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ultrashort echo time

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https://www.readbyqxmd.com/read/29775663/free-breathing-ultrashort-echo-time-lung-magnetic-resonance-imaging-using-stack-of-spirals-acquisition-a-feasibility-study-in-oncology-patients
#1
Min Jae Cha, Hyun Jeong Park, Mun Young Paek, Alto Stemmer, Eun Sun Lee, Sung Bin Park, Yang Soo Kim
OBJECTIVES: To investigate the diagnostic accuracy of lung magnetic resonance imaging (MRI) with a free-breathing three-dimensional ultrashort echo time spoiled gradient echo sequence using a stack-of-spirals acquisition (spiral 3D UTE) for pulmonary nodule detection at 3 T in oncology patients. METHODS: The institutional review board approved this retrospective study. Between June and September of 2017, 32 oncology patients underwent both free-breathing spiral 3D UTE of the lungs and thin-section chest computed tomography (CT) for pulmonary metastasis workups...
May 15, 2018: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/29769457/3d-cones-acquisition-of-human-extremity-imaging-using-a-1-5t-superconducting-magnet-and-an-unshielded-gradient-coil-set
#2
Ayana Setoi, Katsumi Kose
We developed ultrashort echo-time (UTE) imaging sequences with 3D Cones trajectories for a home-built compact MRI system using a 1.5T superconducting magnet and an unshielded gradient coil set. We achieved less than 7 min imaging time and obtained clear in vivo images of a human forearm with a TE of 0.4 ms. We concluded that UTE imaging using 3D Cones acquisition was successfully implemented in our 1.5T MRI system.
May 16, 2018: Magnetic Resonance in Medical Sciences: MRMS
https://www.readbyqxmd.com/read/29763997/technical-note-deep-learning-based-mrac-using-rapid-ultra-short-echo-time-imaging
#3
Hyungseok Jang, Fang Liu, Gengyan Zhao, Tyler Bradshaw, Alan B McMillan
PURPOSE: In this study, we explore the feasibility of a novel framework for MR-based attenuation correction for PET/MR imaging based on deep learning via convolutional neural networks, which enables fully automated and robust estimation of a pseudo CT image based on ultrashort echo time (UTE), fat, and water images obtained by a rapid MR acquisition. METHODS: MR images for MRAC are acquired using dual echo ramped hybrid encoding (dRHE), where both UTE and out-of-phase echo images are obtained within a short single acquisition (35 sec)...
May 15, 2018: Medical Physics
https://www.readbyqxmd.com/read/29729437/influence-of-k-space-trajectory-corrections-on-proton-density-mapping-with-ultrashort-echo-time-imaging-application-for-imaging-of-short-t2-components-in-white-matter
#4
Peter Latta, Zenon Starčuk, Marco L H Gruwel, Barbora Lattova, Petra Lattova, Pavel Štourač, Boguslaw Tomanek
PURPOSE: To evaluate the impact of MR gradient system imperfections and limitations for the quantitative mapping of short T2* signals performed by ultrashort echo time (UTE) acquisition approach. MATERIALS AND METHODS: The measurement of short T2* signals from a phantom and a healthy volunteer study (8 subjects of average age 28 ± 4 years) were performed on a 3T scanner. The characteristics of the gradient system were obtained using calibration method performed directly on the measured subject or phantom...
May 2, 2018: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/29569463/gradient-echo-based-3d-sub-millisecond-echo-time-pulmonary-mr-imaging-a-preliminary-usability-study-on-clinical-and-preclinical-mr-scanners
#5
Soon Ho Yoon, Chanhee Lee, Jinil Park, Jin Mo Goo, Jang-Yeon Park
OBJECTIVE: To preliminarily investigate a technical feasibility of a sub-millisecond echo-time concurrent-dephasing-and-excitation (CODE) sequence for pulmonary MR imaging on clinical and preclinical MR scanners Methods: CODE imaging (echo time, 0.14~0.18ms) was performed with ACR phantom at 3T, seven healthy volunteers at 1.5T and 3T, ten rabbits at 3T, and two rodents at 9.4T. Signal-to-noise ratio (SNR) was compared in phantom. Image quality of human MRI was visually assessed on a five-point scale for comparison between CODE and conventional lung MRI sequences...
March 23, 2018: British Journal of Radiology
https://www.readbyqxmd.com/read/29526643/theoretical-analysis-and-optimization-of-ultrashort-echo-time-ute-imaging-contrast-with-off-resonance-saturation
#6
Michael Carl, Yajun Ma, Jiang Du
PURPOSE: Off-resonance saturation (ORS) is a tool which can be used in ultrashort echo time (UTE) magnetic resonance imaging to selectively reduce short T2 signals. When these ORS prepared UTE images are subtracted from a non-suppressed UTE acquisition, the short T2 signals are highlighted. The aim of this paper is to develop a theoretical ORS model and optimize short T2 contrast. THEORY: Using a theoretical model the sequence parameters such as saturation flip angle and off-resonance frequency were optimized to maximize short T2 contrast...
March 8, 2018: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/29517831/variable-flip-angle-3d-ultrashort-echo-time-ute-t-1-mapping-of-mouse-lung-a-repeatability-assessment
#7
Daniel F Alamidi, Amir Smailagic, Abdel W Bidar, Nicole S Parker, Marita Olsson, Paul D Hockings, Kerstin M Lagerstrand, Lars E Olsson
BACKGROUND: Lung T1 is a potential translational biomarker of lung disease. The precision and repeatability of variable flip angle (VFA) T1 mapping using modern 3D ultrashort echo time (UTE) imaging of the whole lung needs to be established before it can be used to assess response to disease and therapy. PURPOSE: To evaluate the feasibility of regional lung T1 quantification with VFA 3D-UTE and to investigate long- and short-term T1 repeatability in the lungs of naive mice...
March 8, 2018: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/29493004/3d-adiabatic-t-1%C3%AF-prepared-ultrashort-echo-time-cones-sequence-for-whole-knee-imaging
#8
Ya-Jun Ma, Michael Carl, Adam Searleman, Xing Lu, Eric Y Chang, Jiang Du
PURPOSE: To develop a 3D adiabatic T1ρ prepared ultrashort echo time cones (3D AdiabT1ρ UTE-Cones) sequence for whole knee imaging on a clinical 3T scanner. METHODS: A train of adiabatic full passage pulses were used for spin locking, followed by time-efficient multispoke UTE acquisition to detect signals from both short and long T2 tissues in the whole knee joint. A modified signal model was proposed for multispoke UTE data fitting. The feasibility of this 3D AdiabT1ρ UTE-Cones technique was demonstrated through numerical simulation, phantom, and ex vivo knee sample studies...
February 28, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29451138/detection-of-repair-of-the-zone-of-calcified-cartilage-with-osteoarthritis-through-mesenchymal-stem-cells-by-ultrashort-echo-time-magnetic-resonance-imaging
#9
REVIEW
Quan Zhou, Shao-Lin Li, Ya-Jun Ma, Vicki de Tal, Wei Li, Ying-Hua Zhao
Objective: Currently, magnetic resonance imaging (MRI) is the most commonly used imaging modality for observing the growth and development of mesenchymal stem cells (MSCs) after in vivo transplantation to treat osteoarthritis (OA). However, it is a challenge to accurately monitor the treatment effects of MSCs in the zone of calcified cartilage (ZCC) with OA. This is especially true in the physiological and biochemical views that are not accurately detected by MRI contrast agents. In contrast, ultrashort time echo (UTE) MRI has been shown to be sensitive to the presence of the ZCC, creating the potential for more effectively observing the repair of the ZCC in OA by MSCs...
May 5, 2018: Chinese Medical Journal
https://www.readbyqxmd.com/read/29426012/mri-ute-t2-profile-characteristics-correlate-to-walking-mechanics-and-patient-reported-outcomes-2-years-after-acl-reconstruction
#10
A A Williams, M R Titchenal, T P Andriacchi, C R Chu
OBJECTIVE: Quantitative magnetic resonance imaging (MRI) ultrashort echo time (UTE) T2* is sensitive to cartilage deep tissue matrix changes after anterior cruciate ligament reconstruction (ACLR). This study was performed to determine whether UTE-T2* profile analysis is a useful clinical metric for assessing cartilage matrix degeneration. This work tests the hypotheses that UTE-T2* depthwise rates of change (profile slopes) correlate with clinical outcome metrics of walking mechanics and patient reported outcomes (PRO) in patients 2 years after ACLR...
April 2018: Osteoarthritis and Cartilage
https://www.readbyqxmd.com/read/29404669/clinical-and-magnetic-resonance-imaging-assessment-of-anatomical-lateral-ankle-ligament-reconstruction-comparison-of-tendon-allograft-and-autograft
#11
Qianru Li, Kui Ma, Hongyue Tao, Yinghui Hua, Shuang Chen, Shiyi Chen, Yutong Zhao
PURPOSE: To compare the results of anatomical lateral ankle ligament (LAL) reconstruction with tendon allograft and autograft using clinical scores and ultrashort echo time (UTE) sequence of MRI. METHODS: A total of 26 patients with LAL reconstruction were recruited in this study, including 16 using semitendinosus allografts and 10 using semitendinosus autograft. All of them were diagnosed as chronic ankle instability and accepted anatomic reconstruction. The American Orthopedic Foot and Ankle Society (AOFAS) score, Karlsson score, and radiological evaluation using MRI UTE scanning were extracted from each patient...
March 2018: International Orthopaedics
https://www.readbyqxmd.com/read/29399473/pre-and-post-operative-visualization-of-neonatal-esophageal-atresia-tracheoesophageal-fistula-via-magnetic-resonance-imaging
#12
Nara S Higano, Alister J Bates, Jean A Tkach, Robert J Fleck, Foong Y Lim, Jason C Woods, Paul S Kingma
Esophageal atresia (EA) is a relatively uncommon congenital anomaly, often observed in conjunction with tracheoesophageal fistula (TEF). Surgical repair in neonates typically takes place with little information about the pre-existing EA/TEF structure because there are currently no acceptable tools for evaluating EA/TEF anatomy prior to repair; chest x-ray radiograph does not identify malformation sub-type or gap length, while x-ray computed tomography (CT) demonstrate an unacceptably high exposure to ionizing radiation...
February 2018: Journal of Pediatric Surgery Case Reports
https://www.readbyqxmd.com/read/29396694/feasibility-of-using-an-inversion-recovery-ultrashort-echo-time-ute-sequence-for-quantification-of-glenoid-bone-loss
#13
Ya-Jun Ma, Justin West, Amin Nazaran, Xin Cheng, Heinz Hoenecke, Jiang Du, Eric Y Chang
OBJECTIVE: To utilize the 3D inversion recovery prepared ultrashort echo time with cones readout (IR-UTE-Cones) MRI technique for direct imaging of lamellar bone with comparison to the gold standard of computed tomography (CT). MATERIALS AND METHODS: CT and MRI was performed on 11 shoulder specimens and three patients. Five specimens had imaging performed before and after glenoid fracture (osteotomy). 2D and 3D volume-rendered CT images were reconstructed and conventional T1-weighted and 3D IR-UTE-Cones MRI techniques were performed...
February 2, 2018: Skeletal Radiology
https://www.readbyqxmd.com/read/29363781/advanced-hemophilic-arthropathy-sensitivity-of-soft-tissue-discrimination-with-musculoskeletal-ultrasound
#14
Annette von Drygalski, Randy E Moore, Sonha Nguyen, Richard F W Barnes, Lena M Volland, Tudor H Hughes, Jiang Du, Eric Y Chang
OBJECTIVES: Point-of-care musculoskeletal ultrasound (US) is increasingly used by hemophilia providers to guide management; however, pathologic tissue differentiation with US is uncertain. We sought to determine the extent to which point-of-care musculoskeletal US can identify and discriminate pathologic soft tissue changes in hemophilic arthropathy. METHODS: Thirty-six adult patients with hemophilia A/B were prospectively enrolled. Point-of-care musculoskeletal US examinations were performed on arthropathic joints (16 knees, 10 ankles, and 10 elbows) using standard views by a musculoskeletal US-trained and certified hematologist, who recorded abnormal intra-articular soft tissue accumulation...
January 24, 2018: Journal of Ultrasound in Medicine: Official Journal of the American Institute of Ultrasound in Medicine
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
#15
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
#16
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-t-1-mapping-of-short-t-2-tissues-using-a-three-dimensional-ultrashort-echo-time-cones-actual-flip-angle-imaging-variable-repetition-time-3d-ute-cones-afi-vtr-method
#17
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
#18
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...
April 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
#19
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
#20
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 visualized 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 optimization of UTE sequences. The aims of this study were to (a) characterize the MRI signal properties of a photopolymer resin that can be 3D printed, (b) develop multicompartment phantoms based on the resin, and (c) demonstrate the feasibility of using these phantoms to mimic human anatomy in the assessment of UTE sequences...
February 2018: Medical Physics
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