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ultrashort echo time

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https://www.readbyqxmd.com/read/29354012/in-vivo-visualization-of-iron-oxide-enhancement-in-focal-pulmonary-inflammatory-lesions-using-a-three-dimensional-radial-gradient-echo-based-ultrashort-echo-time-sequence-a-preliminary-study
#1
Soon Ho Yoon, Chanhee Lee, Jinil Park, Jin Mo Goo, Jang-Yeon Park
Objective: To preliminarily evaluate technical feasibility of a dual-echo ultrashort echo time (UTE) subtraction MR imaging by using concurrent dephasing and excitation (CODE) sequence for visualization of iron-oxide enhancement in focal inflammatory pulmonary lesions. Materials and Methods: A UTE pulmonary MR imaging before and after the injection of clinically usable superparamagnetic iron-oxide nanoparticles, ferumoxytol, was conducted using CODE sequence with dual echo times of 0...
January 2018: Korean Journal of Radiology: Official Journal of the Korean Radiological Society
https://www.readbyqxmd.com/read/29342064/minimally-manipulated-bone-marrow-concentrate-compared-with-microfracture-treatment-of-full-thickness-chondral-defects-a-one-year-study-in-an-equine-model
#2
Constance R Chu, Lisa A Fortier, Ashley Williams, Karin A Payne, Taralyn M McCarrel, Megan E Bowers, Diego Jaramillo
BACKGROUND: Microfracture is commonly performed for cartilage repair but usually results in fibrocartilage. Microfracture augmented by autologous bone marrow concentrate (BMC) was previously shown to yield structurally superior cartilage repairs in an equine model compared with microfracture alone. The current study was performed to test the hypothesis that autologous BMC without concomitant microfracture improves cartilage repair compared with microfracture alone. METHODS: Autologous sternal bone marrow aspirate (BMA) was concentrated using a commercial system...
January 17, 2018: Journal of Bone and Joint Surgery. American Volume
https://www.readbyqxmd.com/read/29314235/accurate-t1-mapping-of-short-t2-tissues-using-a-three-dimensional-ultrashort-echo-time-cones-actual-flip-angle-imaging-variable-repetition-time-3d-ute-cones-afi-vtr-method
#3
Ya-Jun Ma, Xing Lu, Michael Carl, Yanchun Zhu, Nikolaus M Szeverenyi, Graeme M Bydder, Eric Y Chang, Jiang Du
PURPOSE: To develop an accurate T1 measurement method for short T2 tissues using a combination of a 3-dimensional ultrashort echo time cones actual flip angle imaging technique and a variable repetition time technique (3D UTE-Cones AFI-VTR) on a clinical 3T scanner. METHODS: First, the longitudinal magnetization mapping function of the excitation pulse was obtained with the 3D UTE-Cones AFI method, which provided information about excitation efficiency and B1 inhomogeneity...
January 3, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29314215/simultaneous-quantitative-susceptibility-mapping-qsm-and-r2-for-high-iron-concentration-quantification-with-3d-ultrashort-echo-time-sequences-an-echo-dependence-study
#4
Xing Lu, Yajun Ma, Eric Y Chang, Qun He, Adam Searleman, Annette von Drygalski, Jiang Du
PURPOSE: To evaluate the echo dependence of 3D ultrashort echo time (TE) quantitative susceptibility mapping (3D UTE-QSM) and effective transverse relaxation rate ( R2*) measurement in the setting of high concentrations of iron oxide nanoparticles. METHODS: A phantom study with iron concentrations ranging from 2 to 22 mM was performed using a 3D UTE Cones sequence. Simultaneous QSM processing with morphology-enabled dipole inversion (MEDI) and R2* single exponential fitting was conducted offline with the acquired 3D UTE data...
January 4, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29248239/magnetic-resonance-imaging-characteristics-of-lesions-relate-to-the-difficulty-of-peripheral-arterial-endovascular-procedures
#5
Trisha L Roy, Hou-Jen Chen, Andrew D Dueck, Graham A Wright
OBJECTIVE: Limitations with current peripheral arterial imaging modalities make selection of patients for percutaneous vascular interventions difficult. The purpose of this study was to determine whether a novel preprocedural magnetic resonance imaging (MRI) method can identify lesions that would be more challenging to cross during percutaneous vascular intervention. METHODS: Fourteen patients with peripheral arterial disease underwent MRI before their intervention...
December 13, 2017: Journal of Vascular Surgery
https://www.readbyqxmd.com/read/29237232/3d-printed-phantoms-mimicking-cortical-bone-for-the-assessment-of-ultrashort-echo-time-magnetic-resonance-imaging
#6
Robba Rai, David Manton, Michael G Jameson, Sonal Josan, Michael B Barton, Lois C Holloway, Gary P Liney
PURPOSE: Human cortical bone has a rapid T2 * decay, and it can be visualised using ultrashort echo time (UTE) techniques in magnetic resonance imaging (MRI). These sequences operate at the limits of gradient and transmit-receive signal performance. Development of multicompartment anthropomorphic phantoms that can mimic human cortical bone can assist with quality assurance and optimisation of UTE sequences. The aims of this study were to 1) characterise the MRI signal properties of a photopolymer resin that can be 3D printed, 2) develop multi-compartment phantoms based on the resin, and 3) demonstrate the feasibility of using these phantoms to mimic human anatomy in the assessment of UTE sequences...
December 13, 2017: Medical Physics
https://www.readbyqxmd.com/read/29219218/rotator-cuff-tendon-assessment-using-magic-angle-insensitive-3d-ultrashort-echo-time-cones-magnetization-transfer-ute-cones-mt-imaging-and-modeling-with-histological-correlation
#7
Yanchun Zhu, Xin Cheng, Yajun Ma, Jonathan H Wong, Yaoqin Xie, Jiang Du, Eric Y Chang
BACKGROUND: Rotator cuff tendons (RCTs) are challenging to image due to the "magic angle effect" and their short T2 . PURPOSE: To assess the degree of magic angle sensitivity of human RCTs and to utilize a 3D ultrashort echo time Cones sequence with magnetization transfer preparation (UTE-Cones-MT) and two-pool quantitative MT modeling with histological correlation. We hypothesized that MT parameters would be less sensitive to the magic angle compared with conventional T2 measurements...
December 8, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/29194734/in-vivo-characterization-of-brain-ultrashort-t2-components
#8
Tanguy Boucneau, Peng Cao, Shuyu Tang, Misung Han, Duan Xu, Roland G Henry, Peder E Z Larson
PURPOSE: Recent nuclear magnetic resonance and MRI studies have measured a fast-relaxing signal component with T2∗<1 ms in white matter and myelin extracts. In ex vivo studies, evidence suggests that a large fraction of this component directly arises from bound protons in the myelin phospholipid membranes. Based on these results, this ultrashort-T2 component in nervous tissue is a new potential imaging biomarker of myelination, which plays a critical role in neuronal signal conduction across the brain and loss or degradation of myelin is a key feature of many neurological disorders...
December 1, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29160917/visualization-of-calcium-phosphate-cement-in-teeth-by-zero-echo-time-1-h-mri-at-high-field
#9
Weiqiang Dou, Simone Mastrogiacomo, Andor Veltien, Hamdan S Alghamdi, X Frank Walboomers, Arend Heerschap
(1) H magnetic resonance imaging (MRI) by a zero echo time (ZTE) sequence is an excellent method to image teeth. Calcium phosphate cement (CPC) materials are applied in the restoration of tooth lesions, but it has not yet been investigated whether they can be detected by computed tomography (CT) or MRI. The aim of this study was to optimize high-field ZTE imaging to enable the visualization of a new CPC formulation implanted in teeth and to apply this in the assessment of its decomposition in vivo. CPC was implanted in three human and three goat teeth ex vivo and in three goat teeth in vivo...
November 21, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/29096054/comparison-of-ferumoxytol-based-cerebral-blood-volume-estimates-using-quantitative-r1-and-r2-relaxometry
#10
Leonardo A Rivera-Rivera, Tilman Schubert, Gesine Knobloch, Patrick A Turski, Oliver Wieben, Scott B Reeder, Kevin M Johnson
PURPOSE: Cerebral perfusion is commonly assessed clinically with dynamic susceptibility contrast MRI using a bolus injection of gadolinium-based contrast agents, resulting in semi-quantitative values of cerebral blood volume (CBV). Steady-state imaging with ferumoxytol allows estimation of CBV with the potential for higher precision and accuracy. Prior CBV studies have focused on the signal disrupting T2* effects, but ferumoxytol also has high signal-enhancing T1 relaxivity. The purpose of this study was to investigate and compare CBV estimation using T1 and T2*, with the goal of understanding the contrast mechanisms and quantitative differences...
November 2, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29067730/simultaneous-qsm-and-metabolic-imaging-of-the-brain-using-spice
#11
Xi Peng, Fan Lam, Yudu Li, Bryan Clifford, Zhi-Pei Liang
PURPOSE: To map brain metabolites and tissue magnetic susceptibility simultaneously using a single three-dimensional (1) H-MRSI acquisition without water suppression. METHODS: The proposed technique builds on a subspace imaging method called spectroscopic imaging by exploiting spatiospectral correlation (SPICE), which enables ultrashort echo time (TE)/short pulse repetition time (TR) acquisitions for (1) H-MRSI without water suppression. This data acquisition scheme simultaneously captures both the spectral information of brain metabolites and the phase information of the water signals that is directly related to tissue magnetic susceptibility variations...
October 24, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29048157/paramagnetic-19-f-relaxation-enhancement-in-nickel-ii-complexes-of-n-trifluoroethyl-cyclam-derivatives-and-cell-labeling-for-19-f-mri
#12
Jan Blahut, Karel Bernášek, Andrea Gálisová, Vít Herynek, Ivana Císařová, Jan Kotek, Jan Lang, Stanislava Matějková, Petr Hermann
1,8-Bis(2,2,2-trifluoroethyl)cyclam (te2f) derivatives with two coordinating pendant arms involving methylenecarboxylic acid (H2te2f2a), methylenephosphonic acid (H4te2f2p), (2-pyridyl)methyl (te2f2py), and 2-aminoethyl arms (te2f2ae) in 4,11-positions were prepared, and their nickel(II) complexes were investigated as possible (19)F MR tracers. The solid-state structures of several synthetic intermediates, ligands, and all complexes were confirmed by X-ray diffraction analysis. The average Ni···F distances were determined to be about 5...
November 6, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/29023975/motion-robust-high-resolution-3d-free-breathing-pulmonary-mri-using-dynamic-3d-image-self-navigator
#13
Wenwen Jiang, Frank Ong, Kevin M Johnson, Scott K Nagle, Thomas A Hope, Michael Lustig, Peder E Z Larson
PURPOSE: To achieve motion robust high resolution 3D free-breathing pulmonary MRI utilizing a novel dynamic 3D image navigator derived directly from imaging data. METHODS: Five-minute free-breathing scans were acquired with a 3D ultrashort echo time (UTE) sequence with 1.25 mm isotropic resolution. From this data, dynamic 3D self-navigating images were reconstructed under locally low rank (LLR) constraints and used for motion compensation with one of two methods: a soft-gating technique to penalize the respiratory motion induced data inconsistency, and a respiratory motion-resolved technique to provide images of all respiratory motion states...
October 11, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28984733/cartilage-endplate-thickness-variation-measured-by-ultrashort-echo-time-mri-is-associated-with-adjacent-disc-degeneration
#14
Britta Berg-Johansen, Misung Han, Aaron J Fields, Ellen C Liebenberg, Brandon J Lim, Peder Ez Larson, Cigdem Gunduz-Demir, Galateia J Kazakia, Roland Krug, Jeffrey C Lotz
STUDY DESIGN: A magnetic resonance imaging study of human cadaver spines. OBJECTIVE: To investigate associations between cartilage endplate (CEP) thickness and disc degeneration. SUMMARY OF BACKGROUND DATA: Damage to the CEP is associated with spinal injury and back pain. However, CEP morphology and its association with disc degeneration have not been well characterized. METHODS: Ten lumbar motion segments with varying degrees of disc degeneration were harvested from six cadaveric spines and scanned with MRI in the sagittal plane using a T2-weighted 2D sequence, a 3D ultrashort echo-time (UTE) imaging sequence, and a 3D T1ρ mapping sequence...
October 3, 2017: Spine
https://www.readbyqxmd.com/read/28971513/rapid-dual-echo-ramped-hybrid-encoding-mr-based-attenuation-correction-drhe-mrac-for-pet-mr
#15
Hyungseok Jang, Fang Liu, Tyler Bradshaw, Alan B McMillan
PURPOSE: In this study, we propose a rapid acquisition for MR-based attenuation correction (MRAC) in positron emission tomography (PET)/MR imaging, in which an ultrashort echo time (UTE) image and an out-of-phase echo image are obtained within a single rapid scan (35 s) at high spatial resolution (1 mm(3) ), which allows accurate estimation of a pseudo CT image using 4-class tissue classification (discrete bone, discrete air, continuous fat, and continuous water). METHODS: In dual-echo ramped hybrid encoding (dRHE), a UTE echo is directly followed by a second out-of-phase echo, in which hybrid spatial encoding combining single-point imaging and 3-dimensional radial frequency encoding is used to improve the quality of both images...
October 2, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28913879/short-t2-imaging-using-a-3d-double-adiabatic-inversion-recovery-prepared-ultrashort-echo-time-cones-3d-dir-ute-cones-sequence
#16
Ya-Jun Ma, Yanchun Zhu, Xing Lu, Michael Carl, Eric Y Chang, Jiang Du
PURPOSE: To investigate high contrast imaging of short T2 tissues with a three-dimensional double adiabatic inversion recovery prepared ultrashort echo time Cones (3D DIR-UTE-Cones) sequence. METHODS: The sequence used two sequential adiabatic inversion pulses to suppress signals from long T2 tissues, followed by multispoke UTE acquisition to detect signals from short T2 tissues. The two adiabatic inversion pulses are identical with a center frequency located at the water peak, but the spectral width is broad enough to cover both water and fat frequencies...
September 14, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28862351/chemical-shift-encoding-cse-for-sensitive-fluorine-19-mri-of-perfluorocarbons-with-complex-spectra
#17
Ruud B van Heeswijk, Roberto Colotti, Emeline Darçot, Jean Delacoste, Maxime Pellegrin, Davide Piccini, Diego Hernando
PURPOSE: To implement a fluorine-19 ((19) F) chemical shift encoding (CSE) approach for the sensitive imaging of molecules with multi-resonance spectra to remove their chemical shift displacement (CSD) artifacts, and to characterize its sensitivity versus established pulse sequences. METHODS: The feasibility of CSE spoiled gradient echo (GRE) and balanced steady-state free precession (bSSFP) was first demonstrated in a phantom study. The dependence of the sensitivity of CSE-bSSFP on several pulse sequence parameters was then established, after which the occurrence of out-of-plane excitation was assessed for 2D and 3D techniques...
September 1, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28833407/fully-phase-encoded-mri-near-metallic-implants-using-ultrashort-echo-times-and-broadband-excitation
#18
Curtis N Wiens, Nathan S Artz, Hyungseok Jang, Alan B McMillan, Kevin M Koch, Scott B Reeder
PURPOSE: To develop a fully phase-encoded MRI method for distortion-free imaging near metallic implants, in clinically feasible acquisition times. THEORY AND METHODS: An accelerated 3D fully phase-encoded acquisition with broadband excitation and ultrashort echo times is presented, which uses a broadband radiofrequency pulse to excite the entire off-resonance induced by the metallic implant. Furthermore, fully phase-encoded imaging is used to prevent distortions caused by frequency encoding, and to obtain ultrashort echo times for rapidly decaying signal...
August 21, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28812309/murine-pulmonary-imaging-at-7t-t2-and-t1-with-anisotropic-ute
#19
Jinbang Guo, Xuefeng Cao, Zackary I Cleveland, Jason C Woods
PURPOSE: To measure the T2* and T1 of mouse lung at 7T via anisotropic-resolution radial ultrashort echo-time imaging with ellipsoidal k-space coverage. METHODS: Ellipsoidal field-of-view was created by expanding uniform spherical k-space coverage. The effects of T2* and ellipsoidal sampling on image resolution were investigated by using point-spread-function analysis and resolution phantoms. Finally, this ellipsoidal sampling approach was used to measure the lung T2* and T1 of healthy C57BL/6 mice at the increasingly common preclinical field strength of 7T...
August 15, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28780188/ultrashort-echo-time-t2-%C3%A2-values-decrease-in-tendons-with-application-of-static-tensile-loads
#20
Saeed Jerban, Amin Nazaran, Xin Cheng, Michael Carl, Nikolaus Szeverenyi, Jiang Du, Eric Y Chang
In early stages of tendon disease, mechanical properties may become altered prior to changes in morphological anatomy. Ultrashort echo time (UTE) magnetic resonance imaging (MRI) can be used to directly detect signal from tissues with very short T2 values, including unique viscoelastic tissues such as tendons. The purpose of this study was to use UTE sequences to measure T2(∗), T1 and magnetization transfer ratio (MTR) variations of tendon samples under static tensile loads. Six human peroneal tendons were imaged before and under static loading using UTE sequences on a clinical 3T MRI scanner...
August 16, 2017: Journal of Biomechanics
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