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https://www.readbyqxmd.com/read/29775791/an-imaging-biomarker-for-assessing-hepatic-function-in-patients-with-primary-sclerosing-cholangitis
#1
Jennifer Schulze, Henrike Lenzen, Jan B Hinrichs, Burckhardt Ringe, Michael P Manns, Frank Wacker, Kristina I Ringe
BACKGROUND & AIMS: We aimed to evaluate the potential of hepatobiliary phase magnetic resonance imaging (MRI) as parameter for assessment of hepatocellular function in patients with primary sclerosing cholangitis (PSC). METHODS: We collected data from 111 patients (83 male, 28 female; median, 44 years old), from March 2012 through March 2016, with a confirmed diagnosis of PSC who underwent MRI evaluation before and after injection (hepatobiliary phase) of a hepatocyte-specific contrast agent (gadoxetate disodium)...
May 15, 2018: Clinical Gastroenterology and Hepatology
https://www.readbyqxmd.com/read/29775537/amplification-of-dynamic-nuclear-polarization-at-200-ghz-by-arbitrary-pulse-shaping-of-the-electron-spin-saturation-profile
#2
Ilia Kaminker, Songi Han
Dynamic nuclear polarization (DNP) takes center stage in nuclear magnetic resonance (NMR) as a tool to amplify its signal by orders of magnitude through the transfer of polarization from electron to nuclear spins. In contrast to modern NMR and electron paramagnetic resonance (EPR) that extensively rely on pulses for spin manipulation in the time domain, the current mainstream DNP technology exclusively relies on monochromatic continuous wave (CW) irradiation. This study introduces arbitrary phase shaped pulses that constitute a train of coherent chirp pulses in the time domain at 200 GHz (7 Tesla) to dramatically enhance the saturation bandwidth and DNP performance compared to CW DNP, yielding up to 500-fold in NMR signal enhancements...
May 18, 2018: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/29775325/absence-of-long-range-order-in-a-triangular-spin-system-with-dipolar-interactions
#3
Ahmet Keleş, Erhai Zhao
The antiferromagnetic Heisenberg model on the triangular lattice is perhaps the best known example of frustrated magnets, but it orders at low temperatures. Recent density matrix renormalization group (DMRG) calculations find that the next nearest neighbor interaction J_{2} enhances the frustration, and it leads to a spin liquid for J_{2}/J_{1}∈(0.08,0.15). In addition, a DMRG study of a dipolar Heisenberg model with longer range interactions gives evidence for a spin liquid at a small dipole tilting angle θ∈[0,10°)...
May 4, 2018: Physical Review Letters
https://www.readbyqxmd.com/read/29774406/reduced-global-myocardial-perfusion-reserve-in-dcm-and-hcm-patients-assessed-by-cmr-based-velocity-encoded-coronary-sinus-flow-measurements-and-first-pass-perfusion-imaging
#4
Michael Bietenbeck, Anca Florian, Zornitsa Shomanova, Claudia Meier, Ali Yilmaz
BACKGROUND: Coronary microvascular dysfunction (CMD) is an independent predictor of poor prognosis in patients suffering from dilative or hypertrophic cardiomyopathy (DCM/HCM). To assess CMD, quantitative myocardial first-pass perfusion (1P) cardiovascular magnetic resonance (CMR) can be performed. Coronary sinus flow (CSF) measurements at rest and during maximal vasodilatation are an alternative and well-validated approach for the quantification of global myocardial blood flow (MBF) in CMR...
May 17, 2018: Clinical Research in Cardiology: Official Journal of the German Cardiac Society
https://www.readbyqxmd.com/read/29774382/iodine-material-density-images-in-dual-energy-ct-quantification-of-contrast-uptake-and-washout-in-hcc
#5
Daniela Pfeiffer, Anushri Parakh, Manuel Patino, Avinash Kambadakone, Ernst J Rummeny, Dushyant V Sahani
PURPOSE: To determine the diagnostic potential of Material Density (MD) iodine images in dual-energy CT (DECT) for visualization and quantification of arterial phase hyperenhancement and washout in hepatocellular carcinomas compared to magnetic resonance imaging (MRI). MATERIALS AND METHODS: The study complied with HIPAA guidelines and was approved by the ethics committee of the institutional review board. Thirty-one patients (23 men, 8 women; age range, 36-87 years) with known or suspected Hepatocellular Carcinoma (HCC) were included...
May 17, 2018: Abdominal Radiology
https://www.readbyqxmd.com/read/29772936/the-effect-of-supine-positioning-on-maternal-hemodynamics-during-late-pregnancy
#6
Aimee Humphries, S Ali Mirjalili, Gregory P Tarr, John M D Thompson, Peter Stone
INTRODUCTION: Recent studies have demonstrated an association between maternal supine sleep position and an increased risk of late stillbirth. During late pregnancy the gravid uterus compresses the inferior vena cava when a woman lies in the supine position. The azygos system of veins is the dominant pathway of collateral venous return back to the heart in the event of acute obstruction of the inferior vena cava. It is suggested that this pathway provides adequate collateral venous circulation in the event of inferior vena caval compression in the supine position during late pregnancy...
May 17, 2018: Journal of Maternal-fetal & Neonatal Medicine
https://www.readbyqxmd.com/read/29770848/imaging-biomarkers-from-multiparametric-magnetic-resonance-imaging-are-associated-with-survival-outcomes-in-patients-with-brain-metastases-from-breast-cancer
#7
Bang-Bin Chen, Yen-Shen Lu, Chih-Wei Yu, Ching-Hung Lin, Tom Wei-Wu Chen, Shwu-Yuan Wei, Ann-Lii Cheng, Tiffany Ting-Fang Shih
OBJECTIVES: The aim of this study is to investigate the correlation of survival outcomes with imaging biomarkers from multiparametric magnetic resonance imaging (MRI) in patients with brain metastases from breast cancer (BMBC). METHODS: This study was approved by the institutional review board. Twenty-two patients with BMBC who underwent treatment involving bevacizumab on day 1, etoposide on days 2-4, and cisplatin on day 2 in 21-day cycles were prospectively enrolled for a phase II study...
May 16, 2018: European Radiology
https://www.readbyqxmd.com/read/29770490/functional-magnetic-resonance-electrical-impedance-tomography-fmreit-sensitivity-analysis-using-an-active-bidomain-finite-element-model-of-neural-tissue
#8
Rosalind J Sadleir, Fanrui Fu, Munish Chauhan
PURPOSE: A direct method of imaging neural activity was simulated to determine typical signal sizes. METHODS: An active bidomain finite-element model was used to estimate approximate perturbations in MR phase data as a result of neural tissue activity, and when an external MR electrical impedance tomography imaging current was added to the region containing neural current sources. RESULTS: Modeling-predicted, activity-related conductivity changes should produce measurable differential phase signals in practical MR electrical impedance tomography experiments conducted at moderate resolution at noise levels typical of high field systems...
May 16, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29770412/first-principles-prediction-of-two-dimensional-metal-bis-dithiolene-complexes-as-promising-gas-sensors
#9
Hongmei Liu, Xiaolong Li, Changmin Shi, Dongchao Wang, Li Chen, Yuanyuan He, Jianwei Zhao
The recently synthesized two-dimensional metal bis(dithiolene) complex (MDT), a kind of metal-organic framework with a kagome lattice structure, has been found to be a promising material for electronic devices. Here we report the surface adsorption effects of gas molecules on the electronic properties and transport behaviors of two-dimensional MDT (M = Fe, Co, Ni, Pd, and Pt) films. The first-principles results reveal that the MDT nanosheets are selectively sensitive to different adsorbed molecules, such as CO, NO, and O2 molecules...
May 17, 2018: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/29767506/effect-of-the-substitution-pattern-peripheral-vs-non-peripheral-on-the-spectroscopic-electrochemical-and-magnetic-properties-of-octahexylsulfanyl-copper-phthalocyanines
#10
Tulin Ateş Turkmen, Lihan Zeng, Yan Cui, İsmail Fidan, Fabienne Dumoulin, Catherine Hirel, Yunus Zorlu, Vefa Ahsen, Alexander A Chernonosov, Yurii Chumakov, Karl M Kadish, Ayşe Gül Gürek, Sibel Tokdemir Öztürk
In order to investigate the substitution position effect on the spectroscopic, electrochemical, and magnetic properties of copper phthalocyanines, a detailed structure-property analysis has been performed by examining two copper phthalocyanines that are octasubstituted by hexylsulfanyl chains respectively in the peripheral (Cu-P) and non-peripheral (Cu-NP) positions. Cu-NP showed a marked near-IR maximum absorption compared to Cu-P and, accordingly, a smaller HOMO-LUMO energy gap, calculated via the electrochemical results and simulations in the gas phase, as well as for Cu-NP from its crystallographic data...
May 16, 2018: Inorganic Chemistry
https://www.readbyqxmd.com/read/29762918/impact-of-heart-rate-on-flow-measurements-in-aortic-regurgitation
#11
Mats Lidén, Maciej Wodecki, Per Thunberg, Peter Rask
BACKGROUND: Flow measurements using cardiac magnetic resonance imaging (CMRI) enable quantification of the stroke volume, regurgitant volume (RV) and regurgitant fraction (RF) in patients with aortic regurgitation (AR). These variables are used to assess the severity of the valve disease and for the timing of surgery. The aim of the study was to investigate the impact of an increased heart rate on measurement of the RV and RF in patients with AR. METHODS: Among 13 patients with known moderate or severe AR, regurgitant flow measurements, using phase-contrast cine magnetic resonance imaging, were obtained in the ascending aorta...
September 2017: Journal of Heart Valve Disease
https://www.readbyqxmd.com/read/29762258/fast-abdominal-contrast-enhanced-imaging-with-high-parallel-imaging-factors-using-a-60-channel-receiver-coil-setup-comparison-with-the-standard-coil-setup
#12
Jakob Weiss, Petros Martirosian, Steffen Wolf, Wilhelm Horger, Jana Taron, Konstantin Nikolaou, Mike Notohamiprodjo, Ahmed E Othman
PURPOSE: The aim of this study was to assess a novel 60-channel receiver body coil (B60) setup for accelerated contrast-enhanced abdominal magnetic resonance imaging (MR) imaging with respect to signal-to-noise ratio (SNR) and image quality using high parallel-imaging technique (PAT) factors in comparison to a standard 30-channel coil setup. METHODS: All imaging data were acquired on a 3 T MR scanner using a novel B60 receiver coil setup in comparison to a standard 30-channel setup serving as reference standard...
May 14, 2018: Investigative Radiology
https://www.readbyqxmd.com/read/29760276/early-blood-brain-barrier-disruption-in-ischemic-stroke-initiates-multifocally-around-capillaries-venules
#13
Angelika Hoffmann, Tassilo Dege, Reiner Kunze, Anne-Sophie Ernst, Holger Lorenz, Laura-Inés Böhler, Thomas Korff, Hugo H Marti, Sabine Heiland, Martin Bendszus, Xavier Helluy, Mirko Pham
BACKGROUND AND PURPOSE: Detection and localization of the early phase of blood-brain barrier disruption (BBBD) in vivo during cerebral ischemia/reperfusion injury remain a major challenge but may be a relevant outcome parameter in stroke. METHODS: We studied early BBBD in mice after transient middle cerebral artery occlusion by multimodal, high-field (9.4T) in vivo magnetic resonance imaging, including the contrast agent gadofluorineM as an albumin-binding tracer...
May 14, 2018: Stroke; a Journal of Cerebral Circulation
https://www.readbyqxmd.com/read/29759739/aortic-valve-bypass-surgery-in-severe-aortic-valve-stenosis-insights-from-cardiac-and-brain-magnetic-resonance-imaging
#14
Cesare Mantini, Massimo Caulo, Daniele Marinelli, Piero Chiacchiaretta, Armando Tartaro, Antonio Raffaele Cotroneo, Gabriele Di Giammarco
OBJECTIVE: To investigate and describe the distribution of aortic and cerebral blood flow (CBF) in patients with severe valvular aortic stenosis (AS) before and after aortic valve bypass (AVB) surgery. METHODS: We enrolled 10 consecutive patients who underwent AVB surgery for severe AS. Cardiovascular magnetic resonance imaging (CMR) and brain magnetic resonance imaging were performed as baseline before surgery and twice after surgery. Quantitative flow measurements were obtained using 1...
April 13, 2018: Journal of Thoracic and Cardiovascular Surgery
https://www.readbyqxmd.com/read/29757425/four-dimensional-flow-mri-analysis-of-cerebral-blood-flow-before-and-after-high-flow-extracranial-intracranial-bypass-surgery-with-internal-carotid-artery-ligation
#15
Erika Orita, Yasuo Murai, Tetsuro Sekine, Ryo Takagi, Yasuo Amano, Takahiro Ando, Kotomi Iwata, Makoto Obara, Shinichiro Kumita
BACKGROUND: The hemodynamic changes that occur after high-flow (extracranial-intracranial) EC-IC bypass surgery with internal carotid artery (ICA) ligation are not well known. OBJECTIVE: To assess blood flow changes after high-flow EC-IC bypass with ICA ligation by time-resolved 3-dimensional phase-contrast (4D Flow) magnetic resonance imaging (MRI). METHODS: We enrolled 11 patients who underwent high-flow EC-IC bypass. 4D Flow MRI was performed before and after surgery to quantify the blood flow volume (BFV) of the ipsilateral ICA (BFViICA), bypass artery (BFVbypass), contralateral ICA (BFVcICA), and basilar artery (BFVBA)...
May 11, 2018: Neurosurgery
https://www.readbyqxmd.com/read/29756881/light-induced-type-ii-band-inversion-and-quantum-anomalous-hall-state-in-monolayer-fese
#16
Z F Wang, Zhao Liu, Jinlong Yang, Feng Liu
Coupling a quantum anomalous Hall (QAH) state with a superconducting state offers an attractive approach to detect the signature alluding to a topological superconducting state [Q. L. He et al., Science 357, 294 (2017)SCIEAS0036-807510.1126/science.aag2792], but its explanation could be clouded by disorder effects in magnetic doped QAH materials. On the other hand, an antiferromagnetic (AFM) quantum spin Hall (QSH) state is identified in the well-known high-temperature 2D superconductor of monolayer FeSe [Z...
April 13, 2018: Physical Review Letters
https://www.readbyqxmd.com/read/29755315/does-post-task-declarative-learning-have-an-influence-on-early-motor-memory-consolidation-over-day-an-fmri-study
#17
Inken Rothkirch, Stephan Wolff, Nils G Margraf, Anya Pedersen, Karsten Witt
Previous studies demonstrated the influence of the post-learning period on procedural motor memory consolidation. In an early period after the acquisition, motor skills are vulnerable to modifications during wakefulness. Indeed, specific interventions such as world-list learning within this early phase of motor memory consolidation seem to enhance motor performance as an indicator for successful consolidation. This finding highlights the idea that manipulations of procedural and declarative memory systems during the early phase of memory consolidation over wakefulness may influence off-line consolidation...
2018: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/29743457/-multiple-hepatic-sclerosed-hemangiomas-that-are-difficult-to-diagnose-preoperatively-a-case-report
#18
Yu Hada, Shintaro Takaki, Yasuyuki Aisaka, Yohji Honda, Nami Mori, Keiji Tsuji, Megumu Fujiwara, Takashi Maeda, Yoshinari Furukawa, Kazuaki Chayama
An 83-year-old woman was admitted to our hospital because of a space-occupying lesion (SOL) in the liver. Enhanced computed tomography (CT) showed a nodule measuring 20mm in size in the posterosuperior segment of the right hepatic lobe (S7) and another nodule measuring 14mm in size in the anterosuperior segment of the right hepatic lobe (S8). The margins of these nodules showed faint enhancement in the arterial phase and presented as low-density areas in the equilibrium phase. The S8 SOL could not be easily identified using ultrasonography (US)...
2018: Nihon Shokakibyo Gakkai Zasshi, the Japanese Journal of Gastro-enterology
https://www.readbyqxmd.com/read/29739186/rapid-catalyst-capture-enables-metal-free-para-hydrogen-based-hyperpolarized-contrast-agents
#19
Danila A Barskiy, Lucia A Ke, Xingyang Li, Vincent Stevenson, Nevin Widarman, Hao Zhang, Ashley Truxal, Alexander Pines
Hyperpolarization techniques based on the use of para-hydrogen provide orders of magnitude signal enhancement for magnetic resonance spectroscopy and imaging. The main drawback limiting widespread applicability of para-hydrogen-based techniques in biomedicine is the presence of organometallic compounds (the polarization transfer catalysts) in solution with hyperpolarized contrast agents. These catalysts are typically complexes of platinum-group metals, and their administration in vivo should be avoided. Herein, we show how extraction of a hyperpolarized compound from an organic phase to an aqueous phase combined with a rapid (less than 10 s) Ir-based catalyst capture by metal scavenging agents can produce pure para-hydrogen-based hyperpolarized contrast agents, as demonstrated by high-resolution nuclear magnetic resonance (NMR) spectroscopy and inductively coupled plasma atomic emission spectroscopy (ICP-AES)...
May 10, 2018: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/29736847/changes-in-sensorimotor-related-thalamic-diffusion-properties-and-cerebrospinal-fluid-hydrodynamics-predict-gait-responses-to-tap-test-in-idiopathic-normal-pressure-hydrocephalus
#20
Ping-Huei Tsai, Yung-Chieh Chen, Shih-Wei Chiang, Teng-Yi Huang, Ming-Chung Chou, Hua-Shan Liu, Hsiao-Wen Chung, Giia-Sheun Peng, Hsin-I Ma, Hung-Wen Kao, Cheng-Yu Chen
OBJECTIVES: To compare diffusion tensor (DT)-derived indices from the thalamic nuclei and cerebrospinal fluid (CSF) hydrodynamic parameters for the prediction of gait responsiveness to the CSF tap test in early iNPH patients. METHODS: In this study, 22 patients with iNPH and 16 normal controls were enrolled with the approval of an institutional review board. DT imaging and phase-contrast magnetic resonance imaging were performed in patients and controls to determine DT-related indices of the sensorimotor-related thalamic nuclei and CSF hydrodynamics...
May 7, 2018: European Radiology
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