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https://www.readbyqxmd.com/read/28391818/a-computational-measurement-of-cartilaginous-endplate-structure-using-ultrashort-time-to-echo-mri-scanning
#1
Ri-Chu Jin, Yong-Can Huang, Keith D K Luk, Yong Hu
BACKGROUND AND OBJECTIVE: Ultrashort time-to-echo (UTE) MRI scanning has been applied to observe the cartilaginous endplate (CEP) in intervertebral disc. CEP plays a critical role in IVD health and disease. Nevertheless, current measurements of CEP based on UTE MRI technique are still by manual segmentation, and observation of signal abnormality was usually time-consuming and often disturbed by subjective bias. This study hence proposed an efficient way to harvest the global parameters of CEP after UTE MRI scanning...
May 2017: Computer Methods and Programs in Biomedicine
https://www.readbyqxmd.com/read/28371091/novel-magnetic-resonance-imaging-for-assessment-of-bronchial-stenosis-in-lung-transplant-recipients
#2
Kamran Mahmood, Lukas Ebner, Mu He, Scott Haile Robertson, Ziyi Wang, H Page McAdams, Momen M Wahidi, Scott L Shofer, Yuh-Chin T Huang, Bastiaan Driehuys
Bronchial stenosis in lung transplant recipients is a common disorder that adversely affects clinical outcomes. It is evaluated by spirometry, CT scan and bronchoscopy with significant limitations. We hypothesize that magnetic resonance imaging (MRI) employing both ultrashort echo time (UTE) scans and hyperpolarized (HP) (129) Xe gas can offer structural and functional assessment of bronchial stenosis seen after lung transplantation. Six patients with lung transplantation-related bronchial stenosis underwent HP (129) Xe MRI and UTE MRI...
March 29, 2017: American Journal of Transplantation
https://www.readbyqxmd.com/read/28318066/three-dimensional-ultrashort-echo-time-cones-t1%C3%AF-3d-ute-cones-t1%C3%AF-imaging
#3
Ya-Jun Ma, Michael Carl, Hongda Shao, Anthony S Tadros, Eric Y Chang, Jiang Du
We report a novel three-dimensional (3D) ultrashort echo time (UTE) sequence employing Cones trajectory and T1ρ preparation (UTE-Cones-T1ρ ) for quantitative T1ρ assessment of short T2 tissues in the musculoskeletal system. A basic 3D UTE-Cones sequence was combined with a spin-locking preparation pulse for T1ρ contrast. A relatively short TR was used to decrease the scan time, which required T1 measurement and compensation using 3D UTE-Cones data acquisitions with variable TRs. Another strategy to reduce the total scan time was to acquire multiple Cones spokes (Nsp ) after each T1ρ preparation and fat saturation...
March 20, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28306546/substitute-ct-generation-from-a-single-ultra-short-time-echo-mri-sequence-preliminary-study
#4
Soumya Ghose, Jason A Dowling, Robba Rai, Gary P Liney
In MR guided radiation therapy planning both MR and CT images for a patient are acquired and co-registered to obtain a tissue specific HU map. Generation of the HU map directly from the MRI would eliminate the CT acquisition and may improve radiation therapy planning. In this preliminary study of substitute CT (sCT) generation, two porcine leg phantoms were scanned using a 3D ultrashort echo time (PETRA) sequence and co-registered to corresponding CT images to build tissue specific regression models. The model was created from one co-registered CT-PETRA pair to generate the sCT for the other PETRA image...
April 21, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28283853/long-t2-suppression-in-native-lung-3-d-imaging-using-k-space-reordered-inversion-recovery-dual-echo-ultrashort-echo-time-mri
#5
Neville D Gai, Ashkan A Malayeri, David A Bluemke
OBJECTIVE: Long T2 species can interfere with visualization of short T2 tissue imaging. For example, visualization of lung parenchyma can be hindered by breathing artifacts primarily from fat in the chest wall. The purpose of this work was to design and evaluate a scheme for long T2 species suppression in lung parenchyma imaging using 3-D inversion recovery double-echo ultrashort echo time imaging with a k-space reordering scheme for artifact suppression. MATERIALS AND METHODS: A hyperbolic secant (HS) pulse was evaluated for different tissues (T1/T2)...
March 10, 2017: Magma
https://www.readbyqxmd.com/read/28263700/standard-reduced-and-no-dose-thin-section-radiologic-examinations-comparison-of-capability-for-nodule-detection-and-nodule-type-assessment-in-patients-suspected-of-having-pulmonary-nodules
#6
Yoshiharu Ohno, Hisanobu Koyama, Takeshi Yoshikawa, Yuji Kishida, Shinichiro Seki, Daisuke Takenaka, Masao Yui, Mitsue Miyazaki, Kazuro Sugimura
Purpose To compare the capability of pulmonary thin-section magnetic resonance (MR) imaging with ultrashort echo time (UTE) with that of standard- and reduced-dose thin-section computed tomography (CT) in nodule detection and evaluation of nodule type. Materials and Methods The institutional review board approved this study, and written informed consent was obtained from each patient. Standard- and reduced-dose chest CT (60 and 250 mA) and MR imaging with UTE were used to examine 52 patients; 29 were men (mean age, 66...
March 6, 2017: Radiology
https://www.readbyqxmd.com/read/28263448/bicomponent-ultrashort-echo-time-t2-analysis-for-assessment-of-patients-with-patellar-tendinopathy
#7
Richard Kijowski, John J Wilson, Fang Liu
PURPOSE: To compare bicomponent ultrashort echo time (UTE) T2* parameters of patellar tendon between healthy volunteers and patients with patellar tendinopathy. MATERIALS AND METHODS: This study was performed with Institutional Review Board approval and with all subjects signing informed consent. A UTE- T2* mapping sequence was performed at 3.0T on the knees of 10 healthy volunteers and in 11 patients with patellar tendinopathy. The UTE- T2* relaxation times of the fast relaxing macromolecular bound water component ( T2*F) and the slow relaxing bulk water component ( T2*S) and the fraction of the fast relaxing macromolecular bound water component (FF ) of patellar tendon were measured in all subjects...
March 6, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28261863/bone-quantitative-susceptibility-mapping-using-a-chemical-species-specific-r2-signal-model-with-ultrashort-and-conventional-echo-data
#8
Alexey V Dimov, Zhe Liu, Pascal Spincemaille, Martin R Prince, Jiang Du, Yi Wang
PURPOSE: To develop quantitative susceptibility mapping (QSM) of bone using an ultrashort echo time (UTE) gradient echo (GRE) sequence for signal acquisition and a bone-specific effective transverse relaxation rate ( R2*) to model water-fat MR signals for field mapping. METHODS: Three-dimensional radial UTE data (echo times ≥ 40 μs) was acquired on a 3 Tesla scanner and fitted with a bone-specific signal model to map the chemical species and susceptibility field...
March 5, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28247561/the-challenge-of-bias-free-coil-combination-for-quantitative-susceptibility-mapping-at-ultra-high-field
#9
Steffen Bollmann, Simon Daniel Robinson, Kieran O'Brien, Viktor Vegh, Andrew Janke, Lars Marstaller, David Reutens, Markus Barth
PURPOSE: Quantitative susceptibility mapping is a technique to estimate the magnetic property of tissue with particularly high sensitivity at ultra-high field. However, a key challenge at ultra-high field is the combination of phase data acquired using phased array receive coils. Several methods for combining phase data have been proposed, but the influence of coil combination choices on susceptibility quantitation has not been studied systematically. METHODS: We combined phase data using COMPOSER (COMbining Phase data using a Short Echo-time Reference scan) and a reference-free channel-by-channel method...
March 1, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28219648/direct-magnitude-and-phase-imaging-of-myelin-using-ultrashort-echo-time-ute-pulse-sequences-a-feasibility-study
#10
Qun He, Yajun Ma, Shujuan Fan, Hongda Shao, Vipul Sheth, Graeme M Bydder, Jiang Du
In this paper, we aimed to investigate the feasibility of direct visualization of myelin, including myelin lipid and myelin basic protein (MBP), using two-dimensional ultrashort echo time (2D UTE) sequences and utilize phase information as a contrast mechanism in phantoms and in volunteers. The standard UTE sequence was used to detect both myelin and long T2 signal. An adiabatic inversion recovery UTE (IR-UTE) sequence was used to selectively detect myelin by suppressing signal from long T2 water protons. Magnitude and phase imaging and T2* were investigated on myelin lipid and MBP in the forms of lyophilized powders as well as paste-like phantoms with the powder mixed with D2O, and rubber phantoms as well as healthy volunteers...
February 20, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28160357/quantification-of-neonatal-lung-parenchymal-density-via-ultrashort-echo-time-mri-with-comparison-to-ct
#11
Nara S Higano, Robert J Fleck, David R Spielberg, Laura L Walkup, Andrew D Hahn, Robert P Thomen, Stephanie L Merhar, Paul S Kingma, Jean A Tkach, Sean B Fain, Jason C Woods
PURPOSE: To demonstrate that ultrashort echo time (UTE) magnetic resonance imaging (MRI) can achieve computed tomography (CT)-like quantification of lung parenchyma in free-breathing, non-sedated neonates. Because infant CTs are used sparingly, parenchymal disease evaluation via UTE MRI has potential for translational impact. MATERIALS AND METHODS: Two neonatal control cohorts without suspected pulmonary morbidities underwent either a research UTE MRI (n = 5; 1...
February 3, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28154823/ute-t2-%C3%A2-analysis-of-diseased-and-healthy-achilles-tendons-and-correlation-with-clinical-score-an-in-vivo-preliminary-study
#12
COMPARATIVE STUDY
Yang Qiao, Hong-Yue Tao, Kui Ma, Zi-Ying Wu, Jian-Xun Qu, Shuang Chen
Objective. To compare T2(⁎) value of healthy and diseased Achilles tendons (AT) with a recently introduced three-dimensional ultrashort echo time (3D-UTE) sequence and analyze the correlation between T2(⁎) value and clinical scores. Methods. Ten patients with symptomatic Achilles tendon and ten healthy volunteers were investigated with 3D-UTE sequence on a 3T magnetic resonance (MR) scanner. T2(⁎) values of four regions in Achilles tendons were calculated. The clinical outcomes of patients were evaluated according to the American Orthopaedic Foot and Ankle Society (AOFAS) score and Achilles Tendon Rupture Score (ATRS)...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28090666/quantitative-ultrashort-echo-time-imaging-for-assessment-of-massive-iron-overload-at-1-5-and-3-tesla
#13
Axel J Krafft, Ralf B Loeffler, Ruitian Song, Aaryani Tipirneni-Sajja, M Beth McCarville, Matthew D Robson, Jane S Hankins, Claudia M Hillenbrand
PURPOSE: Hepatic iron content (HIC) quantification via transverse relaxation rate (R2*)-MRI using multi-gradient echo (mGRE) imaging is compromised toward high HIC or at higher fields due to the rapid signal decay. Our study aims at presenting an optimized 2D ultrashort echo time (UTE) sequence for R2* quantification to overcome these limitations. METHODS: Two-dimensional UTE imaging was realized via half-pulse excitation and radial center-out sampling. The sequence includes chemically selective saturation pulses to reduce streaking artifacts from subcutaneous fat, and spatial saturation (sSAT) bands to suppress out-of-slice signals...
January 16, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28090450/quantitative-magnetic-resonance-imaging-of-the-lumbar-intervertebral-discs
#14
REVIEW
Dosik Hwang, Sewon Kim, Nirusha A Abeydeera, Sheronda Statum, Koichi Masuda, Christine B Chung, Palanan Siriwanarangsun, Won C Bae
Human lumbar spine is composed of multiple tissue components that serve to provide structural stability and proper nutrition. Conventional magnetic resonance (MR) imaging techniques have been useful for evaluation of IVD, but inadequate at imaging the discovertebral junction and ligamentous tissues due primarily to their short T2 nature. Ultrashort time to echo (UTE) MR techniques acquire sufficient MR signal from these short T2 tissues, thereby allowing direct and quantitative evaluation. This article discusses the anatomy of the lumbar spine, MR techniques available for morphologic and quantitative MR evaluation of long and short T2 tissues of the lumbar spine, considerations for T2 relaxation modeling and fitting, and existing and new techniques for spine image post-processing, focusing on segmentation...
December 2016: Quantitative Imaging in Medicine and Surgery
https://www.readbyqxmd.com/read/28090449/ultrashort-time-to-echo-magnetic-resonance-techniques-for-the-musculoskeletal-system
#15
REVIEW
Palanan Siriwanarangsun, Sheronda Statum, Reni Biswas, Won C Bae, Christine B Chung
Magnetic resonance (MR) imaging has been widely implemented as a non-invasive modality to investigate musculoskeletal (MSK) tissue disease, injury, and pathology. Advancements in MR sequences provide not only enhanced morphologic contrast for soft tissues, but also quantitative biochemical evaluation. Ultrashort time to echo (UTE) sequence, in particular, enables novel morphologic and quantitative evaluation of previously unseen MSK tissues. By using short minimum echo times (TE) below 1 msec, the UTE sequence can unveil short T2 properties of tissues including the deepest layers of the articular cartilage, cartilaginous endplate at the discovertebral junction, the meniscus, and the cortical bone...
December 2016: Quantitative Imaging in Medicine and Surgery
https://www.readbyqxmd.com/read/28074498/imaging-and-t2-relaxometry-of-short-t2-connective-tissues-in-the-knee-using-ultrashort-echo-time-double-echo-steady-state-utedess
#16
Akshay S Chaudhari, Bragi Sveinsson, Catherine J Moran, Emily J McWalter, Ethan M Johnson, Tao Zhang, Garry E Gold, Brian A Hargreaves
PURPOSE: To develop a radial, double-echo steady-state (DESS) sequence with ultra-short echo-time (UTE) capabilities for T2 measurement of short-T2 tissues along with simultaneous rapid, signal-to-noise ratio (SNR)-efficient, and high-isotropic-resolution morphological knee imaging. METHODS: THe 3D radial UTE readouts were incorporated into DESS, termed UTEDESS. Multiple-echo-time UTEDESS was used for performing T2 relaxometry for short-T2 tendons, ligaments, and menisci; and for Dixon water-fat imaging...
January 11, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28051911/quantification-of-human-cortical-bone-bound-and-free-water-in-vivo-with-ultrashort-echo-time-mr-imaging-a-model-based-approach
#17
Shahrokh Abbasi-Rad, Hamidreza Saligheh Rad
Purpose To quantify free and bound water components of cortical bone with a model-based numeric approach with use of ultrashort echo time (UTE) magnetic resonance (MR) imaging in vivo in order to introduce a new predictor for age-related deterioration of cortical bone structure. Materials and Methods Human studies were compliant with HIPAA and approved by the institutional review board. Dual-repetition time three-dimensional hybrid-radial UTE imaging was performed, followed by the application of postprocessing algorithms, to quantify free and bound water parameters (concentration [ρ] and longitudinal relaxation time [T1]) of human cortical bone in vivo...
January 4, 2017: Radiology
https://www.readbyqxmd.com/read/28048790/su-f-j-112-clinical-feasibility-test-of-an-rf-pulse-based-mri-method-for-the-quantitative-fat-water-segmentation
#18
S Yee, J Wloch, M Pirkola
PURPOSE: Quantitative fat-water segmentation is important not only because of the clinical utility of fat-suppressed MRI images in better detecting lesions of clinical significance (in the midst of bright fat signal) but also because of the possible physical need, in which CT-like images based on the materials' photon attenuation properties may have to be generated from MR images; particularly, as in the case of MR-only radiation oncology environment to obtain radiation dose calculation or as in the case of hybrid PET/MR modality to obtain attenuation correction map for the quantitative PET reconstruction...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28038965/inversion-recovery-ultrashort-echo-time-magnetic-resonance-imaging-a-method-for-simultaneous-direct-detection-of-myelin-and-high-signal-demonstration-of-iron-deposition-in-the-brain-a-feasibility-study
#19
Vipul R Sheth, Shujuan Fan, Qun He, Yajun Ma, Jacopo Annese, Robert Switzer, Jody Corey-Bloom, Graeme M Bydder, Jiang Du
Multiple sclerosis (MS) causes demyelinating lesions in the white matter and increased iron deposition in the subcortical gray matter. Myelin protons have an extremely short T2* (<1ms) and are not directly detected with conventional clinical magnetic resonance (MR) imaging sequences. Iron deposition also reduces T2*, leading to reduced signal on clinical sequences. In this study we tested the hypothesis that the inversion recovery ultrashort echo time (IR-UTE) pulse sequence can directly and simultaneously image myelin and iron deposition using a clinical 3T scanner...
May 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/27919416/a-3d-model-of-the-achilles-tendon-to-determine-the-mechanisms-underlying-nonuniform-tendon-displacements
#20
Geoffrey G Handsfield, Joshua M Inouye, Laura C Slane, Darryl G Thelen, G Wilson Miller, Silvia S Blemker
The Achilles is the thickest tendon in the body and is the primary elastic energy-storing component during running. The form and function of the human Achilles is complex: twisted structure, intratendinous interactions, and differential motor control from the triceps surae muscles make Achilles behavior difficult to intuit. Recent in vivo imaging of the Achilles has revealed nonuniform displacement patterns that are not fully understood and may result from complex architecture and musculotendon interactions...
January 25, 2017: Journal of Biomechanics
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