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https://www.readbyqxmd.com/read/28079713/interrogating-idh-mutation-in-brain-tumor-magnetic-resonance-and-hyperpolarization
#1
Jingzhe Hu, Travis C Salzillo, Napapon Sailasuta, Frederick F Lang, Pratip Bhattacharya
Magnetic resonance spectroscopy (MRS) offers the possibility to noninvasively quantify 2HG concentration in the brain in the clinic, thereby serving as a valuable tool for patient-stratification as well as targeted treatment monitoring. Recently, hyperpolarized magnetic resonance techniques have opened up new opportunities for metabolic imaging not possible with conventional MRS in the brain. With over 10,000-fold increase in signal-to-noise ratio (SNR), dynamic metabolic processes can be interrogated in vivo with very high specificity by hyperpolarized MRI...
January 11, 2017: Topics in Magnetic Resonance Imaging: TMRI
https://www.readbyqxmd.com/read/28078906/arduino-based-noise-robust-online-heart-rate-detection
#2
Sangita Das, Saurabh Pal, Madhuchhanda Mitra
This paper introduces a noise robust real time heart rate detection system from electrocardiogram (ECG) data. An online data acquisition system is developed to collect ECG signals from human subjects. Heart rate is detected using window-based autocorrelation peak localisation technique. A low-cost Arduino UNO board is used to implement the complete automated process. The performance of the system is compared with PC-based heart rate detection technique. Accuracy of the system is validated through simulated noisy ECG data with various levels of signal to noise ratio (SNR)...
January 12, 2017: Journal of Medical Engineering & Technology
https://www.readbyqxmd.com/read/28077268/development-of-high-resolution-3d-hyperpolarized-carbon-13-mr-molecular-imaging-techniques
#3
Eugene Milshteyn, Cornelius von Morze, Galen D Reed, Hong Shang, Peter J Shin, Zihan Zhu, Hsin-Yu Chen, Robert Bok, Andrei Goga, John Kurhanewicz, Peder E Z Larson, Daniel B Vigneron
The goal of this project was to develop and apply techniques for T2 mapping and 3D high resolution (1.5 mm isotropic; 0.003 cm(3)) (13)C imaging of hyperpolarized (HP) probes [1-(13)C]lactate, [1-(13)C]pyruvate, [2-(13)C]pyruvate, and [(13)C,(15)N2]urea in vivo. A specialized 2D bSSFP sequence was implemented on a clinical 3T scanner and used to obtain the first high resolution T2 maps of these different hyperpolarized compounds in both rats and tumor-bearing mice. These maps were first used to optimize timings for highest SNR for single time-point 3D bSSFP acquisitions with a 1...
January 7, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28076337/coded-excitation-for-diverging-wave-cardiac-imaging-a-feasibility-study
#4
Feifei Zhao, Ling Tong, Qiong He, Jianwen Luo
Diverging wave (DW) based cardiac imaging has gained increasing interest in recent years given its capacity to achieve ultrahigh frame rate. However, the signal-to-noise ratio (SNR), contrast, and penetration depth of the resulting B-mode images are typically low as DWs spread energy over a large region. Coded excitation is known to be capable of increasing the SNR and penetration for ultrasound imaging. The aim of this study was therefore to test the feasibility of applying coded excitation in DW imaging to improve the corresponding SNR, contrast and penetration depth...
January 11, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28076294/simulation-of-effects-of-the-electrode-structure-and-material-in-the-density-measuring-system-of-the-peripheral-nerve-based-on-micro-electrical-impedance-tomography
#5
Saber Behkami, Javad Frounchi, Firouz Ghaderi Pakdel, Thomas Stieglitz
The electrode structure in micro-electrical impedance tomography (MEIT) highly influences the measurement sensitivity and therefore the reconstructed image quality. Hence, optimizing the electrode structure leads to the improvement of image quality in the reconstruction procedure. Although there have been many investigations on electrical impedance tomography (EIT) electrodes, there is no comprehensive study on their influence on images of the peripheral nerve. In this paper, we present a simulation method to study the effects of the electrode structure in the density measurement system of the peripheral nerve based on MEIT...
January 11, 2017: Biomedizinische Technik. Biomedical Engineering
https://www.readbyqxmd.com/read/28074498/imaging-and-t2-relaxometry-of-short-t2-connective-tissues-in-the-knee-using-ultrashort-echo-time-double-echo-steady-state-utedess
#6
Akshay S Chaudhari, Bragi Sveinsson, Catherine J Moran, Emily J McWalter, Ethan M Johnson, Tao Zhang, Garry E Gold, Brian A Hargreaves
PURPOSE: To develop a radial, double-echo steady-state (DESS) sequence with ultra-short echo-time (UTE) capabilities for T2 measurement of short-T2 tissues along with simultaneous rapid, signal-to-noise ratio (SNR)-efficient, and high-isotropic-resolution morphological knee imaging. METHODS: THe 3D radial UTE readouts were incorporated into DESS, termed UTEDESS. Multiple-echo-time UTEDESS was used for performing T2 relaxometry for short-T2 tendons, ligaments, and menisci; and for Dixon water-fat imaging...
January 11, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28072579/development-of-advanced-signal-processing-and-source-imaging-methods-for-superparamagnetic-relaxometry
#7
Ming-Xiong Huang, Bill Anderson, Charles W Huang, Gerd J Kunde, Erika C Vreeland, Jeffrey W Huang, Andrei N Matlashov, Todor Karaulanov, Christopher P Nettles, Andrew Gomez, Kayla Minser, Caroline Weldon, Giulio Paciotti, Michael Harsh, Roland R Lee, Edward R Flynn
Superparamagnetic relaxometry (SPMR) is a highly sensitive technique for the in vivo detection of tumor cells and may improve early stage detection of cancers. SPMR employs superparamagnetic iron oxide nanoparticles (SPION). After a brief magnetizing pulse is used to align the SPION, SPMR measures the time decay of SPION using super-conducting quantum interference device (SQUID) sensors. Substantial research has been carried out in developing the SQUID hardware and in improving the properties of the SPION. However, little research has been done in the pre-processing of sensor signals and post-processing source modeling in SPMR...
January 10, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28070869/fast-t1-and-t2-mapping-methods-the-zoomed-u-flare-sequence-compared-with-epi-and-snapshot-flash-for-abdominal-imaging-at-11-7-tesla
#8
Géraldine Pastor, María Jiménez-González, Sandra Plaza-García, Marta Beraza, Torsten Reese
OBJECTIVE: A newly adapted zoomed ultrafast low-angle RARE (U-FLARE) sequence is described for abdominal imaging applications at 11.7 Tesla and compared with the standard echo-plannar imaging (EPI) and snapshot fast low angle shot (FLASH) methods. MATERIALS AND METHODS: Ultrafast EPI and snapshot-FLASH protocols were evaluated to determine relaxation times in phantoms and in the mouse kidney in vivo. Owing to their apparent shortcomings, imaging artefacts, signal-to-noise ratio (SNR), and variability in the determination of relaxation times, these methods are compared with the newly implemented zoomed U-FLARE sequence...
January 9, 2017: Magma
https://www.readbyqxmd.com/read/28070843/noise-optimized-monoenergetic-post-processing-improves-visualization-of-incidental-pulmonary-embolism-in-cancer-patients-undergoing-single-pass-dual-energy-computed-tomography
#9
Jakob Weiss, Mike Notohamiprodjo, Malte Bongers, Christoph Schabel, Stefanie Mangold, Konstantin Nikolaou, Fabian Bamberg, Ahmed E Othman
PURPOSE: To evaluate noise-optimized monoenergetic postprocessing of dual-energy CT (DE-CT) on image quality in patients with incidental pulmonary embolism in single-pass portal-venous phase CT (CTpv). MATERIALS AND METHODS: 20 Consecutive patients with incidental pulmonary embolism in contrast-enhanced oncological follow-up DE-CTpv examination were included in this study. Images were acquired with a 3rd generation DE-CT system in DE mode (100/Sn150 kV) and activated tube current modulation 90 s after contrast agent administration...
January 9, 2017: La Radiologia Medica
https://www.readbyqxmd.com/read/28068874/short-lag-spatial-coherence-ultrasound-imaging-with-adaptive-synthetic-transmit-aperture-focusing
#10
Jinxin Zhao, Yuanyuan Wang, Jinhua Yu, Wei Guo, Shun Zhang, Saeid Aliabadi
The short-lag spatial coherence (SLSC) imaging has been demonstrated to be advantageous over the traditional B-mode ultrasound imaging. With focused scanning beams, the SLSC imaging has an excellent performance in clutter reduction and lesion detection, especially in the low signal-to-noise ratio (SNR) scenarios. The synthetic aperture (SA) imaging is an appropriate mode for the SLSC imaging as the dynamic transmit focusing could keep a good focusing quality at any depth. However, the SLSC image may still suffer a bad resolution performance when a low lag value is used in the coherence summation to ensure the contrast enhancement...
January 1, 2017: Ultrasonic Imaging
https://www.readbyqxmd.com/read/28068370/visualization-of-radial-peripapillary-capillaries-using-optical-coherence-tomography-angiography-the-effect-of-image-averaging
#11
Shelley Mo, Erika Phillips, Brian D Krawitz, Reena Garg, Sarwat Salim, Lawrence S Geyman, Eleni Efstathiadis, Joseph Carroll, Richard B Rosen, Toco Y P Chui
OBJECTIVES: To assess the effect of image registration and averaging on the visualization and quantification of the radial peripapillary capillary (RPC) network on optical coherence tomography angiography (OCTA). METHODS: Twenty-two healthy controls were imaged with a commercial OCTA system (AngioVue, Optovue, Inc.). Ten 10x10° scans of the optic disc were obtained, and the most superficial layer (50-μm slab extending from the inner limiting membrane) was extracted for analysis...
2017: PloS One
https://www.readbyqxmd.com/read/28067973/simultaneous-multislice-readout-segmented-echo-planar-imaging-for-accelerated-diffusion-tensor-imaging-of-the-mandibular-nerve-a-feasibility-study
#12
Andrei Manoliu, Michael Ho, Marco Piccirelli, Daniel Nanz, Lukas Filli, Evelyn Dappa, Wei Liu, Dominik A Ettlin, Andreas Boss, Gustav Andreisek, Felix P Kuhn
PURPOSE: To assess the feasibility of diffusion tensor imaging (DTI) using simultaneous multislice (SMS) acquisition with blipped controlled aliasing in parallel imaging (CAIPI) for accelerated readout-segmented echo planar imaging (rs-EPI) of the mandibular nerves. DTI of the mandibular nerves using EPI is challenging due to susceptibility artifacts. Rs-EPI is less prone to artifacts but associated with longer scan durations. MATERIALS AND METHODS: Eight asymptomatic volunteers were imaged at 3T using a 64-channel head/neck coil...
January 9, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28065376/dual-energy-ct-virtual-non-calcium-technique-for-detection-of-bone-marrow-edema-in-patients-with-vertebral-fractures-a-prospective-feasibility-study-on-a-single-source-volume-ct-scanner
#13
T Diekhoff, K G Hermann, M Pumberger, B Hamm, M Putzier, M Fuchs
OBJECTIVES: Dual-energy computed tomography (DECT) is a recent development for detecting bone marrow edema (BME) in patients with vertebral compression fractures. The aim of this pilot study was to determine the reliability of single-source DECT in detecting vertebral BME using magnetic resonance imaging (MRI) as standard of reference. MATERIALS AND METHODS: Nine patients with radiographic thoracic or lumbar vertebral compression fractures underwent both, DECT on a 320-row single-source scanner and 1...
February 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/28064140/reduced-radiation-dose-and-improved-image-quality-using-a-mini-mobile-digital-imaging-system-in-a-neonatal-intensive-care-unit
#14
Tae-Hoon Kim, Jong-Hyun Ryu, Chang-Won Jeong, Hong Young Jun, Dong-Woon Heo, Seung Hyun Lee, Yeon Kyun Oh, Mi-Jung Lee, Kwon-Ha Yoon
This study was aimed to assess the radiation dose and image quality of a mini-mobile digital imaging (mini-DI) system for neonatal chest radiography and compared to conventional digital radiography (DR). A total of 64 neonates were examined and anatomical landmarks were assessed. The entrance surface dose of mini DI and conventional DR was 26.64±0.15 μGy and 49.11±1.46 μGy, respectively (p<0.001). The mean SNR values for mini-DI and DR were 233.2±5.1 and 31.6±1.2, and 10% MTF values were 131 and 161μm...
December 6, 2016: Clinical Imaging
https://www.readbyqxmd.com/read/28060906/steady-state-motion-visual-evoked-potential-ssmvep-based-on-equal-luminance-colored-enhancement
#15
Wenqiang Yan, Guanghua Xu, Min Li, Jun Xie, Chengcheng Han, Sicong Zhang, Ailing Luo, Chaoyang Chen
Steady-state visual evoked potential (SSVEP) is one of the typical stimulation paradigms of brain-computer interface (BCI). It has become a research approach to improve the performance of human-computer interaction, because of its advantages including multiple objectives, less recording electrodes for electroencephalogram (EEG) signals, and strong anti-interference capacity. Traditional SSVEP using light flicker stimulation may cause visual fatigue with a consequent reduction of recognition accuracy. To avoid the negative impacts on the brain response caused by prolonged strong visual stimulation for SSVEP, steady-state motion visual evoked potential (SSMVEP) stimulation method was used in this study by an equal-luminance colored ring-shaped checkerboard paradigm...
2017: PloS One
https://www.readbyqxmd.com/read/28059397/accurate-frequency-referencing-for-fieldable-dual-comb-spectroscopy
#16
Gar-Wing Truong, Eleanor M Waxman, Kevin C Cossel, Esther Baumann, Andrew Klose, Fabrizio R Giorgetta, William C Swann, Nathan R Newbury, Ian Coddington
We describe a dual-comb spectrometer that can operate independently of laboratory-based rf and optical frequency references but is nevertheless capable of ultra-high spectral resolution, high SNR, and frequency-accurate spectral measurements. The instrument is based on a "bootstrapped" frequency referencing scheme in which short-term optical phase coherence between combs is attained by referencing each to a free-running diode laser, whilst high frequency resolution and long-term accuracy is derived from a stable quartz oscillator...
December 26, 2016: Optics Express
https://www.readbyqxmd.com/read/28059235/performance-evaluation-of-a-two-detector-camera-for-real-time-video
#17
Benjamin Lochocki, Adrián Gambín-Regadera, Pablo Artal
Single pixel imaging can be the preferred method over traditional 2D-array imaging in spectral ranges where conventional cameras are not available. However, when it comes to real-time video imaging, single pixel imaging cannot compete with the framerates of conventional cameras, especially when high-resolution images are desired. Here we evaluate the performance of an imaging approach using two detectors simultaneously. First, we present theoretical results on how low SNR affects final image quality followed by experimentally determined results...
December 20, 2016: Applied Optics
https://www.readbyqxmd.com/read/28054912/the-effect-of-conventional-and-transparent-surgical-masks-on-speech-understanding-in-individuals-with-and-without-hearing-loss
#18
Samuel R Atcherson, Lisa Lucks Mendel, Wesley J Baltimore, Chhayakanta Patro, Sungmin Lee, Monique Pousson, M Joshua Spann
BACKGROUND: It is generally well known that speech perception is often improved with integrated audiovisual input whether in quiet or in noise. In many health-care environments, however, conventional surgical masks block visual access to the mouth and obscure other potential facial cues. In addition, these environments can be noisy. Although these masks may not alter the acoustic properties, the presence of noise in addition to the lack of visual input can have a deleterious effect on speech understanding...
January 2017: Journal of the American Academy of Audiology
https://www.readbyqxmd.com/read/28052516/detection-of-intermolecular-transferred-noe-interactions-in-small-and-medium-size-protein-complexes-rantes-complexed-with-a-ccr5-n-terminal-peptide
#19
Meital Abayev, Gautam Srivastava, Boris Arshava, Fred Naider, Jacob Anglister
NMR is a powerful tool to study structural details of protein/peptide complexes exhibiting weak to medium binding (KD >10 µM). However, it has been assumed that intermolecular nuclear Overhauser effect (NOE) interactions are difficult to observe in such complexes. We demonstrate that intermolecular NOEs can be revealed by combining the (13) C-edited/(13) C-filtered experiment with the transferred-NOE effect (TRNOE). Due to the TRNOE phenomenon intermolecular NOE cross peaks are characterized by both the chemical shifts of the protein protons and the average chemical shifts of the peptide protons, which are dominated by the chemical shifts of the protons of the free peptide...
January 4, 2017: FEBS Journal
https://www.readbyqxmd.com/read/28052436/quantification-of-1-h-mrs-signals-based-on-sparse-metabolite-profiles-in-the-time-frequency-domain
#20
Mohammad Ali Parto Dezfouli, Mohsen Parto Dezfouli, Alireza Ahmadian, Alejandro F Frangi, Melika Esmaeili Rad, Hamidreza Saligheh Rad
MRS is an analytical approach used for both quantitative and qualitative analysis of human body metabolites. The accurate and robust quantification capability of proton MRS ((1) H-MRS) enables the accurate estimation of living tissue metabolite concentrations. However, such methods can be efficiently employed for quantification of metabolite concentrations only if the overlapping nature of metabolites, existing static field inhomogeneity and low signal-to-noise ratio (SNR) are taken into consideration. Representation of (1) H-MRS signals in the time-frequency domain enables us to handle the baseline and noise better...
January 4, 2017: NMR in Biomedicine
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