional imaging of the lungs using hyperpolarized noble gases has entered the clinical stage. Both helium ((3)He) and xenon ((129)Xe) gas have been thoroughly investigated for their ability to assess both the global and regional patterns of lung ventilation. With advances in polarizer technology and the current transition towards the widely available (129)Xe gas, this method is ready for translation to the clinic. Currently, hyperpolarized (HP) noble gas lung MRI is limited to selected academic institutions; yet, the promising results from initial clinical trials have drawn the attention of the pulmonary medicine community...
September 16, 2016: European Journal of Radiology
Lukas Ebner, Mu He, Rohan S Virgincar, Timothy Heacock, Suryanarayanan S Kaushik, Matthew S Freemann, H Page McAdams, Monica Kraft, Bastiaan Driehuys
OBJECTIVES: The aim of this study was to investigate ventilation in mild to moderate asthmatic patients and age-matched controls using hyperpolarized (HP) Xenon magnetic resonance imaging (MRI) and correlate findings with pulmonary function tests (PFTs). MATERIALS AND METHODS: This single-center, Health Insurance Portability and Accountability Act-compliant prospective study was approved by our institutional review board. Thirty subjects (10 young asthmatic patients, 26 ± 6 years; 3 males, 7 females; 10 older asthmatic patients, 64 ± 6 years; 3 males, 7 females; 10 healthy controls) were enrolled...
September 22, 2016: Investigative Radiology
Yanfei Wang, Ivan J Dmochowski
Molecular imaging holds considerable promise for elucidating biological processes in normal physiology as well as disease states, by determining the location and relative concentration of specific molecules of interest. Proton-based magnetic resonance imaging ((1)H MRI) is nonionizing and provides good spatial resolution for clinical imaging but lacks sensitivity for imaging low-abundance (i.e., submicromolar) molecular markers of disease or environments with low proton densities. To address these limitations, hyperpolarized (hp) (129)Xe NMR spectroscopy and MRI have emerged as attractive complementary methodologies...
October 18, 2016: Accounts of Chemical Research
Shota Hodono, Hirohiko Imai, Yukiko Yamauchi, Ayano Kawamura, Hironobu Matsumoto, Shintaro Okumura, Hideaki Fujiwara, Atsuomi Kimura
The use of a quenching gas, isobutene, with a low vapor pressure was investigated to enhance the utility of hyperpolarized (129) Xe (HP Xe) MRI. Xenon mixed with isobutene was hyperpolarized using a home-built apparatus for continuously producing HP Xe. The isobutene was then readily liquefied and separated almost totally by continuous condensation at about 173 K, because the vapor pressure of isobutene (0.247 kPa) is much lower than that of Xe (157 kPa). Finally, the neat Xe gas was continuously delivered to mice by spontaneous inhalation...
October 2016: NMR in Biomedicine
Laura L Walkup, Robert P Thomen, Teckla G Akinyi, Erin Watters, Kai Ruppert, John P Clancy, Jason C Woods, Zackary I Cleveland
BACKGROUND: Hyperpolarized (129)Xe is a promising contrast agent for MRI of pediatric lung function, but its safety and tolerability in children have not been rigorously assessed. OBJECTIVE: To assess the feasibility, safety and tolerability of hyperpolarized (129)Xe gas as an inhaled contrast agent for pediatric pulmonary MRI in healthy control subjects and in children with cystic fibrosis. MATERIALS AND METHODS: Seventeen healthy control subjects (ages 6-15 years, 11 boys) and 11 children with cystic fibrosis (ages 8-16 years, 4 boys) underwent (129)Xe MRI, receiving up to three doses of (129)Xe gas prepared by either a commercially available or a homebuilt (129)Xe polarizer...
August 5, 2016: Pediatric Radiology
Weiwei Ruan, Jianping Zhong, Ke Wang, Guangyao Wu, Yeqing Han, Xianping Sun, Chaohui Ye, Xin Zhou
PURPOSE: To demonstrate the feasibility to quantify the lung respiratory airway in vivo with hyperpolarized xenon diffusion magnetic resonance imaging (MRI), which is able to detect mild emphysema in the rat model. MATERIALS AND METHODS: The lung respiratory airways were quantified in vivo using hyperpolarized xenon diffusion MRI (7T) with eight b values (5, 10, 15, 20, 25, 30, 35, 40 s/cm(2) ) in five control rats and five mild emphysematous rats, which were induced by elastase...
July 29, 2016: Journal of Magnetic Resonance Imaging: JMRI
Yanfei Wang, Benjamin W Roose, Eugene J Palovcak, Vincenzo Carnevale, Ivan J Dmochowski
Molecular imaging holds considerable promise for elucidating biological processes in normal physiology as well as disease states, but requires noninvasive methods for identifying analytes at sub-micromolar concentrations. Particularly useful are genetically encoded, single-protein reporters that harness the power of molecular biology to visualize specific molecular processes, but such reporters have been conspicuously lacking for in vivo magnetic resonance imaging (MRI). Herein, we report TEM-1 β-lactamase (bla) as a single-protein reporter for hyperpolarized (HP) (129) Xe NMR, with significant saturation contrast at 0...
July 25, 2016: Angewandte Chemie
Madhwesha Rao, Neil J Stewart, Graham Norquay, Paul D Griffiths, Jim M Wild
PURPOSE: Upon inhalation, xenon diffuses into the bloodstream and is transported to the brain, where it dissolves in various compartments of the brain. Although up to five chemically distinct peaks have been previously observed in (129) Xe rat head spectra, to date only three peaks have been reported in the human head. This study demonstrates high resolution spectroscopy and chemical shift imaging (CSI) of (129) Xe dissolved in the human head at 1.5 Tesla. METHODS: A (129) Xe radiofrequency coil was built in-house and (129) Xe gas was polarized using spin-exchange optical pumping...
June 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Francis T Hane, Peter S Smylie, Tao Li, Julia Ruberto, Krista Dowhos, Iain Ball, Boguslaw Tomanek, Brenton DeBoef, Mitchell S Albert
Xenon based biosensors have the potential to detect and localize biomarkers associated with a wide variety of diseases. The development and nuclear magnetic resonance (NMR) characterization of cage molecules which encapsulate hyperpolarized xenon is imperative for the development of these xenon biosensors. We acquired (129) Xe NMR spectra, and magnetic resonance images and a HyperCEST saturation map of cucurbit[6]uril (CB6) in whole bovine blood. We observed a mean HyperCEST depletion of 84% (n = 5) at a concentration of 5 mM and 74% at 2...
July 2016: Contrast Media & Molecular Imaging
Sergei I Obruchkov, Michael D Noseworthy
BACKGROUND: One disadvantage of magnetic resonance imaging (MRI) is the inability to adequately image the lungs. Recent advances in hyperpolarized gas technology [e.g., helium-3 ((3)He) and xenon-129 ((129)Xe)] have changed this. However, the required technology is expensive and often needing extra physics or engineering staff. Hence there is considerable interest in developing (1)H (proton)-based MRI approaches that can be readily implemented on standard clinical systems. Thus, the purpose of this work was to compare a newly developed free breathing proton-based MR lung imaging method to that of a standard gadolinium (Gd) based perfusion approach...
February 2016: Quantitative Imaging in Medicine and Surgery
Ashley E Truxal, Clancy C Slack, Muller D Gomes, Christophoros C Vassiliou, David E Wemmer, Alexander Pines
Studies of hyperpolarized xenon-129 (hp-(129)Xe) in media such as liquid crystals and cell suspensions are in demand for applications ranging from biomedical imaging to materials engineering but have been hindered by the inability to bubble Xe through the desired media as a result of viscosity or perturbations caused by bubbles. Herein a device is reported that can be reliably used to dissolve hp-(129)Xe into viscous aqueous and organic samples without bubbling. This method is robust, requires small sample volumes (<60 μL), is compatible with existing NMR hardware, and is made from readily available materials...
April 4, 2016: Angewandte Chemie
M Repetto, S Zimmer, F Allmendinger, P Blümler, M Doll, J O Grasdijk, W Heil, K Jungmann, S Karpuk, H-J Krause, A Offenhäusser, U Schmidt, Y Sobolev, L Willmann
Recently the spin-lattice relaxation time T1 of hyperpolarized (HP)-(129)Xe was significantly improved by using uncoated and Rb-free storage vessels of GE180 glass. For these cells, a simple procedure was established to obtain reproducible wall relaxation times of about 18 h. Then the limiting relaxation mechanism in pure Xe is due to the coupling between the nuclear spins and the angular momentum of the Xe-Xe van-der-Waals-molecules. This mechanism can be significantly reduced by using different buffer gases of which CO2 was discovered to be the most efficient so far...
April 2016: Journal of Magnetic Resonance
Haidong Li, Zhiying Zhang, Jianping Zhong, Weiwei Ruan, Yeqing Han, Xianping Sun, Chaohui Ye, Xin Zhou
Hyperpolarized (HP) (129) Xe MR offers unique advantages for brain functional imaging (fMRI) because of its extremely high sensitivity to different chemical environments and the total absence of background noise in biological tissues. However, its advancement and applications are currently plagued by issues of signal strength. Generally, xenon atoms found in the brain after inhalation are transferred from the lung via the bloodstream. The longitudinal relaxation time (T1 ) of HP (129) Xe is inversely proportional to the pulmonary oxygen concentration in the lung because oxygen molecules are paramagnetic...
March 2016: NMR in Biomedicine
Sergey Korchak, Wolfgang Kilian, Leif Schröder, Lorenz Mitschang
Exchange spectroscopy is used in combination with a variation of xenon concentration to disentangle the kinetics of the reversible binding of xenon to cryptophane-A. The signal intensity of either free or crytophane-bound xenon decays in a manner characteristic of the underlying exchange reactions when the spins in the other pool are perturbed. Three experimental approaches, including the well-known Hyper-CEST method, are shown to effectively entail a simple linear dependence of the signal depletion rate, or of a related quantity, on free xenon concentration...
April 2016: Journal of Magnetic Resonance
Qianni Guo, Qingbin Zeng, Weiping Jiang, Xiaoxiao Zhang, Qing Luo, Xu Zhang, Louis-S Bouchard, Maili Liu, Xin Zhou
Mercury pollution, in the form of mercury ions (Hg(2+)), is a major health and environmental hazard. Commonly used sensors are invasive and limited to point measurements. Fluorescence-based sensors do not provide depth resolution needed to image spatial distributions. Herein we report a novel sensor capable of yielding spatial distributions by MRI using hyperpolarized (129)Xe. A molecular clamp probe was developed consisting of dipyrrolylquinoxaline (DPQ) derivatives and twocryptophane-A cages. The DPQ derivatives act as cation receptors whereas cryptophane-A acts as a suitable host molecule for xenon...
March 14, 2016: Chemistry: a European Journal
David M L Lilburn, Amanda L Tatler, Joseph S Six, Clémentine Lesbats, Anthony Habgood, Joanne Porte, Theodore Hughes-Riley, Dominick E Shaw, Gisli Jenkins, Thomas Meersmann
PURPOSE: Asthma is a disease of increasing worldwide importance that calls for new investigative methods. Ex vivo lung tissue is being increasingly used to study functional respiratory parameters independent of confounding systemic considerations but also to reduce animal numbers and associated research costs. In this work, a straightforward laboratory method is advanced to probe dynamic changes in gas inhalation patterns by using an ex vivo small animal ovalbumin (OVA) model of human asthma...
October 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
B Neal, Q Chen
PURPOSE: To correlate ventilation parameters computed from 4D CT to ventilation, profusion, and gas exchange measured with hyperpolarized Xenon-129 MRI for a set of lung cancer patients. METHODS: Hyperpolarized Xe-129 MRI lung scans were acquired for lung cancer patients, before and after radiation therapy, measuring ventilation, perfusion, and gas exchange. In the standard clinical workflow, these patients also received 4D CT scans before treatment. Ventilation was computed from 4D CT using deformable image registration (DIR)...
June 2015: Medical Physics
Francesco Zamberlan, Clémentine Lesbats, Nicola J Rogers, James L Krupa, Galina E Pavlovskaya, Neil R Thomas, Henryk M Faas, Thomas Meersmann
An approach for hyperpolarized (129) Xe molecular sensors is explored using paramagnetic relaxation agents that can be deactivated upon chemical or enzymatic reaction with an analyte. Cryptophane encapsulated (129) Xe within the vicinity of the paramagnetic center experiences fast relaxation that, through chemical exchange of xenon atoms between cage and solvent pool, causes accelerated hyperpolarized (129) Xe signal decay in the dissolved phase. In this proof-of-concept work, the relaxivity of Gadolinium(III) -DOTA on (129) Xe in the solvent was increased eightfold through tethering of the paramagnetic molecule to a cryptophane cage...
August 3, 2015: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
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