Filters








898 Hits in 6.6 sec

Fast Bias Field Correction For 9.4 Tesla Magnetic Resonance Imaging

Meritxell Bach Cuadra, Rolf Gruetter, Nathalie Just, Nicolas Kunz, Xavier Peña Piña, Jean-Philippe Thiran
2008 Zenodo  
It has also a fundamental importance in preclinical research [1] , which recently has further evolved towards different magnetic fields: 9.4 and 14.1 Tesla (T) for animals, while human magnets can be  ...  In this work the problem of bias correction at high magnetic field is addressed.  ... 
doi:10.5281/zenodo.41127 fatcat:qy7xhdi4ujb7dfk7qpuxwytziu

Survey of water proton longitudinal relaxation in liver in vivo

John Charles Waterton
2021 Magnetic Resonance Materials in Physics, Biology and Medicine  
Seventeen field strengths were included between 0.04 T and 9.4 T.  ...  Between-study variation also incorporates between-population variation, together with bias from interactions between methodology and physiology.  ...  Gilligan LA, Dillman JR, Tkach JA, Xanthakos SA, Gill JK, Trout AT (2019) Magnetic resonance imaging T1 relaxation times for the liver, pancreas and spleen in healthy children at 1.5 and 3 tesla.  ... 
doi:10.1007/s10334-021-00928-x pmid:33978944 pmcid:PMC8578172 fatcat:pvrsrdgdwff4nfisseo3puj2ga

PCr/ATP ratio mapping of the human head by simultaneously imaging of multiple spectral peaks with interleaved excitations and flexible twisted projection imaging readout trajectories at 9.4 T

Aiming Lu, Ian C. Atkinson, Xiaohong Joe Zhou, Keith R. Thulborn
2012 Magnetic Resonance in Medicine  
We report herein the results of combining the increased detection sensitivity of an ultra-high field 9.4 Tesla scanner designed for human imaging with a new pulse sequence termed Simultaneously Imaging  ...  of Multiple Spectral Peaks with InterLeaved Excitations and flexible Twisted Projection Imaging Readout Trajectories (SIMPLE-TPI) to rapidly sample multiple resonances in the 31 P spectrum.  ...  With the increased sensitivity provided by the 9.4 Tesla (T) magnet (11) , we demonstrate the feasibility of using a novel acquisition strategy termed SIMPLE-TPI to sample PCr and γ-ATP signals over the  ... 
doi:10.1002/mrm.24281 pmid:22529019 pmcid:PMC4552734 fatcat:q6eqqpiqt5hfjl6c775lsyhw7u

Reproducibility of Neurite Orientation Dispersion and Density Imaging (NODDI) in rats at 9.4 Tesla

Patrick McCunn, Kyle M. Gilbert, Peter Zeman, Alex X. Li, Michael J. Strong, Ali R. Khan, Robert Bartha, Aaron Jon Newman
2019 PLoS ONE  
The purpose of this study was to determine the reproducibility of NODDI in the rat brain at 9.4 Tesla.  ...  Neurite Orientation Dispersion and Density Imaging (NODDI) is a diffusion MRI (dMRI) technique used to characterize tissue microstructure by compartmental modelling of neural water fractions.  ...  a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 Introduction Diffusion weighted magnetic resonance imaging (dMRI) is a powerful magnetic resonance modality that provides a wealth of information  ... 
doi:10.1371/journal.pone.0215974 pmid:31034490 pmcid:PMC6488046 fatcat:ak5ojxvswnfwnlfrquclu7jx3a

3D 31 P MRSI of the human brain at 9.4 Tesla: Optimization and quantitative analysis of metabolic images

Loreen Ruhm, Johanna Dorst, Nikolai Avdievitch, Andrew Martin Wright, Anke Henning
2021 Magnetic Resonance in Medicine  
For SNR optimization, the nuclear Overhauser enhancement at 9.4 Tesla was investigated.  ...  With an ultrahigh field strength B0 = 9.4 Tesla, 31 P MRSI moves further toward quantitative metabolic imaging, and subtle differences in concentrations between different tissue types can be detected.  ...  It allowed for a fast (approximately 3 min) calibration of the phosphorus transmit field, which enabled an individual 31 P B + 1 calibration for each volunteer.  ... 
doi:10.1002/mrm.28891 pmid:34219281 fatcat:idad24gnkzacng5wzwashkzhea

Comparison ofT1relaxation times of the neurochemical profile in rat brain at 9.4 tesla and 14.1 tesla

Cristina Cudalbu, Vladimír Mlynárik, Lijing Xin, Rolf Gruetter
2009 Magnetic Resonance in Medicine  
Magn Reson Med 62:862-867, 2009.  ...  Furthermore, the similarity of T 1 among the metabolites (ϳ1.5 s) suggests that T 1 relaxation time corrections for metabolite quantification are likely to be similar when using rapid pulsing conditions  ...  The aspartyl resonance of NAA (NAA*) and methylene resonance of CrϩPCr had shorter T 1 (ϳ1.2 s for NAA* and ϳ1.1 s for CrϩPCr* at both magnetic fields) than the corresponding methyl resonances.  ... 
doi:10.1002/mrm.22022 pmid:19645007 fatcat:6i7jd6kf2zeoxjmgaogkztikpu

Test-retest reproducibility of in vivo magnetization transfer ratio and saturation index in mice at 9.4 Tesla [article]

Naila Rahman, Jordan Ramnarine, Kathy Xu, Arthur Brown, Corey A Baron
2021 bioRxiv   pre-print
Field Strength/Sequence: Magnetization Transfer Imaging at 9.4 T. Assessment: All mice were scanned at two timepoints (5 days apart).  ...  Keywords: magnetization transfer ratio, magnetization transfer saturation, reproducibility, preclinical rodent imaging  ...  In vivo MRI In vivo magnetic resonance imaging (MRI) experiments were performed on a 9.4 Tesla (T) Bruker small animal scanner equipped with a gradient coil set of 1 T/m strength (slew rate = 4100 T/m/  ... 
doi:10.1101/2021.12.10.472129 fatcat:u5gebsk7mng3bbkq4akesl3aay

Comparison of feature tracking, fast‐SENC, and myocardial tagging for global and segmental left ventricular strain

Paulius Bucius, Jennifer Erley, Radu Tanacli, Victoria Zieschang, Sorin Giusca, Grigorious Korosoglou, Henning Steen, Christian Stehning, Burkert Pieske, Elisabeth Pieske‐Kraigher, Andreas Schuster, Tomas Lapinskas (+1 others)
2019 ESC Heart Failure  
A multitude of cardiac magnetic resonance (CMR) techniques are used for myocardial strain assessment; however, studies comparing them are limited.  ...  Bland-Altman analysis revealed considerable inter-technique biases for GLS (FT vs. fast-SENC 3.71%; FT vs. TAG 8.35%; and TAG vs. fast-SENC 4.54%) and GCS (FT vs. fast-SENC 2.15%; FT vs.  ...  Cardiovascular magnetic resonance acquisition Cardiovascular magnetic resonance scans were performed on a 1.5 Tesla MRI scanner (Achieva, Philips Healthcare, Best, the Netherlands).  ... 
doi:10.1002/ehf2.12576 pmid:31800152 fatcat:xs4wcctumnepfkkzieo6dvnzwm

Advanced methods for quantification of infarct size in mice using three-dimensional high-field late gadolinium enhancement MRI

Steffen Bohl, Craig A. Lygate, Hannah Barnes, Debra Medway, Lee-Anne Stork, Jeanette Schulz-Menger, Stefan Neubauer, Jurgen E. Schneider
2009 American Journal of Physiology. Heart and Circulatory Physiology  
Myocardial T1 relaxation was quantified at 9.4 Tesla in five mice, and reproducibility was tested by repeat imaging after 5 days.  ...  This method is particularly suited to studies requiring early quantification of initial infarct size, for example, to measure damage before intervention with stem cells. murine cardiac magnetic resonance  ...  The British Heart Foundation Experimental Magnetic Resonance Unit is funded by the British Heart Foundation.  ... 
doi:10.1152/ajpheart.01294.2008 pmid:19218501 pmcid:PMC2670705 fatcat:e4zca3r5hfhvhjibaly6zwrksu

Sub-millimetre resolution laminar fMRI using Arterial Spin Labelling in humans at 7 T

Sriranga Kashyap, Dimo Ivanov, Martin Havlicek, Laurentius Huber, Benedikt A Poser, Kâmil Uludağ
2021 PLoS ONE  
Laminar fMRI at ultra-high magnetic field strength is typically carried out using the Blood Oxygenation Level-Dependent (BOLD) contrast.  ...  However, ASL for laminar imaging is challenging due to the lower SNR of the perfusion signal and higher RF power deposition i.e., specific absorption rate (SAR) of ASL sequences.  ...  MP2RAGE, a self bias-field corrected sequence for improved segmentation and T1-mapping at high field. Neuro-Image. 2010; 49(2):1271-1281. https://doi.org/10.1016/j.neuroimage.2009.10.002 55. Kim SG.  ... 
doi:10.1371/journal.pone.0250504 pmid:33901230 pmcid:PMC8075193 fatcat:4u24nbmpf5cjroxycsr2i7xuwi

Transverse water relaxation in whole blood and erythrocytes at 3T, 7T, 9.4T, 11.7T and 16.4T; determination of intracellular hemoglobin and extracellular albumin relaxivities

Ksenija Grgac, Wenbo Li, Alan Huang, Qin Qin, Peter C.M. van Zijl
2017 Magnetic Resonance Imaging  
R 2CPMG values of blood plasma, lysed packed erythrocytes, lysed plasma/erythrocyte mixtures, and whole blood at 3 T, 7 T, 9.4 T, 11.7 T and 16.4 T were measured as a function of hematocrit or hemoglobin  ...  Knowing the water transverse (R 2 ) relaxation rates from these different blood compartments is a prerequisite for quantifying the blood oxygenation level-dependent (BOLD) effect.  ...  Kristine Glunde for her help with editing this manuscript and Drs. Nirbhay Yadav and VP Chacko for experimental help. Grant support from: P41 EB015909  ... 
doi:10.1016/j.mri.2016.12.012 pmid:27993533 pmcid:PMC5437867 fatcat:xzf62oqcj5f5zhtdy5kv6bsxfm

Diffusion-weighted Renal MRI at 9.4 Tesla Using RARE to Improve Anatomical Integrity

Joāo dos Santos Periquito, Katharina Paul, Till Huelnhagen, Min-Chi Ku, Yiyi Ji, Kathleen Cantow, Thomas Gladytz, Dirk Grosenick, Bert Flemming, Erdmann Seeliger, Sonia Waiczies, Thoralf Niendorf (+1 others)
2019 Scientific Reports  
(RARE) technique for high field preclinical DWI at 9.4 T.  ...  Diffusion-weighted magnetic resonance imaging (DWI) is a non-invasive imaging technique sensitive to tissue water movement.  ...  Magnetic resonance imaging. All MRI measurements were carried out on a 9.4 Tesla small animal MR system (Bruker Biospec 94/20; Bruker Biospin, Ettlingen, Germany).  ... 
doi:10.1038/s41598-019-56184-6 pmid:31873155 pmcid:PMC6928203 fatcat:tlrobtzilrc6terpv6iob3m5ti

Experimental Protocol for MRI Mapping of the Blood Oxygenation-Sensitive Parameters T2* and T2 in the Kidney

Andreas Pohlmann, Kaixuan Zhao, Sean B Fain, Pottumarthi V Prasad, Thoralf Niendorf
2021 Msphere  
Here we describe a step-by-step experimental protocol for indirect monitoring of renal blood oxygenation in rodents via the deoxyhemoglobin sensitive MR parameters T2* and T2-a contrast mechanism known  ...  Since an absolute quantification of renal oxygenation from T2*/T2 remains challenging, the effects of controlled and standardized variations in the fraction of inspired oxygen are used for bench marking  ...  "Hardware Considerations for Preclinical Magnetic Resonance of the Kidney."  ... 
doi:10.1007/978-1-0716-0978-1_23 pmid:33476013 fatcat:lrllwrj2fbhxzmbe6vax5rt37q

Two repetition time saturation transfer (TwiST) with spill-over correction to measure creatine kinase reaction rates in human hearts

Michael Schär, Refaat E. Gabr, AbdEl-Monem M. El-Sharkawy, Angela Steinberg, Paul A. Bottomley, Robert G. Weiss
2015 Journal of Cardiovascular Magnetic Resonance  
Phosphorus saturation transfer (ST) magnetic resonance spectroscopy can measure the rate of ATP generated from phosphocreatine (PCr) via creatine kinase (CK) in the human heart.  ...  Results: Simulations showed that both k f measured by TwiST and T 1 intrinsic require spill-over corrections.  ...  Xiong et al. published a very fast ST method applied to in vivo swine hearts at ultra-high field strength (4.7 T -9.4 T) [25, 26] .  ... 
doi:10.1186/s12968-015-0175-4 pmid:26253320 pmcid:PMC4529717 fatcat:65pkyzmobrhvjpu4eigjspmqba

MRI-Guided Biopsy of the Prostate Increases Diagnostic Performance in Men with Elevated or Increasing PSA Levels after Previous Negative TRUS Biopsies

Aristotelis G. Anastasiadis, Matthias P. Lichy, Udo Nagele, Markus A. Kuczyk, Axel S. Merseburger, Joerg Hennenlotter, Stefan Corvin, Karl-Dietrich Sievert, Claus D. Claussen, Arnulf Stenzl, Heinz-Peter Schlemmer
2006 European Urology  
This study was performed to investigate if magnetic resonance imaging (MRI)-guided transrectal biopsy increases diagnostic performance in individuals with elevated or increasing PSA levels after previous  ...  MRI-guided biopsy was performed with a closed unit at 1.5 Tesla, an MRI-compatible biopsy device, a needle guide, and a titanium double-shoot biopsy gun.  ...  Acknowledgments The authors would like to thank Mr Jan Sabisch and Mr Axel Winkel from MRI Devices Daum GmbH, Schwerin, Germany, for their excellent technical assistance.  ... 
doi:10.1016/j.eururo.2006.03.007 pmid:16630688 fatcat:xhmkxgae5jgrdgzclris3653w4
« Previous Showing results 1 — 15 out of 898 results