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https://www.readbyqxmd.com/read/29775663/free-breathing-ultrashort-echo-time-lung-magnetic-resonance-imaging-using-stack-of-spirals-acquisition-a-feasibility-study-in-oncology-patients
#1
Min Jae Cha, Hyun Jeong Park, Mun Young Paek, Alto Stemmer, Eun Sun Lee, Sung Bin Park, Yang Soo Kim
OBJECTIVES: To investigate the diagnostic accuracy of lung magnetic resonance imaging (MRI) with a free-breathing three-dimensional ultrashort echo time spoiled gradient echo sequence using a stack-of-spirals acquisition (spiral 3D UTE) for pulmonary nodule detection at 3 T in oncology patients. METHODS: The institutional review board approved this retrospective study. Between June and September of 2017, 32 oncology patients underwent both free-breathing spiral 3D UTE of the lungs and thin-section chest computed tomography (CT) for pulmonary metastasis workups...
May 15, 2018: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/29775578/c-terminal-end-directed-protein-elimination-by-crl2-ubiquitin-ligases
#2
Hsiu-Chuan Lin, Chi-Wei Yeh, Yen-Fu Chen, Ting-Ting Lee, Pei-Yun Hsieh, Domnita V Rusnac, Sung-Ya Lin, Stephen J Elledge, Ning Zheng, Hsueh-Chi S Yen
The proteolysis-assisted protein quality control system guards the proteome from potentially detrimental aberrant proteins. How miscellaneous defective proteins are specifically eliminated and which molecular characteristics direct them for removal are fundamental questions. We reveal a mechanism, DesCEND (destruction via C-end degrons), by which CRL2 ubiquitin ligase uses interchangeable substrate receptors to recognize the unusual C termini of abnormal proteins (i.e., C-end degrons). C-end degrons are mostly less than ten residues in length and comprise a few indispensable residues along with some rather degenerate ones...
May 17, 2018: Molecular Cell
https://www.readbyqxmd.com/read/29775343/observation-of-discrete-time-crystal-signatures-in-an-ordered-dipolar-many-body-system
#3
Jared Rovny, Robert L Blum, Sean E Barrett
A discrete time crystal (DTC) is a robust phase of driven systems that breaks the discrete time translation symmetry of the driving Hamiltonian. Recent experiments have observed DTC signatures in two distinct systems. Here we show nuclear magnetic resonance observations of DTC signatures in a third, strikingly different system: an ordered spatial crystal. We use a novel DTC echo experiment to probe the coherence of the driven system. Finally, we show that interactions during the pulse of the DTC sequence contribute to the decay of the signal, complicating attempts to measure the intrinsic lifetime of the DTC...
May 4, 2018: Physical Review Letters
https://www.readbyqxmd.com/read/29775146/setting-pressure-can-change-the-size-and-shape-of-mri-artifacts-caused-by-adjustable-shunt-valves-a-study-of-the-4-newest-models
#4
Daiki Uchida, Yuki Amano, Hirokazu Nakatogawa, Takayuki Masui, Naoto Ando, Teiji Nakayama, Haruhiko Sato, Tetsuro Sameshima, Tokutaro Tanaka
OBJECTIVE Adjustable shunt valves that have been developed for the management of hydrocephalus all rely on intrinsically magnetic components, and artifacts with these valves on MRI are thus inevitable. The authors have previously reported that the shapes of shunt artifacts differ under different valve pressures with the proGAV 2.0 valve. In the present study the authors compared the size and shape of artifacts at different pressure settings with 4 new-model shunt valves. METHODS The authors attached 4 new models of MRI-resistant shunt valve to the temporal scalp of a healthy volunteer: the proGAV 2...
May 18, 2018: Journal of Neurosurgery
https://www.readbyqxmd.com/read/29774625/effect-of-phase-encoding-direction-on-group-analysis-of-resting-state-functional-magnetic-resonance-imaging
#5
Yasuo Mori, Jun Miyata, Masanori Isobe, Shuraku Son, Yujiro Yoshihara, Toshihiko Aso, Takanori Kouchiyama, Toshiya Murai, Hidehiko Takahashi
AIM: Echo-planar imaging is a common technique used in functional magnetic resonance imaging (fMRI), however it suffers from image distortion and signal loss because of large susceptibility effects that are related to the phase-encoding direction of the scan. Despite this relationship, the majority of neuroimaging studies have not considered the influence of phase-encoding direction. Here, we aimed to clarify how phase-encoding direction can affect the outcome of an fMRI connectivity study of schizophrenia...
May 17, 2018: Psychiatry and Clinical Neurosciences
https://www.readbyqxmd.com/read/29774599/deep-convolutional-neural-network-for-segmentation-of-knee-joint-anatomy
#6
Zhaoye Zhou, Gengyan Zhao, Richard Kijowski, Fang Liu
PURPOSE: To describe and evaluate a new segmentation method using deep convolutional neural network (CNN), 3D fully connected conditional random field (CRF), and 3D simplex deformable modeling to improve the efficiency and accuracy of knee joint tissue segmentation. METHODS: A segmentation pipeline was built by combining a semantic segmentation CNN, 3D fully connected CRF, and 3D simplex deformable modeling. A convolutional encoder-decoder network was designed as the core of the segmentation method to perform high resolution pixel-wise multi-class tissue classification for 12 different joint structures...
May 17, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29774429/the-utility-of-superb-microvascular-imaging-for-the-detection-of-deep-vein-thrombosis
#7
Yuta Hagiwara, Rie Sasaki, Takahiro Shimizu, Kaima Soga, Chihiro Hatada, Motoki Miyauchi, Takanori Okamura, Masaru Sakurai, Hisanao Akiyama, Yasuhiro Hasegawa
Superb microvascular imaging (SMI) reduces motion artifacts significantly and allows visualization of low-velocity blood flow in vessels; thus, thrombi are clearly demonstrated compared to conventional B-mode and color Doppler imaging. Ultrasonographic images of the lower extremities of a 69-year-old woman with acute ischemic stroke complicated with deep vein thrombosis (DVT) are presented. Because SMI allows visualization of low-velocity blood flow, echo contrast between the thrombus and the surrounding flow makes it possible to clearly visualize the thrombus...
May 17, 2018: Journal of Medical Ultrasonics
https://www.readbyqxmd.com/read/29774391/comparison-of-left-ventricular-hypertrophy-by-electrocardiography-and-echocardiography-in-children-using-analytics-tool
#8
Lauren Tague, Justin Wiggs, Qianxi Li, Robert McCarter, Elizabeth Sherwin, Jacqueline Weinberg, Craig Sable
Left ventricular hypertrophy (LVH) is a common finding on pediatric electrocardiography (ECG) leading to many referrals for echocardiography (echo). This study utilizes a novel analytics tool that combines ECG and echo databases to evaluate ECG as a screening tool for LVH. SQL Server 2012 data warehouse incorporated ECG and echo databases for all patients from a single institution from 2006 to 2016. Customized queries identified patients 0-18 years old with LVH on ECG and an echo performed within 24 h. Using data visualization (Tableau) and analytic (Stata 14) software, ECG and echo findings were compared...
May 17, 2018: Pediatric Cardiology
https://www.readbyqxmd.com/read/29774313/echoes-from-the-40-th-annual-san-antonio-breast-cancer-symposium-2017
#9
Bekir Kuru
The Annual San Antonio Symposium was held on 5-9, December, 2017 in San Antonio, Texas, USA (1). As expected, many new studies were presented for the first time at the sessions. The unofficial opening lecture in my point of view was given on locoregional recurrence by Monica Morrow from MSKCC, New York. As always, Morrow's lecture on "Challenges in the surgical management of locoregional recurrence" attracted great interest. The other prominent conferences were given on "Individualizing Management of the Axillary Nodes" by Tari A...
April 2018: European Journal of Breast Health
https://www.readbyqxmd.com/read/29773892/metabolite-cycled-density-weighted-concentric-rings-k-space-trajectory-dw-crt-enables-high-resolution-1-h-magnetic-resonance-spectroscopic-imaging-at-3-tesla
#10
Adam Steel, Mark Chiew, Peter Jezzard, Natalie L Voets, Puneet Plaha, Michael Albert Thomas, Charlotte J Stagg, Uzay E Emir
Magnetic resonance spectroscopic imaging (MRSI) is a promising technique in both experimental and clinical settings. However, to date, MRSI has been hampered by prohibitively long acquisition times and artifacts caused by subject motion and hardware-related frequency drift. In the present study, we demonstrate that density weighted concentric ring trajectory (DW-CRT) k-space sampling in combination with semi-LASER excitation and metabolite-cycling enables high-resolution MRSI data to be rapidly acquired at 3 Tesla...
May 17, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29773823/comparison-of-conventional-sonographic-signs-and-magnetic-resonance-imaging-proton-density-fat-fraction-for-assessment-of-hepatic-steatosis
#11
Mimi Kim, Bo-Kyeong Kang, Dae Won Jun
This study correlated conventional ultrasonography (US) signs with the magnetic resonance imaging (MRI) proton density fat fraction (PDFF) to evaluate the diagnostic performance of US signs (alone or combined) to predict presence and degree of hepatic steatosis (HS). Overall, 182 subjects met the study inclusion criteria between February 2014 and October 2016. Four US signs were evaluated independently by two radiologists. MRI PDFF was defined as the average of 24 non-overlapping regions of interest (ROIs) within eight liver segments obtained by drawing three ROIs within each segment...
May 17, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29773322/polarization-of-the-vaccination-debate-on-facebook
#12
Ana Lucía Schmidt, Fabiana Zollo, Antonio Scala, Cornelia Betsch, Walter Quattrociocchi
BACKGROUND: Vaccine hesitancy has been recognized as a major global health threat. Having access to any type of information in social media has been suggested as a potential influence on the growth of anti-vaccination groups. Recent studies w.r.t. other topics than vaccination show that access to a wide amount of content through the Internet without intermediaries resolved into major segregation of the users in polarized groups. Users select information adhering to theirs system of beliefs and tend to ignore dissenting information...
May 14, 2018: Vaccine
https://www.readbyqxmd.com/read/29772066/3d-specific-absorption-rate-estimation-from-high-intensity-focused-ultrasound-sonications-using-the-green-s-function-heat-kernel
#13
Nicholas J Freeman, Henrik Odéen, Dennis L Parker
PURPOSE: Evaluate a numerical inverse Green's function method of deriving specific absorption rates (SARs) from high intensity focused ultrasound (HIFU) sonications given tissue parameters (thermal conductivity, specific heat capacity, and mass density) and 3-D magnetic resonance imaging (MRI) temperature measurements. METHODS: SAR estimates were evaluated using simulations and MR temperature measurements from HIFU sonications. For simulations, a "true" SAR was calculated using the hybrid angular spectrum method for ultrasound simulations...
May 17, 2018: Medical Physics
https://www.readbyqxmd.com/read/29772058/technical-note-interleaved-bipolar-acquisition-and-low-rank-reconstruction-for-water-fat-separation-in-mri
#14
JaeJin Cho, HyunWook Park
PURPOSE: To acquire interleaved bipolar data and reconstruct the full data using low-rank property for water fat separation. METHODS: Bipolar acquisition suffers from issues related to gradient switching, the opposite gradient polarities, and other system imperfections, which prevent accurate water-fat separation. In this study, an interleaved bipolar acquisition scheme and a low-rank reconstruction method were proposed to reduce issues from the bipolar gradients while achieving a short imaging time...
May 17, 2018: Medical Physics
https://www.readbyqxmd.com/read/29771727/modeling-gadoxetate-liver-uptake-and-efflux-using-dynamic-contrast-enhanced-magnetic-resonance-imaging-enables-preclinical-quantification-of-transporter-drug-drug-interactions
#15
Leonidas Georgiou, Jeffrey Penny, Glynis Nicholls, Neil Woodhouse, François-Xavier Blé, Josephine H Naish, Penny L Hubbard Cristinacce
OBJECTIVES: The aim of this study was to model the in vivo transporter-mediated uptake and efflux of the hepatobiliary contrast agent gadoxetate in the liver. The efficacy of the proposed technique was assessed for its ability to provide quantitative insights into drug-drug interactions (DDIs), using rifampicin as inhibitor. MATERIALS AND METHODS: Three groups of C57 mice were scanned twice with a dynamic gadoxetate-enhanced magnetic resonance imaging protocol, using a 3-dimensional spoiled gradient-echo sequence for approximately 72 minutes...
May 15, 2018: Investigative Radiology
https://www.readbyqxmd.com/read/29771187/advanced-stage-breast-cancer-is-associated-with-catheter-tip-thrombus-formation-following-implantable-central-venous-port-placement
#16
Mina S Makary, Alexander Lionberg, Mamdouh Khayat, Maryam B Lustberg, Jamal AlTaani, Xueliang J Pan, Richard R Layman, Subha V Raman, Rachel M Layman, Joshua D Dowell
Purpose Catheter-tip associated thrombosis is not uncommon in patients with implantable central venous ports; however, the prevalence and clinical impact of this complication on patient management is unclear. This study aims to identify risk factors for thrombus formation in a large population receiving serial echocardiograms (echo) following port placement. Methods A total of 396 female breast cancer patients underwent internal jugular vein chest port placement between 2007 and 2013 and received echo studies every third month...
January 1, 2018: Phlebology
https://www.readbyqxmd.com/read/29771111/the-chemical-history-of-a-bubble
#17
Kenneth S Suslick, Nathan C Eddingsaas, David J Flannigan, Stephen D Hopkins, Hangxun Xu
Acoustic cavitation (the growth, oscillation, and rapid collapse of bubbles in a liquid) occurs in all liquids irradiated with sufficient intensity of sound or ultrasound. The collapse of such bubbles creates local heating and provides a unique source of energy for driving chemical reactions. In addition to sonochemical bond scission and formation, cavitation also induces light emission in many liquids. This phenomenon of sonoluminescence (SL) has captured the imagination of many researchers since it was first observed 85 years ago...
May 17, 2018: Accounts of Chemical Research
https://www.readbyqxmd.com/read/29770800/current-and-future-circulating-biomarkers-for-cardiac-amyloidosis
#18
REVIEW
Marco Luciani, Luca Troncone, Federica Del Monte
Cardiac amyloidosis (CA) comprises a heterogeneous group of medical conditions affecting the myocardium. It presents with proteinaceous infiltration with variable degrees of severity, prevalence and evolution. Despite this heterogeneity, erroneous protein folding is the common pathophysiologic process, yielding the formation of a single misfolded protein (monomer) that progressively evolves and ultimately forms amyloid fibers. Additionally, by seeding out from the organs of origin, intermediates called oligomers metastasize and restart the process...
May 17, 2018: Acta Pharmacologica Sinica
https://www.readbyqxmd.com/read/29770495/prostate-dce-mri-with-b1-correction-using-an-approximated-analytical-approach
#19
Xinran Zhong, Thomas Martin, Holden H Wu, Krishna S Nayak, Kyunghyun Sung
PURPOSE: To develop and evaluate a practical B1+ correction method for prostate dynamic contrast-enhanced (DCE) MRI analysis. THEORY: We proposed a simple analytical B1+ correction method using a Taylor series approximation to the steady-state spoiled gradient echo signal equation. This approach only requires B1+ maps and uncorrected pharmacokinetic (PK) parameters as input to estimate the corrected PK parameters. METHODS: The proposed method was evaluated using a prostate digital reference object (DRO), and 82 in vivo prostate DCE-MRI cases...
May 16, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29770484/inter-method-reproducibility-of-biexponential-r-2-mr-relaxometry-for-estimation-of-liver-iron-concentration
#20
Ali Pirasteh, Qing Yuan, Diego Hernando, Scott B Reeder, Ivan Pedrosa, Takeshi Yokoo
PURPOSE: To assess the reproducibility of biexponential R2 -relaxometry MRI for estimation of liver iron concentration (LIC) between proprietary and nonproprietary analysis methods. METHODS: This single-center retrospective study, approved by investigational review board and compliant with the Health Insurance Portability and Accountability Act, included 40 liver MRI exams in 38 subjects with suspected or known iron overload. From spin-echo images of the liver, acquired at 5 different echo times (TE = 6-18 ms), biexponential R2 maps were calculated using 1 proprietary (FerriScan, Resonance Health Ltd...
May 16, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
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