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https://www.readbyqxmd.com/read/28449249/t2-mapping-evaluation-of-early-cartilage-alteration-of-talus-for-chronic-lateral-ankle-instability-with-isolated-anterior-talofibular-ligament-tear-or-combined-with-calcaneofibular-ligament-tear
#1
Hongyue Tao, Yiwen Hu, Yang Qiao, Kui Ma, Xu Yan, Yinghui Hua, Shuang Chen
PURPOSE: To quantitatively evaluate the cartilage alteration of talus for chronic lateral ankle instability (LAI) with isolated anterior talofibular ligament (ATFL) tear and combined ATFL and calcaneofibular ligament (CFL) tear using T2 -mapping at 3.0T. MATERIALS AND METHODS: In all, 27 patients including 17 with isolated ATFL tear and 10 with ATFL+CFL tear, and 21 healthy subjects were recruited. All participants underwent T2 -mapping scan at 3T and patients completed American Orthopaedic Foot and Ankle Society (AOFAS) scoring...
April 27, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28448233/t1-and-t2-mapping-in-recognition-of-early-cardiac-involvement-in-systemic-sarcoidosis
#2
Valentina O Puntmann, Alexander Isted, Rocio Hinojar, Lucy Foote, Gerald Carr-White, Eike Nagel
Purpose To determine whether quantitative tissue characterization with T1 and T2 mapping supports recognition of myocardial involvement in patients with systemic sarcoidosis. Materials and Methods Fifty-three consecutive patients with a biopsy-proven extracardiac diagnosis of systemic sarcoidosis (21 men; median age, 45 years; interquartile range, 22 years) and 36 normotensive previously healthy control subjects (14 men; median age, 43 years; interquartile range, 18 years) underwent cardiovascular magnetic resonance imaging, which was performed to assess cardiac function and late gadolinium enhancement, and T1 and T2 mapping...
April 27, 2017: Radiology
https://www.readbyqxmd.com/read/28441369/cardiac-magnetic-resonance-imaging-in-oncology
#3
Daniel Jeong, Aarti Patel, Christopher J Francois, Kenneth L Gage, Michael G Fradley
BACKGROUND: Cardiac magnetic resonance imaging (MRI) is emerging as an important diagnostic modality in the management of cardiovascular-related dysfunction in oncological diseases. Advances in imaging techniques have enhanced the detection and evaluation of cardiac masses; meanwhile, innovative applications have created a growing role for cardiac MRI for the management of cardiotoxicity caused by cancer therapies. METHODS: An overview is provided of the clinical indications and technical considerations of cardiac MRI...
April 2017: Cancer Control: Journal of the Moffitt Cancer Center
https://www.readbyqxmd.com/read/28438711/can-transverse-relaxation-rates-in-deep-gray-matter-be-approximated-from-functional-and-t2-weighted-flair-scans-for-relative-brain-iron-quantification
#4
Benjamín Garzón, Rouslan Sitnikov, Lars Bäckman, Grégoria Kalpouzos
Alterations in iron concentration in certain deep gray matter regions are known to occur in aging and several clinical conditions. In vivo measurements of R2(∗) transverse relaxation rates and quantitative susceptibility mapping (QSM) have been shown to be strongly correlated with iron concentration in tissue, but their calculation requires the acquisition of a multi-echo gradient recalled echo sequence (MGRE). In the current study, we examined the feasibility of approximating R2(∗) rates using metrics derived from fMRI-EPI and T2-weighted FLAIR images, which are widely available...
April 21, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28438709/characterization-of-high-resolution-gradient-echo-and-spin-echo-epi-for-fmri-in-the-human-visual-cortex-at-7t
#5
Catarina Rua, Mauro Costagli, Mark R Symms, Laura Biagi, Graziella Donatelli, Mirco Cosottini, Alberto Del Guerra, Michela Tosetti
The increased signal-to-noise ratio (SNR) offered by functional Magnetic Resonance Imaging (fMRI) at 7T allows the acquisition of functional data at sub-millimetric spatial resolutions. However, simply reducing partial volume effects is not sufficient to precisely localize task-induced activation due to the indirect mechanisms that relate brain function and the changes in the measured signal. In this work T2* and T2 weighted Echo Planar Imaging (EPI) schemes based on Gradient Recalled Echo (GRE) and Spin Echo (SE) were evaluated in terms of temporal SNR, percent signal change, contrast to noise ratio (CNR), activation volume, and sensitivity and specificity to gray matter...
April 21, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28435102/simultaneous-time-interleaved-multislice-stims-for-rapid-susceptibility-weighted-acquisition
#6
Berkin Bilgic, Huihui Ye, Lawrence L Wald, Kawin Setsompop
T2⁎ weighted 3D Gradient Echo (GRE) acquisition is the main sequence used for Susceptibility Weighted Imaging (SWI) and Quantitative Susceptibility Mapping (QSM). These applications require a long echo time (TE) to build up phase contrast, requiring a long repetition time (TR), and leading to excessively lengthy scans. The long TE acquisition creates a significant amount of unused time within each TR, which can be utilized for either multi-echo sampling or additional image encoding with the echo-shift technique...
April 20, 2017: NeuroImage
https://www.readbyqxmd.com/read/28432852/correlation-between-expression-of-high-temperature-requirement-serine-protease-a1-htra1-in-nucleus-pulposus-and-t2-value-of-magnetic-resonance-imaging
#7
Dapeng Li, Jiawei Yue, Lu Jiang, Yonghui Huang, Jifu Sun, Yan Wu
BACKGROUND Degrading enzymes play an important role in the process of disc degeneration. The objective of this study was to investigate the correlation between the expression of high temperature requirement serine protease A1 (HtrA1) in the nucleus pulposus and the T2 value of the nucleus pulposus region in magnetic resonance imaging (MRI). MATERIAL AND METHODS Thirty-six patients who had undergone surgical excision of the nucleus pulposus were examined by MRI before surgery. Pfirrmann grading of the target intervertebral disc was performed according to the sagittal T2-weighted imaging, and the T2 value of the target nucleus pulposus was measured according to the median sagittal T2 mapping...
April 22, 2017: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
https://www.readbyqxmd.com/read/28431631/neuroimaging-findings-in-joubert-syndrome-with-c5orf42-gene-mutations-a-milder-form-of-molar-tooth-sign-and-vermian-hypoplasia
#8
Mikako Enokizono, Noriko Aida, Tetsu Niwa, Hitoshi Osaka, Takuya Naruto, Kenji Kurosawa, Chihiro Ohba, Toshifumi Suzuki, Hirotomo Saitsu, Tomohide Goto, Naomichi Matsumoto
PURPOSE: Little is known regarding neuroimaging-genotype correlations in Joubert syndrome (JBTS). To elucidate one of these correlations, we investigated the neuroimaging findings of JBTS patients with C5orf42 mutations. MATERIALS AND METHODS: Neuroimaging findings in five JBTS patients with C5orf42 mutations were retrospectively assessed with regard to the infratentorial and supratentorial structures on T1-magnetization prepared rapid gradient echo (MPRAGE), T2-weighted images, and color-coded fractional anisotropy (FA) maps; the findings were compared to those in four JBTS patients with mutations in other genes (including three with AHI1 and one with TMEM67 mutations)...
May 15, 2017: Journal of the Neurological Sciences
https://www.readbyqxmd.com/read/28431589/t2-relaxometry-helps-prognosticate-seizure-outcome-in-patients-with-solitary-cerebral-cysticercosis
#9
Aaron de Souza, Atchayaram Nalini, Jitender Saini, Kandavel Thennarasu
OBJECTIVE: Correlate serial T2 relaxometry (T2R) values with long term seizure outcome in patients with solitary cerebral cysticercosis (SCC) in order to establish its usefulness as a prognostic marker in these patients. METHODS: Patients with new-onset seizures due to SCC were imaged serially using a pre-determined MRI protocol at enrolment and after 3, 6, 12 and 24months. T2 relaxometry was performed using a dual echo sequence with maps generated manually from the measured image intensities at the level of the lesion...
May 15, 2017: Journal of the Neurological Sciences
https://www.readbyqxmd.com/read/28427489/effects-of-structural-changes-in-subchondral-bone-on-articular-cartilage-in-a-beagle-dog-model
#10
Dong Yan, Tong Xi Liu, Bao Yue Liu, Ling Wang, Zhan Hua Qian, Xiao Guang Cheng, Kun Cheng Li
OBJECTIVE: Using MR T2-mapping and histopathologic score for articular cartilage to evaluate the effect of structural changes in subchondral bone on articular cartilage. METHODS: Twenty-four male Beagle dogs were randomly divided into a subchondral bone defect group (n = 12) and a bone cement group (n = 12). Models of subchondral bone defectin the medial tibial plateau and subchondral bone filled with bone cement were constructed. In all dogs, the left knee joint was used as the experimental sideand the right knee as the sham side...
March 2017: Biomedical and Environmental Sciences: BES
https://www.readbyqxmd.com/read/28426147/propagation-of-error-from-parameter-constraints-in-quantitative-mri-example-application-of-multiple-spin-echo-t2-mapping
#11
Christopher L Lankford, Mark D Does
PURPOSE: Quantitative MRI may require correcting for nuisance parameters which can or must be constrained to independently measured or assumed values. The noise and/or bias in these constraints propagate to fitted parameters. For example, the case of refocusing pulse flip angle constraint in multiple spin echo T2 mapping is explored. METHODS: An analytical expression for the mean-squared error of a parameter of interest was derived as a function of the accuracy and precision of an independent estimate of a nuisance parameter...
April 20, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28423027/comparison-of-t2-weighted-and-qsm-contrasts-in-parkinson-s-disease-to-visualize-the-stn-with-mri
#12
Anneke Alkemade, Gilles de Hollander, Max C Keuken, Andreas Schäfer, Derek V M Ott, Johannes Schwarz, David Weise, Sonja A Kotz, Birte U Forstmann
The subthalamic nucleus (STN) plays a crucial role in the surgical treatment of Parkinson's disease (PD). Studies investigating optimal protocols for STN visualization using state of the art magnetic resonance imaging (MRI) techniques have shown that susceptibility weighted images, which display the magnetic susceptibility distribution, yield better results than T1-weighted, T2-weighted, and T2*-weighted contrasts. However, these findings are based on young healthy individuals, and require validation in elderly individuals and persons suffering from PD...
2017: PloS One
https://www.readbyqxmd.com/read/28422800/evaluation-of-water-content-in-lumbar-intervertebral-discs-and-facet-joints-before-and-after-physiological-loading-using-t2-mapping-mri
#13
Daisuke Yamabe, Hideki Murakami, Kou Chokan, Hirooki Endo, Ryosuke Oikawa, Shoitsu Sawamura, Minoru Doita
STUDY DESIGN: T2 mapping was used to quantify the water content of lumbar spine intervertebral discs (IVD) and facet joints before and after physiological loading. OBJECTIVE: To clarify the interaction between lumbar spine IVD and facet joints as load-bearing structures by measuring the water content of their matrix after physiological loading using T2 mapping magnetic resonance imaging (MRI). SUMMARY OF BACKGROUND DATA: To date, few reports have functionally evaluated lumbar spine IVD and facet joints, and their interaction in vivo...
April 18, 2017: Spine
https://www.readbyqxmd.com/read/28419612/delayed-gadolinium-enhanced-mri-of-cartilage-dgemric-and-t2-mapping-of-talar-osteochondral-lesions-indicators-of-clinical-outcomes
#14
Christoph Rehnitz, Benita Kuni, Felix Wuennemann, Dimitrios Chloridis, Anand Kirwadi, Iris Burkholder, Hans-Ulrich Kauczor, Marc-André Weber
PURPOSE: To evaluate the utility of delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) and T2 mapping in evaluation of type II osteochondral lesions (OCLs) of the talus and define cutoff values for identifying patients with good/poor clinical outcomes. MATERIALS AND METHODS: 28 patients (mean age, 42.3 years) underwent T2 mapping and dGEMRIC at least 1.5 years (mean duration, 3.5 years) after microfracture (n = 12) or conservative (n = 16) treatment for type II OCL...
April 17, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28419591/application-of-spin-echoes-in-the-regime-of-weak-dephasing-to-t1-mapping-of-the-lung
#15
Jakob Assländer, Steffen J Glaser, Jürgen Hennig
PURPOSE: This work presents an approach to mapping the entire lung's proton density and T1 within a single breath-hold and analyzes the apparent T1 when exciting with a spin echo generating pulse in comparison to a standard gradient echo acquisition. METHODS: An inversion-recovery SNAPSHOT-FLASH sequence with a stack-of-stars k-space readout with a golden angle increment was modified to use a spin echo generating radiofrequency-pulse for excitation. Data of five volunteers were acquired on a 3T scanner and image reconstruction was performed by an iterative algorithm adopted from MR-Fingerprinting...
April 17, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28416453/high-resolution-data-analysis-strategies-for-mesoscale-human-functional-mri-at-7-and-9-4t
#16
Valentin G Kemper, Federico De Martino, Thomas C Emmerling, Essa Yacoub, Rainer Goebel
The advent of ultra-high field functional magnetic resonance imaging (fMRI) has greatly facilitated submillimeter resolution acquisitions (voxel volume below (1mm³)), allowing the investigation of cortical columns and cortical depth dependent (i.e. laminar) structures in the human brain. Advanced data analysis techniques are essential to exploit the information in high resolution functional measures. In this article, we use recent, exemplary 9.4T human functional and anatomical data to review the advantages and disadvantages of (1) pooling high resolution data across regions of interest for cortical depth profile analysis, (2) pooling across cortical depths for mapping patches of cortex while discarding depth-dependent (i...
April 14, 2017: NeuroImage
https://www.readbyqxmd.com/read/28415581/tumor-physiological-changes-during-hypofractionated-stereotactic-body-radiation-therapy-assessed-using-multi-parametric-magnetic-resonance-imaging
#17
Heling Zhou, Zhang Zhang, Rebecca Denney, Jessica S Williams, Jeni Gerberich, Strahinja Stojadinovic, Debabrata Saha, John M Shelton, Ralph P Mason
Radiation therapy is a primary treatment for non-resectable lung cancer and hypoxia is thought to influence tumor response. Hypoxia is expected to be particularly relevant to the evolving new radiation treatment scheme of hypofractionated stereotactic body radiation therapy (SBRT). As such, we sought to develop non-invasive tools to assess tumor pathophysiology and response to irradiation. We applied blood oxygen level dependent (BOLD) and tissue oxygen level dependent (TOLD) MRI, together with dynamic contrast enhanced (DCE) MRI to explore the longitudinal effects of SBRT on tumor oxygenation and vascular perfusion using A549 human lung cancer xenografts in a subcutaneous rat model...
March 21, 2017: Oncotarget
https://www.readbyqxmd.com/read/28412673/effect-of-controlled-hypotension-on-myocardial-ischemia-marker-in-eye-nose-related-surgery
#18
Yuexi Jin, Wanna Jiang, Wenlian Ye, Aifen Jiang, Le Liu
We aimed to investigate the effect of different controlled hypotension levels on myocardial enzymes and myocardial ischemia protein in elderly hypertension patients, and then provide clinical evidence of suitable controlled hypotension level for them. Then, 45 elderly hypertension patients received elective eye-nose related surgery with nasal endoscope, who were randomly and evenly divided into three groups, including A, B and C groups, with mean arterial pressure (MAP) decreased by 20%, 30% and 40% respectively...
November 2016: Pakistan Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28411394/improved-magnetic-resonance-fingerprinting-reconstruction-with-low-rank-and-subspace-modeling
#19
Bo Zhao, Kawin Setsompop, Elfar Adalsteinsson, Borjan Gagoski, Huihui Ye, Dan Ma, Yun Jiang, P Ellen Grant, Mark A Griswold, Lawrence L Wald
PURPOSE: This article introduces a constrained imaging method based on low-rank and subspace modeling to improve the accuracy and speed of MR fingerprinting (MRF). THEORY AND METHODS: A new model-based imaging method is developed for MRF to reconstruct high-quality time-series images and accurate tissue parameter maps (e.g., T1 , T2 , and spin density maps). Specifically, the proposed method exploits low-rank approximations of MRF time-series images, and further enforces temporal subspace constraints to capture magnetization dynamics...
April 15, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28409357/diffusion-weighted-mri-to-assess-response-to-chemoradiotherapy-in-rectal-cancer-main-interpretation-pitfalls-and-their-use-for-teaching
#20
Doenja M J Lambregts, Miriam M van Heeswijk, Andrea Delli Pizzi, Saskia G C van Elderen, Luisa Andrade, Nicky H G M Peters, Peter A M Kint, Margreet Osinga-de Jong, Shandra Bipat, Rik Ooms, Max J Lahaye, Monique Maas, Geerard L Beets, Frans C H Bakers, Regina G H Beets-Tan
OBJECTIVES: To establish the most common image interpretation pitfalls for non-expert readers using diffusion-weighted imaging (DWI) to assess response to chemoradiotherapy in patients with rectal cancer and to explore the use of these pitfalls in an expert teaching setting. METHODS: Two independent non-expert readers (R1 and R2) scored the restaging DW MRI scans (b1,000 DWI, in conjunction with ADC maps and T2-W MRI scans for anatomical reference) in 100 patients for the likelihood of a complete response versus residual tumour using a five-point confidence score...
April 13, 2017: European Radiology
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