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T2 mapping Imaging

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https://www.readbyqxmd.com/read/28088837/disease-severity-classification-using-quantitative-magnetic-resonance-imaging-data-of-cartilage-in-femoroacetabular-impingement
#1
Lisa L Henn, John Hughes, Eleena Iisakka, Jutta Ellermann, Shabnam Mortazavi, Connor Ziegler, Mikko J Nissi, Patrick Morgan
Femoroacetabular impingement (FAI) is a condition in which subtle deformities of the femoral head and acetabulum (hip socket) result in pathological abutment during hip motion. FAI is a common cause of hip pain and can lead to acetabular cartilage damage and osteoarthritis. For some patients with FAI, surgical intervention is indicated, and it can improve quality of life and potentially delay the onset of osteoarthritis. For other patients, however, surgery is contraindicated because significant cartilage damage has already occurred...
January 15, 2017: Statistics in Medicine
https://www.readbyqxmd.com/read/28081157/simultaneous-quantitative-mri-mapping-of-t1-t2-and-magnetic-susceptibility-with-multi-echo-mp2rage
#2
Riccardo Metere, Tobias Kober, Harald E Möller, Andreas Schäfer
The knowledge of relaxation times is essential for understanding the biophysical mechanisms underlying contrast in magnetic resonance imaging. Quantitative experiments, while offering major advantages in terms of reproducibility, may benefit from simultaneous acquisitions. In this work, we demonstrate the possibility of simultaneously recording relaxation-time and susceptibility maps with a prototype Multi-Echo (ME) Magnetization-Prepared 2 RApid Gradient Echoes (MP2RAGE) sequence. T1 maps can be obtained using the MP2RAGE sequence, which is relatively insensitive to inhomogeneities of the radio-frequency transmit field, [Formula: see text]...
2017: PloS One
https://www.readbyqxmd.com/read/28077268/development-of-high-resolution-3d-hyperpolarized-carbon-13-mr-molecular-imaging-techniques
#3
Eugene Milshteyn, Cornelius von Morze, Galen D Reed, Hong Shang, Peter J Shin, Zihan Zhu, Hsin-Yu Chen, Robert Bok, Andrei Goga, John Kurhanewicz, Peder E Z Larson, Daniel B Vigneron
The goal of this project was to develop and apply techniques for T2 mapping and 3D high resolution (1.5 mm isotropic; 0.003 cm(3)) (13)C imaging of hyperpolarized (HP) probes [1-(13)C]lactate, [1-(13)C]pyruvate, [2-(13)C]pyruvate, and [(13)C,(15)N2]urea in vivo. A specialized 2D bSSFP sequence was implemented on a clinical 3T scanner and used to obtain the first high resolution T2 maps of these different hyperpolarized compounds in both rats and tumor-bearing mice. These maps were first used to optimize timings for highest SNR for single time-point 3D bSSFP acquisitions with a 1...
January 7, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28077133/t1-and-t2-mapping-for-evaluation-of-myocardial-involvement-in-patients-with-anca-associated-vasculitides
#4
Simon Greulich, Agnes Mayr, Daniel Kitterer, Joerg Latus, Joerg Henes, Hannah Steubing, Philipp Kaesemann, Alexandru Patrascu, Andreas Greiser, Stefan Groeninger, Niko Braun, M Dominik Alscher, Udo Sechtem, Heiko Mahrholdt
BACKGROUND: Myocardial involvement in AAV patients might be silent, presenting with no or nonspecific symptoms, normal ECG, and preserved left-ventricular ejection fraction (LV-EF). Since up to 50% of deaths in these patients may be due to myocardial involvement, a reliable diagnostic tool is warranted. In contrast to LGE-CMR, which has its strengths in detecting focal inflammatory or fibrotic processes, recent mapping techniques are able to detect even subtle, diffuse inflammatory or fibrotic processes...
January 6, 2017: Journal of Cardiovascular Magnetic Resonance
https://www.readbyqxmd.com/read/28070869/fast-t1-and-t2-mapping-methods-the-zoomed-u-flare-sequence-compared-with-epi-and-snapshot-flash-for-abdominal-imaging-at-11-7-tesla
#5
Géraldine Pastor, María Jiménez-González, Sandra Plaza-García, Marta Beraza, Torsten Reese
OBJECTIVE: A newly adapted zoomed ultrafast low-angle RARE (U-FLARE) sequence is described for abdominal imaging applications at 11.7 Tesla and compared with the standard echo-plannar imaging (EPI) and snapshot fast low angle shot (FLASH) methods. MATERIALS AND METHODS: Ultrafast EPI and snapshot-FLASH protocols were evaluated to determine relaxation times in phantoms and in the mouse kidney in vivo. Owing to their apparent shortcomings, imaging artefacts, signal-to-noise ratio (SNR), and variability in the determination of relaxation times, these methods are compared with the newly implemented zoomed U-FLARE sequence...
January 9, 2017: Magma
https://www.readbyqxmd.com/read/28065851/high-resolution-distortion-free-diffusion-imaging-using-hybrid-spin-warp-and-echo-planar-psf-encoding-approach
#6
Myung-Ho In, Oleg Posnansky, Oliver Speck
High-resolution diffusion-weighted imaging (DWI) has great potential to provide unique information about tissue microstructure in-vivo. Although single-shot echo-planar imaging (EPI) is a most popular tool for DWI, its application for high-resolution DWI is limited due to T2⁎ blurring and susceptibility- and eddy-current-induced geometric distortions, especially at ultra-high field (UHF) such as 7T. In this study, we adapt a hybrid spin-warp and echo-planar encoding strategy inspired by point spread function (PSF) mapping and optimize it for high-resolution and distortion-free diffusion imaging applications...
January 5, 2017: NeuroImage
https://www.readbyqxmd.com/read/28064350/a-descriptive-study-of-potential-effect-of-anterior-tibial-translation-femoral-tunnel-and-anterior-cruciate-ligament-graft-inclination-on-clinical-outcome-and-degenerative-changes
#7
Žiga Snoj, Oskar Zupanc, Klemen Stražar, Vladka Salapura
INTRODUCTION: There is no evidence that anatomically correct anterior cruciate ligament reconstruction (ACLR) offers lower rate of degenerative changes development or that it would lead to a better outcome. The significance and understanding of the abnormal anterior tibial translation (ATT) in ACLR patients is yet to be established. METHODS: Sixty subjects (40 patients at 5.9 years after ACLR, 20 healthy controls) underwent 3 T MRI. Quantitative cartilage T2 mapping and morphological whole organ magnetic resonance imaging score (WORMS) evaluation was performed...
January 7, 2017: International Orthopaedics
https://www.readbyqxmd.com/read/28063997/colorectal-carcinoma-ex-vivo-evaluation-using-3-t-high-spatial-resolution-quantitative-t2-mapping-and-its-correlation-with-histopathologic-findings
#8
Ichiro Yamada, Norio Yoshino, Keigo Hikishima, Naoyuki Miyasaka, Shinichi Yamauchi, Hiroyuki Uetake, Masamichi Yasuno, Yukihisa Saida, Ukihide Tateishi, Daisuke Kobayashi, Yoshinobu Eishi
PURPOSE: In this study, we aimed to evaluate the feasibility of determining the mural invasion depths of colorectal carcinomas using high-spatial-resolution (HSR) quantitative T2 mapping on a 3-T magnetic resonance (MR) scanner. MATERIALS AND METHODS: Twenty colorectal specimens containing adenocarcinomas were imaged on a 3-T MR system equipped with a 4-channel phased-array surface coil. HSR quantitative T2 maps were acquired using a spin-echo sequence with a repetition time/echo time of 7650/22...
January 4, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28058480/everyman-s-prostate-phantom-kiwi-fruit-substitute-for-human-prostates-at-magnetic-resonance-imaging-diffusion-weighted-imaging-and-magnetic-resonance-spectroscopy
#9
Ullrich G Mueller-Lisse, Sophie Murer, Ulrike L Mueller-Lisse, Marissa Kuhn, Juergen Scheidler, Michael Scherr
OBJECTIVES: To apply an easy-to-assemble phantom substitute for human prostates in T2-weighted magnetic resonance imaging (T2WI), diffusion-weighted imaging (DWI) and 3D magnetic resonance spectroscopy (MRS). METHODS: Kiwi fruit were fixed with gel hot and cold compress packs on two plastic nursery pots, separated by a plastic plate, and submerged in tap water inside a 1-L open-spout plastic watering can for T2WI (TR/TE 7500/101 ms), DWI (5500/61 ms, ADC b50-800 s/mm(2) map) and MRS (940/145 ms) at 3...
January 5, 2017: European Radiology
https://www.readbyqxmd.com/read/28048910/su-g-jep2-10-on-the-need-for-a-dynamic-model-for-patient-specific-distortion-corrections-for-mr-only-pelvis-treatment-planning
#10
C Glide-Hurst, W Zheng, C Stehning, S Weiss, S Renisch
PURPOSE: Patient-specific distortions, particularly near tissue/air interfaces, require assessment and possible corrections for MRI-only radiation treatment planning (RTP). However, patients are dynamic due to changes in physiological status and motion during imaging sessions. This work investigated the need for dynamic patient-specific distortion corrections to support pelvis MR-only RTP. METHODS: The pelvises of healthy volunteers were imaged at 1.0T, 1.5T, and 3...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048894/su-f-i-58-image-quality-comparisons-of-different-motion-magnitudes-and-tr-values-in-mr-pet
#11
J Patrick, M Tavallaei, R Thompson, R Stodilka, M Drangova, S Gaede
PURPOSE: The aim of this work is to evaluate the accuracy and sensitivity of a respiratory-triggered MR-PET protocol in detecting four different sized lesions at two different magnitudes of motion, with two different TR values, using a novel PET-MR-CT compatible respiratory motion phantom. METHODS: The eight-compartment torso phantom was setup adjacent to the motion stage, which moved four spherical compartments (28, 22, 17, 10 mm diameter) in two separate (1 and 2 cm) linear motion profiles, simulating a 3...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048805/su-f-r-42-association-of-radiomic-and-metabolic-tumor-volumes-in-radiation-treatment-of-glioblastoma-multiforme
#12
C Lopez, N Nagornaya, N Parra, D Kwon, F Ishkanian, A Markoe, A Maudsley, R Stoyanova
PURPOSE: High-throughput extraction of imaging and metabolomic quantitative features from MRI and MR Spectroscopy Imaging (MRSI) of Glioblastoma Multiforme (GBM) results in tens of variables per patient. In radiotherapy (RT) of GBM, the relevant metabolic tumor volumes (MTVs) are related to aberrant levels of N-acetyl Aspartate (NAA) and Choline (Cho). Corresponding Clinical Target Volumes (CTVs) for RT planning are based on Contrast Enhancing T1-weighted MRI (CE-T1w) and T2-weighted/Fluid Attenuated Inversion Recovery (FLAIR) MRI...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048262/su-g-iep1-07-inaccuracy-of-lesion-blood-flow-quantification-related-to-the-proton-density-reference-image-in-arterial-spin-labeling-mri-of-brain-tumors
#13
M Jen, J Johnson, P Hou, H Liu
PURPOSE: Cerebral blood flow quantification in arterial spin labeling (ASL) MRI requires an estimate of the equilibrium magnetization of blood, which is often obtained by a set of proton density (PD) reference image. Normally, a constant blood-brain partition coefficient is assumed across the brain. However, this assumption may not be valid for brain lesions. This study aimed to evaluate the impact of lesion-related PD variations on ASL quantification in patients with brain tumors. METHODS: MR images for posttreatment evaluation of 42 patients with brain tumors were retrospectively analyzed...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28048075/su-f-i-22-development-and-implementation-of-task-specific-modular-phantom-for-mri-quality-evaluation
#14
H Cho, C Hong, I Doh, B Ahn
PURPOSE: To investigate the potential of a newly developed modular phantom with image quality test structure for MRI quality control. METHODS: The modular phantom consists of individual basic mapping (BM) modules, image quality control (QC) modules, and accessories to improve combination variability for multipurpose use. BM modules were designed based on the stud-and-tube coupling system with an internal hollow and an individual enclosed structure. The QC modules include signal-to-noise ratio, image intensity uniformity, geometric accuracy, high-contrast spatial resolution, slice thickness accuracy, slice position accuracy and low-contrast object detectability evaluation test structure...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047934/tu-d-207b-04-identifying-high-risk-tumor-volume-based-on-multi-region-and-integrated-analysis-of-multi-parametric-mr-images-for-prognostication-of-glioblastoma
#15
X Ren, Y Cui, H Gao, R Li
PURPOSE: To identify high-risk tumor volume for predicting survival in patients with glioblastoma on the basis of multi-region and integrated analysis of multi-parametric MR images. METHODS: In this retrospectively study, 34 patients with glioblastoma from the Cancer Imaging Archive (TCIA) were analyzed. The patients were included if all of the pre-operative 1) T1-weighted contrast-enhanced (T1c), 2) T2-weighted fluid-attenuation inversion recovery (FLAIR), and 3) diffusion-weighted (DW) MR images were available...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047779/we-h-207a-08-characterization-of-a-broad-spectrum-cancer-targeted-mri-contrast-agent
#16
C Brunnquell, R Zhang, A Pinchuk, J Weichert
PURPOSE: To characterize the relaxation properties and tumor targeting capabilities of a novel alkylphosphocholine (APC) analog MR contrast agent, Gd-DO3A-404. METHODS: Relaxivities were measured via T1 and T2 mapping of Gd-DO3A-404 with inversion recovery and spin echo pulse sequences, respectively. Uptake was characterized in flank xenograft models of non-small cell lung cancer (A549) and glioma (U87) and compared with uptake of Dotarem. Mice (N=3 per model per agent) were delivered 2...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047502/su-g-iep1-04-comparison-of-cerebral-blood-volume-estimated-by-dsc-and-dcemri
#17
M Aryal, Y Cao
PURPOSE: The cerebral blood volume (CBV) is commonly estimated from T2*/T2-weighted dynamic susceptibility contrast (DSC) MRI acquired by an EPI sequence. There are several challenges with DSC imaging, including geometric distortion, limited brain spatial coverage, and unreliable arterial input function (AIF) due to the partial volume effect. However, CBV can be estimated from T1-weighted dynamic contrast enhanced (DCE) MRI. This study aimed to examine whether CBV estimated from DCE-MRI is comparable to one from DSC-MRI...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28047432/su-g-iep1-11-resting-state-fluctuation-of-bold-signal-amplitude-for-mapping-cerebrovascular-reactivity-in-presurgical-functional-mri
#18
P Wang, P Hou, S Kesler, R Colen, A Kumar, S Prabhu, H Liu
PURPOSE: Cerebrovascular reactivity (CVR) MRI with hypercapnia challenges, such as a breath-hold (BH) task, has been proposed to indicate areas with neurovascular uncoupling potentials for presurgical functional MRI (fMRI). This study aimed to explore the use of resting-state (RS) fMRI, in particular, the RS fluctuation of amplitude (RSFA) for detecting the impaired CVR and compare with BH MRI in patients with gliomas. METHODS: The BH and RS fMRI from six patients as part of their presurgical fMRI studies were analyzed...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046971/th-cd-206-01-expectation-maximization-algorithm-based-tissue-mixture-quantification-for-perfusion-mri
#19
H Han, Z Liang, L Li, L Xing
PURPOSE: To investigate the feasibility of estimating the tissue mixture perfusions and quantifying cerebral blood flow change in arterial spin labeled (ASL) perfusion MR images. METHODS: The proposed perfusion MR image analysis framework consists of 5 steps: (1) Inhomogeneity correction was performed on the T1- and T2-weighted images, which are available for each studied perfusion MR dataset. (2) We used the publicly available FSL toolbox to strip off the non-brain structures from the T1- and T2-weighted MR images...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046932/su-g-jep2-02-a-unifying-multi-atlas-approach-to-electron-density-mapping-using-multi-parametric-mri-for-radiation-treatment-planning
#20
S Ren, W Hara, Q Le, L Wang, L Xing, R Li
PURPOSE: MRI has a number of advantages over CT as a primary modality for radiation treatment planning (RTP). However, one key bottleneck problem still remains, which is the lack of electron density information in MRI. In the work, a reliable method to map electron density is developed by leveraging the differential contrast of multi-parametric MRI. METHODS: We propose a probabilistic Bayesian approach for electron density mapping based on T1 and T2-weighted MRI, using multiple patients as atlases...
June 2016: Medical Physics
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