keyword
MENU ▼
Read by QxMD icon Read
search

Phase contrast Magnetic

keyword
https://www.readbyqxmd.com/read/29332078/magnetic-resonance-guided-high-intensity-focused-ultrasound-for-treating-movement-disorders
#1
Young Goo Kim, Eun Jung Kweon, Won Seok Chang, Hyun Ho Jung, Jin Woo Chang
Transcranial magnetic resonance-guided focused ultrasound (MRgFUS) surgery has recently gained favor as a novel, noninvasive alternative to conventional neurosurgery. In contrast to traditional ablative interventions, transcranial MRgFUS surgery is entirely imaging-guided and uses continuous temperature measurements at the target and surrounding tissue taken in real-time. Unlike Gamma Knife radiosurgery, MRgFUS surgery can make a lesion immediately and does not use ionizing radiation. Moreover, since no metallic device is implanted, MR imaging-based diagnosis is not restricted throughout life...
2018: Progress in Neurological Surgery
https://www.readbyqxmd.com/read/29331612/arterial-spin-labeling-cerebral-perfusion-magnetic-resonance-imaging-in-migraine-aura-an-observational-study
#2
Marc E Wolf, Shuhei Okazaki, Philipp Eisele, Christina Rossmanith, Johannes Gregori, Martin Griebe, Matthias Günther, Achim Gass, Michael G Hennerici, Kristina Szabo, Rolf Kern
BACKGROUND: Changes in cerebral perfusion during migraine with aura (MA) have been assessed mainly using dynamic susceptibility contrast (DSC) magnetic resonance perfusion imaging. A contrast agent-free method to assess these changes would be desirable. We assessed changes in cerebral perfusion during MA using arterial spin labeling (ASL) perfusion magnetic resonance imaging. METHODS: We investigated 4 patients with a standardized protocol including ASL perfusion imaging during MA (n = 2) or early headache phase (n = 2) and asymptomatic follow-up...
January 10, 2018: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
https://www.readbyqxmd.com/read/29330616/-magnetic-resonance-cisternography
#3
REVIEW
U Yilmaz
CLINICAL/METHODICAL ISSUE: Conventional MRI can be insufficient to depict certain pathologies of the cerebrospinal fluid (CSF)-filled spaces. STANDARD RADIOLOGICAL METHODS: 3-D T2-weighted sequences and phase-contrast imaging have a high sensitivity for pathologies of the CSF-filled spaces, but are susceptible to artifacts in some cases. METHODICAL INNOVATIONS/PERFORMANCE: Magnetic resonance (MR) cisternography directly depicts the connection between CSF-filled spaces...
January 12, 2018: Der Radiologe
https://www.readbyqxmd.com/read/29328239/te-polarized-design-for-metallic-slit-lenses-a-way-to-deep-subwavelength-focusing-over-a-broad-wavelength-range
#4
Yechuan Zhu, Weizheng Yuan, Wenli Li, Hao Sun, Kunlun Qi, Yiting Yu
Slit arrays based on noble metals have been widely proposed as planar transverse-magnetic (TM)-lenses, illuminated by a linearly polarized light with the polarization perpendicular to slits and implementing the focusing capability beyond the diffraction limit. However, due to intrinsic plasmonic losses, these TM-lenses cannot work efficiently in the ultraviolet wavelengths. In this Letter, taking advantage of the unique transmission through metallic slits not involving plasmonic losses, a metallic slit array with transverse-electric (TE)-polarized design is proposed, showing for the first time, to the best of our knowledge, the realization of sub-diffraction-limit focusing for ultraviolet light...
January 15, 2018: Optics Letters
https://www.readbyqxmd.com/read/29323284/phases-and-rates-of-iron-and-magnetism-changes-during-paddy-soil-development-on-calcareous-marine-sediment-and-acid-quaternary-red-clay
#5
Laiming Huang, Xiaoxu Jia, Ming'an Shao, Liumei Chen, Guangzhong Han, Ganlin Zhang
Dynamic changes in Fe oxides and magnetic properties during natural pedogenesis are well documented, but variations and controls of Fe and magnetism changes during anthropedogenesis of paddy soils strongly affected by human activities remain poorly understood. We investigated temporal changes in different Fe pools and magnetic parameters in soil profiles from two contrasting paddy soil chronosequences developed on calcareous marine sediment and acid Quaternary red clay in Southern China to understand the directions, phases and rates of Fe and magnetism evolution in Anthrosols...
January 11, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29322551/improving-parallel-imaging-by-jointly-reconstructing-multi-contrast-data
#6
Berkin Bilgic, Tae Hyung Kim, Congyu Liao, Mary Kate Manhard, Lawrence L Wald, Justin P Haldar, Kawin Setsompop
PURPOSE: To develop parallel imaging techniques that simultaneously exploit coil sensitivity encoding, image phase prior information, similarities across multiple images, and complementary k-space sampling for highly accelerated data acquisition. METHODS: We introduce joint virtual coil (JVC)-generalized autocalibrating partially parallel acquisitions (GRAPPA) to jointly reconstruct data acquired with different contrast preparations, and show its application in 2D, 3D, and simultaneous multi-slice (SMS) acquisitions...
January 10, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29317434/investigating-low-velocity-fluid-flow-in-tumors-using-convection-mri
#7
Simon Walker-Samuel, Thomas A Roberts, Rajiv Ramasawmy, Jake S Burrell, Sean P Johnson, Bernard M Siow, Simon Richardson, Miguel R Goncalves, Douglas Pendse, Simon P Robinson, R Barbara Pedley, Mark F Lythgoe
Several distinct fluid flow phenomena occur in solid tumors, including intravascular blood flow and interstitial convection. Interstitial fluid pressure is often raised in solid tumors, which can limit drug delivery. To probe low-velocity flow in tumors resulting from raised interstitial fluid pressure, we developed a novel magnetic resonance imaging (MRI) technique named convection-MRI, which uses a phase-contrast acquisition with a dual-inversion vascular nulling preparation to separate intra- and extra-vascular flow...
January 9, 2018: Cancer Research
https://www.readbyqxmd.com/read/29314853/periodic-giant-polarization-gradients-in-doped-bifeo3-thin-films
#8
Marco Campanini, Rolf Erni, Chan-Ho Yang, Ramamoorthy Ramesh, Marta D Rossell
The ultimate challenge for the development of new multiferroics with enhanced properties lies in achieving nanoscale control of the coupling between different ordering parameters. In oxide-based multiferroics, substitutional cation dopants offer the unparalleled possibility to modify both the electric and magnetic properties at a local scale. Herein it is demonstrated the formation of a dopant-controlled polar pattern in BiFeO3 leading to the spontaneous instauration of periodic polarization waves. In particular, non-polar Ca-doped rich regions act as spacers between consecutive dopant-depleted regions displaying coupled ferroelectric states...
January 9, 2018: Nano Letters
https://www.readbyqxmd.com/read/29313241/cd146-positive-human-dental-pulp-stem-cells-promote-regeneration-of-dentin-pulp-like-structures
#9
Mikiko Matsui, Tomoko Kobayashi, Takeo W Tsutsui
CD146 and STRO-1 are endothelial biomarkers that are co-expressed on the cellular membranes of blood vessels within human dental pulp tissue. This study characterized the percentage of dentin-like structures produced by CD146-positive (CD146+) human dental pulp stem cells (DPSCs), compared with their CD146-negative (CD146-) counterparts. DPSC populations were enriched using magnetic-activated cell sorting (MACS), yielding CD146+ and CD146- cells, as well as mixtures composed of 25% CD146+ cells and 75% CD146- cells (CD146+/-)...
January 8, 2018: Human Cell
https://www.readbyqxmd.com/read/29310945/image-based-computational-assessment-of-vascular-wall-mechanics-and-hemodynamics-in-pulmonary-arterial-hypertension-patients
#10
Byron A Zambrano, Nathan A McLean, Xiaodan Zhao, Ju-Le Tan, Liang Zhong, C Alberto Figueroa, Lik Chuan Lee, Seungik Baek
Pulmonary arterial hypertension (PAH) is a disease characterized by an elevated pulmonary arterial (PA) pressure. While several computational hemodynamic models of the pulmonary vasculature have been developed to understand PAH, they are lacking in some aspects, such as the vessel wall deformation and its lack of calibration against measurements in humans. Here, we describe a computational modeling framework that addresses these limitations. Specifically, computational models describing the coupling of hemodynamics and vessel wall mechanics in the pulmonary vasculature of a PAH patient and a normal subject were developed...
December 27, 2017: Journal of Biomechanics
https://www.readbyqxmd.com/read/29300915/in-vivo-identification-of-thick-thin-and-pale-stripes-of-macaque-area-v2-using-submillimeter-resolution-f-mri-at-3-t
#11
Xiaolian Li, Qi Zhu, Thomas Janssens, John T Arsenault, Wim Vanduffel
Primate area V2 contains a repetitive pattern of thick, thin and pale cytochrome oxidase stripes that are characterized by largely discrete in- and output channels, as well as differences in function, and myelo- and cytoarchitecture. Stripes have been identified mainly using microscope-based imaging of tiny portions of superficially located V2, or by postmortem methods, hence, the quest for (quasi) noninvasive tools to study these mesoscale functional units. Only recently, stripe-like V2 patterns have been demonstrated in humans with high-field (functional) magnetic resonance imaging (f)MRI, but in both such studies only 2 stripe compartments could be identified...
December 28, 2017: Cerebral Cortex
https://www.readbyqxmd.com/read/29300851/magnetic-resonance-imaging-predicts-histopathologic-composition-of-ileal-crohn-s-disease
#12
Mathilde Wagner, Huaibin Mabel Ko, Manjil Chatterji, Cecilia Besa, Joana Torres, Xiaofei Zhang, Hinaben Panchal, Stefanie Hectors, Judy Cho, Jean-Frederic Colombel, Noam Harpaz, Bachir Taouli
Background and aims: Recently, smooth muscle hypertrophy has been suggested to be a contributor in small bowel lesions secondary to Crohn's disease (CD), in addition to inflammation and fibrosis. Here, we assess the value of magnetic resonance imaging (MRI) for the characterization of histopathologic tissue composition of small bowel CD, including inflammation, fibrosis and smooth muscle hypertrophy. Methods: 35 consecutive patients (M/F 17/18, mean age 33y) with ileal CD who underwent small bowel resection (for stricture in 27 patients) and a preoperative contrast-enhanced MRI exam within one month before surgery were retrospectively included...
January 2, 2018: Journal of Crohn's & Colitis
https://www.readbyqxmd.com/read/29300738/hemodynamics-in-a-giant-intracranial-aneurysm-characterized-by-in-vitro-4d-flow-mri
#13
Omid Amili, Daniele Schiavazzi, Sean Moen, Bharathi Jagadeesan, Pierre-François Van de Moortele, Filippo Coletti
Experimental and computational data suggest that hemodynamics play a critical role in the development, growth, and rupture of cerebral aneurysms. The flow structure, especially in aneurysms with a large sac, is highly complex and three-dimensional. Therefore, volumetric and time-resolved measurements of the flow properties are crucial to fully characterize the hemodynamics. In this study, phase-contrast Magnetic Resonance Imaging is used to assess the fluid dynamics inside a 3D-printed replica of a giant intracranial aneurysm, whose hemodynamics was previously simulated by multiple research groups...
2018: PloS One
https://www.readbyqxmd.com/read/29290484/pulsed-wave-doppler-recordings-in-the-proximal-descending-aorta-in-patients-with-chronic-aortic-regurgitation-insights-from-cardiovascular-magnetic-resonance
#14
Odd Bech-Hanssen, Christian L Polte, Frida Svensson, Åse A Johnsson, Kerstin M Lagerstrand, Ulf Cederbom, Sinsia A Gao
BACKGROUND: The pulsed-wave Doppler recording in the descending aorta (PWDDAO) is one of the parameters used in grading aortic regurgitation (AR) severity. The aim of the present study was to investigate the assessment of chronic AR by PWDDAO with insights from cardiovascular magnetic resonance (CMR). METHODS: This prospective study comprised 40 patients investigated with echocardiography and CMR within 4 hours either prior to valve surgery (n = 23) or as part of their follow-up (n = 17) due to moderate or severe AR...
December 29, 2017: Journal of the American Society of Echocardiography
https://www.readbyqxmd.com/read/29288036/a-study-of-mri-gradient-echo-signals-from-discrete-magnetic-particles-with-considerations-of-several-parameters-in-simulations
#15
Paul Kokeny, Yu-Chung N Cheng, He Xie
Modeling MRI signal behaviors in the presence of discrete magnetic particles is important, as magnetic particles appear in nanoparticle labeled cells, contrast agents, and other biological forms of iron. Currently, many models that take into account the discrete particle nature in a system have been used to predict magnitude signal decays in the form of R2* or R2' from one single voxel. Little work has been done for predicting phase signals. In addition, most calculations of phase signals rely on the assumption that a system containing discrete particles behaves as a continuous medium...
December 26, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/29286815/quantum-spin-ice-under-a-111-magnetic-field-from-pyrochlore-to-kagome
#16
Troels Arnfred Bojesen, Shigeki Onoda
Quantum spin ice, modeled for magnetic rare-earth pyrochlores, has attracted great interest for hosting a U(1) quantum spin liquid, which involves spin-ice monopoles as gapped deconfined spinons, as well as gapless excitations analogous to photons. However, the global phase diagram under a [111] magnetic field remains open. Here we uncover by means of unbiased quantum Monte Carlo simulations that a supersolid of monopoles, showing both a superfluidity and a partial ionization, intervenes the kagome spin ice and a fully ionized monopole insulator, in contrast to classical spin ice where a direct discontinuous phase transition takes place...
December 1, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/29279525/planimetry-of-the-orifice-area-in-aortic-valve-stenosis-using-phase-contrast-cardiac-magnetic-resonance-imaging
#17
Hajime Abe, Nobuo Iguchi, Yuko Utanohara, Kaori Takada, Yasuki Hen, Haruhiko Machida, Norihiko Takeda, Tetsuya Sumiyoshi
Manual planimetry is a well-established method using transesophageal echocardiography (TEE) to assess the severity of aortic stenosis (AS). TEE, however, is a less than optimal approach in patients with calcified valves. Even when using cine-cardiac magnetic resonance (CMR), it is often difficult to evaluate the true border of the aortic orifice because of jet turbulence. With phase-contrast sequences of CMR, high flow signals at the aortic orifice can be clearly visualized, even in cases with severe calcification and jet turbulence...
December 27, 2017: International Heart Journal
https://www.readbyqxmd.com/read/29279500/hepatic-angiomyolipoma-staining-in-the-post-vascular-phase-of-contrast-enhanced-ultrasound-due-to-the-presence-of-macrophages
#18
Kei Endo, Hidekatsu Kuroda, Keisuke Kakisaka, Takayoshi Oikawa, Kei Sawara, Kazuyuki Ishida, Tamotsu Sugai, Yasuhiro Takikawa
A 47-year-old Japanese man was referred to hospital after the detection of a liver tumor. Dynamic computed tomography and Gd-EOB-DTPA-enhanced magnetic resonance imaging were consistent with a diagnosis of hepatocellular carcinoma (HCC). No perfusion defect was observed in the post-vascular phase of contrast-enhanced ultrasound (CEUS). Histopathological staining of the tumor cells was positive for antibodies against HMB-45 and CD68, confirming the diagnosis of hepatic angiomyolipoma (HAML). These findings indicated the presence of macrophages in HAML...
December 27, 2017: Internal Medicine
https://www.readbyqxmd.com/read/29274251/quantitative-flow-imaging-in-human-umbilical-vessels-in-utero-using-nongated-2d-phase-contrast-mri
#19
Uday Krishnamurthy, Brijesh K Yadav, Pavan K Jella, Ewart Mark Haacke, Edgar Hernandez-Andrade, Swati Mody, Lami Yeo, Sonia S Hassan, Roberto Romero, Jaladhar Neelavalli
BACKGROUND: Volumetric assessment of afferent blood flow rate provides a measure of global organ perfusion. Phase-contrast magnetic resonance imaging (PCMRI) is a reliable tool for volumetric flow quantification, but given the challenges with motion and lack of physiologic gating signal, such studies, in vivo on the human placenta, are scant. PURPOSE: To evaluate and apply a nongated (ng) PCMRI technique for quantifying blood flow rates in utero in umbilical vessels...
December 23, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/29273948/icp-curve-morphology-and-intracranial-flow-volume-changes-a-simultaneous-icp-and-cine-phase-contrast-mri-study-in-humans
#20
Mårten Unnerbäck, Johnny T Ottesen, Peter Reinstrup
BACKGROUND: The intracranial pressure (ICP) curve with its different peaks has been extensively studied, but the exact physiological mechanisms behind its morphology are still not fully understood. Both intracranial volume change (ΔICV) and transmission of the arterial blood pressure have been proposed to shape the ICP curve. This study tested the hypothesis that the ICP curve correlates to intracranial volume changes. METHODS: Cine phase contrast magnetic resonance imaging (MRI) examinations were performed in neuro-intensive care patients with simultaneous ICP monitoring...
December 22, 2017: Acta Neurochirurgica
keyword
keyword
112495
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"