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ultrashort echo time

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https://www.readbyqxmd.com/read/28643355/ultra-short-echo-time-images-quantify-high-liver-iron
#1
Eamon K Doyle, Kristin Toy, Bertin Valdez, Jonathan M Chia, Thomas Coates, John C Wood
PURPOSE: 1.5T gradient echo-based R2∗ estimates are standard-of-care for assessing liver iron concentration (LIC). Despite growing popularity of 3T, echo time (TE) limitations prevent 3T liver iron quantitation in the upper half of the clinical range (LIC ⪆20 mg/g). In this work, a 3D radial pulse sequence was assessed to double the dynamic range of 3T LIC estimates. THEORY AND METHODS: The minimum TE limits the dynamic range of pulse sequences to estimate R2∗...
June 22, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28570096/advanced-mri-techniques-for-the-ankle
#2
Palanan Siriwanarangsun, Won C Bae, Sheronda Statum, Christine B Chung
OBJECTIVE: The purposes of this article are to present a state-of-the-art routine protocol for MRI of the ankle, to provide problem-solving tools based on specific clinical indications, and to introduce principles for the implementation of ultrashort echo time MRI of the ankle, including morphologic and quantitative assessment. CONCLUSION: Ankle injury is common among both athletes and the general population, and MRI is the established noninvasive means of evaluation...
June 1, 2017: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/28570032/free-breathing-pediatric-chest-mri-performance-of-self-navigated-golden-angle-ordered-conical-ultrashort-echo-time-acquisition
#3
Evan J Zucker, Joseph Y Cheng, Anshul Haldipur, Michael Carl, Shreyas S Vasanawala
PURPOSE: To assess the feasibility and performance of conical k-space trajectory free-breathing ultrashort echo time (UTE) chest magnetic resonance imaging (MRI) versus four-dimensional (4D) flow and effects of 50% data subsampling and soft-gated motion correction. MATERIALS AND METHODS: Thirty-two consecutive children who underwent both 4D flow and UTE ferumoxytol-enhanced chest MR (mean age: 5.4 years, range: 6 days to 15.7 years) in one 3T exam were recruited...
June 1, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28561910/assessment-of-porosity-index-of-the-femoral-neck-and-tibia-by-3d-ultra-short-echo-time-mri
#4
Min Chen, Huishu Yuan
PURPOSE: To measure the porosity index (PI) by ultrashort echo-time magnetic resonance imaging (UTE MRI) of the femoral neck and tibia; assess its correlations with age, gender, and body mass index (BMI); and analyze the PI correlations between both sites to assess whether tibial PI can reflect changes of femoral neck PI. MATERIALS AND METHODS: In all, 68 healthy men and women (mean age, 45.7 ± 15.9 years) underwent 3D UTE MRI (3.0T) of the hip and mid-shaft tibia...
May 31, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28504544/radial-ultrashort-te-imaging-removes-the-need-for-breath-holding-in-hepatic-iron-overload-quantification-by-r2-mri
#5
Aaryani Tipirneni-Sajja, Axel J Krafft, M Beth McCarville, Ralf B Loeffler, Ruitian Song, Jane S Hankins, Claudia M Hillenbrand
OBJECTIVE: The objective of this study is to evaluate radial free-breathing (FB) multiecho ultrashort TE (UTE) imaging as an alternative to Cartesian FB multiecho gradient-recalled echo (GRE) imaging for quantitative assessment of hepatic iron content (HIC) in sedated patients and subjects unable to perform breath-hold (BH) maneuvers. MATERIALS AND METHODS: FB multiecho GRE imaging and FB multiecho UTE imaging were conducted for 46 test group patients with iron overload who could not complete BH maneuvers (38 patients were sedated, and eight were not sedated) and 16 control patients who could complete BH maneuvers...
May 15, 2017: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/28497643/three-dimensional-ultrashort-echo-time-mri-and-short-t2-images-generated-from-subtraction-for-determination-of-tumor-burden-in-lung-cancer-preclinical-investigation-in-transgenic-mice
#6
Andreas Müller, Philippe Jagoda, Peter Fries, Stefan Gräber, Robert Bals, Arno Buecker, Christopher Jungnickel, Christoph Beisswenger
PURPOSE: To investigate the potential of 3D ultrashort echo time MRI and short T2 images generated by subtraction for determination of total tumor burden in lung cancer. METHODS: As an animal model of spontaneously developing non-small cell lung cancer, the K-rasLA1 transgenic mouse was used. Three-dimensional MR imaging was performed with radial k-space acquisition and echo times of 20 µs and 1 ms. For investigation of the short T2 component in the recorded signal, subtraction images were generated from these data sets and used for consensus identification of tumors...
May 11, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28470838/quantitative-magnetization-transfer-ultrashort-echo-time-imaging-using-a-time-efficient-3d-multispoke-cones-sequence
#7
Ya-Jun Ma, Eric Y Chang, Michael Carl, Jiang Du
PURPOSE: To accelerate the quantitative ultrashort echo time imaging using a time-efficient 3D multispoke Cones sequence with magnetization transfer (3D UTE-Cones-MT) and signal modeling. THEORY AND METHODS: A 3D UTE-Cones-MT acquisition scheme with multispoke per MT preparation and a modified rectangular pulse (RP) approximation was developed for two-pool MT modeling of macromolecular and water components including their relative fractions, relaxation times and exchange rates...
May 3, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28391818/a-computational-measurement-of-cartilaginous-endplate-structure-using-ultrashort-time-to-echo-mri-scanning
#8
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
#9
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
#10
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
#11
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
#12
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
#13
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
#14
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
#15
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
#16
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
#17
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...
June 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
#18
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
#19
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
#20
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
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