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https://www.readbyqxmd.com/read/27882425/assessment-of-regional-emphysema-air-trapping-and-xenon-ventilation-using-dual-energy-computed-tomography-in-chronic-obstructive-pulmonary-disease-patients
#1
Sang Min Lee, Joon Beom Seo, Hye Jeon Hwang, Namkug Kim, Sang Young Oh, Jae Seung Lee, Sei Won Lee, Yeon-Mok Oh, Tae Hoon Kim
OBJECTIVES: To compare the parenchymal attenuation change between inspiration/expiration CTs with dynamic ventilation change between xenon wash-in (WI) inspiration and wash-out (WO) expiration CTs. METHODS: 52 prospectively enrolled COPD patients underwent xenon ventilation dual-energy CT during WI and WO periods and pulmonary function tests (PFTs). The parenchymal attenuation parameters (emphysema index (EI), gas-trapping index (GTI) and air-trapping index (ATI)) and xenon ventilation parameters (xenon in WI (Xe-WI), xenon in WO (Xe-WO) and xenon dynamic (Xe-Dyna)) of whole lung and three divided areas (emphysema, hyperinflation and normal) were calculated on virtual non-contrast images and ventilation images...
November 23, 2016: European Radiology
https://www.readbyqxmd.com/read/27732160/chronic-obstructive-pulmonary-disease-lobar-analysis-with-hyperpolarized-129-xe-mr-imaging
#2
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
https://www.readbyqxmd.com/read/27649152/correlations-of-hepatic-hemodynamics-liver-function-and-fibrosis-markers-in-nonalcoholic-fatty-liver-disease-comparison-with-chronic-hepatitis-related-to-hepatitis-c-virus
#3
Ryuta Shigefuku, Hideaki Takahashi, Hiroyasu Nakano, Tsunamasa Watanabe, Kotaro Matsunaga, Nobuyuki Matsumoto, Masaki Kato, Ryo Morita, Yousuke Michikawa, Tomohiro Tamura, Tetsuya Hiraishi, Nobuhiro Hattori, Yohei Noguchi, Kazunari Nakahara, Hiroki Ikeda, Toshiya Ishii, Chiaki Okuse, Shigeru Sase, Fumio Itoh, Michihiro Suzuki
The progression of chronic liver disease differs by etiology. The aim of this study was to elucidate the difference in disease progression between chronic hepatitis C (CHC) and nonalcoholic fatty liver disease (NAFLD) by means of fibrosis markers, liver function, and hepatic tissue blood flow (TBF). Xenon computed tomography (Xe-CT) was performed in 139 patients with NAFLD and 152 patients with CHC (including liver cirrhosis (LC)). The cutoff values for fibrosis markers were compared between NAFLD and CHC, and correlations between hepatic TBF and liver function tests were examined at each fibrosis stage...
2016: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/27526397/finite-element-modeling-of-129-xe-diffusive-gas-exchange-nmr-in-the-human-alveoli
#4
Neil J Stewart, Juan Parra-Robles, Jim M Wild
Existing models of (129)Xe diffusive exchange for lung microstructural modeling with time-resolved MR spectroscopy data have considered analytical solutions to one-dimensional, homogeneous models of the lungs with specific assumptions about the alveolar geometry. In order to establish a model system for simulating the effects of physiologically-realistic changes in physical and microstructural parameters on (129)Xe exchange NMR, we have developed a 3D alveolar capillary model for finite element analysis. To account for the heterogeneity of the alveolar geometry across the lungs, we have derived realistic geometries for finite element analysis based on 2D histological samples and 3D micro-CT image volumes obtained from ex vivo biopsies of lung tissue from normal subjects and patients with interstitial lung disease...
October 2016: Journal of Magnetic Resonance
https://www.readbyqxmd.com/read/27477942/hyperpolarized-129-xe-for-investigation-of-mild-cystic-fibrosis-lung-disease-in-pediatric-patients
#5
Robert P Thomen, Laura L Walkup, David J Roach, Zackary I Cleveland, John P Clancy, Jason C Woods
BACKGROUND: Cystic fibrosis (CF) is a genetic disease which carries high morbidity and mortality from lung-function decline. Monitoring disease progression and treatment response in young patients is desirable, but serial imaging via CT is often considered prohibitive, and detailed functional information cannot be obtained using conventional imaging techniques. Hyperpolarized (129)Xe magnetic resonance imaging (MRI) can depict and quantify regional ventilation, but has not been investigated in pediatrics...
July 28, 2016: Journal of Cystic Fibrosis: Official Journal of the European Cystic Fibrosis Society
https://www.readbyqxmd.com/read/27356957/early-cerebral-circulation-disturbance-in-patients-suffering-from-severe-traumatic-brain-injury-tbi-a-xenon-ct-and-perfusion-ct-study
#6
Mitsuru Honda, Ryo Ichibayashi, Hiroki Yokomuro, Katsunori Yoshihara, Hiroyuki Masuda, Daisuke Haga, Yoshikatsu Seiki, Chiaki Kudoh, Taichi Kishi
Traumatic brain injury (TBI) is widely known to cause dynamic changes in cerebral blood flow (CBF). Ischemia is a common and deleterious secondary injury following TBI. Detecting early ischemia in TBI patients is important to prevent further advancement and deterioration of the brain tissue. The purpose of this study was to clarify the cerebral circulatory disturbance during the early phase and whether it can be used to predict patient outcome. A total of 90 patients with TBI underwent a xenon-computed tomography (Xe-CT) and subsequently perfusion CT to evaluate the cerebral circulation on days 1-3...
August 15, 2016: Neurologia Medico-chirurgica
https://www.readbyqxmd.com/read/26842717/bedside-xenon-ct-shows-lower-cbf-in-sah-patients-with-impaired-cbf-pressure-autoregulation-as-defined-by-pressure-reactivity-index-prx
#7
Ulf Johnson, Henrik Engquist, Tim Howells, Pelle Nilsson, Elisabeth Ronne-Engström, Anders Lewén, Elham Rostami, Per Enblad
BACKGROUND: Subarachnoid hemorrhage (SAH) is a disease with a high rate of unfavorable outcome, often related to delayed cerebral ischemia (DCI), i.e., ischemic injury that develops days-weeks after onset, with a multifactorial etiology. Disturbances in cerebral pressure autoregulation, the ability to maintain a steady cerebral blood flow (CBF), despite fluctuations in systemic blood pressure, have been suggested to play a role in the development of DCI. Pressure reactivity index (PRx) is a well-established measure of cerebral pressure autoregulation that has been used to study traumatic brain injury, but not extensively in SAH...
August 2016: Neurocritical Care
https://www.readbyqxmd.com/read/25980630/single-breath-clinical-imaging-of-hyperpolarized-129-xe-in-the-airspaces-barrier-and-red-blood-cells-using-an-interleaved-3d-radial-1-point-dixon-acquisition
#8
S Sivaram Kaushik, Scott H Robertson, Matthew S Freeman, Mu He, Kevin T Kelly, Justus E Roos, Craig R Rackley, W Michael Foster, H Page McAdams, Bastiaan Driehuys
PURPOSE: We sought to develop and test a clinically feasible 1-point Dixon, three-dimensional (3D) radial acquisition strategy to create isotropic 3D MR images of (129)Xe in the airspaces, barrier, and red blood cells (RBCs) in a single breath. The approach was evaluated in healthy volunteers and subjects with idiopathic pulmonary fibrosis (IPF). METHODS: A calibration scan determined the echo time at which (129)Xe in RBCs and barrier were 90° out of phase. At this TE, interleaved dissolved and gas-phase images were acquired using a 3D radial acquisition and were reconstructed separately using the NUFFT algorithm...
April 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/25527938/near-infrared-and-ultraviolet-induced-isomerization-of-crotonic-acid-in-n2-and-xe-cryomatrices-first-observation-of-two-high-energy-trans-c-o-conformers-and-mechanistic-insights
#9
Nihal Kuş, Rui Fausto
E-crotonic acid was isolated in cryogenic solid N2 and xenon matrices, and subjected to Laser ultraviolet (UV) and near-infrared (NIR) irradiations. In the deposited matrices, the two low-energy cis C-O E-cc and E-ct conformers, which are the only forms significantly populated in the gas phase, were observed. UV irradiation (λ= 250 nm) of the compound in N2 matrix allows for experimental detection, not just of the two low-energy cis C-O isomers of Z-crotonic acid previously observed in the experiments carried out in argon matrix [Z-cc and Z-ct; R...
December 21, 2014: Journal of Chemical Physics
https://www.readbyqxmd.com/read/25347853/hyperpolarized-3he-and-129xe-magnetic-resonance-imaging-apparent-diffusion-coefficients-physiological-relevance-in-older-never-and-ex-smokers
#10
Miranda Kirby, Alexei Ouriadov, Sarah Svenningsen, Amir Owrangi, Andrew Wheatley, Roya Etemad-Rezai, Giles E Santyr, David G McCormack, Grace Parraga
Noble gas pulmonary magnetic resonance imaging (MRI) is transitioning away from (3)He to (129)Xe gas, but the physiological/clinical relevance of (129)Xe apparent diffusion coefficient (ADC) parenchyma measurements is not well understood. Therefore, our objective was to generate (129)Xe MRI ADC for comparison with (3)He ADC and with well-established measurements of alveolar structure and function in older never-smokers and ex-smokers with chronic obstructive pulmonary disease (COPD). In four never-smokers and 10 COPD ex-smokers, (3)He (b = 1...
2014: Physiological Reports
https://www.readbyqxmd.com/read/25105721/in-vivo-regional-ventilation-mapping-using-fluorinated-gas-mri-with-an-x-centric-fgre-method
#11
Alexei V Ouriadov, Matthew S Fox, Marcus J Couch, Tao Li, Iain K Ball, Mitchell S Albert
PURPOSE: Inert fluorinated gas lung MRI is a new and promising alternative to hyperpolarized gas lung MRI; it is less expensive and does not require expensive isotopes/polarizers. The thermally polarized nature of signal obtained from fluorinated gases makes it relatively easy to use for dynamic lung imaging and for obtaining lung ventilation maps. In this study, we propose that the sensitivity and resolution of fluorine-19 (19F) in vivo images can be improved using the x-centric pulse sequence, thereby achieving a short echo time/pulse repetition time...
August 2015: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/25019579/quantitative-lobar-cerebral-blood-flow-for-outcome-prediction-after-traumatic-brain-injury
#12
Jared Fridley, Claudia Robertson, Shankar Gopinath
The aim of this study was to examine cortical cerebral blood flow (CBF) in patients with traumatic brain injury (TBI) and determine whether lobar cortical CBF is a better predictor of long-term neurological outcome assessed by the Glasgow Outcome Scale (GOS) than global cortical CBF. Ninety-eight patients with TBI had a stable xenon computed tomography scan (Xe/CT-CBF study) performed at various time points after their initial injury. Spearman's correlation coefficients and Kruskall-Wallis' test were used to examine the relationship between patient age, emergency room Glasgow Coma Scale (GCS), Injury Severity Score, prehospital hypotension, prehospital hypoxia, mechanism of injury, type of injury, side of injury, global average CBF, lobar CBF, number of lobes with CBF below normal, and GOS (discharge, 3 and 6 months)...
January 15, 2015: Journal of Neurotrauma
https://www.readbyqxmd.com/read/24900034/compression-of-the-right-pulmonary-artery-by-a-massive-descending-aortic-aneurysm-causing-bilateral-perfusion-defects-on-pulmonary-scintigraphy
#13
William Makis, Vilma Derbekyan
A 67-year-old woman, who presented with a 2 month history of dyspnea, had a ventilation and perfusion lung scan that showed absent perfusion of the entire right lung with normal ventilation, as well as a rounded matched defect in the left lower lung adjacent to midline, suspicious for an aortic aneurysm or dissection. CT pulmonary angiography revealed a massive descending aortic aneurysm compressing the right pulmonary artery as well as the left lung parenchyma, accounting for the bilateral perfusion scan defects...
March 2012: Nuclear Medicine and Molecular Imaging
https://www.readbyqxmd.com/read/24554798/comparability-of-diagnostic-methods-proximal-endoscopy-ct-and-eus-in-determining-stomach-tumor-localization-and-their-importance-in-the-preoperative-analysis-of-process-progression
#14
Zora Vukobrat-Bijedic, Azra Husic-Selimovic, Amela Sofic, Nina Bijedic, Bisera Gogov, Amila Mehmedovic, Aida Saray, Sanjin Glavas, Ivana Bjelogrlic
INTRODUCTION: Gastric cancer is one of the most common tumors in humans and is on the 14th place by frequency in the United States and it is at the 8th place by the mortality rate. In the world it takes seventh place by incidence. Today prevail the opinion and the surveys show, that it is twice as common in men as compared to women. Although there are advancements in diagnostics it must be noted that gastric cancer is still discovered late and when it already has metastasized, so that the therapeutic approach is limited and low survival rate...
December 2013: Acta Informatica Medica: AIM
https://www.readbyqxmd.com/read/24424317/evaluation-of-hepatic-tissue-blood-flow-using-xenon-computed-tomography-with-fibrosis-progression-in-nonalcoholic-fatty-liver-disease-comparison-with-chronic-hepatitis-c
#15
COMPARATIVE STUDY
Ryuta Shigefuku, Hideaki Takahashi, Masaki Kato, Yoshihito Yoshida, Keigo Suetani, Yohei Noguchi, Moriaki Hatsugai, Kazunari Nakahara, Hiroki Ikeda, Minoru Kobayashi, Kotaro Matsunaga, Nobuyuki Matsumoto, Chiaki Okuse, Fumio Itoh, Shiro Maeyama, Shigeru Sase, Michihiro Suzuki
AIMS: The present study evaluated the utility of xenon computed tomography (Xe-CT) as a noninvasive diagnostic procedure for the measurement of hepatic tissue blood flow (TBF) in patients with nonalcoholic fatty liver disease (NAFLD) or chronic hepatitis C (CH-C). METHODS: Xe-CT was performed in 93 patients with NAFLD and in 109 patients with CH-C. Subjects were classified into one of three groups, based on fibrosis stage: group 1, no bridging fibrosis; group 2, bridging fibrosis; and group 3, liver cirrhosis...
January 14, 2014: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/24238634/evaluation-of-cerebrovascular-reserve-using-xenon-enhanced-ct-scanning-in-patients-with-symptomatic-middle-cerebral-artery-stenosis
#16
Wenjie Cao, Xin Cheng, Haoxiong Li, Liang Wang, Xiaolong Zhang, Qiang Dong
Cerebrovascular reserve (CVR) is an important prognostic factor in patients with major cerebral arterial steno-occlusive disease. However, few studies have examined CVR in symptomatic intracranial stenosis without ipsilateral extracranial internal carotid artery stenosis. This study sought to evaluate CVR in patients with symptomatic middle cerebral artery (MCA) stenosis using xenon-enhanced computed tomography (Xe/CT) with acetazolamide (ACZ) challenge. Twelve patients with symptomatic MCA stenosis were recruited...
February 2014: Journal of Clinical Neuroscience: Official Journal of the Neurosurgical Society of Australasia
https://www.readbyqxmd.com/read/24019158/xenon-enhanced-ct-assessment-of-cerebral-blood-flow-in-stroke-in-progress-patients-with-unilateral-internal-carotid-artery-or-middle-cerebral-artery-stenosis
#17
Zhen-Ni Guo, Ge Yang, Hong-Wei Zhou, Jing Wang, Jiang Wu, Yi Yang
Carotid or cerebral artery stenosis resulting in low perfusion is a major cause of ischemic stroke. Understanding the unique hemodynamic features in each patient undergoing a stroke-in-progress (SIP) and the correlation between progression and cerebral blood flow (CBF) status would help in the diagnosis and treatment of individual patients. We used xenon-enhanced CT (Xe-CT) to examine cerebral perfusion in patients with or without SIP (30 patients/group), recruited from October 2009 to October 2010. Only SIP patients with unilateral stenosis in the internal or middle cerebral artery were recruited...
December 2013: Neuroscience Bulletin
https://www.readbyqxmd.com/read/23668642/validation-of-noninvasive-morphological-and-diffusion-imaging-in-mouse-emphysema-by-micro-computed-tomography-and-hyperpolarized-129-xe-magnetic-resonance-imaging
#18
Satoshi Tetsumoto, Yoshito Takeda, Hirohiko Imai, Atsuomi Kimura, Yingji Jin, Kaori Nakanishi, Yohei Maeda, Hanako Kuhara, Kazuyuki Tsujino, Takeo Iwasaki, Hiroshi Shigeta, Yasushi Kondo, Mari Ito, Toshiyuki Minami, Haruhiko Hirata, Ryo Takahashi, Satoshi Kohmo, Izumi Nagatomo, Koji Inoue, Hiroshi Kida, Takashi Kijima, Isao Tachibana, Norikazu Maeda, Toru Funahashi, Iichiro Shimomura, Hideaki Fujiwara, Atsushi Kumanogoh
Animal disease models are pivotal in investigating the pathogenesis of emphysema and developing novel drugs, but the modalities to evaluate murine emphysema models have been of limited validity and sensitivity. In this study, we evaluated hyperpolarized (129)Xe magnetic resonance imaging (MRI) and micro-computed tomography (micro-CT) compared with traditional methods, such as plethysmography and histology. Elastase-treated mice and adiponectin knockout mice were used as murine emphysema models to evaluate these modalities...
October 2013: American Journal of Respiratory Cell and Molecular Biology
https://www.readbyqxmd.com/read/23649901/comparison-of-hyperpolarized-3-he-and-129-xe-mri-for-the-measurement-of-absolute-ventilated-lung-volume-in-rats
#19
COMPARATIVE STUDY
Matthew S Fox, Alexei Ouriadov, Giles E Santyr
PURPOSE: MRI using hyperpolarized noble gases, (3)He and (129)Xe, provides noninvasive assessments of lung structure and function. Previous work demonstrated that absolute ventilated lung volumes (aVLV) measured in rats using hyperpolarized (3)He agree well with micro-CT. METHODS: In this work, aVLV measurements were performed in rats using hyperpolarized (129)Xe MRI and compared with hyperpolarized (3)He measurements of aVLV under matched ventilation conditions...
March 2014: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/23589465/hyperpolarized-3-he-and-129-xe-mri-differences-in-asthma-before-bronchodilation
#20
RANDOMIZED CONTROLLED TRIAL
Sarah Svenningsen, Miranda Kirby, Danielle Starr, Del Leary, Andrew Wheatley, Geoffrey N Maksym, David G McCormack, Grace Parraga
PURPOSE: To compare hyperpolarized helium-3 ((3) He) and xenon-129 ((129) Xe) MRI in asthmatics before and after salbutamol inhalation. MATERIALS AND METHODS: Seven asthmatics provided written informed consent and underwent spirometry, plethysmography, and MRI before and after salbutamol inhalation. (3) He and (129) Xe ventilation defect percent (VDP) and ventilation coefficient of variation (COV) were measured. To characterize the airways spatially related to ventilation defects, wall area percent (WA%) and lumen area (LA) were evaluated for two subjects who had thoracic x-ray computed tomography (CT) acquired 1 year before MRI...
December 2013: Journal of Magnetic Resonance Imaging: JMRI
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