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https://www.readbyqxmd.com/read/28521169/heterotrophic-ammonia-and-nitrate-bio-removal-over-nitrite-hanbon-performance-and-microflora
#1
Wei Li, Zhao-Yang Cai, Zi-Jun Duo, Yao-Feng Lu, Ke-Xin Gao, Ghulam Abbas, Meng Zhang, Ping Zheng
A novel Heterotrophic Ammonia and Nitrate Bio-removal Over Nitrite (Hanbon) process, combining Short Nitrate Reduction (SNR) with Anaerobic Ammonia Oxidation (Anammox), was developed in a lab-scale continuous up-flow reactor. The substrate effects were investigated to characterize the performance of Hanbon process, and the corresponding microflora information was also revealed. Our results showed that the optimal substrate ratio of NH4(+)-N:NO3(-)-N:COD for the Hanbon process was 0.65:1:2.2. The volumetric nitrogen removal rate was up to 9...
May 13, 2017: Chemosphere
https://www.readbyqxmd.com/read/28520793/how-does-motion-affect-gaba-measurements-order-statistic-filtering-compared-to-conventional-analysis-of-mega-press-mrs
#2
Sofie Tapper, Anders Tisell, Peter Lundberg
PURPOSE: The aim of this study was to evaluate two post-processing techniques applied to MRS MEGA-PRESS data influenced by motion-induced artifacts. In contrast to the conventional averaging technique, order statistic filtering (OSF) is a known method for artifact reduction. Therefore, this method may be suitable to incorporate in the GABA quantification. METHODS: Twelve healthy volunteers were scanned three times using a 3 T MR system. One measurement protocol consisted of two MEGA-PRESS measurements, one reference measurement and one measurement including head motions...
2017: PloS One
https://www.readbyqxmd.com/read/28520782/adaptive-double-threshold-energy-detection-based-on-markov-model-for-cognitive-radio
#3
Yulei Liu, Jun Liang, Nan Xiao, Xiaogang Yuan, Zhenhao Zhang, Meng Hu, Yulong Hu
The rapid development in the area of cognitive radio technology leads the society to higher standards of spectrum sensing performance, particularly in low signal-to-noise ratio (SNR) environment. This article proposes an adaptive double-threshold energy sensing method based on Markov model (ADEMM). When using the double-threshold energy sensing method, the modified Markov model that accounts for the time varying characteristic of the channel occupancy was presented to resolve the 'confused' channel state. Furthermore, in order to overcome the effect of noise uncertainty, the findings of this article introduce an adaptive double-threshold spectrum sensing method that adjusts its thresholds according to the achievable maximal detection probability...
2017: PloS One
https://www.readbyqxmd.com/read/28516482/multiple-boli-arterial-spin-labeling-for-high-signal-to-noise-rodent-brain-perfusion-imaging
#4
Antoine Vallatos, Lesley Gilmour, Anthony J Chalmers, William M Holmes
PURPOSE: A systematic method is proposed for optimizing a promising preclinical arterial spin labeling (ASL) sequence based on the use of a train of adiabatic radiofrequency pulses labeling successive boli of blood water. METHODS: The sequence optimization is performed and evaluated using brain imaging experiments in mice and in rats. It involves the investigation of several parameters, ranging from the number of adiabatic pulses and labeling duration to the properties of the adiabatic hyperbolic secant pulses (ie, amplitude and frequency modulation)...
May 17, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28516046/image-quality-assessment-of-a-1-5t-dedicated-magnetic-resonance-simulator-for-radiotherapy-with-a-flexible-radio-frequency-coil-setting-using-the-standard-american-college-of-radiology-magnetic-resonance-imaging-phantom-test
#5
Oi Lei Wong, Jing Yuan, Siu Ki Yu, Kin Yin Cheung
BACKGROUND: A flexible RF coil setting has to be used on an MR-simulator (MR-sim) in the head and neck simulation scan for radiotherapy (RT) purpose, while the image quality might be compromised due to the sub-optimized flexible coil compared to the normal diagnostic radiological (DR) head coil. In this study, we assessed the image quality of an MR-sim by conducting the standard American College of Radiology (ACR) MRI phantom test on a 1.5T MR-sim under RT-setting and comparing it to DR-setting...
April 2017: Quantitative Imaging in Medicine and Surgery
https://www.readbyqxmd.com/read/28516045/exploration-of-highly-accelerated-magnetic-resonance-elastography-using-high-density-array-coils
#6
John C Bosshard, Naresh Yallapragada, Mary P McDougall, Steven M Wright
BACKGROUND: Magnetic resonance elastography (MRE) measures tissue mechanical properties by applying a shear wave and capturing its propagation using magnetic resonance imaging (MRI). By using high density array coils, MRE images are acquired using single echo acquisition (SEA) and at high resolutions with significantly reduced scan times. METHODS: Sixty-four channel uniplanar and 32×32 channel biplanar receive arrays are used to acquire MRE wave image sets from agar samples containing regions of varying stiffness...
April 2017: Quantitative Imaging in Medicine and Surgery
https://www.readbyqxmd.com/read/28516044/design-of-catheter-radio-frequency-coils-using-coaxial-transmission-line-resonators-for-interventional-neurovascular-mr-imaging
#7
Xiaoliang Zhang, Alastair Martin, Caroline Jordan, Prasheel Lillaney, Aaron Losey, Yong Pang, Jeffrey Hu, Mark Wilson, Daniel Cooke, Steven W Hetts
BACKGROUND: It is technically challenging to design compact yet sensitive miniature catheter radio frequency (RF) coils for endovascular interventional MR imaging. METHODS: In this work, a new design method for catheter RF coils is proposed based on the coaxial transmission line resonator (TLR) technique. Due to its distributed circuit, the TLR catheter coil does not need any lumped capacitors to support its resonance, which simplifies the practical design and construction and provides a straightforward technique for designing miniature catheter-mounted imaging coils that are appropriate for interventional neurovascular procedures...
April 2017: Quantitative Imaging in Medicine and Surgery
https://www.readbyqxmd.com/read/28516042/sensitivity-enhancement-of-traveling-wave-mri-using-free-local-resonators-an-experimental-demonstration
#8
Xiaoliang Zhang
BACKGROUND: Traveling wave MR uses the far fields in signal excitation and reception, therefore its acquisition efficiency is low in contrast to the conventional near field magnetic resonance (MR). Here we show a simple and efficient method based on the local resonator to improving sensitivity of traveling wave MR technique. The proposed method utilizes a standalone or free local resonator to amplify the radio frequency magnetic fields in the interested target. The resonators have no wire connections to the MR system and thus can be conveniently placed to any place around imaging simples...
April 2017: Quantitative Imaging in Medicine and Surgery
https://www.readbyqxmd.com/read/28513847/transmission-characteristics-of-a-two-dimensional-antiscatter-grid-prototype-for-cbct
#9
Cem Altunbas, Brian Kavanagh, Timur Alexeev, Moyed Miften
AIM: High fraction of scattered radiation in cone-beam CT (CBCT) imaging degrades CT number accuracy and visualization of low contrast objects. To suppress scatter in CBCT projections, we developed a focused, two-dimensional antiscatter grid (2DASG) prototype. In this work, we report on the primary and scatter transmission characteristics of the 2DASG prototype aimed for linac mounted, offset detector geometry CBCT systems in radiation therapy, and compared its performance to a conventional one-dimensional ASG (1DASG)...
May 17, 2017: Medical Physics
https://www.readbyqxmd.com/read/28513211/image-quality-of-low-radiation-dose-left-atrial-ct-using-filtered-back-projection-and-an-iterative-reconstruction-algorithm-intra-individual-comparison-in-unselected-patients-undergoing-pulmonary-vein-isolation
#10
Ute Lina Fahlenkamp, Ivan Diaz Ramirez, Moritz Wagner, Carsten Schwenke, Alexander Huppertz, Bernd Hamm, Alexander Lembcke
Background Computed tomography (CT) of the left atrium (LA) is performed prior to pulmonary vein isolation (PVI) to improve success of circumferential ablation for atrial fibrillation. The ablation procedure itself exposes patients to substantial radiation doses, therefore radiation dose reduction in pre-ablational imaging is of concern. Purpose To assess and compare diagnostic performance of low-radiation dose preprocedural CT in patients scheduled for PVI using two types of reconstruction algorithms. Material and Methods Forty-six patients (61 ± 10 years) scheduled for PVI were enrolled in this study irrespective of body-mass-index or cardiac rhythm at examination...
January 1, 2017: Acta Radiologica
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
#11
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/28506470/coronary-ct-angiography-in-the-emergency-department-utilizing-second-and-third-generation-dual-source-ct
#12
Nandini M Meyersohn, Balint Szilveszter, Pedro V Staziaki, Jan-Erik Scholtz, Richard A P Takx, Udo Hoffmann, Brian B Ghoshhajra
BACKGROUND: Coronary computed tomography angiography (coronary CTA) allows efficient triage of low to intermediate risk patients with suspected acute coronary syndrome (ACS) in the emergency department (ED). Techniques for coronary CTA acquisition in the ED continue to evolve with the establishment of standardized scan protocols and the introduction of newer generations of CT hardware. OBJECTIVES: To evaluate qualitative and quantitative image quality and radiation dose exposure of coronary CTA acquired on 2nd versus 3rd generation dual source CT (DSCT) scanners using a standardized institutional scan protocol designed for the ED...
March 22, 2017: Journal of Cardiovascular Computed Tomography
https://www.readbyqxmd.com/read/28505622/fat-suppressed-contrast-enhanced-t1-weighted-dynamic-magnetic-resonance-imaging-at-3t-comparison-of-image-quality-between-spectrally-adiabatic-iversion-recovery-and-the-multiecho-dixon-technique-in-imaging-of-the-prostate
#13
Yuji Iyama, Takeshi Nakaura, Masafumi Kidoh, Kazuhiro Katahira, Tomohiro Namimoto, Shoji Morishita, Yasuyuki Yamashita
OBJECTIVE: To compare the quality of fat suppression and image quality between multiecho Dixon technique (mDixon) and spectrally adiabatic iversion recovery (SPAIR) in dynamic contrast-enhanced magnetic resonance imaging of the prostate. METHODS: This prospective study assigned thirty consecutive patients to scanning with SPAIR technique (SPAIR protocol) and another consecutive 30 patients to scanning with mDixon technique (mDixon protocol). We calculated the contrast, signal to noise ratio (SNR), contrast to noise ratio (CNR) and the coefficient of variation between the 2 protocols...
May 2017: Journal of Computer Assisted Tomography
https://www.readbyqxmd.com/read/28505505/measuring-listening-related-effort-and-fatigue-in-school-aged-children-using-pupillometry
#14
Ronan McGarrigle, Piers Dawes, Andrew J Stewart, Stefanie E Kuchinsky, Kevin J Munro
Stress and fatigue from effortful listening may compromise well-being, learning, and academic achievement in school-aged children. The aim of this study was to investigate the effect of a signal-to-noise ratio (SNR) typical of those in school classrooms on listening effort (behavioral and pupillometric) and listening-related fatigue (self-report and pupillometric) in a group of school-aged children. A sample of 41 normal-hearing children aged 8-11years performed a narrative speech-picture verification task in a condition with recommended levels of background noise ("ideal": +15dB SNR) and a condition with typical classroom background noise levels ("typical": -2dB SNR)...
May 12, 2017: Journal of Experimental Child Psychology
https://www.readbyqxmd.com/read/28503434/comparison-of-isolated-check-visual-evoked-potential-and-standard-automated-perimetry-in-early-glaucoma-and-high-risk-ocular-hypertension
#15
Xiang-Wu Chen, Ying-Xi Zhao
AIM: To compare the diagnostic performance of isolated-check visual evoked potential (icVEP) and standard automated perimetry (SAP), for evaluating the application values of icVEP in the detection of early glaucoma. METHODS: Totally 144 subjects (288 eyes) were enrolled in this study. icVEP testing was performed with the Neucodia visual electrophysiological diagnostic system. A 15% positive-contrast (bright) condition pattern was used in this device to differentiate between glaucoma patients and healthy control subjects...
2017: International Journal of Ophthalmology
https://www.readbyqxmd.com/read/28499849/a-geometrically-adjustable-receive-array-for-imaging-marmoset-cohorts
#16
Kyle M Gilbert, Joseph S Gati, L Martyn Klassen, Peter Zeman, David J Schaeffer, Stefan Everling, Ravi S Menon
The common marmoset (Callithrix jacchus) is an increasingly popular animal model for translational neuroscience studies, during which anatomical and functional MRI can be useful investigative tools. To attain the requisite SNR for high-resolution acquisitions, the radiofrequency coil must be optimized for the marmoset; however, relatively few custom coils have been developed that maximize SNR and are compatible with accelerated acquisitions. For the study of large populations of animals, the heterogeneity in animal size reduces the effectiveness of a "one size fits all" approach to coil sizing and makes coils tailored to individual animals cost and time prohibitive...
May 10, 2017: NeuroImage
https://www.readbyqxmd.com/read/28497418/assessing-time-of-flight-signal-to-noise-ratio-gains-within-the-myocardium-and-subsequent-reductions-in-administered-activity-in-cardiac-pet-studies
#17
Ian S Armstrong, Christine M Tonge, Parthiban Arumugam
BACKGROUND: Time-of-flight (TOF) is known to increase signal-to-noise ratio (SNR) and facilitate reductions in administered activity. Established measures of SNR gain are derived from areas of uniform uptake, which is not applicable to the heterogeneous uptake in cardiac PET images using fluoro-deoxyglucose (FDG). This study aimed to develop a technique to quantify SNR gains within the myocardium due to TOF. METHODS: Reference TOF SNR gains were measured in 88 FDG oncology patients...
May 11, 2017: Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology
https://www.readbyqxmd.com/read/28493070/quality-of-routine-diagnostic-abdominal-images-generated-from-a-novel-detector-based-spectral-ct-scanner-a-technical-report-on-a-phantom-and-clinical-study
#18
Mojgan Hojjati, Steven Van Hedent, Negin Rassouli, Curtis Tatsuoka, David Jordan, Amar Dhanantwari, Prabhakar Rajiah
PURPOSE: To evaluate the image quality of routine diagnostic images generated from a novel detector-based spectral detector CT (SDCT) and compare it with CT images obtained from a conventional scanner with an energy-integrating detector (Brilliance iCT), Routine diagnostic (conventional/polyenergetic) images are non-material-specific images that resemble single-energy images obtained at the same radiation, METHODS: ACR guideline-based phantom evaluations were performed on both SDCT and iCT for CT adult body protocol...
May 10, 2017: Abdominal Radiology
https://www.readbyqxmd.com/read/28489803/reproducibility-analysis-on-shear-wave-elastography-swe-based-quantitative-assessment-for-skin-elasticity
#19
Yang Sun, Chuan Ma, XiaoLong Liang, Run Wang, Ying Fu, ShuMin Wang, LiGang Cui, ChunLei Zhang
Shear Wave Elastography (SWE) is an objective and non-invasive method widely used to quantify the tissue solidity. However, there are concerns about the accuracy of the skin SWE results due to the low signal-to-noise ratio (SNR) caused by subcutaneous fat, muscle and bone. This article analyzed the reproducibility of the result for skin SWE and therefore evaluated the availability of SME for skin elasticity involved diseases. Thirty volunteers (mean age: 37 ± 12 years) were selected. SWE were taken on the skin of abdomen and the middle tibia in order to assess the impact of fat, muscle and bone on SWE results...
May 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28488179/novel-contrast-injection-protocol-for-high-resolution-abdominal-ct-angiography-vascular-visualization-improvement-with-vasodilator
#20
Minori Hoshika, Kotaro Yasui, Takefumi Niguma, Toru Kojima, Norimi Nishiyama, Daisuke Suzuki, Izumi Togami
PURPOSE: To evaluate the usefulness of a novel contrast-injection protocol for high-resolution abdominal computed tomography angiography (CTA) using nitroglycerin (NTG). METHODS: Abdominal CTA was performed in 80 patients using two 64-detector-row CT scanners. Forty patients were examined after administration of sublingual NTG (NTG group), while 40 were examined without NTG administration (non-NTG group). Arterial phase images were acquired with maximum intensity projection and volume rendering...
May 9, 2017: Abdominal Radiology
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