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https://www.readbyqxmd.com/read/28547666/effects-of-caffeine-intake-prior-to-stress-cardiac-magnetic-resonance-perfusion-imaging-on-regadenoson-versus-adenosine-induced-hyperemia-as-measured-by-t1-mapping
#1
R van Dijk, D Kuijpers, T A M Kaandorp, P R M van Dijkman, R Vliegenthart, P van der Harst, M Oudkerk
The antagonistic effects of caffeine on adenosine receptors are a possible cause of false-negative stress perfusion imaging. The purpose of this study was to determine the effects of coffee intake <4 h prior to stress perfusion cardiac magnetic resonance imaging (CMR) in regadenoson- versus adenosine-induced hyperemia as measured with T1-mapping. 98 consecutive patients with suspected coronary artery disease referred for either adenosine or regadenoson perfusion CMR were included in this analysis. Twenty-four patients reported coffee consumption <4 h before CMR (15 patients with adenosine, and 9 patients with regadenoson); 74 patients reported no coffee intake (50 patients with adenosine, and 24 patients with regadenoson)...
May 25, 2017: International Journal of Cardiovascular Imaging
https://www.readbyqxmd.com/read/28544256/intrinsic-functional-connectivity-alterations-in-progressive-supranuclear-palsy-differential-effects-in-frontal-cortex-motor-and-midbrain-networks
#2
Johannes Rosskopf, Martin Gorges, Hans-Peter Müller, Dorothée Lulé, Ingo Uttner, Albert C Ludolph, Elmar Pinkhardt, Freimut D Juengling, Jan Kassubek
BACKGROUND: The topography of functional network changes in progressive supranuclear palsy can be mapped by intrinsic functional connectivity MRI. The objective of this study was to study functional connectivity and its clinical and behavioral correlates in dedicated networks comprising the cognition-related default mode and the motor and midbrain functional networks in patients with PSP. METHODS: Whole-brain-based "resting-state" functional MRI and high-resolution T1-weighted magnetic resonance imaging data together with neuropsychological and video-oculographic data from 34 PSP patients (22 with Richardson subtype and 12 with parkinsonian subtype) and 35 matched healthy controls were subjected to network-based functional connectivity and voxel-based morphometry analysis...
May 22, 2017: Movement Disorders: Official Journal of the Movement Disorder Society
https://www.readbyqxmd.com/read/28543430/planet-an-ellipse-fitting-approach-for-simultaneous-t1-and-t2-mapping-using-phase-cycled-balanced-steady-state-free-precession
#3
Yulia Shcherbakova, Cornelis A T van den Berg, Chrit T W Moonen, Lambertus W Bartels
PURPOSE: To demonstrate the feasibility of a novel, ellipse fitting approach, named PLANET, for simultaneous estimation of relaxation times T1 and T2 from a single 3D phase-cycled balanced steady-state free precession (bSSFP) sequence. METHODS: A method is presented in which the elliptical signal model is used to describe the phase-cycled bSSFP steady-state signal. The fitting of the model to the acquired data is reformulated into a linear convex problem, which is solved directly by a linear least squares method, specific to ellipses...
May 22, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28536501/multimodal-memprage-flair-and-formula-see-text-segmentation-to-resolve-dura-and-vessels-from-cortical-gray-matter
#4
Roberto Viviani, Eberhard D Pracht, Daniel Brenner, Petra Beschoner, Julia C Stingl, Tony Stöcker
While widely in use in automated segmentation approaches for the detection of group differences or of changes associated with continuous predictors in gray matter volume, T1-weighted images are known to represent dura and cortical vessels with signal intensities similar to those of gray matter. By considering multiple signal sources at once, multimodal segmentation approaches may be able to resolve these different tissue classes and address this potential confound. We explored here the simultaneous use of FLAIR and apparent transverse relaxation rates (a signal related to [Formula: see text] relaxation maps and having similar contrast) with T1-weighted images...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28533982/lid-opening-and-conformational-stability-of-t1-lipase-is-mediated-by-increasing-chain-length-polar-solvents
#5
Jonathan Maiangwa, Mohd Shukuri Mohamad Ali, Abu Bakar Salleh, Raja Noor Zaliha Raja Abd Rahman, Yahaya M Normi, Fairolniza Mohd Shariff, Thean Chor Leow
The dynamics and conformational landscape of proteins in organic solvents are events of potential interest in nonaqueous process catalysis. Conformational changes, folding transitions, and stability often correspond to structural rearrangements that alter contacts between solvent molecules and amino acid residues. However, in nonaqueous enzymology, organic solvents limit stability and further application of proteins. In the present study, molecular dynamics (MD) of a thermostable Geobacillus zalihae T1 lipase was performed in different chain length polar organic solvents (methanol, ethanol, propanol, butanol, and pentanol) and water mixture systems to a concentration of 50%...
2017: PeerJ
https://www.readbyqxmd.com/read/28533636/comparison-of-spect-ct-and-planar-lympho-scintigraphy-in-sentinel-node-biopsies-of-oral-cavity-squamous-cell-carcinomas
#6
Piyush Chandra, Sanket Dhake, Sneha Shah, Archi Agrawal, Nilendu Purandare, Venkatesh Rangarajan
INTRODUCTION: Evidence supporting the use of Sentinel node biopsy (SNB) for nodal staging of early oral squamous cell carcinomas (OSCC) appears to be very promising. Pre-operative lymphatic mapping using planar lymphoscinitigraphy (PL) with or without SPECT/CT in the SNB procedure is useful in sentinel node localization and for planning appropriate surgery. Recently, a large prospective multi-centric study evaluating SNB in cutaneous melanoma, breast and pelvic malignancies, demonstrated that adding SPECT to PL leads to surgical adjustments in a considerable number of patients...
April 2017: Indian Journal of Nuclear Medicine: IJNM: the Official Journal of the Society of Nuclear Medicine, India
https://www.readbyqxmd.com/read/28526235/zero-echo-time-mri-only-treatment-planning-for-radiation-therapy-of-brain-tumors-after-resection
#7
C Boydev, B Demol, D Pasquier, H Saint-Jalmes, G Delpon, N Reynaert
Using magnetic resonance imaging (MRI) as the sole imaging modality for patient modeling in radiation therapy (RT) is a challenging task due to the need to derive electron density information from MRI and construct a so-called pseudo-computed tomography (pCT) image. We have previously published a new method to derive pCT images from head T1-weighted (T1-w) MR images using a single-atlas propagation scheme followed by a post hoc correction of the mapped CT numbers using local intensity information. The purpose of this study was to investigate the performance of our method with head zero echo time (ZTE) MR images...
May 16, 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28524543/snapshot-whole-brain-t1-relaxometry-using-steady-state-prepared-spiral-multislice-variable-flip-angle-imaging
#8
Rahel Heule, Josef Pfeuffer, Oliver Bieri
PURPOSE: Variable flip angle (VFA) imaging is widely used for whole-brain T1 quantification. Because of the requirement to acquire at least two sets of MR images at different flip angles, VFA relaxometry is relatively slow. Here, whole-brain VFA T1 mapping at 1.5 T is accelerated by using efficient spiral non-Cartesian imaging METHODS: To quantify T1 in the human brain, radiofrequency spoiled gradient-echo imaging is performed at two optimized flip angles using an interleaved 2D multislice sequence with high spoiling efficiency...
May 19, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28523247/effects-of-a-new-type-of-clear-overlay-retainer-on-occlusal-contacts
#9
Kyoung Yeon Kim, Hyo-Won Ahn, Seong-Hun Kim, Gerald Nelson
The popularity of clear overlay retainers (CORs) has increased recently because of their advantages such as better esthetics, cost effectiveness, easy fabrication, and good compliance. However, a deficiency in posterior occlusal settling is a reported limitation of CORs. The aim of this study was to evaluate the posterior occlusal contact changes in a new type of clear orthodontic retainer called Oral-treaper (OTP), which consists of three layers and has stronger mechanical characteristics than do conventional retainers...
May 2017: Korean Journal of Orthodontics
https://www.readbyqxmd.com/read/28522755/increased-left-ventricular-extracellular-volume-and-enhanced-twist-function-in-type-1-diabetic-individuals
#10
Zainisha Vasanji, Ronald J Sigal, Neil Derek Eves, Debra L Isaac, Matthias G Friedrich, Kelvin Chow, Richard B Thompson
Individuals with type 1 diabetes (T1D) characteristically have high glycemic levels that over time can result in reactive fibrosis and abnormalities in myocardial function. T1 mapping with magnetic resonance imaging (MRI) can estimate the extent of reactive fibrosis by measurement of the extracellular volume fraction (ECV). The extent of alterations in the ECV and associated changes in left ventricular (LV) function and morphology in individuals with T1D is unknown. Fourteen individuals with long-term T1D and fourteen sex-, age-, and body mass index-matched controls without diabetes underwent MRI measurement of myocardial T1 and ECV values as well as LV function and morphology...
May 18, 2017: Journal of Applied Physiology
https://www.readbyqxmd.com/read/28522663/the-use-of-noncontrast-quantitative-mri-to-detect-gadolinium-enhancing-multiple-sclerosis-brain-lesions-a-systematic-review-and-meta-analysis
#11
A Gupta, K Al-Dasuqi, F Xia, G Askin, Y Zhao, D Delgado, Y Wang
BACKGROUND: Concerns have arisen about the long-term health effects of repeat gadolinium injections in patients with multiple sclerosis and the incomplete characterization of MS lesion pathophysiology that results from relying on enhancement characteristics alone. PURPOSE: Our aim was to perform a systematic review and meta-analysis analyzing whether noncontrast MR imaging biomarkers can distinguish enhancing and nonenhancing brain MS lesions. DATA SOURCES: Our sources were Ovid MEDLINE, Ovid Embase, and the Cochrane data base from inception to August 2016...
May 18, 2017: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/28520577/the-effects-of-remifentanil-on-hemodynamic-response-attenuation-after-electroconvulsive-therapy-under-sevoflurane-anesthesia
#12
Feray Erdil, Ulku Ozgul, Mukadder Şanli, Gülay Kayhan, Cemil Çolak, Mahmut Durmuş
PURPOSE: We evaluated the effects of a single loading dose of remifentanil (1 μg/kg) administered as an adjunct to sevoflurane, on the duration of seizure activity, recovery times, and hemodynamic profiles, during electroconvulsive therapy. METHODS: The patients were randomly allocated to receive sevoflurane-saline (Group SS) or sevoflurane-remifentanil (Group SR). Sevoflurane (8%) was initiated for anesthesia induction in both groups until loss of consciousness was achieved...
May 18, 2017: Journal of ECT
https://www.readbyqxmd.com/read/28520198/dynamic-and-steady-state-oxygen-dependent-lung-relaxometry-using-inversion-recovery-ultra-fast-steady-state-free-precession-imaging-at-1-5-t
#13
Grzegorz Bauman, Orso Pusterla, Francesco Santini, Oliver Bieri
PURPOSE: To demonstrate the feasibility of oxygen-dependent relaxometry in human lung using an inversion recovery ultra-fast steady-state free precession (IR-ufSSFP) technique. METHODS: Electrocardiogram-triggered pulmonary relaxometry with IR-ufSSFP was performed in 7 healthy human subjects at 1.5 T. The data were acquired under both normoxic and hyperoxic conditions. In a single breath-hold of less than 9 seconds, 30 transient state IR-ufSSFP images were acquired, yielding longitudinal (T1) and transversal (T2) relaxometry parameter maps using voxel-wise nonlinear fitting...
May 18, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28515413/magnetic-susceptibility-changes-in-the-basal-ganglia-and-brain-stem-of-patients-with-wilson-s-disease-evaluation-with-quantitative-susceptibility-mapping
#14
Selim Doganay, Kazim Gumus, Gonca Koc, Ayse Kacar Bayram, Mehmet Sait Dogan, Duran Arslan, Hakan Gumus, Sureyya Burcu Gorkem, Saliha Ciraci, Halil Ibrahim Serin, Abdulhakim Coskun
OBJECTIVES: Wilson's disease (WD) is characterized with the accumulation of copper in the liver and brain. The objective of this study is to quantitatively measure the susceptibility changes of basal ganglia and brain stem of pediatric patients with neurological WD using quantitative susceptibility mapping (QSM) in comparison to healthy controls. METHODS: Eleven patients with neurological WD (mean age 15 ± 3.3 years, range 10-22 years) and 14 age-matched controls were prospectively recruited...
May 18, 2017: Magnetic Resonance in Medical Sciences: MRMS
https://www.readbyqxmd.com/read/28515409/saturation-recovery-myocardial-t1-mapping-with-a-composite-radiofrequency-pulse-on-a-3t-mr-imaging-system
#15
Kosuke Morita, Seitaro Oda, Daisuke Utsunomiya, Takeshi Nakaura, Takatoshi Matsubara, Makoto Goto, Tomoyuki Okuaki, Hideaki Yuki, Yasunori Nagayama, Masafumi Kidoh, Kenichiro Hirata, Yuij Iyama, Narumi Taguchi, Masahiro Hatemura, Masahiro Hashida, Yasuyuki Yamashita
PURPOSE: To evaluate the effect of a composite radiofrequency (RF) pulse on saturation recovery (SR) myocardial T1 mapping using a 3T magnetic resonance (MR) system. MATERIALS AND METHODS: Phantom and in vivo studies were performed with a clinical 3T MR scanner. Accuracy and reproducibility of the SR T1 mapping using conventional and composite RF pulses were first compared in phantom experiments. An in vivo study was performed of 10 healthy volunteers who were imaged with conventional and composite RF pulse methods twice each...
May 18, 2017: Magnetic Resonance in Medical Sciences: MRMS
https://www.readbyqxmd.com/read/28514284/comparison-in-anesthetic-effects-of-propofol-among-patients-with-different-abo-blood-groups
#16
Yiri Du, Haixia Shi, Jianshe Yu
Our study was aimed to investigate anesthetic effects of propofol in patients with different blood groups.A total of 72 participants were enrolled from patients arranged for surgeries of cholecystectomy, tonsillectomy, and spinal operation. Each blood group (A, B, AB, and O) contained 18 participants. Mean arterial pressure (MAP), heart rate (HR), and bispectral index (BIS) were assayed with Philips monitor. These indexes were observed before propofol anesthesia (T0), and then were recorded when concentration of propofol was 1 μg/mL (T1), 2 μg/mL (T2), 3 μg/mL (T3), and 4 μg/mL (T4)...
May 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28512761/deconstructing-white-matter-connectivity-of-human-amygdala-nuclei-with-thalamus-and-cortex-subdivisions-in-vivo
#17
Aslan Abivardi, Dominik R Bach
Structural alterations in long-range amygdala connections are proposed to crucially underlie several neuropsychiatric disorders. While progress has been made in elucidating the function of these connections, our understanding of their structure in humans remains sparse and non-systematic. Harnessing diffusion-weighted imaging and probabilistic tractography in humans, we investigate connections between two main amygdala nucleus groups, thalamic nuclei, and cortex. We first parcellated amygdala into deep (basolateral) and superficial (centrocortical) nucleus groups, and thalamus into six subregions, using previously established protocols based on connectivity...
May 17, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28509903/gray-matter-anomalies-in-pedophiles-with-and-without-a-history-of-child-sexual-offending
#18
B Schiffer, T Amelung, A Pohl, C Kaergel, G Tenbergen, H Gerwinn, S Mohnke, C Massau, W Matthias, S Weiß, V Marr, K M Beier, M Walter, J Ponseti, T H C Krüger, K Schiltz, H Walter
Pedophilia is a psychiatric disorder that is inter-related with but distinct from child sexual offending (CSO). Neural alterations reportedly contribute to both pedophilia and CSO, but until now, no study has distinguished the brain structural anomalies associated with pedophilia from those specifically associated with CSO in pedophilic men. Using high-resolution T1-weighted brain images and voxel-based morphometry, we analyzed the gray matter (GM) volume of the following 219 men recruited at four acquisition sites in Germany: 58 pedophiles with a history of CSO, 60 pedophiles without any history of CSO and 101 non-pedophilic, non-offending controls to control for the effects of age, education level, verbal IQ, sexual orientation and the acquisition site...
May 16, 2017: Translational Psychiatry
https://www.readbyqxmd.com/read/28506023/optimization-method-of-mri-scan-parameters-of-a-double-inversion-recovery-sequence-using-a-t1-map-and-a-developed-analysis-algorithm
#19
Norio Hayashi, Kazuma Yarita, Kozue Sakata, Shunichi Motegi, Hiroyuki Nagase, Kouichi Ujita, Akio Ogura, Toshihiro Ogura, Takehiro Shimada, Yoshito Tsushima
BACKGROUND: Optimizing scan parameters for double inversion recovery (DIR) sequences remains difficult. OBJECTIVE: To evaluate a new method for optimizing DIR sequence scan parameters using T1 mapping and a newly developed analysis algorithm. METHODS: Twelve healthy volunteers underwent T1 mapping and DIR magnetic resonance imaging. The following steps were used for image optimization including: 1) measurement of gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) T1 values to create a T1 map; 2) calculation of optimized scan parameters by using a developed analysis algorithm; 3) performance assessment of DIR magnetic resonance imaging by using the calculated optimized imaging parameters...
May 6, 2017: Journal of X-ray Science and Technology
https://www.readbyqxmd.com/read/28503732/imaging-short-lived-reactive-oxygen-species-ros-with-endogenous-contrast-mri
#20
Rong-Wen Tain, Alessandro M Scotti, Weiguo Li, Xiaohong Joe Zhou, Kejia Cai
PURPOSE: To characterize the relaxation properties of reactive oxygen species (ROS) for the development of endogenous ROS contrast magnetic resonance imaging (MRI). MATERIALS AND METHODS: ROS-producing phantoms and animal models were imaged at 9.4T MRI to obtain T1 and T2 maps. Egg white samples treated with varied concentrations of hydrogen peroxide (H2 O2 ) were used to evaluate the effect of produced ROS in T1 and T2 for up to 4 hours. pH and temperature changes due to H2 O2 treatment in egg white were also monitored...
May 15, 2017: Journal of Magnetic Resonance Imaging: JMRI
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