keyword
MENU ▼
Read by QxMD icon Read
search

Echo planar

keyword
https://www.readbyqxmd.com/read/28216452/water-and-lipid-diffusion-mri-using-chemical-shift-displacement-based-separation-of-lipid-tissue-split
#1
Naoki Ohno, Hirohito Kan, Tosiaki Miyati, Toshitaka Aoki, Shota Ishida, Toshifumi Gabata
PURPOSE: To obtain water and lipid diffusion-weighted images (DWIs) simultaneously, we devised a novel method utilizing chemical shift displacement-based separation of lipid tissue (SPLIT) imaging. MATERIALS AND METHODS: Single-shot diffusion echo-planar imaging without fat suppression was used and the imaging parameters were optimized to separate water and lipid DWIs by chemical shift displacement of the lipid signals along the phase-encoding direction. Using the optimized conditions, transverse DWIs at the maximum diameter of the right calf were scanned with multiple b-values in five healthy subjects...
February 16, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28207858/non-small-cell-lung-cancer-whole-lesion-histogram-analysis-of-the-apparent-diffusion-coefficient-for-assessment-of-tumor-grade-lymphovascular-invasion-and-pleural-invasion
#2
Naoko Tsuchiya, Mariko Doai, Katsuo Usuda, Hidetaka Uramoto, Hisao Tonami
PURPOSE: Investigating the diagnostic accuracy of histogram analyses of apparent diffusion coefficient (ADC) values for determining non-small cell lung cancer (NSCLC) tumor grades, lymphovascular invasion, and pleural invasion. MATERIALS AND METHODS: We studied 60 surgically diagnosed NSCLC patients. Diffusion-weighted imaging (DWI) was performed in the axial plane using a navigator-triggered single-shot, echo-planar imaging sequence with prospective acquisition correction...
2017: PloS One
https://www.readbyqxmd.com/read/28205251/multishot-echo-planar-mreit-for-fast-imaging-of-conductivity-current-density-and-electric-field-distributions
#3
Munish Chauhan, Rohini Vidya Shankar, Neeta Ashok Kumar, Vikram D Kodibagkar, Rosalind Sadleir
PURPOSE: Magnetic resonance electrical impedance tomography (MREIT) sequences typically use conventional spin or gradient echo-based acquisition methods for reconstruction of conductivity and current density maps. Use of MREIT in functional and electroporation studies requires higher temporal resolution and faster sequences. Here, single and multishot echo planar imaging (EPI) based MREIT sequences were evaluated to see whether high-quality MREIT phase data could be obtained for rapid reconstruction of current density, conductivity, and electric fields...
February 16, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28199041/feasibility-of-accelerated-simultaneous-multislice-diffusion-weighted-mri-of-the-prostate
#4
Jakob Weiss, Petros Martirosian, Jana Taron, Ahmed E Othman, Thomas Kuestner, Michael Erb, Jens Bedke, Fabian Bamberg, Konstantin Nikolaou, Mike Notohamiprodjo
PURPOSE: To assess the feasibility of simultaneous multislice (SMS) single-shot echo-planar-imaging (EPI) for accelerated diffusion-weighted imaging (DWI) of the prostate. MATERIALS AND METHODS: For phantom measurements a dedicated DWI phantom with different sucrose concentrations was used. In addition, 10 volunteers and 16 patients with suspected prostate cancer were examined for in vivo measurements. All examinations were performed with a 3T magnetic resonance imaging (MRI) system...
February 15, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28195998/a-meta-analysis-on-the-diagnostic-performance-of-non-echoplanar-diffusion-weighted-imaging-in-detecting-middle-ear-cholesteatoma-10-years-on
#5
Ravi K Lingam, Paul Bassett
OBJECTIVE: To describe via a meta-analysis of the published literature, the performance of non-echo-planar diffusion weighted imaging (DWI) in detecting middle ear cholesteatoma. METHODOLOGY: A systematic review of the published literature was performed to identify original studies evaluating the diagnostic performance of non-echo-planar DWI in detecting middle ear cholesteatoma. Only studies with surgical correlation were included. A bi-variate meta-analysis and hierarchical summary receiver operating characteristic model was performed...
February 10, 2017: Otology & Neurotology
https://www.readbyqxmd.com/read/28194821/image-formation-in-diffusion-mri-a-review-of-recent-technical-developments
#6
REVIEW
Wenchuan Wu, Karla L Miller
: Diffusion magnetic resonance imaging (MRI) is a standard imaging tool in clinical neurology, and is becoming increasingly important for neuroscience studies due to its ability to depict complex neuroanatomy (eg, white matter connectivity). Single-shot echo-planar imaging is currently the predominant formation method for diffusion MRI, but suffers from blurring, distortion, and low spatial resolution. A number of methods have been proposed to address these limitations and improve diffusion MRI acquisition...
February 14, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28185433/model-based-iterative-reconstruction-for-single-shot-epi-at-7t
#7
Uten Yarach, Myung-Ho In, Itthi Chatnuntawech, Berkin Bilgic, Frank Godenschweger, Hendrik Mattern, Alessandro Sciarra, Oliver Speck
PURPOSE: To describe a model-based reconstruction strategy for single-shot echo planar imaging (EPI) that intrinsically accounts for k-space nonuniformity, Nyquist ghosting, and geometric distortions during rather than before or after image reconstruction. METHODS: Ramp sampling and inhomogeneous B0 field-induced distortion cause the EPI samples to lie on a non-Cartesian grid, thus requiring the nonuniform fast Fourier transform. Additionally, a 2D Nyquist ghost phase correction without the need for extra navigator acquisition is included in the proposed reconstruction...
February 10, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28180186/non-parametric-intravoxel-incoherent-motion-analysis-of-the-thyroid-gland
#8
Anton S Becker, Moritz C Wurnig, Tim Finkenstaedt, Andreas Boss
PURPOSE: To implement a protocol for intravoxel incoherent motion (IVIM) of the thyroid, to determine base parameters in healthy volunteers, and to provide preliminary experience on clinical applicability in one patient. MATERIALS AND METHODS: Eight healthy volunteers underwent 3T MRI using a diffusion weighted echo-planar imaging sequence with 12 different b-values between 0-800 s/mm(2). The IVIM parameters diffusion coefficient D, pseudo-diffusion coefficient D*, perfusion fraction Fp, and the optimal b-values thresholds were calculated for each thyroid lobe, muscle tissue and the cerebrospinal fluid (CSF) using a non-parametric multi-step algorithm and compared with a Student's t-test...
January 2017: Heliyon
https://www.readbyqxmd.com/read/28173745/characterization-of-chronic-axonal-degeneration-using-diffusion-tensor-imaging-in-canine-spinal-cord-injury-a-quantitative-analysis-of-dti-parameters-according-to-histopathological-differences
#9
Hakyoung Yoon, Jaehwan Kim, Won-Jin Moon, Sang-Soep Nahm, Jun Zhao, Hyoung-Moon Kim, Kidong Eom
Diffusion tensor imaging (DTI) is more sensitive than conventional magnetic resonance imaging (MRI) for the identification of axonal degeneration. However, no study to date has used DTI to evaluate the severity of axonal degeneration in canine spinal cord injury. Therefore, the aim of this study was to characterize multi-grade axonal degeneration (mild, moderate, and severe) in a canine model of spinal cord compression injury using DTI. MRI data were obtained from six normal dogs and five dogs with lumbar spinal cord injury 78 days after spinal cord injury (L1-L3) using a 3T MRI scanner...
February 7, 2017: Journal of Neurotrauma
https://www.readbyqxmd.com/read/28166488/single-shot-t2-mapping-through-overlapping-echo-detachment-oled-planar-imaging
#10
Congbo Cai, Yiqing Zeng, Yuchuan Zhuang, Shuhui Cai, Lin Chen, Xinghao Ding, Lijun Bao, Jianhui Zhong, Zhong Chen
OBJECTIVE: Develop a reliable single-shot T2 mapping method with extra robustness to motion and the potential for realtime dynamic and quantitative MR imaging. METHODS: A singleshot T2 mapping sequence was proposed based on spin-echo planar imaging (SE-EPI) acquisition scheme. Two overlapped echo signals with different T2 weighting were obtained simultaneously by using two small flip-angle excitation pulses and corresponding echo-shifting gradients. Detachment algorithm based on structure similarity constraint was proposed to separate the two echo signals...
January 31, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28160227/assessment-of-brain-core-temperature-using-mr-dwi-thermometry-in-alzheimer-disease-patients-compared-to-healthy-subjects
#11
Gianvincenzo Sparacia, Koji Sakai, Kei Yamada, Giovanna Giordano, Rosalia Coppola, Massimo Midiri, Luigi Maria Grimaldi
PURPOSE: To assess the brain core temperature of Alzheimer disease (AD) patients in comparison with healthy volunteers using diffusion-weighted thermometry. MATERIALS AND METHODS: Fourteen AD patients (3 men, 11 women; age range 60-81 years, mean age 73.8 ± 6.1 years) and 14 healthy volunteers, age and sex-matched (mean age 70.1 ± 6.9 years; range 62-84 years; 5 men, 9 women) underwent MR examination between February 2014 and March 2016. MR imaging studies were performed with a 1...
February 3, 2017: Japanese Journal of Radiology
https://www.readbyqxmd.com/read/28156202/diffusion-tensor-imaging-of-the-physes-a-possible-biomarker-for-skeletal-growth-experience-with-151-children
#12
Maria A Bedoya, Jorge Delgado, Jeffrey I Berman, Nancy A Chauvin, David Zurakowski, Raul Ramirez-Grueso, Aikaterini Ntoulia, Diego Jaramillo
Purpose To determine the changes of diffusion-tensor imaging (DTI) and tractography in the distal femur and proximal tibia related to age, sex, and height. Materials and Methods Following institutional review board approval, with waiver of consent and with HIPAA compliance, the authors retrospectively analyzed DTI images of the knee in 151 children, 73 girls (median age, 14.1 years; range, 6.5-17.8 years) and 78 boys (median age, 16.6 years; range, 6.9-17.9 years), studied from January 2013 to October 2014...
February 2, 2017: Radiology
https://www.readbyqxmd.com/read/28152266/bold-fmri-with-median-nerve-electrical-stimulation-predict-hemodynamic-improvement-after-revascularization-in-patients-with-moyamoya-disease
#13
Peng-Gang Qiao, Cong Han, Tianyi Qian, Gong-Jie Li, Hong Yin
PURPOSE: To assess the severity of cerebral hemodynamic impairment and hemodynamic improvements, after revascularization in moyamoya disease (MMD) by means of blood-oxygen-level dependent functional magnetic resonance imaging (BOLD-fMRI). MATERIALS AND METHODS: BOLD-fMRI with median nerve electrical stimulation based on echo planar imaging was performed in 73 volunteers with MMD and 15 healthy volunteers using a 3.0 Tesla MRI scanner. Twenty-four MMD patients were reexamined after encephaloduroarteriosynangiosis...
February 2, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28152252/can-diffusion-weighted-imaging-serve-as-a-biomarker-of-fibrosis-in-pancreatic-adenocarcinoma
#14
Elizabeth M Hecht, Michael Z Liu, Martin R Prince, Sachin Jambawalikar, Helen E Remotti, Stuart W Weisberg, Donald Garmon, Sara Lopez-Pintado, Yanghee Woo, Michael D Kluger, John A Chabot
PURPOSE: To assess the relationship between diffusion-weighted imaging (DWI) and intravoxel incoherent motion (IVIM)-derived quantitative parameters (apparent diffusion coefficient [ADC], perfusion fraction [f], Dslow , diffusion coefficient [D], and Dfast , pseudodiffusion coefficient [D*]) and histopathology in pancreatic adenocarcinoma (PAC). MATERIALS AND METHODS: Subjects with suspected surgically resectable PAC were prospectively enrolled in this Health Insurance Portability and Accountability Act (HIPAA)-compliant, Institutional Review Board-approved study...
February 2, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28152240/spatiotemporal-alignment-of-in-utero-bold-mri-series
#15
Esra Abaci Turk, Jie Luo, Borjan Gagoski, Javier Pascau, Carolina Bibbo, Julian N Robinson, P Ellen Grant, Elfar Adalsteinsson, Polina Golland, Norberto Malpica
PURPOSE: To present a method for spatiotemporal alignment of in-utero magnetic resonance imaging (MRI) time series acquired during maternal hyperoxia for enabling improved quantitative tracking of blood oxygen level-dependent (BOLD) signal changes that characterize oxygen transport through the placenta to fetal organs. MATERIALS AND METHODS: The proposed pipeline for spatiotemporal alignment of images acquired with a single-shot gradient echo echo-planar imaging includes 1) signal nonuniformity correction, 2) intravolume motion correction based on nonrigid registration, 3) correction of motion and nonrigid deformations across volumes, and 4) detection of the outlier volumes to be discarded from subsequent analysis...
February 2, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28127590/motion-robust-reconstruction-based-on-simultaneous-multi-slice-registration-for-diffusion-weighted-mri-of-moving-subjects
#16
Bahram Marami, Benoit Scherrer, Onur Afacan, Simon K Warfield, Ali Gholipour
Simultaneous multi-slice (SMS) echo-planar imaging has had a huge impact on the acceleration and routine use of diffusion-weighted MRI (DWI) in neuroimaging studies in particular the human connectome project; but also holds the potential to facilitate DWI of moving subjects, as proposed by the new technique developed in this paper. We present a novel registration-based motion tracking technique that takes advantage of the multi-plane coverage of the anatomy by simultaneously acquired slices to enable robust reconstruction of neural microstructure from SMS DWI of moving subjects...
October 2016: Medical Image Computing and Computer-assisted Intervention: MICCAI ..
https://www.readbyqxmd.com/read/28121369/four-dimensional-diffusion-weighted-mr-imaging-4d-dwi-a-feasibility-study
#17
Yilin Liu, Xiaodong Zhong, Brian G Czito, Manisha Palta, Mustafa R Bashir, Brian M Dale, Fang-Fang Yin, Jing Cai
PURPOSE: Diffusion-weighted Magnetic Resonance Imaging (DWI) has been shown to be a powerful tool for cancer detection with high tumor-to-tissue contrast. This study aims to investigate the feasibility of developing a four-dimensional DWI technique (4D-DWI) for imaging respiratory motion for radiation therapy applications. MATERIALS/METHODS: Image acquisition was performed by repeatedly imaging a volume of interest (VOI) using an interleaved multislice single-shot echo-planar imaging (EPI) 2D-DWI sequence in the axial plane...
December 9, 2016: Medical Physics
https://www.readbyqxmd.com/read/28117930/quantitative-assessment-of-lung-stiffness-in-patients-with-interstitial-lung-disease-using-mr-elastography
#18
John P Marinelli, David L Levin, Robert Vassallo, Rickey E Carter, Rolf D Hubmayr, Richard L Ehman, Kiaran P McGee
PURPOSE: To investigate the use of magnetic resonance elastography (MRE) in the quantitative assessment of pulmonary fibrosis by comparing quantitative shear stiffness measurements of lung parenchyma in patients diagnosed with fibrotic interstitial lung disease (ILD) and healthy controls. MATERIALS AND METHODS: A 1.5T spin-echo, echo planar imaging MRE (SE-EPI MRE) pulse sequence was utilized to assess absolute lung shear stiffness in 15 patients with diagnosed ILD and in 11 healthy controls...
January 24, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28113840/a-projection-algorithm-for-gradient-waveforms-design-in-magnetic-resonance-imaging
#19
Nicolas Chauffert, Pierre Weiss, Jonas Kahn, Philippe Ciuciu
Collecting the maximal amount of information in a given scanning time is a major concern in Magnetic Resonance Imaging (MRI) to speed up image acquisition. The hardware constraints (gradient magnitude, slew rate, ...), physical distortions (e.g., off-resonance effects) and sampling theorems (Shannon, compressed sensing) must be taken into account simultaneously, which makes this problem extremely challenging. To date, the main approach to design gradient waveform has consisted of selecting an initial shape (e...
March 21, 2016: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28104438/safety-of-externally-stimulated-intracranial-electrodes-during-functional-mri-at-1-5t
#20
Pallab K Bhattacharyya, Jeffery Mullin, Bryan S Lee, Jorge A Gonzalez-Martinez, Stephen E Jones
Surgical resection of the epileptogenic zone (EZ) is a potential cure for medically refractory focal epilepsy. Proper identification of the EZ is essential for such resection. Synergistic application of functional magnetic resonance imaging (fMRI) simultaneously with stimulation of a single externalized intracranial stereotactic EEG (SEEG) electrode has the potential to improve identification of the EZ. While most EEG-fMRI studies use the electrodes passively to record electrical activity, it is possible to stimulate the brain using the electrodes by connecting them with conducting cables to the stimulation hardware...
January 16, 2017: Magnetic Resonance Imaging
keyword
keyword
105873
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"