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https://www.readbyqxmd.com/read/27906765/hemodynamic-disturbances-in-the-early-phase-after-subarachnoid-hemorrhage-regional-cerebral-blood-flow-studied-by-bedside-xenon-enhanced-ct
#1
Henrik Engquist, Anders Lewén, Tim Howells, Ulf Johnson, Elisabeth Ronne-Engström, Pelle Nilsson, Per Enblad, Elham Rostami
BACKGROUND: The mechanisms leading to neurological deterioration and the devastating course of delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) are still not well understood. Bedside xenon-enhanced computerized tomography (XeCT) enables measurements of regional cerebral blood flow (rCBF) during neurosurgical intensive care. In the present study, CBF characteristics in the early phase after severe SAH were explored and related to clinical characteristics and early clinical course outcome...
November 30, 2016: Journal of Neurosurgical Anesthesiology
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
#2
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/27775747/use-of-a-single-xenon-flash-lamp-for-photoacoustic-computed-tomography-of-multiple-centimeter-thick-biological-tissue-ex-vivo-and-a-whole-mouse-body-in-vivo
#3
Terence T W Wong, Yong Zhou, Alejandro Garcia-Uribe, Lei Li, Konstantin Maslov, Li Lin, Lihong V Wang
No abstract text is available yet for this article.
April 1, 2017: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/27732160/chronic-obstructive-pulmonary-disease-lobar-analysis-with-hyperpolarized-129-xe-mr-imaging
#4
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
#5
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/27573349/grading-of-moyamoya-disease-allows-stratification-for-postoperative-ischemia-in-bilateral-revascularization-surgery
#6
M Czabanka, A Boschi, G Acker, P Peña-Tapia, G A Schubert, P Schmiedek, P Vajkoczy
BACKGROUND: Moyamoya disease (MMD) may be graded based on DSA, the presence of ischemia in MRI and cerebrovascular reserve capacity allowing the prediction of ischemic symptoms in patients. Cerebral ischemia represents a severe complication in revascularization surgery. Focusing on different clinical features of hemodynamic impairment, MMD grading may allow prediction of ischemic complications. It was the aim to analyze whether MMD grading stratifies for ischemic complications in revascularization surgery for MMD...
October 2016: Acta Neurochirurgica
https://www.readbyqxmd.com/read/27533710/pressure-regulated-volume-control-vs-volume-control-ventilation-in-healthy-and-injured-rabbit-lung-an-experimental-study
#7
Liisa Porra, Sam Bayat, Iliona Malaspinas, Gergely Albu, Camille Doras, Ludovic Broche, Satu Strengell, Ferenc Peták, Walid Habre
BACKGROUND: It is not well understood how different ventilation modes affect the regional distribution of ventilation, particularly within the injured lung. OBJECTIVES: We compared respiratory mechanics, lung aeration and regional specific ventilation ((Equation is included in full-text article.)) distributions in healthy and surfactant-depleted rabbits ventilated with pressure-regulated volume control (PRVC) mode with a decelerating inspiratory flow or with volume control (VC) mode...
October 2016: European Journal of Anaesthesiology
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
#8
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/27094991/novel-imaging-approaches-to-cerebrovascular-disease
#9
REVIEW
Ziad A Hage, Ali Alaraj, Gregory D Arnone, Fady T Charbel
Imaging techniques available to the physician treating neurovascular disease have substantially grown over the past several decades. New techniques as well as advances in imaging modalities continuously develop and provide an extensive array of modalities to diagnose, characterize, and understand neurovascular pathology. Modern noninvasive neurovascular imaging is generally based on computed tomography (CT), magnetic resonance (MR) imaging, or nuclear imaging and includes CT angiography, CT perfusion, xenon-enhanced CT, single-photon emission CT, positron emission tomography, magnetic resonance angiography, MR perfusion, functional magnetic resonance imaging with global and regional blood oxygen level dependent imaging, and magnetic resonance angiography with the use of the noninvasive optional vessel analysis software (River Forest, Ill)...
September 2016: Translational Research: the Journal of Laboratory and Clinical Medicine
https://www.readbyqxmd.com/read/27074479/evaluation-of-the-%C3%AE-v-4d-ct-ventilation-calculation-method-using-in-vivo-xenon-ct-ventilation-data-and-comparison-to-other-methods
#10
Geoffrey G Zhang, Kujtim Latifi, Kaifang Du, Joseph M Reinhardt, Gary E Christensen, Kai Ding, Vladimir Feygelman, Eduardo G Moros
Ventilation distribution calculation using 4D CT has shown promising potential in several clinical applications. This study evaluated the direct geometric ventilation calculation method, namely the ΔV method, with xenon-enhanced CT (XeCT) ventilation data from four sheep, and compared it with two other published meth-ods, the Jacobian and the Hounsfield unit (HU) methods. Spearman correlation coefficient (SCC) and Dice similarity coefficient (DSC) were used for the evaluation and comparison. The average SCC with one standard deviation was 0...
2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/26850183/argon-and-xenon-ventilation-during-prolonged-ex-vivo-lung-perfusion
#11
An Martens, Matteo Montoli, Giulio Faggi, Ira Katz, Jan Pype, Bart M Vanaudenaerde, Dirk E M Van Raemdonck, Arne P Neyrinck
BACKGROUND: Evidence supports the use of ex vivo lung perfusion (EVLP) as a platform for active reconditioning before transplantation to increase the potential donor pool and to reduce the incidence of primary graft dysfunction. A promising reconditioning strategy is the administration of inhaled noble gases based on their organoprotective effects. Our aim was to validate a porcine warm ischemic lung injury model and investigate postconditioning with argon (Ar) or xenon (Xe) during prolonged EVLP...
March 2016: Journal of Surgical Research
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
#12
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/26835499/two-dimensional-dynamic-fluid-bowtie-attenuators
#13
James R Hermus, Timothy P Szczykutowicz
Fluence field modulated (FFM) CT allows for improvements in image quality and dose reduction. To date, only one-dimensional modulators have been proposed, as the extension to two-dimensional (2-D) modulation is difficult with solid-metal attenuation-based fluence field modulated designs. This work proposes to use liquid and gas to attenuate the x-ray beam, as unlike solids, these materials can be arranged allowing for 2-D fluence modulation. The thickness of liquid and the pressure for a given path length of gas were determined that provided the same attenuation as 30 cm of soft tissue at 80, 100, 120, and 140 kV...
January 2016: Journal of Medical Imaging
https://www.readbyqxmd.com/read/26318361/hemodynamic-stress-distribution-reflects-ischemic-clinical-symptoms-of-patients-with-moyamoya-disease
#14
Satoshi Takahashi, Yoshio Tanizaki, Hiroaki Kimura, Kazunori Akaji, Masaki Nakazawa, Kazunari Yoshida, Ban Mihara
OBJECTIVE: Currently, the probability of diagnosing asymptomatic moyamoya disease is increasing. In this study, we consider a less invasive method for predicting future ischemic symptoms in patients with moyamoya disease. METHODS: We reviewed cerebral blood flow (CBF)-related data obtained by xenon CT imaging (XeCT) in six patients with ischemic-type or asymptomatic moyamoya disease. The data were obtained as volume data using a 320-row CT, and applied to the automated region-of-interest-determining software (3DSRT) and converted to standardized images...
November 2015: Clinical Neurology and Neurosurgery
https://www.readbyqxmd.com/read/26127513/su-e-j-120-comparing-4d-ct-computed-ventilation-to-lung-function-measured-with-hyperpolarized-xenon-129-mri
#15
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
https://www.readbyqxmd.com/read/26021343/characterization-of-darai-limestone-composition-and-porosity-using-data-constrained-modeling-and-comparison-with-xenon-k-edge-subtraction-imaging
#16
Sheridan C Mayo, Sam Y S Yang, Marina Pervukhina, Michael B Clennell, Lionel Esteban, Sarah C Irvine, Karen K Siu, Anton S Maksimenko, Andrew M Tulloh
Data-constrained modeling is a method that enables three-dimensional distribution of mineral phases and porosity in a sample to be modeled based on micro-computed tomography scans acquired at different X-ray energies. Here we describe an alternative method for measuring porosity, synchrotron K-edge subtraction using xenon gas as a contrast agent. Results from both methods applied to the same Darai limestone sample are compared. Reasonable agreement between the two methods and with other porosity measurements is obtained...
August 2015: Microscopy and Microanalysis
https://www.readbyqxmd.com/read/25997942/effect-of-surfactant-on-regional-lung-function-in-an-experimental-model-of-respiratory-distress-syndrome-in-rabbit
#17
Sam Bayat, Liisa Porra, Ludovic Broche, Gergely Albu, Iliona Malaspinas, Camille Doras, Satu Strengell, Ferenc Peták, Walid Habre
We assessed the changes in regional lung function following instillation of surfactant in a model of respiratory distress syndrome (RDS) induced by whole lung lavage and mechanical ventilation in eight anaesthetized, paralyzed, and mechanically ventilated New Zealand White rabbits. Regional specific ventilation (sV̇) was measured by K-edge subtraction synchrotron computed tomography during xenon washin. Lung regions were classified as poorly aerated (PA), normally aerated (NA), or hyperinflated (HI) based on regional density...
August 1, 2015: Journal of Applied Physiology
https://www.readbyqxmd.com/read/25995696/collateral-ventilation-quantification-using-xenon-enhanced-dynamic-dual-energy-ct-differences-between-canine-and-swine-models-of-bronchial-occlusion
#18
COMPARATIVE STUDY
Eun-Ah Park, Jin Mo Goo, Sang Joon Park, Chang Hyun Lee, Chang Min Park
OBJECTIVE: The aim of this study was to evaluate whether the difference in the degree of collateral ventilation between canine and swine models of bronchial obstruction could be detected by using xenon-enhanced dynamic dual-energy CT. MATERIALS AND METHODS: Eight mongrel dogs and six pigs underwent dynamic dual-energy scanning of 64-slice dual-source CT at 12-second interval for 2-minute wash-in period (60% xenon) and at 24-second interval for 3-minute wash-out period with segmental bronchus occluded...
May 2015: Korean Journal of Radiology: Official Journal of the Korean Radiological Society
https://www.readbyqxmd.com/read/25843191/nonalcoholic-fatty-liver-disease-noninvasive-methods-of-diagnosing-hepatic-steatosis
#19
REVIEW
Rasha AlShaalan, Murad Aljiffry, Said Al-Busafi, Peter Metrakos, Mazen Hassanain
Hepatic steatosis is the buildup of lipids within hepatocytes. It is the simplest stage in nonalcoholic fatty liver disease (NAFLD). It occurs in approximately 30% of the general population and as much as 90% of the obese population in the United States. It may progress to nonalcoholic steatohepatitis, which is a state of hepatocellular inflammation and damage in response to the accumulated fat. Liver biopsy remains the gold standard tool to diagnose and stage NAFLD. However, it comes with the risk of complications ranging from simple pain to life-threatening bleeding...
March 2015: Saudi Journal of Gastroenterology: Official Journal of the Saudi Gastroenterology Association
https://www.readbyqxmd.com/read/25817622/prediction-of-cerebrovascular-reserve-capacity-by-computed-tomography-perfusion-using-320-row-computed-tomography
#20
Satoshi Takahashi, Yoshio Tanizaki, Hiroaki Kimura, Kazunori Akaji, Tadashige Kano, Kentaro Suzuki, Youhei Takayama, Takao Kanzawa, Satoka Shidoh, Masaki Nakazawa, Kazunari Yoshida, Ban Mihara
BACKGROUND: Acetazolamide loading has been the "gold standard" for evaluating cerebrovascular reserve capacity (CVRC). However, life-threatening side effects of acetazolamide have recently been reported. The aim of the study was to identify alternative methods for evaluating CVRC. METHODS: We reviewed 6 patients who underwent both computed tomography perfusion (CTP) imaging and xenon CT (XeCT) imaging with and without acetazolamide loading during the same periods...
May 2015: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
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